BPNN Based Agricultural Land Suitability Evaluation with GIS: Case from Hangzhou, China

Agricultural land suitability evaluation is the most important base for land sustainable use and especially important in urban region for urban expansion decision. This article is studying on Hangzhou case, an urban region with rapid area´s expansion. GIS is using for spatial analysis and mapping, while BPNN for evaluation data process. Topography features, soil conditions, agricultural infrastructure, and geo-environment, are essential for agricultural land use suitability evaluation. In this study, all the above factors have been analyzed and evaluated with BPNN model. Agricultural land suitability in Hangzhou has been divided into four grades. The grade I and grad II zones have high-quality soils, exist around central built-up area. In this region, contradiction between urban expansion and high-quality agricultural land conservation grows more and more severe. The grade III zone locates mainly at the east and west plain area of Hangzhou, with large scale. And the grade IV zone locates mainly in hilly area, with steep gradients, shallow depth of bedrock, and thick arable layer. The grade IV zone is unsuitable for agriculture, but suitable for ecological use. The research shows the advantages of BPNN for land suitability evaluation, and the advantages of the combination of attribute data process (BPNN) and spatial analysis (MapGIS).