GIS支持下的区域耕地质量评价

通过设立耕地代表性样区开展实地采样调查分析 ,利用逐步多元回归分析法筛选和确定区域耕地质量评价的主导因子及其权重 ,借助 GIS技术和动态聚类模型进行区域耕地质量评价 .结果表明 ,有机质含量、≥ 1 0℃积温、道路通达度、CEC、坡度、质地、地下水位和全 K含量等 8个因子与耕地粮食产量关系极为密切 ,可作为闽侯县耕地质量的主导评价因子 ,其中以有机质含量、≥ 1 0℃积温、道路通达度、CEC和坡度对耕地质量的影响较大 ,合计权重达 80 %以上 .闽侯县耕地资源总体质量不高 ,中低产耕地占 68.0 1 % .全县耕地主要限制型为砂、粘、冷和瘦限制 ,分别占耕地总面积的 2 5 .0 4%、1 2 .5 8%、1 2 .1 7%和 1 5 .2 7% .GIS与数学模型集成方法可为快速、准确评价区域耕地质量及动态监测提供理想途径

Quality evaluation of regional cultivated land based on GIS

The major evaluating factors and their weights to assess the quality of regional cultivated land were selected and determined by progressive multiple regression analysis based on the data of field investigation and soil analysis of the representative plots of cultivated land, and then the quality of regional cultivated land was evaluated by GIS technology and dynamic cluster analysis. The results showed that 8 factors, including organic matter content, ≥10 ℃ accumulated temperature, road unobstructed degree, CEC, slope, texture, underground water depth and total potassium content, were most closely related to crop yields of cultivated land so that these 8 factors could be used as major evaluating factors to assess the quality of regional cultivated land. Organic matter content, ≥10 ℃ accumulated temperature, road unobstructed degree, CEC and slope among 8 factors would greatly affect the quality of cultivated land as the sum of their weights were more than 80% of the total. The overall qualities of cultivated land resources were rather low in Minhou County. The areas of cultivated land with middle and lower yields were 68.01% of the total. The major limiting types of cultivated land were sand, clay, low temperature and poor nutrients. The areas under these limiting types were 25.04%, 12.58%, 12.17% and 15.27% of total cultivated land, respectively. The united methods of GIS and mathematical model could provide the best way to evaluate the quality of regional cultivated land quickly, precisely and dynamically.