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GLOWA Volta

SIGNIFICANT DEVELOPMENTS AND PROGRESS TOWARD ESTABL ISHING A SCIENTIFICALLY SOUND DECISION SUPPORT SYSTEM FOR TH E VOLTA BASIN

P.L.G. Vlek and C. Rodgers

Center for Development Research (ZEF), Bonn University, Walter-Flex-Str. 3, 53113 Bonn, Germany Keywords: Volta Basin, Decision Support System, Burkina Faso, Ghana, West Africa Abstract The overall objectives of the GLOWA Volta Project (GVP) remain consistent with the initial proposal: (1) to provide an analysis of the physical and socio-economic determinants of the hydrological cycle within the Volt Basin, and (2) to develop a scientifically sound Decision Support System (DSS) for the assessment, sustainable use and development of the Basin’s water resources. The DSS will provide a comprehensive monitoring and simulation framework, enabling decision makers to evaluate the impacts of climatic and land use trends overlaid on the consequences of deliberate policies, investments and other interventions on the social, economic, and biological productivity of water resources. Integral to this effort is the development of scientific capacity and infrastructure within the Basin to ensure the self-sustainability of the DSS through the completion of formal GVP activities. GLOWA Volta Phase II was initiated in June 2003, with four strategic objectives identified:

• Successful completion of Phase I activities; • Expansion of significant project activities to Burkina Faso; • Technical integration of disciplinary models and knowledge generation frameworks; • Design, testing and preliminary application of a prototype DSS for the White Volta Basin

We are now midway through Phase II. Ongoing activities initiated under Phase I, consisting primarily of academic field research within the Volta Basin, are now largely complete, with two Ph.D. dissertations defended in 2003 and ten completed in 2004. Ten additional Ph.D. candidates have defended or will defend in 2005. Project activities have expanded significantly within Burkina Faso, primarily through collaborative research with Institut de l’Environment et de Recherché Agricoles (INERA) and through the establishment of research networks linking GVP with BIOTA-West Africa and the Virtual Institute – Foundation Dreyer. The White Volta Pilot Project was formally initiated in collaboration with the Ghanaian Water Resources Commission (WRC) in early 2005, joined by the International Food Policy Research Institution (IFPRI) via the Challenge Program on Food & Water, Governance and Modeling Project. The greatest challenges remaining in Phase II involve the technical integration of computational and simulation models developed during and subsequent to Phase I. To date, the mesoscale climate model MM5 has been coupled successfully with the physical hydrology model WaSiM, and significant work has been completed linking WaSiM bidirectionally with GAMS, the high-level programming language used in our economic optimization modeling at a variety of scales.

Project ID: 07 GWK 01 Project duration: 01.05.2003 – 30.05.2006 Report period: 01.06.2003 - 28.02.2005

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Significant Political Developments The overall political situation within Volta Basin riparian states has been conducive to progress during the GVP Phase II period. Political instability in the northern regions of Ghana during 2002 has largely subsided, and the Ghanaian national elections of December of 2004, which returned John Kufour to the Presidency, were widely regarded as fair and peaceful. Instability in Cote d’Ivoire, and more recently in Togo, has had no impact on project activities. The Volta remains, however, one of the few major trans-national basins lacking an Inter-state Basin Commission or comparable legal framework for regulating and allocating flows across international borders and for enabling coordinated development of the Basin’s water resources. Encouraging progress is currently underway toward such a governing structure through the joint IUCN - Global Water Partnership project “Improving Water Governance in the Volta River Basin,” commencing in 2004. Another development with the potential to alter the economic calculus underlying Volta water allocation is the pending approval by the World Bank of funding for the West African Gas Pipeline Project. This US$ 590 Million project will bring Nigerian natural gas to coastal locations in Benin, Togo and Ghana. Economic analysis by the Bank (2002) suggests that electric power can be generated thermally using natural gas at 0.042 USD per KWH, as compared with 0.072 USD per KWH for hydropower generated at the proposed (and controversial) Bui Gorge hydropower dam. These and related developments serve to underscore the value of integrated analysis in the linked water and energy sectors within the Volta region, and are likely to enhance the visibility and importance of GVP research and resulting outputs. Research Infrastructure GVP research infrastructure was expanded significantly though the integration of Project activities and research sites into regional research networks. Important among these are the formation of an integrative multiscale monitoring concept in Burkina Faso linking GVP with BIOTA West Africa (BMBF) and Burkinabé counterpart INERA. The Biophysical Observation Network (BON) combines important features of biophysical ground measurement and remote sensing techniques in order to enable i) monitoring of large scale vegetation, hydrologic and bio-geophysical dynamics and ii) evaluation of climate dynamics based on observations of biosphere – atmosphere interactions. 2004 also saw the inauguration of the Centre de Recherches et de Formation Scientifique (CRFS), an international research facility constructed by the Dreyer Foundation and shared by ZEF/GVP, BIOTA West Africa, Helmholz Institute and INERA. This innovative research site in western Burkina Faso provides residence and research facilities for scholars conducting extended agricultural, environmental and hydrologic studies. Finally, GVP is currently establishing a working relationship with the Kofi Annan Center of Excellence (KACE), a joint India – Ghana facility for Information and Communication Technology training, research and development. KACE hosts a high performance computing center with broadband satellite links to the Internet. Our objective is to transfer computationally intensive aspects of the Volta Basin DSS, including climate forecasting, to the KACE during GVP Phase III. The following progress report is organized to reflect the structure of research clusters as described in the Phase II proposal: Atmosphere (subprojects A1:A3), Land Use (L1:L5), Water Use (W1:W3) and Technical Integration and Decision Support (D1:D4). Research activities described in this document are drawn from and are representative of a much larger body of research completed and ongoing during Phase II.

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ATMOSPHERE CLUSTER

H. Kunstmann1, L. Bharati2, E. Haas1, J. Intsiful2, G. Jung1, P. Laux1, A Marx 1, M. Mast1, A. Moene3, R. Neumann1, D. Schüttemeyer3, J. Szarzynski2, S. Wagner1, J. Werhahn1 1: Institute for Meteorology and Climate Research, Karlsruhe Research Center for Technology and Environment, Kreuzeckbahnstr. 19, D-82467 Garmisch - Partenkirchen 2: Center for Development Research (ZEF), Bonn University, Walter-Flex-Str. 3, 53113 Bonn, Germany 3: Wageningen University, Meteorology and Air Quality Group, Duivendaal 2, 6701 AP Wageningen, Netherlands Keywords: Atmosphere, climate, precipitation, hydrology, SWAT, MM5, WaSiM, remote sensing, heat flux, modelling Abstract Primary objectives of the Atmosphere Cluster are to estimate the impacts of climatic and land use changes on the quantity and timing of precipitation; to quantify feedback mechanisms between land processes and climate and to contribute important components of the Volta Basin DSS. Significant accomplishments during Phase II include the successful generation of regional climate scenarios, calibration of distributed physical hydrologic models at three nested scales, coupling of hydrologic and mesoscale climate models, preliminary analysis of factors influencing the onset of the rainy season and initiation of web-based short-term forecasts for West Africa. Sub-project A1: Regional Climate Simulations The Volta Basin is a climatically sensitive region containing extensive rainfed agriculture, and small changes in the water balance can have a profound influence on living conditions. Analysis of historical records from the northern Volta Basin suggests that increasing temperature and decreasing rainfall trends are already discernable. Coupled climatic - hydrological simulations provide policymakers with the capacity to anticipate the effects of anthropogenic influences on the water balance in the basin, and to design pre-emptive and adoptive strategies. Coupled Climate-Hydrology Simulations Regional climate simulations are being generated successfully using the mesoscale meteorological model MM5, fully coupled to a 1D SVAT model which accounts for soil properties and soil-atmosphere feedback mechanisms. The global climate model ECHAM4 scenario IS92a (“business as usual”), which provides MM5 atmospheric boundary conditions, was dynamically downscaled to a resolution of 9x9 km² over the Volta Basin. Two 10-years time slices were simulated: 1991-2000 (current climate) and 2030-2039 (future climate). MM5 was coupled unidirectionally to the distributed, physically based hydrological model WaSiM to investigate the impact of atmospheric change on terrestrial water balance. Regional climate simulations predict increasing annual precipitation for the Volta region overall, exhibiting strong spatial (-20% to + 50%) and temporal heterogeneity (-20% to +20%). A delay in the onset and a general shortening of the rainy season are also predicted. Model runs predict increasing temperatures ranging from 1° in the maritime South of Ghana to 1.6° in the Sahelian North of Burkina Faso (Fig. A1). Surface runoff, calculated by the SVAT model within MM5,

Project ID: 07 GWK 01 Project duration: 01.05.2003 – 30.05.2006 Report period: 01.06.2003 - 28.02.2005

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displays the nonlinear response with respect to precipitation characteristic of the Volta Basin. Work in progress involves a comparison between simulated water balance components as calculated by the SVAT model (MM5) and WaSiM, respectively.

Fig. A1: Temperature Change [°C] 2030-2039 vs. 1991-2000

Sub-project A2: Hydro-Meteorological Monitoring System The coupled, operational meteorological and hydrological hindcasting system is a critical component of the Decision Support System (DSS). It provides basin-wide estimates of water and energy balances, allowing water managers to monitor river discharge, evapotranspiration, soil moisture and groundwater recharge. To improve the quality of input data, we are exploring the use of satellite-derived land surface parameters. The effect of parameter uncertainties on simulation outputs is being investigated using Monte Carlo procedures. Model WaSiM-ETH (Water balance Simulation Model), a physically based, distributed parameter catchment model is used for hydrological simulations. WaSiM-ETH is currently used at 3 scales: entire Volta (400,000 km²), White Volta (94,000 km²) and Atankwidi (270 km²) basins, respectively. Larger scales use 1 km grid spacing and daily timestep. 1967/1968 is used for calibration due to minimal extent of anthropogenic influences on river runoff (e.g. dams, irrigation) at that time. WaSiM-ETH is coupled to the mesoscale climate model MM5, which runs on four nested domains at resolutions of 81x81 km², 27x27 km², 9x9 km² and 3x3 km², respectively; and 26 vertical layers up to 30 mbar. Boundary conditions for the largest domain are provided by global ECMWF 40 year re-analysis data. Through the assimilation of remotely sensed data, more realistic, spatially explicit fields of land surface properties (e.g. albedo, LAI, land use) are obtained. We are currently investigating improvement in simulation output resulting from the assimilation of satellite-derived (MODIS) land surface properties into the atmospheric and hydrological models. To facilitate the calibration and validation of coupled meteorological and hydrological models, a dense observational network for precipitation and surface runoff was installed in spring 2004 in the Upper East Region in Ghana (Fig. A2). Total rainfall is recorded three times daily and water levels are recorded automatically at hourly or finer intervals. In October 2004, two HydroArgos systems were installed, which transmit measured water levels by satellite to an internet platform, so that this data can be retrieved remotely and analyzed in near-real time. The field measurement campaign is conducted in close collaboration with Ghanaian Hydrological Services. Preliminary results of WaSiM calibration, depicting surface runoff of the Oti River at the Saboba gage, appear in Fig. A3. Calibrated WaSiM-ETH simulates the hydrologic response of the catchment with reasonable accuracy. WaSiM additionally calculates other components of the water balance, including evapotranspiration, base flow and groundwater recharge. As WaSiM-ETH was developed for high-relief catchments in Central Europe, extensive preliminary effort

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was required to adjust the parameters and empirical coefficients to represent low-relief catchment and climatic conditions in West Africa. Calibration is an ongoing process, and we continue to improve model performance.

Fig. A2: Gage locations in the Upper East region

Fig. A3: Comparison of modeled and observed discharge at the gage Saboba (Oti):

Remote Sensing of Latent and Sensible Heat Fluxes Measurement networks are sparse in West Africa, and remote sensing (RS) methods are required for broadscale validation of water balance variables. We applied three methods to estimate sensible heat flux (H) over Ghana: (1) the surface energy balance algorithm (SEBAL), (2) Large Aperture Scintillometer (LAS), and (3) mesoscale climatic simulations with MM5. Satellite-derived H (Fig. A4a) was computed from NOAA-AVHRR images for December 2001 under favorable cloud conditions, and compared to LAS and MM5 simulation results. An algorithm for estimating actual evaporation from Meteosat-derived global radiation and temperature and MODIS-derived vegetation fraction was also applied and validated for a complete drying-up period. The LAS-derived evapotranspiration (ET) and sensible heat fluxes performed well with respect to energy-balance closure, and in comparison with eddy-covariance data, suggesting that they can be used with confidence for validation of RS-derived fluxes. Satellite derived H (Fig. A4a) showed good agreement with LAS data, with RMSE of 39 W/m² for the Tamale site (Fig. A4b). Satellite derived H showed substantial disagreement relative to MM5 due to overestimation of latent heat flux in MM5, with RMSE of 167 W/m² for the Tamale site. Uncertainty analysis of satellite derived H indicated relative uncertainties of 21% for the Tamale site and 32% for the Ejura site. Uncertainty in LAS data is much lower, at 8% for Tamale and 7% for Ejura . The Meteosat-based procedure provides hourly estimates of actual ET under both cloudless and cloudy conditions. The agreement with ground-based data is generally good, but in wet periods (higher fluxes) the RS-based algorithm tends to underestimate real ET. Long term bias of this method is less than 0.5 mm/day. A significant advantage to this method is that it can be used to monitor ET at seasonal time scale, irrespective of cloud conditions. Gaussian error propagation was shown to be a powerful tool for analyzing uncertainty in satellite derived heat fluxes, and a more comprehensive uncertainty analysis is envisaged. The use of extra indicators for sub-optimal ET in the Meteosat-based monitoring algorithm will also be investigated, along with the use of ground-based and model-generated data. We are using a one-dimensional boundary layer column model to investigate which variables, and at which height, carry information that could further improve the ET estimate. Furthermore, a receiving station for MSG data, operating at Wageningen University since fall 2004, is used to archive images for

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the Volta basin and is intended to operationalize the Meteosat-based algorithm to estimate actual ET.

Fig. A4: a) SEBAL estimated sensible heat fluxes using NOAA-AVHRR-16 (DOY 347, 2001); circles indicate test sites Navrongo, Tamale and Ejura; b) Comparison of SEBAL estimates of sensible heat fluxes (using ground based net radiation Rn) to LAS data. Sub-project A3: Onset of the Rainy Season In West Africa, choice of crop, sowing dates and resulting yields strongly depend on the temporal and spatial distribution of rainfall, and on the date of onset of the rainy season. Within the last decades, a shift in the onset date has been reported. Due to the temporal variability of rainfall, prediction of the onset date is crucial to farmers. The success of prediction directly influences farmers' livelihoods and regional food security - planting too early may cause crop failure, whereas planting too late may reduce crop yields. We investigated the behaviour of the onset date using linear discriminant analysis and fuzzy logic. A consistent definition of rainy season onset is required for the analysis. We utilized Stern, et al.’s (1981) definition of the onset date as the first date following March 1st for which: (a) a period of 5 consecutive days occurs in which at least 25 mm of rain falls; (b) the start day and at least two other days within this period are wet; and (c) no dry period of 7 or more consecutive days occurs in the following 30 days. Utilizing historical data from Ghanaian synoptical observation network, we defined two rainfall indices used as predictors: rainfall amount (VRIx) and number of wet days (VRAX) 30, 25, 15, 10 and 5 days before the potential onset. A method based on linear discriminant analysis was then applied to the historical precipitation data. Fig. A5 presents the results of this analysis as the spatial distributions of mean and standard deviation of onset dates (Julian Days) for Ghana based on minimum record lengths of 35 years, obtained by Universal Kriging on the point (station) estimates. Fuzzy logic provides a more sophisticated methodology for evaluating the onset of the rainy season via automated objective circulation pattern (CP) definition and classification. Fuzzy rules are obtained via optimization of the classification performance for precipitation, which is measured by rainfall frequencies and rainfall amounts conditioned on the CP, leading to definitions of wet and dry CPs. We used this method to identify the CPs typically responsible for

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the onset of the rainy season. For 9 Ghanaian weather stations, the percentage of successfully predicted true starts increased from 93% by discriminant analysis to 99% by fuzzy logic. The most reliable predictor for discrimination is the number of wet days 30 days before the potential onset (VRA 30). Future work will focus on fuzzy logic-based circulation pattern analysis of the onset dates, and integration of the results in the overall DSS.

Fig. A5: a) Mean Onset-Date (Julian Day); b) standard deviation of onset dates

Numerical Weather Prediction for West Africa and the Volta Basin Short-term forecasts of precipitation and temperature are essential tools for operational water management and agricultural planning, in particular planting and harvesting decisions. Broadband internet connections allow rapid transfer of data-heavy numerical weather predictions at relatively low cost. We are now providing operational numerical weather prediction for West Africa and the Volta Basin on-line. AVN global re-analyses at 2.5x2.5° resolution are retrieved automatically on a daily basis and dynamically downscaled to 27x27 km² resolution. The forecast is interpreted with respect to temperature, precipitation, surface runoff (infiltration excess) and soil moisture/saturation. It is rendered graphically and placed on the GLOWA Volta server where it can be viewed by any user with access to the internet. Detailed validation extending through Phase III of the Project is anticipated to provide real-time forecasts of increasing accuracy. Forecasts can be accessed at http://www.glowa-volta.de/atm/forecast.htm.

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LAND USE CLUSTER M. Schmidt3, W. Agyare1, M. Erhard 5, S. Fistric2, M. Fosu1, J. Intsiful4, H. Kunstmann5, M. Plotnikova4 1: Savannah Agricultural Research Institute (SARI) 2: University of Würzburg, Remote Sensing Unit, Am Hubland, 97074 Würzburg, Germany 3: German Aerospace Centre (DLR), German Remote Sensing Data Centre (DFD), 82234 Weßling, Germany 4: Center for Development Research (ZEF), Bonn University, Walter-Flex-Str. 3, 53113 Bonn, Germany 5: Institute for Meteorology and Climate Research, Karlsruhe Research Center for Technology and Environment, Kreuzeckbahnstr. 19, D-82467 Garmisch - Partenkirchen Keywords: Land use, Vegetation dynamics, remote sensing, soils, LANDSAT, MODIS Abstract: The “Land Use Cluster” aims to understand the changes in land cover and land use due to socio-economic development and natural impacts and to model and to predict the effect of land conversion on biophysical land surface parameters which influence the atmospheric and land surface water cycle. The tasks within the cluster are (1) to retrieve the basic biophysical parameters to analyze the spatial and temporal dynamics and changes of vegetation; (2) to investigate the response of socio-economic development on biophysical land surface properties. Data of various sensors representing different temporal and spatial resolution are used to provide or a substantial data basis, namely LANDSAT TM/ETM+ (30m spatial resolution) for specific local areas of interest and medium resolution data with MODIS/TERRA (250m-1km spatial resolution) for West Africa. A GIS-based model structure is developed to identify the interactions and feedbacks between socio-economic development and vegetation. Sub-Project L1: Land Use Change Detection and Quantification The main methodological challenges were (1) to develop algorithms and methods to retrieve the land cover and to detect the annual cycles of plant biophysical behaviour (phenology) and (2) to efficiently process a large quantity of data (> 250GB). Time series of biophysical parameters including normalized difference vegetation index (NDVI) and leaf area index (LAI), and land surface parameters including surface albedo, land surface temperature (LST) and surface emissivity were assembled using MODIS/TERRA for the years 2000 - 2004 to detect vegetation dynamics. Table L1: Remote sensing databases and products used within the project

Project ID: 07 GWK 01 Project duration: 01.05.2003 – 30.05.2006 Report period: 01.06.2003 - 28.02.2005

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These data were used to analyze the seasonal response of vegetation to changes in the environment in order to investigate the yearly vegetation dynamics in West Africa for the period 2000 - 2004. Land cover conversion was mapped over the period 1990 - 2000 in the Upper East region using LANDSAT TM/ETM+ data with 30m spatial resolution. A further goal was to establish a model to predict land conversion in the so called “hot spot” areas within the basin. Databases and products used in the retrieval and analysis of spatial and temporal dynamics and changes of the terrestrial vegetation consist of medium and high resolution remote sensing data and higher level biophysical and land surface products. Table L1 gives an overview of the data bases and products for the study areas in the Volta basin and West Africa. Sub-Project L2: Soil Characterization Soil characteristics are input parameters of critical importance for meteorological, hydrological and land use-land conversion models. These parameters are distributed heterogeneously over landscapes, exhibit high variability at short length scales, and are difficult to measure or estimate using remote sensing techniques. Existing FAO level 2 soil maps of the Basin are of relatively coarse resolution. More detailed maps have been prepared by the Ghanaian Soil Research Institute, but these are limited in geographic extent. Over 2000 geo-referenced soil samples were obtained during the common sampling frame field campaign in 2002, which are useful in evaluating local suitability of soils for agricultural uses but nevertheless represent an insufficient sample for developing a basin-wide soils database in the absence of predictive methods that make use of more readily acquired data on climate, topography and vegetation. Modelling of Spatial Distribution of Saturated Hydraulic Conductivity Studies were conducted at two sites in Ghana, Ejura and Tamale, to evaluate a range of analytic techniques for predicting soil hydrologic characteristics (Agyare, 2004). Data collected included soil diagnostic horizons, texture, colour, mottles, structure, roots, gravel concretion fraction, particle size distribution, pH, organic carbon, cation exchange capacity (CEC), bulk density and Ksat for topsoil (0-15 cm) and subsoil (30-45 cm). Semivariogram analysis and Kriging interpolation were used to develop digital elevation maps (DEM) and models of eight terrain attributes at 30 m grids. Numerous pedo-transfer function (PTF) models were evaluated and compared. In addition, an artificial neural network (ANN) was used to model Saturated hydraulic conductivity (Ksat) using various subsets of the available data, and results compared with PTF. Ksat was found to exhibit extremely high spatial variability. It was observed that best predictors of Ksat include location, soil depth, particle size distribution and bulk density. Inclusion of terrain attributes (e.g., gradient, aspect, curvature, stream power index), soil type and land use parameters may improve model performance, but in themselves do not provide a reliable basis for predicting Ksat. Pedo-transfer function models proposed by Campbell, Brutsaert, Ajuha and Rawls, respectively, outperformed competing models, and evidence suggested a wider range of applicability for these models relative to alternatives. When model training data are available and accurate, artificial neural networks were found to provide predictions of Ksat that improve upon PTF’s. We are currently preparing to test PTF and ANN methodologies at far broader scale (106 km2) in the Upper East of Ghana. Field work is currently underway at Navrongo to establish a detailed database, and Agyare’s (2004) methods will be applied and evaluated. If these efforts are successful, we will apply them more generally throughout the Volta Basin in order to enhance the quality of existing soil datasets.

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Sub-Project L3: Vegetation Dynamics The main tasks were identification and time series analysis of the phenological cycle for different vegetation types. Biophysical parameters retrieved from remote sensing data were used to estimate impacts of seasonal climate variability and biodiversity loss. The temporal development of a surface type allows for the detection of the phenology of plants as well as the classification of vegetation cover. Data with high temporal resolution and daily coverage of the research area, such as MODIS provides, are employed to continuously detect vegetation dynamics. Time series of West Africa are processed using mosaics of MODIS products NDVI, LAI, surface albedo, LST and surface emissivity for the years 2000 - 2004. Four MODIS tiles cover the research area. The biophysical and land surface products are important inputs to the mesoscale climate model MM5, and to the hydrological model WASIM. Identification of land cover types using high spatial resolution remote sensing data The focus of this subproject is to characterize the main land cover types within the basin as a basis for investigating the temporal and spatial vegetation dynamics and change detection analysis using high spatial resolution remote sensing data. Due to the high spatial resolution images of the LANDSAT sensors (30m) and the correspondingly large quantity of satellite data (22 images for the basin), a subset of the basin, the Upper East in northern Ghana, is used as study area for land cover conversion analysis for the years 1990 - 2000. Two LANDSAT TM images covering the study area from November 1989 and October 1990 were used to represent the vegetation properties in 1990, the only cloud free images which could be processed. Nevertheless, climate and vegetation conditions during the two time points were comparable and permitted further analysis. Another two LANDSAT ETM+ images representing 2000 conditions, both from November 1999, were used for the same area. The complete data set was atmospherically corrected, geo-referenced to UTM projection WGS 84 and mosaic’d. Figure L1: Land Cover Classification for the time points a) 1990 and b) 2000 covering southern Burkina Faso and northern Ghana including the Upper East Region Unsupervised classification was used to categorize vegetation cover in the study area. GLOWA VOLTA vegetation classes (i) open and (ii) closed woodland, (iii) savanna, (iv) cultivated areas/sparsely vegetated areas and (v) areas without vegetation cover were identified by analyzing LANDSAT spectral channels 1, 2, 3, 4 and 5. Recovering the phenology of this region was not possible due to sparse temporal availability of LANDSAT data, and cultivated areas couldn’t be specified explicitly. The classified land cover maps (Fig. L1) are used for the analysis of land cover conversion in the upper east as described in the following section.

a) 1990 b) 2000

Lakes/Rivers/Dam

Close Woodland

Open Woodland

Savanna

Cultivated/ Urban Built Up/ Spars Vegetation

Fire Scars

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Sub-Project L4: Modelling and Spatial and Temporal Upscaling of Erosion and Hydrological Processes Derivation of Effective Land Surface Parameters for SVAT Models Mesoscale distributed hydrological and regional climate models often use grid resolutions that are too coarse to account for detailed land surface heterogeneity (e.g. soil, vegetation and surface roughness). The impact of this subgrid-scale heterogeneity typically is not accounted for. Land surface information is often available in higher spatial resolution than model lengthscale (e.g. via satellite data), and coarse model resolution reflects only limited CPU resources. If subgrid-scale effects are to be accounted for at grid-scale, aggregation techniques have to be applied that allow the derivation of effective model parameters. A new methodology was developed that allows the upscaling of land surface parameters of a Soil-Vegetation-Atmosphere-Transfer (SVAT) Model. The objective was to derive effective land surface parameters capable of yielding heat fluxes on the grid scale identical to averaged heat fluxes on subgrid-scale. A combination of 1) inverse modeling and 2) Second-Order-First-Moment (SOFM) propagation was used to derive effective parameters. The derived upscaling laws relate mean and variance (first and second moment) of subgrid-scale heterogeneity to a corresponding effective parameter at grid-scale. Explicit upscaling relations were specifically derived for a) roughness length, b) albedo, c) emissivity, d) leaf area index, e) wilting point soil moisture, and f) minimal stomata resistance. Effective parameters were found to be independent of driving meteorology and initial conditions. Slight differences between the stand-alone SVAT model and the fully MM5-integrated SVAT model could be derived. It was also demonstrated that geometric averaging on subgrid scale provides a reasonable approximation for the majority of effective land surface parameters.

180 200 220 240 260 280 300 3200

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Fig.L2: a) comparison between simulated and observed latent heat fluxes, b) dependency of grid-scale effective roughness on subgrid scale mean and standard deviation (Kunstmann, 2005) Sub-project L5: Land Use Change Prediction Large-Scale Vegetation Modeling in the Volta Basin Information on large-scale vegetation dynamics is needed for assessing changes in ecosystem services and biochemical cycles in the Volta basin under climate and land-use change. A top-down approach to simulate vegetation dynamics in the region was used. An updated version of the LPJ-model (Lund – Potsdam - Jena Dynamic Global Vegetation Model) was used. Simulations are based on CRU 0.5 x 0.5° 20th century monthly climatology, down-scaled ECHAM4 data, and IGBP global land cover. The purpose of simulations is to deliver a) projected vegetation dynamics due to climate and land-use changes and disturbance by fire, b) crop yield

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Deforestation and degradation of vegetation between 1990 and 2000

No land cover conversion between 1990 and 2000

data to be used as input for economic modeling with GAMS and c) land surface parameters for climate (MM5) and hydrological modeling (WaSiM). Model results express the impact of climate on natural vegetation. Net ecosystem productivity shows high inter-annual variation in the 20th century, as growing conditions are changing from year to year. Overall rate of carbon storage in the vegetation is very low. Carbon uptake is slightly increasing in the 21st century indicating better average growing conditions in this period. Inter-annual variation is increasing, raising the risk of carbon loss by fires and droughts. Crop yield was simulated with the LPJ crop module for the years 1960 - 2000 for three different vegetation zones (evergreen broadleaf forest, woody savannas and savannas). Yields represent potential yield or crop suitability as function of climate and soil conditions. Yields increase slightly over the study period due to land-use changes and better climatic conditions. Further efforts are necessary to improve quality and reliability of the data. Detection and modelling of land cover conversion in the Upper East Region (Ghana) Causes of land cover conversion include deforestation, degradation as well as natural and anthropogenic fire hazards. Natural vegetation is converted into agricultural areas and settlements or deforested for firewood or timber. Degradation of natural vegetation is caused by climate variability or change over decades whereas the degradation of pasture land is caused primarily by intensive farming. Land cover conversion 1990 - 2000 was detected using land cover classification data retrieved from LANDSAT-data including the Upper East Region in northern Ghana. Figure L3 shows deforestation and degradation detected over this time interval. The main areas of deforestation were located in the southern parts of Burkina Faso whereas minor land conversion took place in the Upper East Region of Ghana. A GIS-based multilayer structure was used for prediction of land use conversion. Input data are land cover and land cover conversion mapped using LANDSAT data, and physical and socio-economic data from the Ghana censuses of 1980 and 2000 for georeferenced Census enumeration areas. The prediction of land use change conversion, expressed as a global probability of land development, is derived from a calibrated logit regression. The purpose of calibration is to establish the relationship between land use change and the development factors affecting it. The dependent variable is the change in land use class, i.e. a change from undeveloped to developed land for each cell. Figure L3: Land cover conversion between 1990 und 2000 in southern Burkina Faso and Northern Ghana including the Upper East Region. The set of explanatory variables used to compute the development probability for each cell includes slope, land elevation measure, variable measuring the range of variation in elevation, distance to settlement, distance to road, land suitability index, population density, industry/occupation of the population and migration status. The calibrated logit regression will be used in the Cellular Automata simulation model of land use change to give a spatially detailed representation of the land use pattern.

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WATER USE CLUSTER E. Youkhana1, I. Eguavoen1, V. Fuest1, M. Gensler1, S. Haffner1, W. Laube1, N. Martin2, B. Nyarko1, C. Rodgers1, A. Sessouma1, C. Traore4, N. Van de Giesen3, C. van der Schaaf1, Y. Tseagaye1, S. Wolf1 1: Center for Development Research (ZEF), Bonn University, Walter-Flex-Str. 3, 53113 Bonn, Germany 2: Federal Institute for Geosciences and Natural Resources (BGR), Germany 3: Delft 4: Ruprecht-Karls-University Heidelberg, Institute of Hygiene, Department of Tropical Hygiene and Public Health Keywords: Groundwater, flood plains, epidemiology, private sector participation, irrigation, transboundary water management Abstract: The Water Use Cluster focuses on sectoral demands and use of water, and its institutional management framework. Important Subproject W1 outputs include establishment of physically based hydrological modeling capacity, and framework and database for evaluation of groundwater supply and demand. Subproject W2 outputs include contributions on water and health, the role of rural credit and changing gender roles. Subproject W3 research documents a range of institutional weakness that adversely affect water sector performance. Formal integration of institutional analysis into DSS will be both politically and technically challenging. Sub-Project W1: Runoff and Hydraulic Routing GVP Phase I activities focused on the development of comprehensive databases on rainfall, runoff and stream discharge; and on conceptual rainfall-runoff models. Lacking a physical basis, however, conceptual models possess limited capacity to simulate impacts of alterations in land use and climate. Phase II research has focused on the development of physically based, distributed parameter models of runoff and channel hydraulics. The development of WaSiM-ETH as a general purpose hydrologic simulation tool has been described under A2. Additional W1 research focuses on floodplain hydrology, on the impacts of dam construction, and on groundwater. Floodplains and wetlands support extensive traditional irrigated agriculture within the Volta, and floodplain development influences runoff and channel hydraulics, particularly during flood events. Groundwater is the primary source of drinking water within rural Ghana and Burkina Faso, and groundwater development, promoted and financed by NGOs, is not currently guided by reliable information concerning recharge and sustainable abstraction rates. In order to assess the impact of increasing groundwater withdrawals on the Basin water budget, the spatial distribution of groundwater abstraction for domestic supply within the Volta was quantified (Martin and van de Giesen, 2005). Data on the location, construction date and capacity of boreholes, hand pumps, piped systems and hand-dug wells was assembled from a wide range of sources to create a database containing information on over 30,000 geo-referenced groundwater sources in Ghana and Burkina Faso. Pumping capacity and corresponding extraction volumes per well were measured or estimated. Calculated spatial distribution of extraction was compared to population densities, groundwater recharge and groundwater

Project ID: 07 GWK 01 Project duration: 01.05.2003 – 30.05.2006 Report period: 01.06.2003 - 28.02.2005

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potential to provide spatial estimates of the sustainability of current and projected groundwater use. Groundwater use was found to have increased substantially over the past decades, and currently stands at around 88 Mm3 per year. Roughly 44% of the Basin population has improved access to groundwater. Current extraction rates are estimated at less than 5% of average annual groundwater recharge, indicating that overall, groundwater extraction does not have a major impact on the hydrologic budget, and further groundwater development should be encouraged, as almost half of the population still lacks access to safe drinking water. Important exceptions include regions of fluoride contamination of groundwater. Research initiated during 2004 (K. Nyarko) involves (i) mapping floodplains and wetlands within the Basin, (ii) developing and testing methodologies to remotely sense antecedent soil moisture conditions, (ii) develop improved digital elevation maps (DEM) of floodplains, and (iv) establish the contribution of wetlands and floodplains to runoff and discharge via analysis of water movement. Antecedent soil moisture and vegetation conditions within floodplains are remotely sensed using radar, which under proper conditions can distinguish between wet and dry soils, and between bare and vegetated surfaces. Runoff-generating mechanisms and flowpaths are determined using isotope tracer methods. Physical rainfall-runoff and overland flow relationships are simulated using kinematic wave models embedded in the model LISFLOOD. LISFLOOD is a GIS-based hydrologic model written in the PCRaster environment, and simulates hydrologic processes, including overland flow and river discharge, as functions of spatially distributed data on topography, soils and land cover. Sub-Project W2: Water and Livelihood The objectives of subproject W2 are to examine the causalities and feedbacks between (1) household access to and demand for water of different quality, (2) intra-household water use behavior, (3) risk of adverse health impacts and (4) household livelihoods. Research on irrigated agriculture, rural credit, migration and related topics, while closely related, is described in Sub-project D2, Household Decision-making. Research Results: Water and Household Economics Agricultural production in the Ghanaian savannah is constrained by rainfall variability and poor soil quality, and there is growing interest in increasing the region’s irrigated area. The Ghana Poverty Reduction Strategy notes that to meet development goals, total irrigated area must be increased by 5000 ha per year to reach 100,000 ha by the year 2015. Regions like the Upper East, which contain a disproportionate concentration of Ghana’s poor, are important venues for the expansion of irrigation. We have analyzed the welfare effects of irrigation technologies in a changing macro-economic environment. Preliminary results indicate that scarce agricultural credit is the major factor constraining farmer investment in irrigation. Household resource endowment, particularly labour, plays a crucial role in irrigation decision-making. Under W2 we are developing Representative Farm Models for scenario analysis to evaluate the impact of different policies and technologies on different farm household types. Research results: Water and Gender Issues Procurement of household water is the responsibility of women. Their contributions to farming activities are increasing as gender roles in agriculture are shifting from traditional patterns. Women’s efforts to provide family and farm with water are increasingly complicated by environmental degradation, new water management initiatives including privatization, unresponsive authorities and other factors. In general, women have no recognized claim to

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resources, and their role in decision making is still marginal. In order to meet development goals, reduce poverty and achieve greater gender equality in the distribution of water, access of women to agricultural resources like land, water, credit and technologies must be improved. Our socioeconomic studies of water and gender inequality in the Upper East Region of Ghana have focused on farming practices and the introduction of new agricultural technologies (Yilma et al 2004). An analysis of the effect of irrigation technology on overall household and gender- differentiated income concluded that the provision of new irrigation technology significantly expands employment opportunities for women. State-driven irrigation projects like LACOSREP along with institutionalized participation of Water User Associations (WUA) in decision making have led to more accountability and acceptance of development strategies (Scannapieco 2003). Research results: Epidemiology of malaria in rural areas in Burkina Faso Malaria is a water-associated disease posing an enormous threat to livelihoods throughout Africa, thus malaria-related research is integral to the Phase II agenda. Today, more than 90% of malaria victims are found in Sub-Saharan Africa (SSA), where malaria accounts for 25% of all child deaths below the age of five. This percentage would likely be higher yet if cases in which malaria is an indirect cause of death were included. The increasing resistance of Plasmodium falciparum to existing first-line drugs such as chloroquine and sulphadoxine/ pyrimethamine, and of the vector Anopheles gambiae to insecticides are matters of grave concern in the region. Research conducted in the zone of the Centre de Recherche en Santé de Nouna (CRSN), situated in Nouna Health District in northwestern Burkina Faso (Traore, 2030) identified malaria as the major cause of morbidity and mortality in children aged 0-3 years living in a holoendemic rural area of Burkina Faso, with children aged 6-12 months being at highest risk. Cerebral malaria was found to be the main cause of malaria-related deaths in these young children, and most children die in the villages without having been seen by a health worker. As chloroquine has been shown to remain an effective first-line treatment drug for falciparum malaria in this area of rural Burkina Faso, it was recommended that malaria control efforts concentrate on early treatment of young febrile children through their mothers in the villages, with follow-up referral to peripheral health centers in cases of non-response. However, the ongoing development of chloroquine resistance requires careful monitoring in Burkina Faso, and new combination therapy protocols may be required to replace single drug treatments in the future. Sub-Project W3: Institutional Analysis Activities under sub-project W3 involve the institutional and political analysis of various actors within the water sector, with present emphasis on Ghana. Analysis of the water sector status quo provides a baseline from which W3 researchers have evaluated constraints as well as possibilities for the implementation of water reforms in various sub-sectors, and for the introduction of integrated water resources management (IWRM) at the local, district, national and international levels. Cooperation strategies for the intermediation of scientific knowledge to local stakeholders were developed and qualitative input for the DSS modeling process generated. In order to grasp the complex structure of incentives that motivates decision making in the water sector, an actor-oriented approach focusing on the motivations of individual actors and their interaction processes had to be adopted. Furthermore, it was clear that the research agenda had to view the water sector within its wider socio-economical and political context. In Ghana, water sector reforms have been strongly influenced by decentralization policies as well as by private sector participation strategies. To evaluate the performance of various water sector organizations

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and to study the interaction between various actors, a number of case studies were conducted on the Water Resources Commission (WRC), the Community Water and Sanitation Agency (CWSA), and the Ghana Water Company Ltd. (GWCL). Furthermore, we examined the involvement of the private sector in the provision of drinking water supplies in small towns in Ghana. Through case studies, it became apparent that agencies charged with providing and regulating water are plagued with institutional weaknesses, and seldom live up to their mandates. They lack sufficient financial and human resources for effective implementation of policies and monitoring of outcomes, and are often beset by principal-agent problems. As an example, the government policy concerning private sector participation in utility provision has been only partially implemented because of party-political maneuvering and public opposition (Wolf, Fuest & Asante, submitted), (Laube & van de Giesen, 2004). Despite the fact that the WRC has an official mandate to develop and to implement coherent policies for the water sector, thus far it lacks sufficient power and acceptance. Research results: Water and Energy reforms and private sector participation in Ghana The lack of continuous and reliable supplies of energy and water are major hindrances to industrial and agricultural productivity at the local and national levels in Ghana. As hydropower is still the main source of electricity in Ghana, the energy and water sectors are closely linked. Public utilities in Ghana, as in many developing countries, face a difficult situation. Despite major reforms of electricity and drinking water providers initiated under the auspices of international donors such as the World Bank and the IMF since the early 1990s, fundamental problems still persist: infrastructure has degraded due to aging, lack of maintenance and lack of adequately trained staff, and as a result many resources are wasted. Utilities run at large operational losses as people illegally tap into the distribution networks, and tariff collection rates are low (Wolf et al 2005). The Ghanaian Public Utilities Regulatory Commission (PURC) has been created to oversee the provision of public goods such as electricity and drinking water. Nevertheless, it has not been able to fully live up to its mandates as it lacks adequate financial and human resources and suffers from principal agent problems. The government policy of private sector participation (PSP) in utility provision has been only partially implemented due to political and public inhibitions. However, PSP has a major influence on drinking water supply in the small towns in Ghana. Following investigations in Bekwai (Ashanti), a number of constraints to private sector involvement were pointed out that require attention: lack of strong and independent regulatory agencies and therefore retraction of public control, low payment morality by public institutions that endangers financial sustainability, elite capture of services (household connections and allocation of public standpipes), low acceptance of new water supply system because of unknown water taste and access to alternative water sources. Furthermore, the study points out that District and Communities need more and regular long term support and financial means placed at local/regional level in order to build up management skills and technical capacity (Youkhana, unpublished report). In order to enhance the chances of successful reforms the interests of various interest groups have to be considered and balanced. There is an urgent need to strengthen the regulatory authorities if they are to function independently and effectively. Research results: Natural resource management in the irrigation sector Within the irrigation sector in northern Ghana - dependent on historical irrigation development - a complex institutional set-up reined by legal pluralism and characterized by multiple foci of power has developed. At the local level the government lacks the power and legitimacy to

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effectively implement policies, and depends on the cooperation of powerful local actors and rural supporters. Therefore, the way in which governmental interventions are locally perceived, adopted, transformed and/or ignored can only partially be controlled. Weak official as well as ‘traditional’ governance structures often characterized by political favouritism, nepotism and rent seeking have led to a situation where the different authorities - and the institutional regimes they stand for - have lost legitimacy and enforceability. Within the ensuing competition for access to irrigable land and water in irrigation schemes, different actors develop different strategies. Actors who lack power, political connection and wealth are often disadvantaged (Laube 2004). In Burkina Faso, many agricultural and water management policies have been adopted but the resources and political will for implementation are often not present at national or local levels. Access and control rights to land and water are frequently contested as local perceptions of rights to land and water differ from the formal regulations and laws. The State has withdrawn from its responsibilities regarding agricultural production and irrigation management, and handed them over to water user groups. The hand-over has led to power takeovers, misappropriation of funds and free-riding, which seem to have become ‘institutionalised’. Existing management structures have thereby lost their legitimacy. The regulating influence of the state administration over water management is weak due to lack of finances, legitimacy and enforcement power, which are constraints to rule compliance. This situation led to uncontrolled water distribution, deterioration of infrastructure and decreased agricultural production (van der Schaaf 2005). Research results: Transboundary water management A first step towards the actual implementation of transboundary IWRM in the Volta Basin is bilateral cooperation between Ghana and Burkina Faso. Both countries have agreed to establish a joint committee for the management of the water resources of the Volta basin. Along the lines of the Helsinki Rules and the UN Watercourse Convention the countries try to manage the waters of the Volta River according to the principles of “equitable and reasonable apportionment”. Significant in this context is the 3-year Volta Water Governance Project, led by the World Conservation Union (IUCN) and the GWP-WAWP. This project started in 2004 and runs until 2006 and is financially supported by the Dutch and Swedish governments. It has been designed to create a knowledge base sufficient for decision support, to support IWRM in the White Volta/Nankambe sub-basin, and to promote adequate policies and institutional change. The implementing agencies on both sides of the border are the WRC and the DGIRH, which receive further support for the pilot project from DANIDA. (Laube and van de Giesen, forthcoming).

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TECHNICAL INTEGRATION AND DECISION SUPPORT C. Rodgers1, B. Arendt1, H. Ahrends3, L. Bharati 1, T. Erdenberger2, J. Intsiful1, H. Kunstmann3, M. Mast3, P. Obeng-Asiedu1, M. Plotnikova1, S. Shumilov2

1: Center for Development Research (ZEF), Bonn University, Walter-Flex-Str. 3, 53113 Bonn, Germany 2: Department of Computer Science and Informatics III, Bonn University 3: Institute for Meteorology and Climate Research, Karlsruhe Research Center for Technology and Environment, Kreuzeckbahnstr. 19, D-82467 Garmisch - Partenkirchen Abstract: The ultimate objective of the GVP is to develop a Decision Support System (DSS) for the management of Volta Basin water resources that is at once scientifically sound and relevant to the needs and interests of diverse water sector stakeholders. Integrated economic-hydrologic models coded in GAMS have been developed at catchment and basin scale, and preliminary output demonstrates the value of integrated analysis in evaluating water-energy sector interactions. Preliminary efforts to link GAMS and WaSiM models recursively are promising, although major challenges remain in developing an extendable integration framework. Keywords: Decision Support System, Optimization, GAMS, irrigation, small reservoirs, IWRM Sub-Project D1: Technical Integration of Socio-Economic and Environmental Models The overall goal of the GVP is to develop, in close collaboration with our local and international partners, a scientific information system that will integrate knowledge and provide decision support for the planning, management and use of water resources in the Volta Basin. We define technical integration as the coupling of numerical and conceptual models developed to describe or simulate the physical environment with those describing and simulating behaviour in social, economic and political domains. Fig. D1 depicts the conceptual linkages between GVP disciplinary research models and the DSS. A core capability demanded of the integrated system is an ability to rigorously apply optimization, or goal-oriented criteria to water resources decision-making. We are pursuing a “smart coupling” strategy, which seeks to identify the minimum degree of coupling required to address each specific, well-posed research or policy question. Our suite of models becomes a toolbox from which the appropriate tools are selected as dictated by task. This process is formalized in the definition of model use cases. As a precondition, we must establish the sensitivity of models to variations in the magnitudes of shared parameters and variables, and to discrepancies in model spatial resolution and/or timestep. In the prototype water use optimization model described in Status Report I, the problems of technical integration were avoided by incorporating simplified representations of hydrologic and economic processes within a single node-link linear optimization framework. During Phase II, the integrated economic-hydrologic optimization approach has been broadened through utilization of GAMS (General Algebraic Modelling System; Brooke, et al., 1998), a high-level mathematical programming language providing seamless linkages between numerical models and a suite of powerful, large scale optimization algorithms such as CONOPT and MINOS. The current Volta River Basin optimization model (Obeng-Asiedu, 2004) encompasses agricultural

Project ID: 07 GWK 01 Project duration: 01.05.2003 – 30.05.2006 Report period: 01.06.2003 - 28.02.2005

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water use, urban and rural domestic uses, industrial demand and hydropower generation. It also simulates regional supply, demand and trade in electricity both from hydro and thermal sources, providing a framework for evaluating the critical tradeoffs between upstream abstractive uses (principally irrigated agriculture) and downstream hydropower generation. Model runs to date suggest (1) that irrigated rice cultivation is economically inefficient, and farm incomes and water resources availability would both improve under crop diversification strategies; (2) increases in irrigated areas have clear negative impacts on hydropower production, both within Burkina Faso and downstream at Akosombo, and (3) small, farmer-managed irrigation systems are more economically viable than large systems. The model also demonstrates that a co-ordinated basin approach to power generation and electricity trading results in substantial collective net savings. Figure D1: Schematic of GVP Model Linkages and DSS To develop a capacity to evaluate how outcomes generated via optimization in GAMS recursively impact the land surface and hydrologic processes that provide GAMS with initial boundary conditions, we are currently developing and evaluating several methods for establishing an efficient bi-directional coupling between WaSIM-ETH and GAMS. We utilize prototype WaSiM and GAMS models of the Atankwidi catchment (270 km²) in the Upper east of Ghana, with the objective of optimizing the conjunctive use of surface and groundwater resources in small-scale irrigated agriculture. GAMS simulates the capture and utilization of runoff in small reservoirs with passive spillways, common to the Upper East and Burkina Faso. Water can be withdrawn for irrigation, or stored in the reservoir and used for aquaculture. Agriculture consists of rainfed or irrigated cultivation of rice, maize, tomatoes or onions. Irrigation water can also be pumped from the underlying aquifer, and pumping costs modeled as proportional to the distance to water table. The aquifer is recharged via percolation from the small reservoirs, irrigation system conveyance losses and deep percolation from irrigated areas. Fixed resources are irrigable land and storage capacity. Allocation of land to various crops; and surface- and groundwater, respectively, to irrigation are decision variables. Physical hydrology of the catchment is simulated using WaSiM-ETH, generating GAMS boundary conditions. One promising line of investigation utilizes the scripting language PERL to couple WaSiM recursively to GAMS. Agricultural water use is optimized subject to minimum instream flow

Remote Sensing Hydrology:

WaSiM

Bio-Climatic Network

Integrated Basin

Modeling: GAMS

Mesoscale Climate:

MM5

Land Conversion: GV-LUDAS

Field Surveys, Anthropologic

Studies

Institutional Mapping &

Analysis

Agent-Based Models

DSS

MoWH MoFA WRC Water Board VRA WAT-SAN DA WUA

Climate, Land Use, Hydrology: Institutions, Economics, Stakeholders:

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requirements and maximum groundwater level drawdown (“red line“), as determined by WaSiM. GAMS accepts hydrologic data generated by WaSiM, introduced via formatted input files, serving as boundary conditions for optimization (“water capacity”). The optimization problem is solved by GAMS using CONOPT3, a large-scale gradient search optimization solver. Optimized variables with the potential to impact hydrologic behavior (irrigated area, cropping decisions, irrigation diversions) are passed back to WaSiM and the water balance recalculated. If the results fulfill the conditions for sustainable water balance (e.g. minimum instream flow requirement, maximum groundwater level), the simulation is closed. If there is an undershoot of a “red line” condition, withdrawal will be reduced and a new iteration initiated. The communication between models (mode of coupling) is programmed in PERL and C-shell (Mast and Kunstmann, 2005). An alternative approach employs the Parameter Estimation Tool (PEST) software (Doherty, 2002), which was designed to automate the optimization of parameter sets of large, complex models (e.g., MODFLOW). In our application, PEST pre-processing capabilities are utilized in combination with UNIX shell scripts to construct a model interface (Intsiful, 2005). The two models are coupled via embedded templates, which allow communication between models through a common mode of access to shared variables. The optimization logic of the PEST-UNIX bidirectional linkage is somewhat different than the PERL approach in that the latter evaluates the potential violation of certain constraints externally to GAMS (in WaSiM), while in the PEST configuration, all formal (programming) constraints remain internal to GAMS. Each effort is ultimately viewed as a prototype for the development of a framework for integration that is model-independent, however, since the GAMS-WaSiM integration task, while of fundamental importance in the construction of the DSS, is but one of several model couplings envisioned. Consistent with the toolbox approach to model integration, we are seeking to develop a framework that permits us to introduce new elements into an existing configuration of models and databases with a minimum of ad hoc programming. Projects we have examined as suitable models for such an extendable framework include the U.S. Watershed and River Systems Management Program (WaRSMP) and COBIDS. WaRSMP, a joint BuREC/ USGS/ TVA/ CADSWES project, is a database-centered suite of river management tools with plug-in capabilities to accomodate new or extended models. COBIDS (Component-Based Integration of Data and Services) is a set of applications, including “mediator components”, for the efficient sharing of data and services in a multi-database, multi-application environment. The design and implementation of this integration framework will be the core technical activity of Phase III. Sub-Project D2: Household Decision-Making and Policy Response The primary research question examined in D2 is how farmers and rural households in the basin are affected by, and cope with erratic and unreliable rainfall. Research is supported primarily by data collected in the 2002 field campaign, augmented by targeted academic field research. We are interested in the factors motivating migration decisions, and in the relationships between climatic uncertainty, technology choice, and other factors influencing farmers’ decisions to adopt irrigated cropping systems. Methodological approaches include econometric as well as agent-based and bio-economic modeling. We are currently conducting a second round of farm sample surveys in collaboration with partners the Ghanaian Institute for Statistical, Social and Economic Research (ISSER), adhering closely to the format established in Phase I (“common sampling framework”) in order to establish a panel data set, although we are re-calibrating the sampling strategy to deliberately capture a greater number of households already practicing irrigation. As irrigated cropland is currently less than 1% of cultivated land in Ghana and Burkina Faso,

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stratified sampling invariably identifies a relatively small subsample of practiced irrigators, insufficient for statistical analysis. We are also conducting the first round of the Burkina Faso sample survey in collaboration with Centre de Cooperation Internationale en Recherche Agronomique pour le Developpement (CIRAD). Many of the agent-based modeling activities of D2 are now enfolded into the joint research agenda of GVP and the International Food Policy Research Institute (IFPRI) Governance and Modeling Challenge Project in the Upper East Region, as key components of the White Volta Pilot Project. Sub-Project D3: Experimental Application of Scientific Knowledge (Policy Pilot Study) The White Volta Basin, encompassing much of northern and eastern Ghana, was selected by the Ghanaian Water Resources Commission (WRC) as a pilot basin in which IWRM policies and practices could be tested and evaluated. WRC identified the following water sector problems: (a) flooding, (b) water shortage, (c) lack of comprehensive institutional and legal framework, and inadequate management information and data for water management, (d) high fluoride concentrations in groundwater, (e) water pollution and improper land use, and (f) high salinity of groundwater. In addition, the White Volta is an international basin, shared with Burkina Faso, where technical cooperation on water resources management had already been initiated (Ampomah, 2004). The specific objectives of the White Volta pilot program are (1) to identify and motivate stakeholders for collaboration and participation in IWRM; (2) to establish the institutional framework for IWRM; (3) to develop a Water Action Plan; and (4) to monitor and evaluate the IWRM process. Initial WVPP activities included a stakeholder identification process, followed by a consultative stakeholder workshop held in November 2002; and the subsequent constitution of the Basin Board (Advisory Committee). The Board membership consists, inter alia, of riparian District Assemblies, research and data collection institutions, water and sanitation NGO’s, religious bodies and traditional authorities (Ampomah, 2004). The WRC and GVP established the WVPP office in Bolgatanga in January 2005, shared by researchers from the CGIAR Challenge Program on Water and Food - Governance and Modeling Project (G&M). Wider co-operation will involve the IUCN, GWP and GEF through their transboundary Land and Water Management Program. The WVPP will serve as a laboratory for developing and testing methods and formats for eliciting stakeholder participation in water management decisions. It is also a laboratory for establishing modes of cooperation between GVP and IFPRI scientific staff and Ghanaian water managers. The primary task of the GVP Scientific Coordinator is to supervise and to participate in the development of the White Volta DSS. He provides scientific support to the Basin Officer by addressing WVPP data requirements, and by making the scientific process transparent to stakeholders. He will also be involved in scientific capacity building activities, and produce scientific documentation and scholarly publications. The Food and Water Challenge Program – Governance and Modeling Project is a collaboration between the International Food Policy Research Institute (IFPRI), ZEF, and partners in Ghana. The primary responsibility if the G&M resident scientist is to interact with the community of stakeholders in order to develop an understanding of how water use decisions are made at household and community level. These processes will be modeled subsequently using agent-based techniques (Berger, et al., 2004), and will in addition provide an important interface with the DSS. The White Volta Pilot Project prototype DSS is scheduled for testing in 2006. The lessons learned will be incorporated into the Volta Basin DSS, which is the primary output of Phase III of the GLOWA Volta Project.

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Appendix A: Theses Completed During GLOWA Volta Phase II

Agyare, W.A. (2004): Soil characterization and modeling of spatial distribution of saturated hydraulic conductivity at two sites in the Volta Basin of Ghana. Ecology and Development Series No. 17

Ajayi , A.E. (2004): Surface runoff and infiltration processes in the Volta Basin, West Africa: Observation and Modeling. Ecology and Development Series No. 18

Braimoh, A.K. (2004): Modeling land-use change in the Volta Basin of Ghana. Ecology and Development Series No. 14

Carbone, Tanja (2004): Plobleme der Trinkwasservertielung in landlichen Haushalten Ghanas – dargestellt am Beispiel des Volta-Beckens. Diploma thesis, Geographical Institute, University of Bonn

Codjoe, S.N.A. (2004): Population and Land Use / Cover Dynamics in the Volta River Basin of Ghana, 1960 - 2010. Ecology and Development Series No. 15

Duadze, S.E.K. (2004): Land use and land cover study of the savannah ecosystem in the Upper West Region (Ghana) using remote sensing. Ecology and Development Series No. 16

Intsiful , J.D. (2004): Upscaling of land surface parameters through inverse SVAT modeling. Ecology and Development Series No. 20

Obeng-Asiedu, P. (2004): Allocation Water Resources for Agricultural and Economic Development in the Volta River Basin. Doctoral thesis, University of Bonn

Oguntunde, P.G. (2004): Evapotranspiration and complimentarity relations in the water balance of the Volta Basin: field measurements and GIS-based regional estimates. Ecology and Development Series No. 22

Osei-Asare, Y. (2004): Household Water Security and Water Demand in the Volta Basin of Ghana. Doctoral thesis, University of Bonn

Scannapieco, P. (2003): Bewässerungsprojekte als Entwicklungschance für Frauen unter Einfluss traditioneller Sozialstrukturen in Nord-Ghana. Diploma thesis, Geographical Institute, Humboldt-University Berlin, Germany

Traore, C. (2003): Epidemiology of Malaria in a holoendemic area of rural Burkina Faso. Doctoral thesis, Medical Faculty, Ruprecht-Karls-University Heidelberg

Appendix B: Articles and Research Documentation 2003 - 2005

Asante, F.A. (2003): Economic Analysis of Decentralisation in Rural Ghana. Development Economics and Policy Vol. 32. Frankfurt a.M.

Berger, T. (2003): Integration der Sozioökonomik in die Wasserressourcenforschung: Nur Wunschdenken und Lippenbekenntnis? 67. Sitzung der DFG-Senatskommission für Wasserforschung, Wissenschaftsforum Berlin, Germany, March 27. Manuscript in: ZEF-Documentation of Research 2/2003

Berger, T. (2004): Agent-based Modeling of Land Use Dynamics and Policy Options. Agrarwirtschaft 53, No. 2: 77-86

Berger, T., Schreinemachers, P. (in press): Multi-Agent Simulation for Development of Less-Favored Areas. Agricultural Systems, Special Issue "Development Strategies for Less-Favored Areas" 2004

Braimoh, A.K. (2004): Seasonal migration and land-use in Ghana. Land Degradation and Development 15: 37-47 Braimoh, A.K., Vlek P.L.G. (2004): Impact of land-cover change on soil properties in Ghana. Land Degradation and Development 15: 65-74

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Braimoh, A.K., Vlek P.L.G. (2004): Land-cover dynamics in an urban area in Ghana. Earth Interactions 8 (1): 1-15

Braimoh, A.K., Vlek, P.L.G. (2004): Scale-dependent relationships between land-use change and its determinants in the Volta basin of Ghana. Earth Interactions 8 (4): 1-23

Braimoh, A.K., Vlek, P.L.G. (2004): Land-cover change analyses in the Volta basin of Ghana. Earth Interactions 8 (21): 1-17

Briët , O.J.T., Dossou-Yovo, J., Akodo, E., van de Giesen, N., Teuscher, T.M. (2003): The relationship between Anopheles gambiae density and rice cultivation in the savannah zone and forest zone of Côte d'Ivoire. Tropical Medicine and International Health, 8(5): 439-448

Carbone, T. (2004): GLOWA Volta Project - Sampling of drinking water quality at household and community level in the Ghanaian Volta Basin. ZEF Documentation of Research 2/2004

Gensler, M. (2004): Parzellierung und Geschichte. Zugang zu und Kontrolle von Bauland in einer westafrikanischen Kleinstadt (Diébougou, Burkina Faso), Paideuma 50: 127-150

Kunstmann, H. (2005): Upscaling of Land Surface Parameters through Direct Moment Propagation. Advances in Geosciences, submitted

Kunstmann, H., Jung, G. (2003): In: Arneth, A. et al. (eds), Report Series in Aerosol Sciences, No. 62B, Proceedings of ILEAPS: Integrated Land Ecosystem - Atmosphere Study, International Open Science Conference, Helsinki, Finland: 215-220

Kunstmann, H., Jung, G. (2003): Investigations of feedback mechanisms between soil moisture, land use and precipitation in West Africa, "Water Resources Systems - Water Availability and Global Change", IAHS Publication No. 280: 149-159

Kunstmann, H., Stadler, C. (2004): Operational High Resolution Meteorological - and Hydrological Analysis as Decision Support System in Integrated Water Resources Management, in: Görgens, A. et al. (eds), IAHS Redbook "Integrated water resources management: Towards sustainable water utilization in the 21st century", accepted for publication

Kunstmann, H., Jung, G. (2005): Impact of regional climate change on water availability in the Volta Basin of West Africa, in: IAHS Publication No. 295 "Regional Hydrological Impact of Climate variability and Change", accepted for publication

Kunstmann, H., Jung, G. (2005): Influence of soil moisture and land use change on Precipitation in West Africa and the Volta Basin. Journal of River Basin Management, submitted

Laube, W., van de Giesen, N. (2003): Ghana Water Law and Policy: Institutional Issues and Hydrological Perspectives, in: Hydrological information in water law and policy: current practice and future potential. Wallace, J.S., Wouters, P., Pazvakavambwa, S. (eds.) Water Policy Series, Kluwer (accepted for publication)

Martin , N. (2003): Il ruolo die pozzi scavati a mano nel combattere la carenza idrica in Ghana (The role of hand dug wells in fighting water scarcity in Ghana). Afriche e Orienti: Economia e politiche dell'acqua, Anno V, No. 3 - 4: 118-125

Martin , N., van de Giesen, N. (2004): Spatial Distribution of Groundwater Production and Development Potential in the Volta River basin of Ghana and Burkina Faso. Water International, in press

Marx , A., Kunstmann, H., Burose, D., Moene, A. (2004): Uncertainty Analysis based on Error Propagation for Satellite Derived Sensible Heat Fluxes and Scintillometer Measurements over Savannah Environment and Comparison to MM5 Simulation Results, Agricultural and Forest Meteorology, submitted

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Masiyandima, M.C., van de Giesen, N., Diatta, S., Windmeijer, P.N., Steenhuis, T.S. (2003): The Hydrology of Inland Valleys in the Sub-Humid Zone of West Africa: Runoff Processes in the M'bé Experimental Watershed. Hydrological Processes, 17: 1213-1225

Mast, M., Kunstmann, H. (2005): Coupled hydrological-econmoical simulations for delineation of optimized irrigation using WaSim and GAMS. Technical Manual, Institute for Meteorology and Climate Research, Forschungszentrum Karlsruhe GmbH

Neumann, R., Jung, G., Kunstmann H. (2004): Climate Trends in the Volta Basin / West Africa Journal of River Basin Management, submitted

Oguntunde, P.G., Fosu, M., Ajayi, A.E., van de Giesen, N. (2004): Effects of charcoal production on maize yield, chemical properties and texture of soil. Biology and Fertility of Soils, 39(4): 295-299

Oguntunde, P., van de Giesen, N. (2004): Crop growth and development effects on surface albedo for maize and cowpea fields in Ghana, West Africa. International Journal of Biometeorology, 49(2): 106-112

Oguntunde, P.G., van de Giesen, N., Vlek, P.L.G., Eggers, H. (2004): Water flux in a cashew orchard during a wet-to-dry transition period: analyses of sap flow and eddy correlation measurements. Earth Interactions, 8: 1-17

Park, S.J., van de Giesen, N. (2004): Delineation of soil-landscape units along hillslopes to identify the spatial domains of hydrological processes. Journal of Hydrology, 295 (1-4): 28-46

Park, S.J., van de Giesen, N., Vlek, P.L.G. (2004): Optimum spatial scale for modelling land use change processes in a savanna landscape in northern Ghana. Agriculture, Ecosystems and Environment, accepted for publication

Tsegai, D., Plotnikova, M. (2004): Impact of wage differentials on household migration decisions: A sample selection approach. Manuscript for a presentation at the 38th Annual Meeting of the Canadian Economics Association (CEA), Toronto, Canada, June 4-6. Online publication, accessible at http://economics.ca/2004/papers/0199.pdf on 17 February, 2005

Tsegai, D., Yilma, T. (2004): GLOWA-Volta Weighting Factors. ZEF Documentation of Research 1/2004

van de Giesen, N. (2003): GLOWA-Volta Projekt in zweite Phase gestartet. ZEF news 13, October 2003

van de Giesen, N., Stomph,T.J., (2003): RUNOFF01 Software for calculating two-dimensional Hortonian flow and associated scale effects, manual and code description. ZEF-Documentation of Research 3/2003 van de Giesen, N., Stomph, T.J., de Ridder, N. (2005): Surface Runoff Scale Effects in West African Watersheds: Modeling and Management Options. Agricultural Water Management, 72 (2): 109-130

van Edig, A., Engel, S., Laube, W. (2003): Ghana's water institutions in the process of reforms: from the international to the local level, in: Neubert, S. et al. (eds.) Reforming Institutions for Sustainable Water Management. German Development Institute, Bonn: 31-50

van Edig, A., Youkhana, E. (2003): Arme und Umwelt - Verlierer der Wasserprivatisierung, in: Kaiser, M. (ed.) WeltWissen. Entwicklungs-zusammenarbeit in der Weltgesellschaft, transcript, Bielefeld

Vescovi, F.D. (2003): La gestione dele risorse idriche in Burkina Faso. Dai satelliti informazioni territoriali storiche ed aggiornate. Afriche e Orienti: Economia e politiche dell'acqua, Anno V, No. 3 - 4: 108-117

Yilma Dessalegn T., Berg, E., Berger, T. (2004): Emancipating African Women through Agricultural Technologies: the Case of Irrigation Technology in Northern Ghana. in: Peters, K.J. et al. (eds.). Proceedings of Deutscher Tropentag, Berlin, October 5-7: Rural Poverty Reduction through Research for

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Development, Online publication, accessible at http://www.tropentag.de/2004/abstracts/full/118.pdf on 31 January 2005

Yilma , T., Berg, E., Berger, T. (2004): Prospects and Challenges of Agricultural Technology-Market Linkage under Liberalization in Ghana: Evidence from a micro-data. African Development and Poverty Reduction: The Macro-Micro Linkage, Forum Paper 2004, Online publication, accessible at http://www.commerce.uct.ac.za/dpru/dpruconference2004/Papers/Prospects_and_Challenges_Yilma.pdf on 31 January, 2005