Questions tagged [hydrography]
Not to be confused with hydrology, hydrography describes the spatiotemporal distribution of water bodies and their features.
45 questions
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Issues with vectorisation of thinned flow accumulation through r.to.vect on QGIS
I'm trying to produce a shapefile river network from a flow accumulation raster using the r.to.vect function and I've overcome some difficulties regarding bit depth and thinned raster.
n.b. I don't ...
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Difference between Linear Hydrography and Area Hydrography
I am looking at the U.S. Census data and downloading the linear hydrography and area hydrography datasets to add to my first GIS map (I'm a new student).
I am self-teaching GIS, and after a multitude ...
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Methods for burning depressions (not rivers) in a DEM
I am using a 2x2m DEM to simulate runoff on a 2D hydrodynamic model. After a baseline simulation, I am interested in evaluating the impact of adding depressions in specific areas that may work as ...
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Detecting automatically where rivers flow, directly into the sea or into another river
I am using this dataset of rivers in France. I'd like to automatically distinguish between rivers flowing directly into the sea versus rivers that flow into another river and draw a map of only those ...
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QGIS problems extracting data from WMS
I use a model from the Netherlands Hydrografic Office (Dienst der Hydrografie) to see what the difference is between Lowest Astronomical Tide (LAT) and Mean Sea Level (MSL).
It's a WMS: https://...
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QGIS: interpolate difference in Z-value on enbankments
I have two layers:
1 polygon layer with a theoretical profile of a harbour.
1 pointlayer with output from my multibeam echousounder.
I made a new pointlayer with a Z-difference between the two ...
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Strange buffer shape when using planar buffer method
I'm doing a very simple operation involving clipping some streams from the National Hydrography Dataset in ArcGIS Desktop 10.3.1, reprojecting them from "GCS North American 1983" into "USA Contiguous ...
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Joining all hydrographic vectors touching each other (inside same feature) using QGIS?
I have a complex hydrographic layer where all the hydrographic lines are separate even if it's from the same river.
How do I select all the vectors who are touching themselves without select vector ...
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Creating catchments/basins around stream feature class using ArcGIS Desktop?
I have a reasonably accurate steam network for a watershed. This network includes the main channel, major forks, and tributaries. Each channel, fork, and tributary are individual records with single ...
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Optimized smoothing of stream lines generated from Arc Hydro? [closed]
Has anyone found an effective ArcGIS 10.3.1 workflow for smoothing streamlines generated from ArcHydro...or hydrology in general?
(Fill -> Flow Dir. -> Flow Acc. -> Stream Def. -> Stream Seg.-> ...
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What are all the straight lines on old nautical charts?
I was checking out this old VOC chart, and I couldn't help but notice a pattern that I've seen on most nautical charts of the time: lines that to me seem to be just every possible line one can draw.
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Source of radar imagery for coastal areas [closed]
For my final year research project I need radar images of coastal areas. And can anyone help me to find links where I can download such data free for research purposes?
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Multiple watershed delination with QGIS [duplicate]
I am trying to divide a DTM model in subbasins but I have set specific outlet points for the subbasins, and not to use a thershold.
Is there a tool similar to r.water.outlet but with multiple outlet ...
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Generating URL using USGS Site-Test-Tool to add as Layer in ArcGIS Online?
I am trying to use http://waterservices.usgs.gov/rest/Site-Test-Tool.html to generate a Rest URL to add as a Layer in ArcGIS Online.
I generated url (http://waterservices.usgs.gov/nwis/site/?format=...
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Creating tool for finding catchments, watersheds and channel network in ArcGIS for Desktop? [closed]
I've been working in QGIS for a while, but I have to use ArcGIS from now on. In QGIS I made a tool in the Graphical Modeler, in order to ease a process I had to do several times. I've been told this ...
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Where can I find data related to hydro power production in india? [duplicate]
This could possibly include meteorological data/precipitation data aggregated on the district level and power line/ electric transmission infrastructure locations
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Is there a dataset for the spatial extents of historic levels of the Great Lakes since the Last Glacial Maximum?
Is there a dataset for the spatial extents of historic levels of the Great Lakes since the Last Glacial Maximum? More specifically, we are looking for the maximum level of the Great Lakes after 5,000 ...
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Separate Intersected layers (as points)
I'm trying to establish watershed outlets as points with two shape files that I have available;
The watersheds polygons
The river network
As I said above I'm trying to define the outlets but due to ...
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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?
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QGIS Upslope/Downstream Areas [closed]
I am trying to locate areas upstream and downstream of a point of interest in QGIS in order to determine possible areas of origin upstream and areas of impact downstream. I have used a DEM to create ...
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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 ...
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Correctly merging DEM rasters and eliminating edge effects
I'm using 10m DEM rasters from the NRCS Data Gateway for a large portion of California. The problem is some strange tiling that appears after merging, but isn't present in the original data (before ...
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Removing disconnected cells in a stream network raster using ArcGIS
I've got a predicted stream network raster with cells values 0 (not a stream) and 1 (is a stream). My end goal is to create a network of connected polylines, but unfortunately there are some areas ...
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does the census bureau provide clipped / water-bounded files as nice as certain cities?
this question says they do but when i compare what i can find in the cartographic boundary files section of the census bureau's gis page, they don't look as good as certain shapefiles provided by the ...
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Basin numbering according to Pfafstetter Method?
I would like to divide my basin into subbasins and numbers according to the Pfafstetter method.
Is there an easy way to implement this in Python using ArcPy?
Or are there some freely available ...
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Extracting point data from Digital Raster Graphic (DRG) in ArcMap?
I am trying to run an IDW analysis based off stream and springs data.
I have the hydrography.eoo file from GeoComm but am now wanting to create a point layer of the springs in the area which show ...
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What satellite imagery would help to show spring locations?
I've got lots of tiny streams on a hydrography shapefile. Historic texts indicate that certain ones have headwaters at "sources" or springs, and I want to try to find these. Browsing the historical ...
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Which File to load from National Hydrography Dataset?
I'm using QGIS 2.0 on MacBook with OS X 10.8.5.
I downloaded a National Hydrography Database file. Unzipped, it is titled NHD11032_NM.gdb.
I try to add the layer as a vector file, and all the sub-...
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Is there a downloadable data source for mapping out rivers with names for the whole world?
I'd like to be able to extract rivers with their names and the flow size (not direction) for the whole world. The scale I'll be drawing it at is about 2 centimeters per 10 real world km - nothing too ...
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merge national hydrography dataset files
I'm having difficulty merging datafiles from the NHD while still keeping functionality as a geometric network. I'm using ArcGIS 10.1, so the USGS merge tool isn't an option.
Using the medium ...
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Tapering huge amounts of drainage vectors
I've performed hydrological analysis using r.watershed using GRASS and now I have some stream vectors for a large area. Next, I'm planning to taper these streams to varying width to make them appear ...
user8723
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Calculate Topographic wetness index in SAGA
i am currently working on a project which involves the quantification of the wetness in certain areas. However it produces quite different results from what i expected. I'll describe the steps i have ...
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Extraction of stream gradient for branched river networks
At the moment I am working on the extraction of stream gradients for a large basin, as a consequence, rivers are strongly branched.So far, I read through the relevant posts on this site, but so far I ...
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Burning stream network into DEM layer using ArcGIS Desktop?
I am working on a DEM that in an area where there is little relief.
I would like to 'burn' the river network into the DEM so I can calculate flow accumulation and flow length accurately.
I am ...
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Stream Gradient - two types - using NHD high resolution data
I need to calculate slope, or stream gradient, two different ways:
Main channel slope from the pour point to the head/source point along the vector stream network
a local slope consisting of 100 ...
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Workflow for determining stream gradient?
As far as data goes, I'm working with NHD .shp files, 10m DEMs, and some LIDAR data.
My goal is to determine gradient for 100m segments of a network of streams.
I'm already able to do this, but I ...
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Is there a way to get the percentage of different landuse types upstream of a given point?
I'm a fairly novice GIS user and know just enough to get in trouble in a lot of cases. I am trying to look at the connection between several measured parameters at a few hundred stations along ...
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Processing time using ArcGIS Hydrology toolbox tools in standalone Python script vs ArcCatalog?
My question is: what might cause the ArcGIS 9.3 Hydrology Toolbox Snap Pour Point and Watershed tools to run significantly slower in a
Python script versus manually running the tools in ArcCatalog (...
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Error assessment of calculation done using unprojected vs. projected data
This question builds off of the one with the subject line "Calculating Flow Direction and Delineating Basins from Projected vs. Unprojected Data.":
Calculating Flow Direction and Delineating Basins ...
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Calculating Flow Direction and Delineating Basins from Projected vs. Unprojected DEM Data [closed]
This is somewhat of a theoretical question stemming from some discussions with colleagues on the topic of implications with delineating basins with projected (e.g., Albers Equal Area) vs. unprojected (...
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Chart Production - chart series, etc
We do subsea surveys - seabed mapping etc. What software do you use to produce charts? I am especially interested in producing chart series.
It would be interesting to hear how you guys produce ...
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Is there any pseudocode for MFD (multiple flow direction) algorithm available?
Still stuck with the simulation system, is there any good pseudocode for the multiple flow direction (MFD) algorithm? I read a pseudocode example and implemented it, however the simulation was linear: ...
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River drainage basin boundary
I'm looking for a set of outlines of the river basins in the UK - I don't need a particularly detailed or highly accurate map - just a map saying point X will drain into the Thames or point Y will ...
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Flood modelling in GRASS?
I am trying to create a flood modelling system. The system consists of two parts mainly a river flooding simulation and rainfall simulation. To do this I am running the latest version of GRASS 6.4. ...
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Error in r.terraflow
I used r.terraflow.short in GRASS, but it displayed this error:
r.terraflow.short elevation=raster_bulacanElevation \
filled=raster_bulacanElevationFlooded1 \
...
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