摘要
以三峡库区王家桥小流域为例，探讨了应用地理信系系统（ＧＩＳ）和数学模型相结合评价土壤肥力的途径。通过系统全面的考虑选取了９个评价指标，应用层次分析法确定其权重，并用模糊数学建立单因子评价模型，再用加权法得到每个评价单元的土壤肥力综合评价指数（ＳＩＦＩ）。根据ＳＩＦＩ值将土壤肥力分为高（＞０．４５）、中（０．２５～０．４５）和低（＜０．２５）３级。应用ＩＤＲＩＳＩ对王家桥小流域的土壤肥力资源进行了分析。结果表明：王家桥小流域的土壤肥力大多处于中下水平，高、中、低肥力土壤的面积比例分别为２４．９％，３１．９％和３８．０％。流域的土壤肥力资源尚有较大的潜力。限制王家桥小流域土壤肥力资源的主要因素是土壤侵蚀、投入水平低。
Taking Wangjiaqiao watershed in Three Gorge area as study area, using GIS and mathematical methodology, an evaluation method of soil integrated fertility index(SIFI) was developed and used. With systematic principle and the data of soil survey in Wangjiaqiao watershed ,the 9 indexes were selected. Applying the analysis hierarchy program, these indexs weight values were calculated. Then with fuzzy principle two types of membership functions of these indexes were developed based on their effects on plants, and their values of function were also calculated .Finally, SIFI of different units of soil was calculated and soil fertility was divided into high(>0.45),middle(0.25￣0.45),low(<0.25) three grade according to SIFI.The characters of soil fertility in this watershed was analyzed by IDRISI. The results as follow:The soil fertility in this watershed was mainly middle and low level, and soil area with high, middle and low fertility amount to 24.9%, 31.9% and 38.0% respectively. Main reasons that affect the full utilization of soil fertility were soil erosion and low input.
基金
国家自然科学基金
