The result is a DEM just over the buffered area. At this point you have extracted all the data you need locally and are ready to begin Hydrologic Terrain Analysis. To turn in. The number of columns and rows, and grid cell size in the Logan DEM. The minimum and maximum elevation values in the Logan DEM. Hydrologic Terrain Analysis This activity will guide you through the initial hydrologic terrain analysis steps of Fill Pits, calculate Flow Direction, and calculate Flow Accumulation (steps 1 to 3). The resulting flow accumulation raster then allows you to identify the contributing area at each grid cell in the domain, a very useful quantity fundamental to much hydrologic analysis. Next an outlet point will be used to define a watershed as all points upstream of the outlet (step 4). Focusing on this watershed streams will be defined using a flow accumulation threshold within this watershed (step 5). Hydrology functions will be used to define separate links (stream segments) and the catchments that drain to them (steps 6 and 7). Next the streams will be converted into a vector representation (step 8) and more Hydrology toolbox functionality used to evaluate stream order (step 9) and the subwatersheds draining directly to each of the eight stream gauges in the example dataset (step 10). The result is quite a comprehensive set of information about the hydrology of this watershed, all derived from the DEM. Fill This function fills the sinks in a grid. If cells with higher elevation surround a cell, the water is trapped in that cell and cannot flow. The Fill function modifies the elevation value to eliminate these problems. Select Spatial Analyst Tools Hydrology Fill. Set the input surface raster as dem and output surface raster as fel in Logan.gdb. Press OK. Upon successful completion of the process, the “fil” layer is added to the map. Let's examine the impact of Fill on the DEM. Select Spatial Analyst Tools Map Algebra Raster Calculator and evaluate fil - dem. Select Spatial Analyst Tools Surface Contour. Set the inputs as follows to determine 20 m contours of the original DEM, dem.
The result is a DEM just over the buffered area. At this point you have extracted all the data you need locally and are ready to begin Hydrologic Terrain Analysis. To turn in. The number of columns and rows, and grid cell size in the Logan DEM. The minimum and maximum elevation values in the Logan DEM. Hydrologic Terrain Analysis This activity will guide you through the initial hydrologic terrain analysis steps of Fill Pits, calculate Flow Direction, and calculate Flow Accumulation (steps 1 to 3). The resulting flow accumulation raster then allows you to identify the contributing area at each grid cell in the domain, a very useful quantity fundamental to much hydrologic analysis. Next an outlet point will be used to define a watershed as all points upstream of the outlet (step 4). Focusing on this watershed streams will be defined using a flow accumulation threshold within this watershed (step 5). Hydrology functions will be used to define separate links (stream segments) and the catchments that drain to them (steps 6 and 7). Next the streams will be converted into a vector representation (step 8) and more Hydrology toolbox functionality used to evaluate stream order (step 9) and the subwatersheds draining directly to each of the eight stream gauges in the example dataset (step 10). The result is quite a comprehensive set of information about the hydrology of this watershed, all derived from the DEM. Fill This function fills the sinks in a grid. If cells with higher elevation surround a cell, the water is trapped in that cell and cannot flow. The Fill function modifies the elevation value to eliminate these problems. Select Spatial Analyst Tools Hydrology Fill. Set the input surface raster as dem and output surface raster as fel in Logan.gdb. Press OK. Upon successful completion of the process, the “fil” layer is added to the map. Let's examine the impact of Fill on the DEM. Select Spatial Analyst Tools Map Algebra Raster Calculator and evaluate fil - dem. Select Spatial Analyst Tools Surface Contour. Set the inputs as follows to determine 20 m contours of the original DEM, dem.
Ex42013.docx