Questions tagged [water]

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35 views

Earth Engine calculation of distance between points to nearest water

I have a list of points and I want to calculate the distance between each of them to the nearest body of water larger than n=10 pixels. In other words, for each point, I want to return a number ...
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1answer
25 views

How to make histogram of NIR band bimodal enough to differentiate water from land in GEE?

I am interested to map water bodies in a desert from swir band of sentinel 2. How I can make a bimodal histogram in GEE . I have one reference water body in scene. Is it possible to do the same in ...
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24 views

DEM water body visualisation (QGIS): extract areas with a min amount of pixels with the same value (= water surface)

I want to create a background map of a DEM (1m spatial resolution) to show the study area. The study area (Northern Germany) contains many water bodies. I have problems with the visualisation of these ...
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0answers
42 views

Given a line/shape how to calculate the area that resemble how the US Census Geography's Inland Water is calculated

I am not a US resident so not quite comfortable asking the US Census directly about this, but I'm just curious how the US Census's Inland water geography is derived, i.e. the methodology of what ...
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0answers
23 views

Linear regression - water column correction

I am curious what the best way is to do a linear regression between depth (y) and b2/b3 radiance (x). My goal is to derive the slope and y-intercept to plug into the equation z = m1*ln(b2/b3) - m0 [m1:...
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0answers
34 views

Estimating the water coverage area behind a dam

I have a task to estimate the area that will be covered by water when a dam is built in the provided location. The only thing I have is the max water level calculated for the reservoir. Is that enough ...
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0answers
15 views

Can anything be inferred if NHD doesn't name a stream but the local municipality does?

Case in point: https://watersgeo.epa.gov/watershedreport/?comid=5781291 It shows up in the NHD as not having a name but I'm pretty sure that the local municipality that that creek is in (City of ...
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0answers
50 views

Working with the FlowDir in the national hydography dataset

In the National Hydrography Dataset there's a FlowDir field. According to https://www.townofnewipswich.org/sites/g/files/vyhlif4766/f/uploads/dataset_dictionary.pdf the two possible values for FlowDir ...
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1answer
117 views

How to remove areas of water from the US census tract map using R/RStudio

I am trying to aggregate all of the census tracts in the United States for analysis and display, including a realistic depiction of water features when zoomed in. I run into memory issues when doing ...
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0answers
27 views

MapBox Studio: Styling Water in template dataset

I am using MapBox Studio with their own template dataset called Outdoors. I discovered that categories of waterways can be addressed by classes such as river, stream, stream_intermittent etc. This ...
2
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1answer
52 views

Creating new vector which is “inverse” of existing vector (e.g. water surrounding island) in QGIS [duplicate]

I want to create a new vector layer which represents the surrounding water of a particular island I am working with in QGIS. Is it possible to create a water shape based on an "inverted selection&...
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24 views

EarthEngine - Create a Clipped Global Surface Water Occurrence Layer

I am looking to create an inland surface water layer using Earth Engine. The JRC Global Surface Water Mapping Layers, v1.2 - Occurrence band is exactly what I want, but as you can see in the attached ...
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32 views

False positive results while mapping water bodies

I am a veterinary epidemiology researcher interested to benefit livestock in a desert. As water is an important resource for herders therefore I have become interested to map water bodies.I learned ...
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3answers
225 views

Generating multiple water level scenarios with only DEM data in QGIS

I want to depict certain water level scenarios (from -0,40mNN to +0,20mNN) by using a two dimensional hypsometric map. Only provided data are DEM-files of the AOI. I managed to create the hypsometric ...
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0answers
53 views

How do I draw polygons from aerial imagery?

I will be working on a project to automatically identify ponds from satellite imagery. I have uploaded the basemap into ArcMap 10.7, but I can't create a feature layer to start editing. How do I add a ...
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0answers
28 views

R SPEI package on waterbalance timeseries for multiple locations with NA's: unexpected data output distribution

I want to use the spei() function in the SPEI package on a waterbalance dataset from 2015-2020 of 99 locations. The waterbalance is calculated out of MODIS PET values (8-day summed to monthly) and ...
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0answers
79 views

Surface area of waterbodies for multiple location using Google Earth Engine

Using this code, I've extracted surface area of water bodies (for a period of 6 years) from sentinel 1 GRD dataset. But how can I compute water area extent of multiple location and produce chart/CSV ...
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1answer
433 views

GEE – Smoothing curve of detected water area

I am trying to plot the time series chart of the detected water area by otsu's method in Sentinel-1 images as a smoothed average curve. I found two approaches to this for the Google Earth Engine: ...
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1answer
74 views

Techniques to map small water bodies in desert

Techniques to map small water bodies in desert I have task to map water bodies in a desert. I used landsat 8 and calculated three indices called NDMI, Tasseled Cap Wetness, & AWEIsh. I am ...
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1answer
112 views

Mapping of small water bodies in desert environments

I am trying to map small surface water bodies in a desert. My issue is: water pixels don't cover full extent water bodies (see screenshot attached). What threshold values would I need so that water ...
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0answers
43 views

Map surface water bodies in a desert

I am interested in mapping surface water bodies in a desert. I have used Tasseled Cap Wetness (TCW) in GEE. After running my code, I found that water bodies (locally called tobas) were not marked. I ...
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0answers
104 views

Checking if network has connection errors

I have given a network of a city in dwg. I made a dxf that only contains the network itself, and created a layer for every type of pipe (like 25KPE, 80KPE etc...). How do I check if the network is ...
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0answers
84 views

ArcGIS Pro Arcade expression to Maintain line-to-point connectivity

A customer was using a geometric network to maintain connectivity between lines and points. Now they are using ArcGIS Pro, which does not support geometric networks. They cannot use the Utility ...
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2answers
940 views

Calculating water occurrence of Sentinel-1 images in Google Earth Engine

I would like to derive the occurrence of surface water bodies from Sentinel-1 image collection in the Google Earth Engine.In my example I could already compute the water mask using Otsu’s method for ...
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0answers
18 views

Scale national economic data down to a watershed

Economic Input Output databases such as e.g. the World Input-Output Database by the European Commission contain economic (and often environmental) statistics. The spatial resolution of data provided ...
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0answers
45 views

Creating a “Stream Order” of canal system using ArcMap

I'm interested in creating a "Stream Order" for our canal system. I am the GIS Specialist for an irrigation district. I would like to have the ability to have a layer for when I click on a section of ...
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0answers
346 views

SVG symbols for water management

I'm searching for SVG of different (german) hydrant types ("Unterflurhydrant", "Überflurhydrant", "Hydrantenschacht") etc. The symbols are currently stored as polygons in MapInfo's proprietary .TAB (...
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1answer
317 views

Extract data from osm.pbf with GDAL

I tried osmosis, osm2pgsql, osmfilter, and probably most of OSM related tools in order to extract polygon rivers and water bodies. Among the tools, OGR is intuitive and returns good results so far ...