Topographic Position Index to Landform Classification and Spatial Planning, Using GIS, for Wadi Araba, South West Jordan
Noah Al-Sababhah
Abstract
This study aimed to carry out a classification of landforms in Wadi Araba, southwest Jordan, using the topographic Position Index (TPI) by GIS. TPI was used at different spatial scales (mean, 50 m, 75 m, 100 m, 200 m, 500 m, 1000 m, 1500 m, and 2000 m) for such classification. Landform classification goes by ten levels: Valleys Bottoms, Midslope Drainage, Upland Drainages, Gentle Valleys, Plains, Open Slopes, Upper Slopes, Local Ridges, Midslope Ridges, and High Ridges. This requires defined classes using the TPI for all scales. The analysis showed that there were ten types of landforms; most of them were ridges, valleys, and steep slopes. In addition, the proportions of these types varied according to the variation of indicator values in the scale. Landform map according to the Neighborhood Values mean (m) showed that areas with upland drainages were about 14%, while areas with Gentle Valleys represented about 5.52%, of the total area of the study area. Finally, it was found possible to rely on the classification maps of the landforms for the purpose of spatial planning, as this included determining the land uses that are appropriate for each landform, as well as determining the levels of risk for landslides and floods.