Watershed Delineation Using ArcGIS Pro | Step-by-Step Tutorial

opened our rgis pro project the waterers shed delineation so now let's get started so the only data set I will be using to get started with this tutorial on Watershed delineation so which could be my uh demm that is my digital elevation model have downloaded from uh USGS Earth Explorer there RTM Dem of 30 m resolution now let me show you that so this is our digital elevation model I have downloaded from USGS so the link will be given in the description to how to download the srtm Dem from USGS Earth Explorer so this is a digital elevation model here so it is in file format that is in tip file format so now to add our digital elevation model into our rgis Pro just click this and drag this into our current view of the map so now we can able to visualize it so as you can see it has zoomed into our correct location of this uh srtm Dem so now let me zoom out and show you the exact location of my Dem is located so it is located uh in India so you can able to uh see that so basically it is located in uh South India so this particular Dem is lying in towards South India so now suppose if you want to visualize the terraine to R elevation more clearly so what you can do is go to this layer and right click and uh click this option called symbology so once you did that the window will be open here symbology of this Tiff that is a d Tiff so here you can select a color the color scheme for your Dem so from here you can select a bit more variety of color schemes so which could reflect the terine elevation so now let me select this part particular color so here you can able to visualize the highest elevation is represented in blue color and the lowest level of elevation is represented in Red so now let us invert this color so now we can able to clearly visualize the highs and lows here the highest uh elevation is uh given in this red color and the lowest level of elevation is given in blue color so you can visually able to identify the hills and Valley so uh this is the valley and this will be our Hills so the low Ling areas are clearly represented in blue color and the highlighting areas are represented in red color red and yellow and here you can able to visualize the drainage patterns here so now when delting water sheds so the very first thing we could like to do is uh so that is we could uh go so we could go ahead and uh fill the sinks in our Dem so the reason we are doing to fill the sink is is to basically to eliminate the small imperfections uh so that are usually presented in this kind of uh dim data so in order to fill the syns uh so what you can do is uh you can basically make use of the fill tool that is available in our rgis Pro and now navigate to this option called analysis and click this option called tools that is our geoprocessing tools so click this so once you did that the window op opens up that is uh ge processing here so here you can click this option called toolbox so in that you have to navigate to spatial analysis tool so in that so in the spatial analysis tool there is a tool called hydrology so click this so in that you can able to uh see the fill tool here so now let me click this so so in this tool basically we're going to input our surface raser that is our elevation digital elevation model our Dem data so now let me rename this particular uh dim data the name of the dim data here so going to replace as dim data so now I have replaced our name of our dim data that is have represented as a dim data here so now let me navigate to G processing here now so in that we're going to select our dim data so we're going to select our srtm dim data so click this now choose your output surface raster the reserver choose your folder location so where you could like to save your file now let me select and now I have selected my folder location called shape files and click open and now let me enter the name so let me enter as fill so now click save so once you did that we're going to click this option called run so now we can able to visualize here our fill has been completed so the filter fill layer is available here in the table of content section and make sure that you give a file extension dodf that is stiff and now I could like to turn off this Dem demm data here so the next next major step in delineating a water shed so next we have to create a flow Direction raster here so what we can do is uh we can basically go back to our Geo processing tool so we have to navigate to the option called spatial analys tool so in that you can able to uh see the tool called flow Direction here so click this uh tool and now the input surface raster will be our fill so we have to select our fill and you can choose your output flow Direction roster so now browse this option to save your output flow Direction roster here so now click save so make sure that you give a file from file extension of Tif and uh now click save so quite an important over here we have to select our flow Direction type so here three different flow Direction uh types available so starting from d8 so the second flow Direction type is uh MFD and the third was DF so if you're not familiar with the flow Direction type so I could like to suggest this option called uh information here so click this option here so just place your cursor over this information symbol here so now we can able to visualize the flow Direction types so the details of this flow Direction type so here the d8 assigns the flow Direction based on the d8 flow method this method assigns the flow direction to the steepest down slope neighbor so this is the default method so we're going to stick to this method so you can also try other methods here so for this video we're going to stick to this particular method called d8 so once you selected your flow Direction type so navigate to this option called run and click run so now the flow Direction raster is available in our table of content here so uh the process has completed so now let me explain about this flow Direction so we have each of the the flow directions are represented in different numbers here so you can able to visualize that the each of the flow directions are represented in specific color starting from one so one here represents uh represents the flow direction towards East so now let me show you that so here you can able to visualize that each of the number here specific shows us a different flow direction for example the one is uh the represents the flow direction to towards the east and the two represents the flow direction towards Southeast and 128 here represents the flow direction towards towards the Northeast likewise each of the specific number represents a different directions uh different direction so in geographic information system the flow direction is the key component in analysis of surface water flow so the d8 flow Direction method is a commonly used approach model the flow of the Border across the raster grid this method assigns the flow direction to each cell in the grid based on the steepest down hill slope so the flow Direction Cotes here assigns a unique code to represents each of the eight possible flow directions these Cod typically uses a compass direction for example North Northeast East and Southeast South Southwest West and and Northwest so corresponding to eight cardinal and the intercardinal directions so the d8 method is a simplified model that assumes the water flow direction to to one of the eight neighboring cell with the steepest descent while it may not capture all the gradations of terine and flow pattern it is computationally efficient and widely used for many applications including flood modeling and watered analysis and environmental planning so now let me get back to our art Pro So based on this direction coding that is the one here represents towards East and the two represents towards the direction coding that is the flow direction is towards the uh Southeast and the 64 here represents the direction towards north so now you can able to visualize that based on the color you can uh just find you can find the direction coding here so that is our flow Direction raster next we could like to create a flow accumulation raster so we had to navigate to this tool that is our Geo processing tool so in that so we're going to select our navigate to spatial analysis tool so in that we're going to select our flow accumulation to that is in uh we're going to select flow accumulation to so click this so once you did that the flow accumulation uh tool is available so now input your flow Direction roster now let just uh select my flow Direction rer here so select it and choose your output file location and now selected my output file location that is a flow accumulation so now click save and make sure that you give a the file extension of Tif so click save and now the output data type will be float and the input float Direction type will be in d8 so click this option called run so now the flow accumulation uh is completed here so you can able to visualize here in the table of content section our flow accumulation raster so now we can able to see we have managed to create a flow accumulation raster raster you can clearly able to visualize here that is of highest flow accumulation raster is marked in white color and the lowest flow accumulation raster is marked in black color so that is the the grid cell with the highest flow accumulation raster is marked in white color so we can able to visualize here the white Tres the highest flow accumulation R rits cells and the black here represents the lowest flow accumulation cells so that is represented in black color so now let me explain about how the flow accumulation works so flow accumulation tool calculates the accumulated flow as accumulated weights of cell flowing into each down slope cell into output raser if no weight raser is provided a weight of one is applied to each cell and the value of cells in the output raster is uh is the number of cell that flows into each cell so in the graph below the top left image shows as a direction of travel from each cell and the top right is the number of cells that flows into each cell so this is our Direction coding the cell with high flow flow accumulation of the areas of concentrated flow and may be used to identify the stream channels and cells with the flow direction of zero or the local uh topographic highs and may be used to identify The Ridges so now I could like to click on a flow accumulation raser right click and select the option called symbology so instead of going with the stretch color type we could like to uh move on to this option called classify so click this option so in the manual classifications so instead of five classes we could like to uh use the two classes here so we're going to select two here so now you could select a different color scheme for your flow accumulation raster so now let me click this particular color here so now you can clearly able to visualize flow accumulation here so here you can able to visualize here the highest flow accumulation raser is marked in this color and the lowest flow accumulation raster is so marked in in this color that is in dark blue color so now I could like to reduce the upper upper bound value of this particular flow accumulation raster so by reducing we can able to visualize most tributaries more tributaries for in this flow accumulation raster here so now I could like to reduce this value so now the upper value is around 23746 35 so I could like to reduce its value now and now we can able to visualize the new branches has been observed on our flow accumulation raster here so we can able to visualize the new tributaries so by reducing values we can able to visualize a few more tributaries uh it is absorbed so in our flow accumulation raster here so now let me reduce further our upper value here we going to redu to 500,000 and now we can able to visualize the tributary of this main river and now let me reduce to to uh upper value up to 250,000 so it is it is currently in 500,000 so you're going to reduce to 250,000 now uh and now we can able to visualize the tributaries and now you can clearly able to start see the river lines and now let me reduce the upper value to 100,000 and now we can clearly able to visualize our River lines so before creating a water sh uh waterers sheds our next step uh will be so what we need to do is uh we basically uh need to identify the point which you which you could like to use uh as the outlet of the waterers shed so for example so if you pick a if you pick a point over somewhere uh in this point so then your water shed will be created by taking into an account of uh the corresponding drainage area so from all of this uh River Region so from this particular entire region so there is uh lying above the particular outlet that is uh lying over here so suppose you're going to select this as the outlet point so for example if you pick the outlet uh to be in this point of the river lines here so uh all this uh drainage will be picked as a watered and ignoring everything else similarly if you're going to pick a watershed Outlet here so it's going to consider all this uh branches that is all this River lines as a water shed and it's going to uh ignore everything else so suppose if you choose your water water outlet has are here in this point and similarly if you're going to pick the outlet point to be this particular area so this particular River Line so it's going to take a water shed for this uh particular area and going to ignore all other uh River lines so when trying to delate a watered boundary using rgis Pro so the way to specify the particular Outlet point is by creating a dedicated uh Point shape file so for that purposes so for that we're going to create a point shape file so we're going to navigate to this option called view so in that we're going to select this option called catalog pan so once you did that so the catalog pan opens here so here in this we're going to navigate to the option called folders so in that you can visualize a folder called shape file so you can also create your own shape file or you can add your folder location just by right click so in that so in that you can create a new shape file so so to add a folder collection so you had to navigate to this folder so in that right click and you can add a folder connection suppose if you want to save your shape file to that particular folder so you can add a folder connection here so I have created a folder connection called shape files here so in that there is uh our shape files and tiffs will be available so now we're going to create a shape file that is a point shape file for that right click and uh we going to select this option called new so in that we're going to select this option called shape files and now let us enter a feature class name that is our Outlet points so now I have entered the feature class name as an outlet point so the geometry type is we going to select as point and uh next we have to select our coordinate system so now let me select the current map so that is in GCS so once you done that we're going to click this option called run so now in the table of content section you can visualize is our Point shape file that is our Outlet points so now we have created an empty Point shape file here so now we could like to create an outlet points using our Point shape file so here you can able to visualize the revers are moving towards the Southwest Direction and now I like to create my uh watered Outlet Point lying somewhere here so what I'm going to do is we're going to select our Point shape file here and navigate this option called edit so in that we're going to click this option called create so in that we're going to select our Outlet points so we're going to click this option called create a point feature so once you selected that uh it appears in the plus La symbol here so now all you have to do is zoom into your desired Outlet Point here and now I have zoomed into my output Point location here so I'm going to place my point point now make sure that you place your point on the top of this uh grid cell now place your point on this high flow accumulation C so now I have placed the point here and now a new record has been created in our Point shape file here so now let me show you that so now we can able to visualize here we have created a new Point uh which is indicated in our attribute table here so now let us finish it off finish it off by clicking this option here apply the changes and now navigate to this option called Save which is available in edit section here click this option so click s to save your edits so once you did that you're going to zoom out here so now we can able to visualize our Outlet Point here so you can clearly able to visualize that and now to clear the selection you have to click this option called clear so it deselects it so you can now able to see the point here so once you have done that we we have to navigate to this option called analysis in that we're going to select tools so in that we have select a special analysis tool so in hydrology tool so in that we're going to select uh and now we could like to select this tool called watered here so it determines the contributing area above the set of cells and raster so click this tool so so here we have to input our flow Direction rer and now select your input flow Direction rer so we like to select our input flow Direction raser so this is our input floow Direction roster and now input raster of the feature P Point data so that is our Outlet points so it is our Outlet points so we're going to select our Outlet points here so once you did that so in our case we have only one Outlet Point here so it will generate a corresponding uh water shed and and once you did that we're going to select the BPO field here so we're going to leave it to a default that is an ID so now the output faster choose the output output file location so let me select it so enter the name as water shet and click save and now go to this option called environments so in that so in that we're going to select our processing extent so let me select the processing extend to be our dim data here so once you're done selecting your processing extent so click this option run and visualize the water shet has been completed here so now we can able to visualize it so we have managed to create our corresponding water shet using our Outlet point so now uh that takes into an account of the the drainage area which drains uh so which drains into this Point uh there is our Outlet point and now let me select this particular layer and go to this option called appearance so in that we going to move on to this option called transparency so now I could like to reduce the transparency of this layer so now we can able to visualize the drainage here inside this water shed so here so let me reduce the transparency here so now I can clearly able to visualize your drainage pattern so this is a water shed and this is the drainage so now you can see this right so this particular stream here so this appears to be our main stream here so which joins to our Outlet point so the all other appears to be the tributaries to this main river here so it joins to outlet point it is still in raster file format so suppose if you want to convert to an A3 shape file format for that so it can be done by using raster to polygon tool that is available in our toolbx so in the conversion conversion tools here so from this particular tool that is from raster so we can use this tool called raster to polygon so in case uh suppose if you want to create uh a subwatershed from within this water shed so in that case so for creating a water shed we have used an outlet point of this particular area to create an outlet Point here for creating a water shet boundary we are use this particular Outlet points here and suppose if you want to create a sub water shed so you can create you can use this uh point to create a sub water shed for example so this entire region is of once water shed boundary so you want to create a sub water shed so you have to use that uh particular Outlet uh Point shape file so you can place a point shape file here so as a result this classif this will be classified into a separate suborder shet and likewise you can place a point here the outlet Point here so it will be classified as a separate subw shed sub order set boundary and likewise you can place a point in this in this area another sub order sh shed will be created and now I'm going to show you how to create a sub water shed so first we have created a watered boundary so now we're going to create a sub watered boundary so for that so navigate to this option called view section so we're going to create new uh Point shape file so go to the navigate uh section so navigate to view section here so in that we're going to click this option called catalog pan so here we're going to navigate to folder called folders so click this here so now we can able to visualize here we have a shape files so in that we have our Outlet points so similarly I going to create new shape file so right click and click this option called new and navigate to shape files so once you did that the Geo processing tool will open create a feature class so in that we going to enter our feature class name so you're going to enter as Outlet uh Outlet point for sub water shet so short will be can write in Outlet sub and now I have entered the feature class as Outlet sub so geometry type will be the point and uh the coordinate reference system will be the current map and now click run to create a new Point shape file so now we can able to visualize here in the table of content section here the outlet sub so for we're going to use this point shape file to create sub water shed so now we're going to select our Outlet sub uh shape file select this and navigate to edit we're going to create this option we're going to click this option called create features so now we're going to click this option that is our Outlet sub represents we're going to create our sub water shet boundaries so click this so once you did that we're going to apply this particular option we're going to click this option create a point shape file so now the plus SL symbol appears again so now we could like to create a sub watered for this particular watered boundary here so now we're going to place some points here so we're going to consider this one of the river lines consider as a sub shet let me turn off other uh layers so now let me place my point Outlet Point here so now next I'm going to place my out Outlet point so we're going to Place Outlet Point here so this will be a a second sub shed for this watered boundary and similarly let me place my watered uh Outlet Point here for sub water and now you can able to visualize here have placed Outlet Point here and this part of the area so and also here also here so once you finish placing Outlet points so navigate to this option in edit section we have to click this option called save to save edits so now click s to save edits so you can be able to visualize here I place an outlet Point here and also here I place an outlet Point here and this particular sub also here here another Outlet points so once you done adding your outlet points click this option and make sure that you save your edits so that is available in edit section you click save so now we're going to navigate to our to the analysis section here so in that we going to click this option called tools so now so go to the spatial analysis tool so this is our spatial analysis tool in that we're going to click hydrology so now click this tool called water shed so now we're going to input our floor Direction roster so click the floor Direction roster and now we're going to input our P points data that is our the outlet sub that is Outlet sub ship so we going to select that outlet sub and uh in ID section you can you have to select your unique uh field ID so F ID will be our unique field ID here and choose your output file location and once you did click this option called run so now we can able to visualize we have managed to create our sub water shed so now to visualize of river lines select this particular layer and go to this option called appearance so in that we navigate to transparency so now let me reduce the transparency here and let me turn this off and now we can able to visualize our River lines so we can able to visualize that so based on our Outlet points it is categorized into different uh subo shits and now we can able to visualize it now me turn this on turn this off and now it is the two files are in raster file format so we had to convert it to a polygon using a tool called the conversion tool raser to polygon tool so suppose if you want to calculate the area so we have to convert it to a polygon and we can calculate area so now we're going to convert our raster that is a sh subwat shed to raster to a polygon for that we're going to navigate to our analysis section here so so in that we're going to select our tools so now we're going to navigate to this tool called conversion tools so in that you can able to uh let me navigate to conversion so in that we can you can able to visualize here from raser so in that we're going to select this tool called raster to polygon and our input raster will be our water shed flow so we're going to insert that water shed flow and the field will be value and the output polygon feature so let me save to the output file location and now I have entered a sub B shet now click save so once you did that we going to click this option called run and now we can able to visualize we have converted our raster to a polygon now let me turn this off here you can be able to visualize it more clearly and now we have managed to create a sub shet so go to this table of content section in that we're going to click the suborder shet right click and select this option called attribute table so now from uh the table of attribute table so you can able to visualize we have nine different sub order so let me select this so now you can able to visualize that so here and now let me close this and now suppose we want to generate this River lines so this particular River lines so for that so we're going to use a tool called reclassify tool so now let me go back and let me enter here we're going to search the tool called reclassify and now we have entered as reclassify so here you can able able to visualize a tool called reclassify so now click this tool called reclassify here so we're going to click this tool so once you did that we're going to input our raster that is our flow accumulation raster so input raster will be our flow accumulation raster so once you that we have our uh the classes here that is from 0 to 100,000 so it will be going to enter as a zero here new class will be from 0 to 100,000 will be named as zero and 100,000 to this particular number will be named as Class 2 so once you did that uh we can click this run and now we can able to visualize our result here so it is reclass flow to and now to generate our River lines from this particular raster we have to uh move to the move on to the tool called U conversion tools from conversion version we have to click this tool called raster to poly line so now we're going to select our input raster so the input raster will be reclass flow to so I'm going to click this uh reclass flow to so field value we going to select here uh let me check here right click and click the attribute table so now we can able to visualize here we have to select the value field so the zero represents this particular value and the two here presence and this poly line that is a river line values here so now let me close this so you're going to select the field value and now click run so it is converting to ret to poly line so the results is available here so let me turn this off here so now we can able to visualize our River lines and let me turn on our suborder shed so we have finally managed to create our River lines with our subed boundaries let me turn on this for the watered boundary here so you can also perform a clip operation to remove this uh other uh the PO lines outside this water WhatsApp water boundary so for that we're going to navigate to this uh we're going to search by clip so now we're going to click this so now click this tool called clip for analysis tool so in that we going to input our River Line River Line shape file so that is this particular shape file raster T reclass going to click this and the clip feature will be our sub sheet so once you did that you can click this option called run and now the clip is completed here so let me turn this off here so now you can able to clearly visualize sub water shed and watered bound and our River delineation for the specific uh study region so in this video I have shown you how to perform a watered delineation using rgis Pro so thanks for watching and please subscribe to our Channel and give us a like

Channel: Terra Spatial

Views: 2,130

Keywords: watershed delineation, arcgis pro, watershed delineation using ArcGIS Pro, hydrological analysis, watershed boundary, watershed delineation using DEM, SRTM DEM, catchment area, stream, DEM, river, stream order, watershed, SRTM

Id: rA-9PfD8LDo

Length: 35min 18sec (2118 seconds)

Published: Mon Nov 20 2023