苏州市耕地保护等级评价

基于国内外相关研究与PSR 模型提出环境压力、土壤质量、破碎度、粮食单产等耕地保护等级评价指标。单项指标评价表明: 苏州耕地环境压力突出、土质较好、破碎化明显、粮食产量高。基于指标相关性分析, 选用层次聚类分析法, 对样本特征聚类分为4 等, 各等面积百分比S1∶S2∶S3∶S4=33.6∶32.4∶26.7∶7.3。S1 在乡村区和湖荡区, 各指标良好; S2 在沿江平原及城市化边缘区, 土质良好, 粮食产量较高; S3 散布在城市化边缘区及湖荡丘陵区, 各指标中等; S4 散布在城市周边及湖荡丘陵区。进而基于各等级的地域特征及指标关系, 将耕地保护等级又分为9 级, 并指出各级耕地保护措施。

Research on Gradation Evaluation of Cultivated Land Conservation in Suzhou City

Under the background of globalization and informatization of the world economy, therapid economic growth and process of urbanization in Suzhou city in future will aggravate theconservation pressure on cultivated land.It is time to consider and redefine the connotation ofcurrent cultivated land conservation concept. ( 1)Based on domestic and foreign related researchesand the framework of PSR( Pressure-State-Response)model, this paper proposes the gradationevaluation indicator system of cultivated land conservation in Suzhou city among which thePressure indicator is the environment pressure of cultivated land, and the State indicator is thesoil 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 landcaused by rapid population and economic growth, urban sprawl and freeway networks infrastructureconstruction is very outstanding; the soil quality of cultivated land is very good, and theland 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 JiangsuProvince ( 5954kg/ha) and the whole country ( 4399kg/ha) .( 3) The correlative analysis of theseindividual indicators show that the correlative coefficient is very small, and the variousrelationships between indicators are performed according to different regional characteristics, andaccordingly their weights are difficult to be defined.Based on the research result of correlativeanalysis of indicators, the paper adopts the Hierarchical Cluster Analysis method for the generalgradation evaluation of cultivated land conservation.The results show that the ratio of the area ofthe 4 ranks is 33.6 ∶32.4 ∶26.7 ∶7.3.The cultivated land of rank S1 is located in the rural areasoutside urbanization region and lake areas where four indicators are very good.The cultivatedland of rank S2 is located in the Yanjiang plains and the urbanized marginal areas where the soilquality is good, and the level of food production is high.The cultivated land of rank S3 isscattered 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 cultivatedland conservation rank, the gradation system of the 4 ranks is subdivided into 9 ranks, and someconservation measures about cultivated land for each rank are also pointed out.