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13

Create a box as a Spatial object and crop your raster by the box. e <- as(extent(-16, -7.25, 4, 12.75), 'SpatialPolygons') crs(e) <- "+proj=longlat +datum=WGS84 +no_defs" r <- crop(worldpopcount, e)


6

You can download hydrology shapefiles from here for a number of countries around the world. Select your country of choice and Inland water as your subject. You should receive 2 types of shapefiles: A line shapefile depicting line features for rivers, canals and basins A polygon shapefile depicting area features for rivers, canals and basins I believe ...


5

It's not authoritative, but at a government open data page they provide location data as both UTM coordinates and WGS84 coordinates. Exactly what UTM CRS that is is not stated, or I could not find it.


4

I would lean on this definition - East African Countries East Africa or Eastern Africa is the easterly region of the African continent, variably defined by geography or geopolitics. In the United Nations Statistics Division scheme of geographic regions, 20 territories constitute Eastern Africa UN Source


4

You could create a custom Chamberlin trimetric projected CRS. From Snyder, John P. Map projections: A working manual. USGS Publications Warehouse. 1987: The Chamberlin Trimetric projection is an approximate "three-point equidistant" projection, constructed so that distances from three chosen points to any other point on the map are approximately ...


3

find here a full solution. First, let's check if EPSG:26910 is suitable for Africa: library(giscoR) library(sf) library(tidyverse) # Wrong projection - full world gisco_coastallines %>% st_transform(26910) %>% ggplot() + geom_sf() It doesn't look very nice. If we check the crs we see the wkt string: st_crs(26910) #> Coordinate Reference ...


3

I've never heard of Africover, but a quick search leads me to the Food and Agriculture Organization of the United Nations' GeoNetwork pages, which appears to have a database of Africover geographic datasets available.


3

I downloaded your data and had a play around in QGIS - if I choose EPSG:102022 (Africa_Albers_EAC) it looks like it lines up. Depending on your plans for this that might be close enough - obviously for real science(tm) you'll need to go back to NOAA (or the publications listed) and check. Or you could try editing the spheroid definition below. PROJCS["...


3

You might try downloading the 30m SRTM for your region and deriving the contours yourself. It's available through EarthExplorer for free. Contours can be generated with the Raster > Extraction > Contour tool in QGIS.


3

A really nice source for admin boundaries all over the world, at different scales with very nice cartographic quality, is found at Natural Earth. If you are downloading shapefiles, there are several options for converting from a shapefile: 1) geojson.io, to which you upload your shapefile and save as geoJson 2) This converter, same idea without the map to ...


3

From the raster package documentation, library(raster) r <- raster(nrow=45, ncol=90) r[] <- 1:ncell(r) # crop Raster* with Spatial* object b <- as(extent(6, 6.4, 49.75, 50), 'SpatialPolygons') crs(b) <- crs(r) rb <- crop(r, b)


3

Ok I know of two products that may help you. This site gives all the grunt work for the hydrologiclly correct layers you would require to conduct such an analysis. The Open-source Water Observation and Information System (WOIS) is now active in Africa. Is is compiled using open-source GIS (link) and includes modules for TSS. It is not a project for ...


3

I have made hydrologically correct river-channels for the Lake Victoria basin. SRTM 90m does a reasonable but imperfect job. For example, I had to adjust numerous regions based on the actual flow of rivers. All is not lost though it sounds as though we can expect the 30m global dataset soon. I would suggest a dry run with 90 m data and then a rerun when the ...


2

Ok I made my own from 10,000 data points. This is the link if interested. bit.ly/LV_Bathy. It only took me two years to get it together after asking the question.


2

Here is the location of a dataset on global border crossing points. http://geonode.wfp.org/layers/geonode:wld_poi_bcp_wfp


2

A data requirement like the one you have outlined requires either a series geostationary satellites, or modeled data based on an amalgamation of data sources. Geostationary satellite: Your best bet would be the Meteosat MSGs. Working with this data is not the easiest task in the world, and accessing data is not easy either. For research projects, this data ...


2

you can digitize roads and other objects of your desire from Google earth pro which will be in a kml format that can be converted into shapefiles . you can then use the shape files in gis softwares...


2

Check out Earth Explorer. You can search many different datasets depending on avaliablity for certian locations.


2

So the answer is probably going to be no, there is no shapefile that is gadm data level 3 or 2 available for all of Africa because some countries only have data up to level 1 (Libya, West Sahara, etc. ). That being said you can download the data and combine it into a shapefile – I was able to get the whole continent at level 1 downloading the rds files ...


1

Whenever you are calculating areas and lengths, the projection is important to consider. Most ee.Geometry methods have parameters for projection and maxError; set them to specify what projection and tolerance to use for calculations. In your script, I've added these arguments to the geometry methods and it computes the correct area and perimeter for the ...


1

Here are the level-3 basins provided by HydroSHEDS You can download these from http://www.hydrosheds.org/download (must create an account), or you can use this link for the next 3 hours: http://www.hydrosheds.org/tempdownloads/hydrosheds-209a52bb01dc03b64a9f.zip


1

I found this Q&A while searching to make the same thing for myself. Two things made it difficult to follow the accepted answer for me: 1) I had already downloaded the whole-of-Earth GADM shapefile. The problem for me was that 'continent' was not a variable name in that dataset - country was the biggest defined area. 2) the countrycodes package didn't ...


1

Take a look at this website: http://gadm.org/country Here you can select 'Côte d'Ivoire' and download the corresponding data in several formats. On the download page, you can already preview if this is what you actually looked for. Normally, the 'GADM database of Global Administrative Areas' is kept up-to-date and contains as many details as possible.


1

Which part of the world are you looking at? Archival SPOT imagery is available in many areas,but may be restricted to education and research uses. Check NASA and USGS for data. Depending on the location and scale there may be something already done that you can use for your purposes so don't reinvent the wheel if you don't have to.


1

You don't have a problem. Using decimal degrees is tantamount to computing in a Plate Carree projection, which distorts distances (and areas) greatly at points away from the Equator. However, within any 3000 m region the change in distortion is inconsequential (unless that region is extremely close to one of the poles). Suppose, then, that the area of any ...


1

Check this site http://www.worldclim.org/. The raster resolution is ~1km (30 arc-seconds).


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