Karst sustainable land use evaluation at county-level base on the method of lattice and ANN-A case of Du´an County in Guangxi

Applying various research technologies and methods including GIS technology, method of lattice and artificial neural networks, this paper studies on the evaluation of karst land sustainable use at county-level. Taking Du´an County in Guangxi as an example, this paper builds an index system on the evaluation of sustainable land use, and using related analytical data in 2005 to gain different kinds of index values. Du´an County was divided into 253 evaluation lattice units, in which gains different kinds of index values according to the theory of gaining index values, and utility function was used to carry on a standardized processing in accordance with the nature of the indexes. Finally, we used the BP model of the ANN to evaluate the sustainable Du´an Karst land use, and to pain a map of evaluated results distribution. The evaluated results show that resource environment, economical, social and other factors, which form Karst land use system in Du´an Country, share obvious differences in spatial distribution, and its sustainable land use also has its own spatial differences. It was divided into five grades in spatial distribution as follows: no, low, moderate, relatively strong and strong sustainability. The evaluated results gave an objective reflection on the condition of Karst sustainable land use in Du´an Country.