Study On Classification,Graduation Of Farmland In Shenmu County Based On GIS

The work of Classification, gradation, and valuation of Agricultural Land is an important component of the national land resources survey and a key element to strengthen land resources survey and evaluation.To do this work is to achieve the management of land resources management from quantity-based to the quantity, quality, coordination and management of ecological and scientific use of an important sign of change, is a basic, public welfare and strategic evaluation of land resources survey.In this paper, relying on the Shaanxi Provincial Agricultural Land Classification and the gradation and valuation of the county pilot project, according to "the regulations for classification on agricultural land" and " the regulations for gradation on agricultural land ", using GIS technology to complete the Shenmu Xian agricultural land on the classification and grading.Based on determining factors and their weighing of farmland classification, unit classification of the natural quality of points was calculated by factor method in the Shenmu county agricultural land classification,then the index of natural quality classification being calculated according to productive potentiality of light and temperature(climate)and coefficient of crop yield rete.Through land use coefficient and economic coefficient,the indices of use classificion and economic classification of farmland were calculateed last.On the base of these indices,the results of natural quality classification,use classification and economic classification were gotten by equidistanse intervals of these indices.Shenmu county agricultural land gradation use two methods,revision method and Factor method.Integrated method compares the two steps, through the forecast trend analysis, overlapping analysis, and the actual verification,the final outcome of the Shenmu county agricultural land gradation determine the main factors,for the Abnormal mutation value in the factor method, in the light of the revision method Combined with the actual results of the investigation and verification, and does not match the actual level of adjustment, final Shenmu cuonty-level agricultural land.Shenmu county natural quality of arable land is divided into three different, and so on, the five class highest, the third class lowest, third class in the area of maximum; Utilization is divided into five different, the maximum is six class and the minimum is second class ,third class in the area of maximum; Economy is divided into three different, the maximum is four class, the minimum is second class, second class in the area of maximum. Grading results comparable in Shaanxi province. Shenmu Xian in the territory of arable land will be further broken down into five levels, and the best level is one, the worst level is five, four level in the largest percentage of the area.The results show that: the farmland quality of Shenmu county is not high,the other in Shenmu county, such as the distribution line with the actual situation.The index of physical quality classification,use classifition and economic classification are all at a relatively low level in Shaanxi province.The level of arable land to a farmer's market and distribution center for the town centre, Quanceng level was decreasing; major roads on both sides, a strip of agricultural land-level decreasing, and the overall landscape-level distribution and generally consistent pattern and water systems, level by level of land use A greater impact on the type.