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研究方法 水土保持规划可用多种标准来制订。其中每一种标准都涉及到一定的作物组合,并包括规划区和非规划区未来的生产力。因此,这一标准和用于评价它们作用的测度作比较是有价值的。 我们分三个方案和二项测度模拟可供选择的政策。三个方案包括:1.沿用1982年的水土保持措施;2.超过T值,即水保专家沿用的土壤流失允许值的种植行间作物的土地,予以退耕;3.由于土壤侵蚀,生产力的降低超过规定T限度的种植行间作物的土地,予以退耕。二项测度是:1.栽种玉米和大豆的面积;2.这种种植模式对土地生产力的百年影响。
Research Methods Soil and water conservation planning can be formulated using a variety of criteria. Each of these standards involves a combination of crops and includes the future productivity of planned and unplanned areas. Therefore, it is worth comparing this measure with the measure used to evaluate their effect. We model alternative policies in three scenarios and two measures. The three options include: (1) Following the 1982 measures for soil and water conservation; (2) Land growing interplanting crops that exceed the allowable value of T for soil conservation experts along with soil conservation experts; (3) Due to soil erosion, productivity Reduce the land for planting intercropping crops that exceed the prescribed T limit and turn them back into cultivation. The two measures are: 1. The area where corn and soybeans are planted; 2. The century-long impact of this planting pattern on land productivity.