基于GIS的陕北黄土高原土地生态系统水土保持价值评价

 【目的】土壤侵蚀是导致人类赖以生存且日趋紧缺的土地资源退化和损失的主要原因，这种损失正在全球悄然进行。定量计算区域土地生态系统水土保持的价值量，为区域土地的持续利用与生态环境和社会经济协调发展提供科学决策依据。【方法】本文根据陕北黄土高原的特点，采用无植被覆盖的潜在土壤侵蚀量来估算各生态系统土壤保持量，然后利用估算的土壤保持量，采用市场价值法、机会成本法和影子工程法从保护土壤肥力、减少表土损失和减轻泥沙淤积3个方面来评价水土保持的经济效益。【结果】而从整个时间段上来看，2000年比1978年的土壤保持量增长94.18%，接近一倍。1978～2000年期间陕北黄土高原水土保持价值是逐渐增加的，1978～1990年期间比1990～2000年期间增加的要快。1978年的陕北黄土高原的水土保持价值为18.503亿元；1990年比1978年陕北黄土高原水土保持价值增加了近8亿元；而2000年比1990年增加了2.414亿元。【结论】近20多年的时间里，1978～1990年时间段增长幅度比1990～2000年的增长幅度要大，这与植被覆盖度有着密切的关系。针对陕北黄土高原所进行的一系列水土保持治理工作，已经取得了巨大的成绩。从空间分布上来看，通过对研究区三类不同地貌类型区进行水土保持价值评价，其结果为，南部低山丘陵区＞北部风沙过渡区＞中部黄土丘陵区。

Research on the Value of Soil and Water Conservation in Loess Plateau in Northern Shaanxi Province

Objective] Soil erosion is caused by mankind's survival increasingly scarce land resources degradation. To quantitatively calculate the value of the Soil and Fertilization Conservation,the paper provide the scientific decision-making for the sustained use of land for regional socio-economic development and ecological environment. Method] Supported by “3S” technology , this paper brought for ththe landuse change in Loess Plateau in northern Shaanxi, from 1978 to 2000 , then studied the distribution rules of soil erosion under different landuse pattern quantificationally by Universal Soi Erosion Equation during that period, and emphasized the impact of changes of landuse patternon soil erosion. So, using market price, opportunity cost and alternative project, the value of vegetation’s soil conservation is calculated on its role in conserving soil fertility, reducing land abandon and reducing sediment accumulation.Results] From the entire time, maintain the soil for the growth of 94.18%, nearly doubled from 1978 to 2000. The value of Soil and Fertilization Conservation in the Loess Plateau in northern Shaanxi province is 18.503 billion in1978;the value in 1990 an increase of nearly 800 million yuan than in 1978;the valure in 1990 is an increase of 241.4 million yuan than that is in 2000. Conclusion] The value of the Soil and Fertilization Conservation in the loess plateau in northern shaanxi province trend from increasing to decreasing in 1978~2000 years, this feature is basically identical with the natural environment. If three different types of landscape areas, the results are : mountains in southern zone> sandstorm transitional zone in northern >Central loess hills area. But from 1978 to 2000 the average amount of soil map can see that The average amount significantly larger areas southward, it is mainly the weather conditions in recent years has had close relations.