The study of the movement, distribution, and quality of water on Earth and other planets, including the hydrologic cycle, water resources and environmental watershed sustainability.

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13 views

How to Create a Catchment Area of a Polygon (Wetland) using DEM in QGIS or Whitebox GAT

I am looking for a way to calculate the upstream catchment area where water would flow into a given wetland. I have delineated the boundary of a wetland (creating a polygon) and would like to ...
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0answers
10 views

Deriving Stream-Velocity out of a DEM

I'm using Arc GIS Toolbox Hydrology...everything works fine. Moreover, it is possible to derive the potential stream velocity just out of the DEM? Informations about rainfall, infiltration, hydraulic ...
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2answers
49 views

Select neighboring cells from a raster under conditions

I generated river networks (raster format) from a DEM and I also want to select the neighboring cells of the river networks from the original DEM, if the neighboring cells have a lower or equal ...
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0answers
35 views

Comparing areas of two raster files

I need to compare the areas of two rasters for calculating the percentage parts from another. For example, I have one raster file which shows separated agriculture fields. The value of each field is 1 ...
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1answer
118 views

Extract river polygons from DEM

I would like to use DEM to extract a river network but I don't want to use the polylines. Is it possible for me to extract polygon (or raster) rivers from DEM? I'm using both ArcGIS 10 and R. If ...
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1answer
49 views

Explanation of HAND (height above nearest drainage) model procedure

i tried to follow this procedure Spatial Analysis - Calculate a cells elevation (height) above the nearest stream cell but i have some problem to understand everything. I mean the 2th answer in the ...
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0answers
30 views

Negative values in r.watershed flow accumulation

I am trying to process a DTM by using r.watershed in QGIS 2.14.3, with the GRASS GIS toolbox. It should be the file named: "Number of cells that drain through each cell". I get some negative values, ...
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0answers
11 views

Why ModelBuilder results do not display in map? [duplicate]

I am automating river network analysis using ModelBuilder by making a tool out of the different Hydrology Spatial Analyst Tools extension. When run individually, each tool in the set of tools has an ...
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0answers
50 views

Getting distance from nearest stream and elevation to nearest stream?

I need to know if there are simple commands for this 2 points: the distance from the nearest stream, D [m], defined as the length of the path that hydrologically connects the location under exam to ...
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1answer
38 views

HEC GeoHMS generates wrong catchment area

I am trying to define a catchment area automatically with HEC Geo HMS (ArcGIS version 10.1). My input-data is a DEM-file (raster 1m). After doing all steps in HEC Geo HMS, the catchment area (see ...
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1answer
27 views

How to calculate stream order in GRASS 7.0.2?

I would like to calculate Strahler's and other stream hierarchy from my input raster but I am not sure how. This manual suggests tat I should use r.stream.order command, however in version 7.0.2 "...
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1answer
208 views

In hydrologic terrain analysis is there a difference between “pits”, “depressions”, and “sinks”?

In hydrologic terrain analysis is there a difference between "pits" and "depressions"? For instance, Planchon and Darboux (2002) state The usual numerical methods for removing the depressions of ...
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2answers
51 views

How to calculate shortest distance from start to end of river?

How can I calculate the straight distance from the start to the end point of a river (red line in image)? I don't know how to do this automatically.
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1answer
61 views

How to define pour points from a stream network at a barrier for watershed calculations?

I'm looking for a way to check if cells from one raster file have contact or get close to cells from a second raster file. For example the blue raster is a barrier and the coloured is the flow ...
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1answer
38 views

Create a flow network from a flow direction ARC GIS

First, I created a flow_direction from a DEM, then I applied corrections to this flow direction. Now my question, how to create a flow network (order flow) from a flow direction, that I already ...
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1answer
55 views

Constructing LS factor for RUSLE without outliers using ArcGIS for Desktop?

I'm using the following formula in RUSLE via raster calculator to obtain a LS factor Power(Flowacc)*1/22.1,.4)*Power(sin(slope)*.01745/.09,1.4)*1.4 My expected outcome is a raster from 0 to ...
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0answers
26 views

Curve Number equation

I have a floating point raster of Curve Numbers (70-91) and I'm attempting to use the curve number equation to create a weight raster for flow accumulation, to determine runoff for a single rainfall ...
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0answers
66 views

Flow Accumulation weight grid

I currently have several rasters relating to Landcover Soil data Topographic Wetness Index (TWI) Slope They are all re-classed to % infiltration. I'm looking to use these together as a weight ...
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0answers
57 views

How to create an elevation profile in google earth from a kml?

I have a KML file of a stream that I originally created as a line shapefile in ArcMap (one stream extracted from a larger watershed data set). I need to create an elevation profile of this stream. ...
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1answer
286 views

Downloading Hec-GeoHMS for ArcGIS 10.3.1?

I can't download geohms from this link http://www.hec.usace.army.mil/software/hec-geohms/. Can anyone help me to get Hec-GeoHMS for ArcGIS 10.3.1? The doesnot responds and I could not get a Hec-...
3
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1answer
78 views

Issue with r.watershed run by QGIS-Python-processing.runalg

I would like to extract flow accumulation and flow direction layers from a DEM calling the grass r.watershed module from a QGIS-python script using the processing class. I obtain just an empty map, ...
2
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1answer
41 views

Cost Path based on Lowest Maximum Elevation Encountered

I am trying to locate the lowest elevation point at which a river will overtop its banks, and spill into lower-lying terrain behind them. I'm working in ArcMap version 10.2, and using a high-...
7
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3answers
228 views

Calculate average stream slope at each location along stream

I'm trying to calculate the time of concentration for every point along a stream network. To calculate the time of concentration, I need the upstream channel length and channel slope. I've been able ...
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1answer
51 views

Using the watershed tool with two pour points

I have two pour points in a stream network created using the flow accumulation methodology in ArcMap. When I use the watershed tool with this pourpoint shape file, I get a watershed between these two ...
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1answer
37 views

Looking for data on river flow speeds

I'm looking for sources containing data on measured river flow speeds, any / all locations worldwide, in any format or language. Googling didn't help much.
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0answers
107 views

Determining Thalweg line of river without bathymetry?

I have the boundaries and centerline of a river. The Thalweg line defines the deepest elevation of a watercourse (see Image taken from Google). I do not have accurate enough bathymetry or Digital ...
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0answers
29 views

Dividing stream network of specified lengths in ArcGIS for Desktop? [closed]

we are trying to find hydro power potential of river basin by using ArcGis and SWAT ,we have created stream network ,but unable to divide stream network at 500mts interval, unable to find the tool
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1answer
51 views

Hydrological model building for flooding analysis [closed]

I am recently studying the topic in investigating the features of river and to perform flooding analysis. I got the elevation data, and I used the elevation data to generate streams in ArcGIS and I ...
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1answer
67 views

Calculating watershed using snap pour points?

I am trying to calculate a watershed layer and have followed instructions from this previous question: General steps to create watershed boundary I have combined all these steps and run it as one in ...
3
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1answer
61 views

How to delete obstacles (corduroy road) from DEM in ArcMap?

I have a DEM which looks like this: The narrow longish lift running from north to south is a corduroy road (hope this is the correct word for "planks which allow people to cross a mire without ...
4
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1answer
250 views

How is “Burn Stream Slope” in ArcHydro working?

I have a DEM with only small relief and many ditches. Because of the small relief, I can't calculate flowdirections for some parts of my DEM. I know that in reality water is flowing from west to east (...
4
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1answer
207 views

Calculating Flooded area / Inundation in ArcGIS for Desktop?

I was tasked to create a layer with the flooded areas if the sea / river level was to go up by X feet. There is no requirement to take Flow and Pour Points into account, just a simple raise in water ...
3
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2answers
96 views

How to plan preservation of wetland using a DEM and ArcMap?

I'm trying to plan a wetland preservation. This is the DEM I have: My aim is to hold as much rainwater as possible in my area of interest (red poly) by building (as few as possible) new and raising ...
3
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1answer
43 views

Get upstream sections of a network

Is there any extension to get all upstream sections of a polyline shapefile which represent an hydrographic network in QGIS? It could work like this: you choose a specific branch and a direction ...
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0answers
67 views

Why does the flow direction tool in ArcGIS desktop give wrong output (unique values from 1-255)?

I ran the flow direction in ArcGIS, and received unique values ranging from 1-255. I know that these values are wrong, and should be along the lines of 1, 2, 4, 8, 16, etc multiples. The DEM is ...
0
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1answer
148 views

Correcting Errors in Height Above Nearest Drainage (HAND) model

I have used this tread Spatial Analysis - Calculate a cells elevation (height) above the nearest stream cell to create a HAND map in ArcGIS. First I used the hydrology toolset to fill in sink in the ...
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0answers
56 views

Measuring river width every mile in Google Earth?

Given an area, can Google Earth tabulate the width of a particular river? This problem I think requires using an API to programmatically: define an area of interest identify a terrain feature ...
0
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1answer
201 views

What is the difference between Specific Catchment Area and Total Catchment Area in hydrology?

I am getting stuck on the concepts of Total Catchment Area (TCA) and Specific Catchment Area (SCA) as I try to learn more about TOPMODEL. What do these metrics mean in hydrology? The context I ...
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0answers
22 views

building artificial dam in a canyon [duplicate]

I want to calculate the water volume dammed by a dam in a canyon. I managed to calculate the water volume but I actually need a dam in a certain place of the gorge so I can pursuit my calculations. I ...
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0answers
34 views

How to join hydrological data from a big area with a small area with better pixel resolution?

I use TAUDEM to make hydrologic analysis. I have a hidro 1K dem file from South America (big area) pixel resolution=1000x1000 meters. I have a specific dem file located in Brazil (small area) pixel ...
2
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1answer
76 views

Connectivity of Streams

I have a line vector layer containing streams (see image below). What is the easiest approach to determine the connectivity of each stream segment (eg. sum of upstream nodes)?
3
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1answer
139 views

How can I select all streams downstream of a polygon

I have an ordered stream network and I want to select all stream features that contain water that has come from a certain area. To start with I'm running a select by location query to find all stream ...
3
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4answers
235 views

How can Identify highs on a DEM?

I have a DEM and I want to find each hill and create a polygon for its area, effectively the out closed contour that encloses the hill. I can do this visually but I'm about to work on a larger area so ...
0
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0answers
32 views

Manually collecting data in ModelBuilder?

I'm not sure how to phrase my question in the title. Currently I'm trying to build a model for automatic watershed delineation. the ppt.shp (snap pour point) cannot be determined until flow ...
0
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0answers
57 views

Batch processing Surface volume calculation in ArcMap?

I'm trying to collect the 2D area, 3D area and volume of a given basin at 0.5 meter increment in plane height, but since I want to graph the relationship between plane height and the areas and volume, ...
1
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1answer
70 views

reading GRASS vector map in python

I know similar questions have been asked several times, but none of the solutions seems suitable for my problem or don't work.. I computed flowlines using the r.flow tool from GRASS GIS, then I ...
2
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1answer
63 views

How do I find out the sea levels?

I have following elevation data of a region (the higher the altitude, the brigher the points): How can I find out, which areas are filled by water, and which not? Can I assume that if the ...
5
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3answers
219 views

Ways to determine winding topographic characteristics of a river

Are there any methods and/or technical guides on how to classify the degree of winding of river bodies? I have the following polygon layer of roughly 100,000 water bodies and would like to write an ...
3
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1answer
57 views

Watershed Tool Straight Edge Problem

I'm trying to accurately delineate a watershed into sub-basins using dams as pour points. I'm using the hydrology toolset, but I can't seem to get rid of straight edges that are along some of the ...
5
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1answer
179 views

How to run a tool from Whitebox GAT in ArcGIS?

I have a series of tools that I need to run in ArcGIS to hydrologically condition my DEM, but the first step in this process is running the Breach Depressions tool from Whitebox GAT (I have found that ...