ArcHYDRO: GIS for Water Resources. Source: Center for Research in Water Resources, University of Texas at Austin. Tutorial: Watershed and Stream Network. The ArcHydro tools work in the ArcGIS environment. To download the data model version and ArcHydro tools for ArcGIS ArcMap Image Classification Tutorial: Exploring Data · Add Orfeo Toolbox to QGis 3.X. Adapted from Arc Hydro Tools – Tutorial. Adapted from the Arc Hydro tutorial prepared by ESRI. by David Maidment and Oscar Robayo. Center for Research in.
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Watershed Delineation by ArcHydro.
Getting Started With Archydro. Overlay delineated Drainage Line on Google Earth. GIS is a powerful tool for developing solutions for water resources such as assessing water quality tutoriap managing water resources on a local or regional scale.
Hydrologists use GIS technology to integrate various data and applications into one, manageable system. ArcGIS with Arc Tutoriql gives you the flexibility to combine watershed datasets from one map source with stream and river networks. The suite of tools contained in Arc Hydro facilitate the creation, manipulation, and tutoriao of hydro features and objects within the ArcGIS environment.
Use ArcGIS Spatial Analyst for hydrologic analysis such as calculating flow across an elevation surface, which provides the basis for creating stream networks and watersheds; calculating flow path length; and assigning tytorial orders. Familiarize with the capabilities of ArcHydro. It is in WGS tutorisl system. DEMs are digital records of terrain elevations for ground positions at regularly spaced horizontal intervals.
Under the Customize menu of ArcMapclick the Extensions… button. Turn on this extension. Go to Toolbar u nder the Customize menu of ArcMapa list of tools will appear. Click the ArcHydro Tools. T he main interface of ArcHydro will open in ArcMap. In the dialog box, navigate to the location of the data; select the raster file Himachal.
In the dialog box, navigate to the location of the data; select the vector file stream. Watershed delineation are all derived from the basic premise that water flows downhill, and in so doing it will follow the path with tutorual largest gradient steepest slope.
In a DEM grid structure, there exist at most 8 cells adjacent to each individual grid cell. Cells on the grid boundary are not bounded on all sides Accordingly, water in one cell travels in 1 out of at most 8 different directions in order to enter the next downstream cell.
This concept is referred to as the 8-direction pour point model.
ArcHydro: how to model the water resources of a territory: 1-Install | Blog GIS & Territories
In this grid representation, water in a grid cell may flow only along one of the eight paths depicted by arrows. The number in each cell represents the direction water travels to enter the nearest downstream cell, and the numbering scheme has been set by convention.
The function needs as input a raw DEM and a linear feature class like the river network that both have to be present in the map document. Change parameter according to following figure. This function fills the sinks in a grid. If cells with higher elevation surround a cell, the water is trapped in that cell and tutorixl flow. The Fill Sinks function modifies the elevation value to eliminate these problems. DEM alteration to allow delineation of inland catchments.
Filling an artificial pit in the DEM. Select Terrain Preprocessing Fill Sinks.
This default name can be overwritten. This process takes a few minutes. This function computes the flow direction for a given grid. The values in the cells of the flow direction grid indicate the direction of the steepest descent from that cell. Flow Direction grid, contains cells with only the numerical values dictated by the 8-direction pour point model.
Area in red is from the previous figure. Select Terrain Preprocessing Flow Direction. This function computes the flow accumulation grid that contains the accumulated number of cells upstream of a cell, for each cell in the input grid. Flow accumulation grid is calculated from Flow direction grid. Flow Accumulation — number of cells draining to a given cell blue along the flow network.
Select Terrain Preprocessing Flow Accumulation. With a flow accumulation grid, streams may be defined through the use of a threshold flow accumulation value.
ArcHydro: how to model the water resources of a territory: 1-Install
For example, if a value of 5 were set as the threshold, tktorial any cell with flow accumulation greater than 5 would be considered a stream. This function computes a stream grid which contains a value of “1” for all the cells in the input flow accumulation grid that have a value greater than the given threshold. All other cells in the Stream Grid contain archydo data.
Stream Definition from the Flow Accumulation Tutkrial and a threshold value — A Grid cells with accumulation greater than or equal to 5 are considered stream cells red ; B Streams identified on the flow network red ; C Stream Grid. Select Terrain Preprocessing Stream Definition. The output is the Stream Grid. A default value is displayed for the river threshold. A smaller threshold will result in a denser stream network and usually in a greater number of delineated catchments. The next step is to divide the stream network into distinct stream segments — this is useful if the purpose of the delineation is to determine the individual Catchments.
If only the overall watershed is desired, the delineation function could be used on the established grids as long tutoiral the outlet cell is defined. For this discussion, Catchments are delineated.
This function creates a grid of stream segments that have a unique identification. Either a segment may be a head segment, or it may be defined as a segment between two segment junctions. All the cells in a particular segment have the same grid code that is specific to that segment.
Select Terrain Preprocessing Stream Segmentation. This function creates a grid in which each cell carries a value grid code indicating to which catchment the cell belongs.
The archyfro corresponds to the value carried by the stream segment that drains that area, archydrl in the stream segment link grid. The output is the Catchment Tuforial layer. You can recolor the grid with unique values to get a nice display. The rasters created up to now have all been stored in a folder named “Layers”. The vector data will be stored in a feature dataset also named “Layers” within the geodatabase associated with the map document.
This function converts uttorial catchment grid into a catchment polygon feature. Open the attribute table of “Catchment”.
Notice that each catchment has a HydroID assigned tutirial is the unique identifier of each catchment within ArcHydro. Each catchment also has Shape Length and Area attributes. These quantities are automatically computed when a feature class becomes part of a geodatabase. This function converts the input Stream Link grid into a Drainage Line feature class. Each line in the feature class carries xrchydro identifier of the catchment in which it resides.
Click ArcToolbox and expand the Conversion Tools. In the Third pull down menu, give output scale 50, Watershed Delineation by ArcHydro 1.
Getting Started With Archydro 4. Overlay delineated Drainage Line on Google Earth 6. Introduction GIS is a powerful tool archydrl developing solutions for water resources such as assessing water quality and managing water resources on a local or regional scale. Getting Started With Archydro 1.
Open ArcMap Step 2: Fill Sinks This function fills the sinks in a grid. Flow Direction This function computes the flow direction for a given grid. Flow Accumulation This function computes the flow accumulation grid that contains the accumulated number of cells upstream of a cell, for each cell in the input grid. Stream Definition With a flow accumulation grid, streams may be defined through the adchydro of archhydro threshold flow accumulation value.
For this discussion, Catchments are delineated Stream Links defined — A Stream Grid representation, B Stream Links numbers defined, link outlets tutlrialwatershed outlet red This function creates a grid of stream segments that have a unique identification. Catchment Grid Delineation This archyrdo creates a grid in which each cell carries a value grid code indicating to which catchment the cell belongs.
How many DrainageLines and Catchments are there? Perform same exercise with thresholds and calculate number of catchment. Make a screen capture of the attribute table of Fdr and give an interpretation for the values in the Value field using a sketch. Generate contour from the DEM and create a layout view.