运用GIS-IDRISI软件,在其空间分析模块支持下,结合植被、土壤和DEM数据建立了一个土壤侵蚀功能模型,并在3种不同植被状况下(1.现有植被;2.植被遭受严重破坏;3.植被得以良好保护和恢复),利用此模型对梅里雪山国家公园的土壤侵蚀状况进行情景分析.结果表明:在梅里雪山国家公园内,土壤侵蚀极敏感和高度敏感区,主要分布于高海拔的高山区域和低海拔的澜沧江河谷区,而中度敏感、轻度敏感和不敏感区主要分布于中间海拔区域.研究区现有植被得到了当地藏族居民的较好保护,但如果该区域的植被受到严重破坏,如情景2所示,那么土壤侵蚀极敏感、高度敏感和中度敏感区面积将大量增加,相反,轻度敏感和不敏感区的面积将大量减少,尤其是不敏感区将几乎全部消失.所以梅里雪山国家公园当前的首要任务为保护好当地的植被和各生态系统.%More and more researchers focus on the ecological services of vegetation.One of the most important ecological services of vegetation is soil and water conservation.In this study, a GIS - based soil erosion model was built by integrating vegetation map, soil map, and DEM data.This model was used to predict the soil erosion with three different vegetation scenarios.In scenario 1, the vegetation data is the current vegetation map.In scenario 2,we assume that the current vegetation was greatly degraded.Especially, all of the forest vegetation was deforested.In scenario 3, we assume that the current vegetation was protected very well, and no disturbance.Some degraded types restore into forest.The results show that the higher soil erosion areas occur on alpine areas and the lower areas along Lancang River.Much less soil erosion occurs on the middle range of altitude (from 2 500 m to 3 900 m)because most of the forest can be found in this area.The prediction result of scenario 3 is quite similar to the scenario 1.The reason is that the current vegetation is protected very well by local Tibetan people.However, the result of scenario 2 shows that if the degradation of vegetation increased the soil erosion would increase dramatically.Almost the whole area is in high hazard of soil erosion.Therefore, the most important objective of the Meili Snow Mountain National Park is to protect the vegetation and ecosystems.
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