Evaluation Of Land Suitability Based On GIS In Liling City, Hunan Province

Under the guidance of system theory, aiming at the remedy of the overall land use planning, at the core of the evaluation of land suitability, this paper combing the GIS technology and the evaluation method, carries through the innovative design and study in theories, methods and techniques.With the support of information technology, a series of preferable land suitability evaluation projects on the platform of database are brought forward in the paper. According to the necessities of the remedy of the overall land use planning in Liling county in Hunan province, all types of land are classified by the suitability grades which are arranged in degrees of the matching between land quality and land-utilization ways; In a land evaluation unit, multitude suitability grades combined to make a result of land multisuitability evaluation. On the foundation of the combination of GIS and statistical software, the emphases of this paper are applying GIS in the land suitability evaluation, depositing and transferring massive data in the database, and putting in land suitability evaluation maps, which are one of the bases for the overall land use planning.In this paper, some software, such as MAPGIS, SuperMap, and ArcView, are used to evaluate land suitability, and Visual FoxPro is used to establish database, and DPS, a statistical software is used to deal with massive data. The methods choose evaluation factors by step-by-step regression analysis and Delphi method, calculate weightings of factors and evaluation data by principal component analysis, and grade land suitability evaluation by "natural breaks method".In the evaluation of land suitability in large area, there meet a problem of how to assure the integrality and veracity of data in order to accomplish the evaluation in high efficiency. Database is centrum of land suitability evaluation, and this paper attemps valuably to storage, conformity and transfer massive data in large area by data stream's expediting via the core of Visual FoxPro.In order to solve the difficulty of the huge work of calculation evaluation data by principal component analysis, this research write the Visual FoxPro programs which improve effectively.In the last, the paper takes land suitability evaluation of Liling as an example and applies evaluation project into practice, presents eight grade maps of land suitability evaluation of corn, oil plants, vegetable and flower, garden plot, holt, grassland, town, factories and mines, and residential area. It indicates that the methods are comparativly true of fact and dig out the exploitation potentiality of land. Accordingly, the results can offer reasons for the measures of land restruction, land utilization,...