What is Geospatial Modelling

In this chapter, the author presents a review of the GIS use during the research carried out during the past three decades dealing with land degradation. The objective is to assess the viability of applying GIS with different modes of remotely sensed data acquisition for quantifying land degradation in Tunisia. Various GIS based modelling approaches for soil erosion hazard assessment such as empirical and physical distributed are discussed. Five case studies are selected from several projects. They apply different methods for land degradation investigation at different scales using GIS and remotely sensed data. The research dealt mainly with: 1) The prediction of soil erosion at the regional level related to conservation techniques; 2) The quantification of soil erosion at the gully level based on GIS, digital photogrammetry and fieldwork; 3) The monitoring of gully erosion using GIS combined to images acquired by a non-metric digital camera on board a kite.