ALN logo; link to Arid Lands Newsletter Home page No. 51, May/June 2002
Using geospatial technologies to understand dryland dynamics

Klock & Udluft Figure 5: Comparisons of techniques for feature mapping

Tsumkwe Training Area
Area
Geology
Extent
Area of hardrocks (%)
Aerial photographs
Satellite images
Geological maps
Aha Dolomite 20°41 E-21° E
19°40 S-19°54 S
27.79
17.69
33.37
Dobe Quartzite Basalts

20°40 E-20°50 E
19°30 S-19°45 S

11.97
7.67
60.6
Makuri Gneiss 20°40 E-20°50E
19°15 S-19°30 S
11.8
9.31
83.38

Results from marking hardrock areas by satellite images, aerial photographs and geological maps for the Tsumkwe training area.

Selected study area sites
Area Geology Extent area of hardrocks (%)
Satellite images
Geological maps
Tsumkwe Gneiss, Dolomite 20°30 E-21° E
19°25 S-19°55 S
11.51
32.52
Hochfeld Quartzite, Schists 17°50 E-18°30 E
21°30 S-21°45 S
41.82
78.13
Gaikos Quartzite, schists, gneiss 18°20 E-18°30 E
19°20 S-19°30° S
31.33
60.39
Hohenstein Schists, granite 16°50 E-17°10 E
20°20 S-20°40 S
44.39
99.5
Lister Quartzite, schists 20°45 E-21° E
21°45 S-22° S
7.66
95.54
Gam Dolomite, schists 20°45 E-21° E
20°10 S-20°20 S
2.26
8.22
Nhoma Quartzite 20°45 E-21° E
18°50 S-19° S
19
78.61

Comparison of results from mapping hardrock areas by satellite images and by geological map for seven example sites in the study area of northeastern Namibia.

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