The Research On Suitability Evaluation Of Carya Cathayensis Sarg. Based On GIS

Carya Cathayensis Sarg. is a species of economic forest which have better economic benefits. Inrecent years, Zhejiang, Anhui and other provinces set off a wave of its industrial development. Thepresent lots of researches for Carya Cathayensis Sarg. have been conducted by the domestic andforeign scholars and experts, which include its biological characters, breed technique, high and stableyield technique and products processing and so on, but the research of Carya Cathayensis Sarg. landsuitability evaluation is still at the qualitative stage. Because it is little information on CaryaCathayensis Sarg. growing limiting factors and lack of quantitative research on relationship betweenits distribution and its land suitability,which result in the failure of introduction and cultivation.Thequantitative research on suitable environment of Carya Cathayensis Sarg. have important directive toguide introduction and expansion of Carya Cathayensis Sarg.In this paper, Lin'an City as the study area,the distribution of Carya Cathayensis Sarg. trees wereextracted from forest resource inventory second-class datas,and deriving terrain factors fromDEM,combined with principal component analysis,analysis hierarchy process(AHP) and membershipfunction in fuzzy mathematics,the comprehensive evaluation model of suitable environmental ofCarya Cathayensis Sarg. was established, which used to predict potential suitable areas ofCarya.Cathayensis Sarg..The main contents and the results are as follows:(1) Establish environment factor database of distribution of Carya Cathayensis Sarg.:30mresolution DEM as a data source, through spatial analysis function of GIS access to property values of elevation, slope, aspect, surface curvature, solar radiation index and index of topographical factorsin study area, combined with the results of field investigation getting the actual distribution of CaryaCathayensis Sarg. and the soil data of soil types, parent material, soil thickness and so on,environment factor database of distribution of Carya Cathayensis Sarg. was established.(2) Dominant factor analysis of distribution of Carya Cathayensis Sarg. and evaluation model ofsuitable environmental of Carya Cathayensis Sarg. was established: the key affecting factor wasdefined by principal component analysis,the weight of the index are determined by AHP and each factor grade was confirmed by membership function in fuzzy mathematics, then the comprehensiveevaluation model of suitable environmental of Carya Cathayensis Sarg.was established.(3) Classification evaluate suitability Carya.Cathayensis Sarg. and forecast suitable regions: Inthis paper,each topological polygon data as evaluation units, using the above comprehensiveevaluation model evaluate suitability in the study area in the ArcGIS,and the evaluation results intothe most suitable regions, the better suitable regions,general suitable regions and unsuitableregions.Through forecast,there are 50.2% of lands in Lin'an suitable for the growth of CaryaCathayensis Sarg.. 47.7% of Carya.Cathayensis Sarg. distribute in the most suitable area with 208462acres; 37.9% of Carya.Cathayensis Sarg. distribute in more suitable area with165664 acres; 11.5% ofCarya.Cathayensis Sarg. distribute in generally suitable area with 50060 acres; 2.9% ofCarya.Cathayensis Sarg. distribute in unsuitable area with 12760 acres.Through the actual distributionmap base on the GIS spatial overlay analysis function,the results show that there are 85.6% of theactual distribution of Carya Cathayensis Sarg. in the most suitable regions and the better suitableregions,there are 11.5% in the general suitable regions, and the prediction has some reference value.