Hello Guys, Today we are going to prepare a slope map this video will show you how to prepare a slope map using a DEM file. for that , first of all we will need to have a Dem file, that can ge downloaded from earthexplorer.usgs.gov. Second, we will need the shapefile of our study area. I have downloaded the both , so i am gonna add both the data. so this is the demfile. it will be easy for us to work only in our study area compared to working on the whole Area. so we will be extracting the raster for our study area from dem file using extract by mask. we will input our raster and the mask and extract it in the designated folder. Once it is complete , i will remove the original demfile and the prepare a contour line. A contour line is a line joining the points at same elevetion. now we will input the extracted raster, assign the output folder and determine the contour interval. contour interval is the distance between eachh contour line. I will take 20 now as the contour is created, we will create tin form contour. tin is triangulated irregularated network . we will determine the coordinate system, i.e. 44N for west and 45N for eastern Nepal we will input contour, and assigh output folder. now the tin is converted to raster using tin to raster feature. the raster prepared doesnt resembelance the shape of our study area. so we will again be extracting the raster using extract by mask. now it looks similar now, we will convert this raster into slope we will input raster, and assigh output folder. but the figure we seeing is pixelated and not clear so, we will go to properties, and under display heading ,we will change nearest neighbour to bilinear interpolation now it willnot pixelate
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now we will reclassify the slope Reclassify allows us to re-categorize the slope categories according to our desire now , input the slope, and click on classify basically we classify into 4 categories for a forest 0-15% (normal), 15-30%slope (productive), 30-45% (sensetive) and >45% (very sensetive area) we will change the breakage value asper our required categories i.e. 15, 30 ,45 and >45 now select the output folder and click ok change to bilinear interpolation to remove pixelation now we will convert the raster to polygon using 'raster to polygon' feature this changes it into individual polygons now we need to dissolve the polygons falling under same categories or group into one single polygon it can be done using dissolve feature under geoprocessing heading we need to check the gridcode box, gricode box is the classes that we made during reclassify. now the polygons are dissolved into one single polygon . now , inside properties, under symbology heading, eight click on categories, and add all the values now change the colour as you wish by double clicking it now we change to layout view and costumize the map we will adjust the map , and insert the north arrow now we will insert the tittle now we will insert the scalebar and scale text accordingly insert the coordinate system we will insert and edit the legend now ww will right click on legend, convert it to graphics and then ungroup it twice. ungrouping frees the legend contents so thet we can edit every content individually.
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