Must be measured in rain gauges. In how many? How to
interpolated/extrapolated?
Slide 6
Inverse of the Distance Weight Regression Model THIESSEN
POLYGON
Slide 7
Depends on: Atmospheric conditions (HR, Temperature, radiation
& wind) Available soil water (above wilting point)
Transpiration surface (Leaf Area Index LAI)
Slide 8
Depends on plants Development and soil cover.
Slide 9
R n is the net radiation, G is the soil heat flux, (e s - e a )
ris the vapour pressure deficit of the air, r a is the mean air
density at constant pressure, c p is the specific heat of the air,
D is the slope of the saturation vapour pressure temperature
relationship, g is the psychrometric constant, and r s and r a are
the (bulk) surface and aerodynamic resistances.
http://www.fao.org/docrep/X0490E/x0490e06.htm
Slide 10
Slide 11
Slide 12
Richards Equation
http://www.mohid.com/wiki/index.php?title=Module_PorousMedia#Water_retenti
on
Rain Intensity Water Content Runoff IST MARETEC 2008 MOHID Land
Watershed
Slide 17
Is the Rain that does not infiltrate. Flows at soil surface,
can infiltrate (and sometimes exfiltrate. Flow is controlled by
friction.
Slide 18
Hydrology Vegetation (evapotranspiration, nutrients,
pesticides, erosion,.) Mineralisation of Organic matter in the soil
(bacterial loop) Irrigation Salts dynamics/chemical equilibrium
Rivers, Reservoirs/lakes, Estuaries and Coastal Lagoons.
Slide 19
All models compute Evapo-transpiration on the same way.
Differences on results depend on the detail of the input data.
Process oriented models (e.g. Hydrus, Mohid, Mike, RZWQM) compute
percolation using the Richards Equation. They need fine grids.
Other models use coarse grids and empirical formulations to compute
flow (e.g. SWAT, HSPF, BASINS).
Slide 20
Meteorological data processor, Climate (seasonal/daily solar
evolution), GIS, Chemical Equilibrium, Plants Optimal Growth,
Management Practices, Graphical interfaces.
Slide 21
Production of plants is the major role of catchments. Diffuse
pollution is mostly due to plant growth improvement: Fertilisation,
Phyto-sanitation, irrigation.
Slide 22
Slide 23
http://www.fao.org/docrep/009/a0100e/a0100e05.htm
Slide 24
NH 4 + REFRACTORY OM CO 2 Psol CO 2 Psol N 2 Pfix LABILE OM
AEROBIC BIOMASS ANAEROBIC BIOMASS NH 4 + CH 4 AUTOTROPHIC BIOMASS
NO 3 - Urea NH 3
MOHID Land SWAT HRU CN, Lag time Vegetation and Erosion
Watershed picture to farm plots; Flush events 2D Overland flow
Precipitation Variable in Time & Space 3D Porous Media 1D
Drainage network Distributed vs partially distribuited models
Slide 29
Produtores Primrios Nutrientes Nitrato Amnia Ortofosfato Slica
Consumo Excreo Morte Produtores Secundrios Detritos / MO Bactrias
Deposio Sedimentos Respirao CO2 O2 Processos de qualidade da gua em
Rios
Slide 30
Kinematic wave equation (equilibrium between gravity and
friction) Trapezoidal shape for channels in both models Rch is the
hydraulic radius for a given depth of flow (m), slpch is the slope
along the channel length (m/m), n is Mannings n coefficient in
channel vc is the flow velocity (m/s). If inertia is
important:
Slide 31
Rain Intensity Water Content Runoff IST MARETEC 2008 MOHID Land
Watershed
Slide 32
Slide 33
Rain Intensity Sediment IST MARETEC 2008 WQ models in river
MOHID Land River
Slide 34
w perc,ly is the amount of water percolating to the underlying
soil layer on a given day (mm H2O), SW ly,excess is the drainable
volume of water in the soil layeron a given day (mm H2O), t is the
length of the time step (hrs), TT perc is the travel time for
percolation (hrs). SAT ly is the amount of water in the soil layer
when completely saturated (mm H2O), FC ly is the water content of
the soil layer at field capacity (mm H2O), K sat is the saturated
hydraulic conductivity for the layer (mmh-1).
Slide 35
Slide 36
Q gw,i is the groundwater flow into the main channel on day i
(mm H2O), Q g w,i-1 is the groundwater flow into the main channel
on day i-1 (mm H2O), gw isthe baseflow recession constant, t is the
time step (1 day), and w rchrg is theamount of recharge entering
the aquifer on day i (mm H2O).
Slide 37
A High infiltration rates. B Moderate infiltration rates. C Low
infiltration rates. D Very low infiltration rates. CN Curve Number
(0% -100% runoff) O CN is a function of: i) permeability, ii) land
use and iii) previous soil water content. CN can change between 0.0
(no runoff) and 100 (all precipitation transformed into
runoff).
Slide 38
Knowing Q surf (acumulated runoff) it is possible to estimate
infiltration S Soil water retention parameter (mm H 2 O)
Slide 39
IST- MARETEC 2009
Slide 40
1 1. Com base na topografia foram geradas 700 sub-bacias para a
RH6 com reas entre 0.001 km2 e 100 km2 2. Sub-bacias foram geradas
em funo das massas de gua
Slide 41
IST- MARETEC 2009 Precipitao 1 Precipitation Flow
Slide 42
Slide 43
1.Cada sub-bacia comporta-se como uma Unidade de Resposta
Hidrolgica (HRU) com o mesmo uso de solo, tipo de solo e declive
1
Slide 44
Slide 45
IST- MARETEC 2009 RH6 Tipologia A2 Esturio mesotidal homogneo
com descargas irregulares de rio Esturio do Sado 6 massas de gua
Esturio do Mira 3 massas de gua 8
Slide 46
IST- MARETEC 2009 28
Slide 47
Poucos dados - estaes da Sado WB1 Poucos dados - estaes da Sado
WB2 Poucos dados - estaes da Sado WB2 (individualmente e com a mdia
das estaes)
