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TERRAHYDRO – a Distributed Hydrological System using Graph Structure for Unified Water Flow Representation. Sergio Rosim Antônio Miguel Vieira Monteiro Camilo Daleles Rennó João Ricardo de Freitas Oliveira National Institute for Space Research - INPE. IGARSS 29/ 07 / 2011. INPE. - PowerPoint PPT Presentation
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TERRAHYDRO – a Distributed Hydrological System using Graph Structure for Unified Water Flow
Representation
Sergio RosimAntônio Miguel Vieira Monteiro
Camilo Daleles RennóJoão Ricardo de Freitas Oliveira
National Institute for Space Research - INPE
IGARSS29/ 07 / 2011
INPE
Mission - To foster science and
technology in earth and space
context to offer products and regular
services in benefit of the country.
TERRAHYDRO
TerraHydro is a Distributed
Hydrological System created to
develop hydrographic basin water
flow GIS applications.
TerraHydro
TerraHydro proposes a different
computational representation for
dealing with water flow in GIS
applications. These applications
involve the concept of local flow,
extracted from terrain, which is the
basis for most spatially explicit
distributed hydrological models.
TerraHydro
Different computer structures based
on regular grids, triangular irregular
networks, contour lines, and irregular
polygon tessellations have been used
to extract local flow, entirely linked to
the data structure chosen for terrain
representation. Then, each local flow
set requires its own specific extraction
algorithms, as well as different formats
to store its associated local flow.
TerraHydro
TerraHydro proposes a data structure
based on Graph Theory that unifies
computer local flow representation,
independent of the data structures
used for terrain representation
permitting that a set of operations for
water management be formally
defined over this new structure.
TerraHydro - Concept
Extract local flows
from different
computer surface
representation
The local flows are
mapped in a
structure similar
to computer
surface
representation
strucutre
TerraHydro - Concept
The local flows are mapped to only one structure that will be used to develop the applications
The applications become independent of the original computer surface representation structure
TerraHydro - LDD to graph map
Each LDD grid cell represents a graph
node and the flow from a given cell
to a neighbor cell defines a graph
edge that links these two cells
TerraHydro - Tin to graph map
As TIN local flow has two types of
propagation geometry, each type
needs a different approach to map
TIN local flow to graph.
Triangle crosses local flow
Each triangle side starting or ending as a
local flow represents a graph node. Local
flow goes from one side to another side of
a triangle, passing through their middle
points. The graph nodes identifiers are
the same associates to the triangles sides
during the triangulation process.
Common triangles edge local flow
When a local flow goes along a triangle side, the vertices of that side represent graph nodes. The graph node identifier corresponding to triangle vertex is computed adding the total number of triangles sides to the vertex identifier from triangulation.
TerraHydro – Contour lines to graph map
The local flow goes from each cell to one or more neighbors, passing through their centers. The graph node stores the cell identification number and a graph edge is a link between two cells. Multi flow issue is intrinsic in the contour lines data model. Each cell represents a water flow uniform space.
TerraHydro – Voronoi to graph map
Each Voronoi polygon is a graph node and each graph edge represents a link between two neighbor polygons. Graph nodes store the Voronoi identification numbers existing in the Voronoi data structure which is similar to the grid cell approach.
TerraHydro – Develop environment
TerraLib - Open-source GIS software
library. TerraLib supports coding of
geographical applications using spatial
databases, and stores data in different
DBMS including MySQL and PostgreSQL
Database
TerraLib
TerraView
Plugins Plugins Hidro
TerraHydro – Develop environment
TerraView - GIS application built using the TerraLib GIS library. TerraView main goal is to make available to the GIS Community an easy geographic data viewer with resources that include database queries and data analysis, exemplifying the use of the TerraLib library
Database
TerraLib
TerraView
Plugins Plugins HidroTerraHydro is a
TerraView plugin,
using all
TerraView
funcionalities
TerraHydro – Funcionality
LDD Extraction: for each grid cell
the local flow is defined considering
the steepest downstream regarding
the 8 grid cell neighbors. LDD is the
basis for developing applications
involving water resources.
Upscaling definition: redefinition
of local flows in a grid of lower
resolution from the local flow
extracted from a high resolution grid
(LDD)
TerraHydro – Funcionality
Accumulation area: each grid cell
receives the accumulated value
along the paths that is linked with
that cell.
Drainage definition: all grid cells
subset having accumulated area
value greater than that of a user
defined threshold.Tocantis Amazonian River drainage definition example
Example of drainage: Tocantis River - Amazonian Basin
Tocantins Drainage Zooms
TerraHydro – Funcionality
River reaches: define drainage
segments, between water springs and
junctions, between junctions, or
between junctions and mouth of the
drainage.
Basin delimitations: the delimitations
can be done by selecting one or more
points over the drainage. TerraHydro
finds the basin for each given point or
for each river reach basin.
TerraHydro – ExampleAccumulation Area / Drainage
Basin Delimitation for a Point
River Reaches
Basin Delimitations for each River Reach
TerraHydro – ExampleBasin and Drainage (SRTM)
Red: Basin delimitationBlue: drianage of main Rivers, extracted from accumulation area
TerraHydro – ExampleBasin and Accumulation Area
Image size: 1.244.160.000 - Lines: 32.400 Columns: 38.400 - Processing time: 360:16:25
Initial pit number: 65.670.466 - Unsolved pit number: 0
TerraHydro X ArcGis Hydro ToolsPurus River
Yellow lines: ArcGisRed lines: TerraHydro
This work was partially supported by
FAPESP
São Paulo Research Foudation