Comparative Study of Landform Mapping Using Terrain Attributes and Topographic Position Index (TPI): a Case Study in Al-Alamien – Ras El-Hekma Region, Egypt

Abstract

The aim of this study is to compare the classification of the landscape of the area located between Al-Alamien and Ras El-Hekma to landform classes using two different classification methods; the terrain attributes method and the topographic position index (TPI) method. Terrain attributes classification method derived from a digital elevation model and were overlaid using cell statistics to generate a landform map with seven classes. The landform classes were: (1) Lower coastal plain (17.86%), (2) Upper coastal plain (43.61%), (3) Piedmont plain (2.33%), (4) Dissected escarpment (2.64%), (5) Plateau (26.79%), (6) Ridges and coastal bars (3.62%), and (7) Inland dunes (3.15%). The topographic position index (TPI) method which generate the landform classes uses only the digital elevation model. The generated landform classes were: (1) Valleys (2.1%), (2) Midslopes drainages and shallow valleys (1.1%), (3) Plains (92.77%), (4) Hills in plains (0.34%), (5) Mesas (2.44%), and (6) Ridges (1.25%). The comparison of the two methods showed that using the terrain attributes method was more detailed.