SOIL EROSION RISK ASSESSMENTS USING GIS TECHNOLOGIES -BULGARIAN EXPERIENCE

摘要

Soil erosion is widely recognized environmental problem. Geographic information systems (GIS) integrate hardware, software, data, procedures and trained personnel for capturing, managing, analyzing, and displaying all forms of geographically referenced information. The report presents briefly two GIS for soil erosion risk assessments, which were developed for use by decision makers for sustainable management of soil resources to evaluate, analyze and predict soil erosion risk and localize the need for application of measures to control soil erosion by rain and wind. These systems integrate models, adapted and evaluated for the conditions in Bulgaria and available information at scales of M 1: 400 000, M 1: 200 000 and M 1: 100 000 about digital elevation, rainfalls, winds, air temperature, soil cover and permanent land cover. The GIS for water erosion risk assessments integrates the USLE approach and the GIS for wind erosion - the WEQ approach. The models were adapted in order to use available datafrom routine large-scale soil survey and published climatic observations in Bulgaria as input parameters. Presented results demonstrate some of the advantages and the disadvantages of the GIS technologies for soil erosion risk assessments, which have influenced directly and indirectly the development of the GIS technologies.