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The stream network derived from DEMs represents the pattern of flow accumulation and the potential location of river networks. The configuration of the landscape is used to generate this feature. As Figure 12 shows, the 92-m resolution has greater difference in stream network than has the 25m-resolution. Much greater detail is evident at 25 m in both DEMs, with greater meandering and therefore longer flow lines. No big differences are evident between 92-m and 25-m resolution, with all the major channels correctly identified.

(A) (B) Figure 12. Comparison of stream networks from the (A) 92-m and (B) 25-m digital elevation models (DEMs). Blue = SRTM DEM and black = cartographically derived TOPO DEM. The watershed system generated with the different models (Figure 13) shows differences in the number of watersheds and in their configuration. Differences were higher between the 92-m DEMs than in the 25-m DEMs.

Figure 13. Watershed boundaries from the four different digital elevation models.

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SRTM for Hydrological research  

Practical use of SRTM data in the tropics – Comparisons with digital elevation models generated from cartographic data Andy Jarvis, Jorge Ru...

SRTM for Hydrological research  

Practical use of SRTM data in the tropics – Comparisons with digital elevation models generated from cartographic data Andy Jarvis, Jorge Ru...

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