Evaluation Of Land Suitability For Cash Crops In HangZhou Based On GIS

In recent years, the evaluation of land suitability for cash crops has become an important part in research on agricultural regionalization.The conditions of soil,topography and climate are the main factors that determine the spatial distribution and quality of cash crops.As the specialty cash crops, tea,carya and torreya play a great role on the Agricultural economy development. Hence, it is of great value to evaluate land suitability for cash crops in Hangzhou. It can provide scientific basis for adjusting and optimizing the agricultural structure.This study was based on GIS and mathematical model.Taking HangZhou city as research region,the unit of evaluation was 50mx50m grid.Firstly, according to natural request about tea,carya and torreya,we choose the factor of suitability evaluation including climatic,topography and soil condition.And we use regression ordinary kriging method interpolation, regression inverse distance weight method interpolation, regression trend surface samples mixed method interpolation to analysis the spatial distribution of Hangzhou's meteorological elements.Finally applying fuzzy synthetic evaluation method to evaluate land suitability for cash crops in HangZhou city.The results were following:Based on 34 stations precipitation data,we apply regression ordinary kriging method interpolation, regression inverse distance weight method interpolation, regression trend surface samples mixed interpolation to study spatial distribution of precipitation of HangZhou.The cross-validation results show that regression ordinary kriging method is better than the other three kinds of interpolation method in average temperature for years and years for sunshine duration.But for average annual rainfall,annual extreme appear more than -13℃frequency, the average relative humidity in April to October,the sunny days in the late April to middle may regression inverse distance weight method interpolation is the best method.2. In this study, the method of fuzzy comprehensive evaluation is applied to the land suitability evaluation for tea,carya and torreya in hangzhou city.The evaluation results show that: (1)The area of the most suitable land resources for tea is 3417.18 km~2 ,which accouts for 22.30% of the area of reaserching land ; The area of the unsuitable land resources for tea is 8355.10km~2 ,which accouts for 54.53% of the area of reaserching land ; The area of the most suitable land resources for tea is 13550.73 km~2 ,which accouts for 23.17% of the area of reaserching land .(2) The area of the most suitable land resources for carya is 4679.42 km~2 ,which accouts for 30.54% of the area of reaserching land ; The area of the more suitable land resources for carya is 7128.74km~2 ,which accouts for 46.52% of the area of reaserching land ; The area of the unsuitable land resources for carya is 3514.85 km~2 ,which accouts for 22.94% of the area of reaserching land . (3) The area of the most suitable land resources for torreya is 5380.98 km~2 ,which accouts for 35.12% of the area of reaserching land ; The area of the more suitable land resources for torreya is 6206.53km~2 ,which accouts for 40.50% of the area of reaserching land ; The area of the unsuitable land resources for torreya is 3735.50 km~2 ,which accouts for 24.38% of the area of reaserching land .3. The land quality for tea was total perferable in Hangzhou. The most suitable and more suitable regions respectively accounted for 29.02% and 70.97% of the areas of all the suitable cultivated land for tea. The most suitable land resources for tea were mailny distributed in yuhang, in the east of XiaoShan and FuYang,in the southeast of TongLu county,in the southwest of JianDe city and in the low mountainous areas in the southeastof ChunAn which accounted for 82.79% of the area of the most suitable regions. The more suitable land were mailny distributed in ChunAn, LlinAn, JianDe and FuYang which accounted for 69.81% of the area of the more suitable regions. The most suitable and more suitable regions respectively accounted for 39.63% and 60.37% of the areas of all the suitable cultivated land for carya. The most suitable land resources for carya were mailny distributed in the center of FuYang,in the low mountainous areas of middle-east of JianDe and the middle-south of LinAn which accounted for 34.84% of the total evaluation areas. The more suitable land were mailny distributed in the middle-north of LinAn and in the south of JianDe and ChunAn.The most suitable land resources for torreya were mailny distributed in the southeast of fuyang,in the middle and east of TongLu,in the northeast of JianDe and in the low mountainous areas of the southeast of ChunAn which accounted for 88.15% of the area of the most suitable regions. The more suitable land were mailny distributed in the low altitude area of the northwestern XiaoShan,northeastern LinAn southwestern FuYang and ChunAn.