USE OF GIS TECHNIQUE TO DESIGN LANDSLIDE RISK ASSESSMENT MAPS FOR AGRICULTURAL LAND.

This study brings forward an application of GIS technique quantifying the landslide risk for an area of agricultural intended use. Considering that the assessment and monitoring of the slopes instability risk require in-depth knowledge of a set of factors with spatial distribution (climate, geomorphology, seismic activity, seeding different types of vegetation in the area etc.), such actions can be performed in an effective and economic manner only within a Geographic Information System (GIS). A slope of approximately 2170 ha located in Romania was assessed in this context and for the purpose of this study. The aim of the approach was to analyse the landslide risk. In order to evaluate the area of the slope in terms of landslide hazard, I calculated the value of the average risk coefficient (Km), enabling to draw up the risk assessment map. The first step was to create the geo-referenced database and the alphanumeric database. Afterwards I applied a mathematical model to determine the value of the average risk coefficient. Based on this Km, I mapped the assessed slope in areas as homogeneous as possible in terms of the factors evaluated on the landslide risk analysis (six factors were analysed according to the methodology applicable in Romania). I used the raster process overlaying the studied area of a rectangular grid of 500 x 500 m sized square cells (pixels). I used a software application in an appropriate GIS environment to design six basic digital maps of the factors involved in the analysis and eventually, the 7th digital map resulting from the application of the mathematical model (Km map). Zoning of the landslide risk on the assessed slope enables to adopt an appropriate strategy to control this natural process. Such measures suggested after the analysis was made can be adopted in a timely manner to prevent the negative and devastating social, environmental as well as economic effects. [ABSTRACT FROM AUTHOR]