maps
Developing Soil Maps and a Soil Health Surveillance System
At present no standards, definitions or criteria exist for the assembly, mapping and interpretation of soil legacy data sets, case definitions, soil health and degradation, diagnostic tests, and sampling designs for assessing and monitoring soil condition. It is thus difficult to derive spatially and temporally consistent evaluations of the occurrence of soil degradation, or to provide evidence-based management recommendations for maintaining and improving soil health.
AfSIS Web Map Service
The Africa Soil Information Service (AfSIS) Web Map Service supports the Open Geospatial Consortium (OGC) OpenGIS Web Map Service (WMS) Implementation Specifications and dynamically produces maps of georeferenced data. Support of this international standard opens the AfSIS map collection to users who can access its contents via machine-to-machine interaction. View our online maps here.
How to Open and View Downloaded SRTM Derivatives
The SRTM-derived base layers are available for download in GeoTIFF format and can be opened using a GIS package. The downloaded folder, which is in .tar.gz format, also contains the metadata catalog record for the selected base layer and a brief description of the AfHySrTM, AfSIS_SCA, and AfSIS_TWI datasets. Once the compressed folder has been downloaded, users will need to:
Step 1. Decompress downloaded folder
For Windows Users: -
Base Maps Documentation: Shuttle Radar Topography Mission (SRTM) Derivatives
Hydrologically Corrected / Adjusted SRTM Digital Elevation Model (AfrHySRTM)
AfrHySRTM is an adjusted elevation raster in which any depressions in the source Digital Elevation Model (DEM) have been eliminated (filled), but allowing for internal drainage since some landscapes contain natural depressions. These landscapes have their own internal drainage systems, which are not connected to adjacent watersheds. Null cells (drains) were placed in depressions exceeding a depth limit of 20 m and with no less than 1000 cells (pixels) during the DEM adjustment process.
