How to generate river network using DEM data


So open the DEM data. Here I have banten_dem with .tif extension image file because I already clip it it and Then the next step we will choose hydrology tool in spatial analyst tools inside ArcToolbox and then select hydrology and the first step will be Fill tool Select the dem data for input Okay, done. And then we go to the second step which is the Flow Direction The input is the previous result, filled dem data. Then just click OK. OK this is the result of Flow Direction. And then the third step will be Flow Accumulation We will input flow direction result so after this three steps Fill, Flow Direction and Flow Accumulation, we can generate the River Network however, this file is raster data. and We cannot divide which one is big river and which one is small river and which one is not river Because the source is Digital Elevation Model Data and that has the big resolution which is 90 meters, so the next step we will re-classify the River Network using map algebra This is and each single output so open the flow accumulation data here put the equation I will put the flow accumulation which more than 3000 and then put the output raster to the folder and put the name And then click okay? Well, this is the result the blue color is non-river areas Green is the river network and then the next step will be Classify the river network to the Big River small river and the smaller River We could use Stream Order tool under Hydrology tool Input data is stream raster and then input Flow Direction and choose the method Here we have two methods. The first one is Stahler and the second is Shreve. You can read all the descriptions of the Stahler method and Shreve method in the help section However, I would choose Stahler because it is most common and Well, we have three orders of stream network Order one is the smallest river The second is small river. And the Order three or the third order is big river. We will change the color to differentiate which one is big and which one is small The purple color is the order three river and the blue is order two and the last one order one the last Step, we will convert the river network to Shapefile Because this StreamO is already in raster file We could use Stream to Feature tool We will input the StreamO Then input the Flow Direction Then click okay So this is the shape file using the shape file, you can adjust the symbology of the river which one is big and which one is small we’ll go to quantities and Graduated symbols Here you will divide the grid code which is the order of River and You will have three order. Order one to three. And then we’ll change color to blue Symbol size we will change it from 0.5 to 2 so we have the shapefile of river network the thicker is the Main River and the thinnest is small river So this is what we get

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