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用地理信息系统收集和补充各种物理参数,需要用11种资源管理系统对爱达荷的托木比尔小流域16个农场的片蚀、沟蚀及水质影响进行估算.为了减少小流域的总侵蚀量和非点源污染,应用线性规划模型来确定适宜的高效率经济系统.用农业非点源污染模型(AGNPS)评价各种适宜的资源管理系统的水质影响.无论是横坡耕作还是等高耕作,少耕法都是减少农地侵蚀速率最高效的经济系统.几乎这两类农场从常规到少耕,使小流域平均侵蚀率减少到了允许水平T[11.2t/(ha·年)].要使平均侵蚀减少到2T,需要对11个农场实行免耕措施,把上述两类农场改造为具有永久覆盖的农场.如果平均侵蚀减少到T,小流域农场总净效益可增加1.5.控制侵蚀可以大大减少总泥沙量、养分(N和P)和化学耗氧量(COD).选用2T的适宜资源管理系统,平均泥沙,养分和(COD)可分别减少45%,38%和24%.选用T的适宜系统可分别减少72%,64%和29%.
Using GIS to collect and supplement various physical parameters, 11 resource management systems are needed to estimate the eclipse, gully erosion and water quality impact of 16 farms in Torbobil Watershed, Idaho. In order to reduce the total Erosion quantity and non-point source pollution, the linear programming model should be used to determine suitable high-efficiency economic system.An agricultural non-point source pollution model (AGNPS) is used to evaluate the water quality impacts of various suitable resource management systems. Both high tillage and less tillage are the most efficient economic systems to reduce the rate of agricultural land erosion.Almost all of the two types of farms, from conventional to tillage, reduced the average erosion rate in small watersheds to permissible levels T [11.2 t / (ha · year) In order to reduce the average erosion to 2T, no-till measures need to be implemented on 11 farms to transform these two types of farms into permanently covered farms, and if the average erosion is reduced to T, the total net benefits of the farm in small watersheds may increase by 1.5. Controlled erosion can greatly reduce the total amount of sediment, nutrients (N and P) and chemical oxygen demand (COD) .Using suitable 2T resource management system, the average sediment, nutrients and (COD) can be reduced by 45%, 38% And 24%. The appropriate choice of T system can be Decreased by 72%, 64% and 29% respectively.