关键词: 耕地保护, 等级评价, PSR 模型, 苏州市

Abstract: Under the background of globalization and informatization of the world economy, the rapid economic growth and process of urbanization in Suzhou city in future will aggravate the conservation pressure on cultivated land.It is time to consider and redefine the connotation of current cultivated land conservation concept. ( 1)Based on domestic and foreign related researches and the framework of PSR( Pressure-State-Response)model, this paper proposes the gradation evaluation indicator system of cultivated land conservation in Suzhou city among which the Pressure indicator is the environment pressure of cultivated land, and the State indicator is the soil quality and land fragmentation, and the Response indicator is per unit area yield of grain.( 2) Individual indicator evaluation results show that the environment pressure of cultivated land caused by rapid population and economic growth, urban sprawl and freeway networks infrastructure construction is very outstanding; the soil quality of cultivated land is very good, and the land is fertile; the fragmentation is evident because of the division of urban, transport land, lakes, rivers and highland terrain; the unit production ( 6683kg/ha) is higher than that of Jiangsu Province ( 5954kg/ha) and the whole country ( 4399kg/ha) .( 3) The correlative analysis of these individual indicators show that the correlative coefficient is very small, and the various relationships between indicators are performed according to different regional characteristics, and accordingly their weights are difficult to be defined.Based on the research result of correlative analysis of indicators, the paper adopts the Hierarchical Cluster Analysis method for the general gradation evaluation of cultivated land conservation.The results show that the ratio of the area of the 4 ranks is 33.6 ∶32.4 ∶26.7 ∶7.3.The cultivated land of rank S1 is located in the rural areas outside urbanization region and lake areas where four indicators are very good.The cultivated land of rank S2 is located in the Yanjiang plains and the urbanized marginal areas where the soil quality is good, and the level of food production is high.The cultivated land of rank S3 is scattered in the urbanized marginal area and lake-hilly areas where four indicators are common. The cultivated land of rank S4 is scattered in the areas around big cities and lakes hilly areas. ( 4) Then on the basis of regional characteristics and indicators relationships of each cultivated land conservation rank, the gradation system of the 4 ranks is subdivided into 9 ranks, and some conservation measures about cultivated land for each rank are also pointed out.

Key words: cultivated land conversation, gradation evaluation, PSR model, Suzhou city