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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21 views

SAGA hydrological analysis in QGIS 2.8 on Mac

I am runnung QGIS 2.8 on a Mac maschine and I want to calculate the catchment area using SAGA - catchment area. It starts running but after a while when QGIS wants to open the generated files there is ...
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0answers
45 views

How to automatically generate pour points along stream network?

The following screenshot shows the results of a water flow analysis where I identified stream order via the Strahler method in ArcGIS. Now I need to generate watersheds for 2nd order streams and ...
2
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0answers
23 views

Hydrology Analysis via SAGA - what is the unit?

I did a couple of analysis via SAGA about an area in Iceland...I've never worked with SAGA before, could anyone tell me what Units the numbers in the legends for "Catchment Area Recursive" and ...
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0answers
31 views

Problem in running r.sim.water

I am trying to run the r.sim.water in GRASS. I have calculated the partial derivatives dx and dy rater map using r.slope.aspect. I am using this elevation map [1] to get the time-series depth map. But ...
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0answers
65 views

Are there any Python scripts available for Hydrology to compute watershed Basin from csv file?

Let's say I have surface data available in CSV format (x,y,z). In order to create a watershed basin from surface data, there are some intermediate steps we need to follow. ASCII to surface raster ...
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38 views

How to separate shared watersheds using ArcGIS for Desktop or QGIS?

I have a similar problem than the one expressed in this question. Here's my situation : I need to have the full watershed of a point downstream of another point.The Watershed tool only gives the ...
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1answer
58 views

Watersheds tool does not create watersheds in ArcMap?

I`m trying to create watersheds and every time I run the Watershed tool, the result will be very interesting. I use snap raster and I set the extent of the output to the extent of the flow direction ...
1
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1answer
39 views

How to calculate the impact and extent of damage of a potential tailings dam breach with ArcGIS?

I would like to be able to delineate an approximate area of a potential tailings dam breach for an emergency response plan purposes. The tailins dam and pond have not yet been built. The data I ...
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41 views

Transfer line direction from one polyline layer to another in a stream network

I have a stream network that has been dissolved by name. In the dissolve process, it loses line direction. I need to get that back. The good news is I have the original network, which is identical ...
4
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1answer
109 views

Does this ArcGIS flow accumulation example have an error?

The lower right corner of the flow accumulation example in ArcGIS Desktop's documentation has a flow accumulation value of 2. However, I only see one cell flowing into the lower right corner (the ...
2
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0answers
49 views

ArcGIS 10 restricted WEIGHTED Flow Accumulation

I have a question very similar to one asked by wxfox4god on 12th June 2013 ("Arcmap 10 restrict Flow Accumulation") that was answered by whuber. (I have had to post it as a new question as I do not ...
1
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1answer
113 views

Evapotranspiration in Modis

I need the Evapotranspiration data for my study (The study area is located in Australia). Somebody told me maybe I can use MOD 16 MODIS actual ET estimates. I could not find this data on earth ...
0
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1answer
21 views

NDVI for natural region

I have a question about remote sensing, I appreciate that if somebody can answer to me. I have remote sensing data which I have got from landsat 7. The area which I am working on is combination of ...
1
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2answers
53 views

Mapping UK river gauges / stations

Do you know a way to map all the river gauges / stations in UK? I found some data from the Environment Agency but it lacks of the longitude and latitude. Thanks
0
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1answer
62 views

How do I export a line shapefile from a network downstream from a point in ArcGIS 10.1?

I'm using the National Hydrological Dataset's flow lines to trace downstream movement of water is a freshwater diversion from the Mississippi river in Louisiana. I've gotten the trace to run using ...
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0answers
45 views

Open-source tools for run-off depth calculation

I am working on modeling surface run-off (in ArcGIS 10.2) due to a rain event (e.g., 5 year rain for a duration of 30 mins.) over an approx. area of 30 km2 for which I have a DEM and necessary soil as ...
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0answers
87 views

Depth of run-off water

I am working on modeling surface run-off due to a rain event (e.g., 5 year rain for a duration of 30 mins.) over an approx. area of 30 km2 for which I have a DEM and necessary soil as well as ...
0
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2answers
90 views

How to determine drainage area upstream from point?

I do not know how to come up with the drainage area (km squared) upstream of Lat 77.84, Long -30.96. I have converted my contour shapefile to a raster, identified and filled the sinks and then created ...
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0answers
32 views

How to load “soil types” in QGis?

I want to show soil transmissivity per pixel. Thus, I determine water holding capacity of each pixel (ignored other effective parameters). Respectively, I wonder, What is the soil data format and How ...
4
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1answer
170 views

How to calculate “water accumulated in each cell” using QGis?

I create channel network and catchment area from a DEM with SAGA GIS. I know that flow is starting from a cell to an other cell. Firstly, a cell is filled with water and then it is starting to flow ...
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0answers
55 views

Hydropower Calculation

I have assigned the elevation and the volume flow to each point at a river (with v.to.db and v.what.rast). Now I want to calculate the Elevation difference between each pair of points and then ...
0
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0answers
48 views

How to decide when flood started depending on the rainfall data?

I created a raster with the point values (mm) of rainfall data by interpolation in the raster menu. So I have a raster rainfall data and a DEM. With this rainfall data and a DEM corresponding to ...
1
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1answer
75 views

Calculate River Runoff Volume (Q) with GRASS

I want to calculate Hydropower between points at a River. I already created a Rivernetwork and the Accumulationmap (without weighting) with r.watershed. My next Step was to set equivalent points along ...
3
votes
1answer
228 views

How to compute average slope and area-weighted average slope?

I am learning GIS for use in hydrologic analysis. Related to computation of overland flow there are two types of slope that I would like to be able to obtain from GIS. The first is average slope for ...
0
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0answers
39 views

Horton Stream Order as Category for r.fixed.segmetpoints with GRASS?

I'm working with Grass GIS. I want to use v.segment to set discrete, equidistant Streampoints (starting from each mouth). Since the water network is too large, it is impossible to define the rules ...
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3answers
74 views

Discrete Waterpoints with Grass

I've been working with Grass GIS for about two months. I have to develop a method for the identification of target regions of small hydropower plants. Boundary conditions are a predetermined minimum ...
2
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0answers
85 views

ArcGIS - Flow Direction (Algorithm)

I am curious about the algorithm of Flow Direction in ArcGIS. Recently I am studying about Hidrology, and I have some questions regard to Flow Direction in GIS. The size of this cell is 100m x 100m, ...
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0answers
75 views

How to do a flood simulation without flooding the whole area and covering surface structures (with DEM)?

I have a high resolution DEM and want to do a flood simulation starting at a river. My hope is that the water runs into historical (now dry) river channels (in which I'm interested in) at first and ...
7
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2answers
264 views

Find headwater polygons

This is a follow up question to this question. I have a river network (multiline) and some drainage polygons (see picture below). My goal is to select only the headwater polygons (green). With ...
2
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1answer
40 views

Is every cell in flowdirection draining towards an outlet

I have created a Flowdirection map in a defined catchment. I want to find out if every cell in my map is flowing towards the creek/outlet. Is there an easy way to do this? I have created the ...
3
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0answers
84 views

Extract representative slope profiles from hillslope polygons

With the help of the Whitebox Geospatial Analysis Tools I was able to easily extract hillslopes from a river network in combination with a flow direction map. Now I would like to extract ...
2
votes
1answer
56 views

Delination of half basins or hillslopes from a flow direction map or/and a stream network

I am using the GrassGIS r.stream.extract extension to delineate a stream network with the options 'mexp' (Montgomery exponent) and 'd8cut' (Use SFD above this threshold). It works perfect so far and ...
2
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2answers
91 views

Merge layers and fill gaps

I have 14 layers, which are polygons. They represent the channel of a river at different periods. I need to fill the gaps that exist once I overlay the polygons, but I can't change the properties of ...
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3answers
183 views

why Input layers do not have the same grid extent in the processing, hydrological analysis?

I'm trying to generate the hydrological analysis using processing and I have already done some terrain processing using the DEM. In this moment, I'm working in he channel network but, when i assign ...
0
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1answer
87 views

Urban Hydrology Using With GIS

I'm researching how can I create a model urban floodplain depending on rainfall. And Which programme should I use? I want to show floodplain depending on temporal and spatial distribution on study ...
2
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1answer
73 views

Water feature growth

I have a water feature layer which includes rivers, lakes and streams. I want to create, essentially, a buffer of these features equal to that of a 50cm increase in elevation from its current ...
0
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0answers
238 views

QGIS SAGA Channel network error: Input layers do not have the same grid extent

I am trying to follow along with this exercise using my own DEM. I have done the first step, creating the catchment area, with no trouble. When I try to run the Channel network algorithm, however, I ...
1
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0answers
55 views

create a weight raster for a hydrology analysis

I determine affecting parameters of flood flow ( evaporation,vegetation,soil type, rainfall etc.). Then, I start to analysis using Arc Hydro. How do I relate among of affecting parameters? How can ...
0
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2answers
48 views

Are there publicly avaiable run-off data for Africa

I was wondering if there are good publicly available dataset for surface run-off (water)? I have a rough idea that surface run-off should be some function of rain-fall and soil ...
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0answers
27 views

Interpreting some hydrology data

This is the historical feed of the Keystone dam for October 2014: http://www.swt-wc.usace.army.mil/chartbin/KEYSOct14.shtml Here is the real time feed: ...
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2answers
57 views

Where can I find hydroelectric generation data for the U.S.?

It is my understanding that the US Army Corps of Engineers has some hydro generation data on their various websites (divisions, districts). For example, there is real-time hydro-electric data ...
3
votes
1answer
80 views

To make a map of sinkholes on grass gis

I would like to make a map of sinkholes. I have a DTM ARC/INFO ASCII GRID of Asiago Plateau and and I'm using grass gis. Does anyone know what is the correct form in grass gis?
2
votes
2answers
92 views

ArcGIS are two rasters the same? - including null values

I am working on a task to calculate Height Above Nearest Drainage (HAND) - that is the height above the nearest point along the flow path that is on a drainage - not the geographically nearest ...
2
votes
1answer
70 views

Aggregating river basins

I am not a hydrologist but am providing GIS infrastructure to our hydrology department which actually doesn't use GIS very much yet. Therefore I am asking for some hydrology related insights. Btw: We ...
3
votes
1answer
167 views

Horton Stream Ordering in ArcGIS?

Is there a way to order streams using the Horton (opposed to Horton-Strahler) method in ArcGIS (10.2.2)? I know the Stream Order tool allows you to use Strahler and Shreve.
0
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0answers
10 views

Difference of Archydro and Hydrology Between [duplicate]

What are differences between archydro and hydrology tools? What does ArcHydro add on hydrology tools?
11
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2answers
1k views

How to cartographically represent water flow?

I am modelling water flow on steep slopes for an erosion study. You can see from the screenshot the results from the ArcGIS-based flow analysis. To produce these flow lines, I generated a ...
5
votes
2answers
216 views

Is there hydrologically correct water-course data for Africa

I was wondering if there are any hydrologically correct river-channel data available for download for Africa? By hydrologically correct, I mean the topology should be correct. Connected river ...
1
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1answer
417 views

How to calculate the river slope for a lot of rivers automatically in ArcMap?

I'm working with ArcMap 10.2 and I'm pretty new in this area.. What I want to do is compute the river slope for a lot of rivers from a DTM...I know that there is a way to do it manually passing by ...
3
votes
1answer
152 views

Practical tools to delineate large scale watershed?

I would like to do some watershed delineation at national/regional level (using SRTM-90 data). I have experimented with r.watershed (GRASS 6.4.3) but it fell over when I tried to do big stuff. I ...