Research On Land Suitability Evaluation On County Scale

Suitability of the land is a certain type of land designated for the appropriate level, which is one of the important content of land resources research at home and abroad in the last 20 years. The land suitability evaluation can be regarded as an important part of land evaluation. And its basic task is to determine the best way of land use is based on the land suitability, to coordinate the relationship between land development and protection effectively, and ensure the land resource can be used sustainably. Providing a reliable basis for the rational use of land resources and scientific planning and management, serving for the decision the use pattems of agricultural resources.This paper is based on the analysis of the land suitability evaluation at home and abroad in recent years, with the support of GIS theory and technology, and the usage of high-precision Geographical Conditions Census Data, fully combining with the actual situation of Qianxi County, according to the principle of selecting the evaluated factors, the evaluation factors and index system have been defined. The selection of the evaluation factors is based on the principles and the and index system have been defined. The grid method is been used to divide the evaluation unit, and the AHP to determine the weight of each evaluation factor. The spatial property database of each evaluation factors has been established under the management of GIS. Finally, we conducted a comprehensive evaluation of land suitability for Qianxi under the support of GIS technology. It is aiming at the existing problems of land use in Qianxi county, some measures for rational utilization of land resources is proposed, which is based on the result of suitability evaluation. The main results and conclusions of the study are listed as follows:(1) The land use status of Qianxi in 2014 were analyzed, and the quality,structure, spatial layout, the combination of feature and land use intensity of each important type of land use were obtained, which laid a foundation for the system to carry out land suitability evaluation.(2) Using AHP to construct the land suitability evaluation index system according to the actual situation of Qianxi county, and determine the weight of each index, integrating use of GIS spatial analysis techniques to extract thematic layers of each index, to carry out land suitability evaluation. Getting each index thematic map and farmland, orchard, woodland suitability evaluation map,and grade land suitability evaluation to highly suitable, generally suitable, marginally suitable and unsuitable four grades by "natural breaks method".(3) The result of land suitability evaluation shows that:The distribution of many farmland and gardens are highly suitable or generally suitable, so have a better distribution, but the distribution of large area of woodland are marginally suitable, and have a poor distribution.(4) According to the result of land suitability evaluation, some land use problems in Qianxi are concluded, and many solutions are raised.