淮河流域沂蒙山区水土保持生态脆弱性的AHP分析

 采用层次分析法,通过选取定量表征淮河流域沂蒙山区不同土地利用类型生态特征的植被状况、地形地貌、地表性质、土壤状况等指标,对该区域内林地、耕地、草地和裸地4种土地利用类型的水土保持生态脆弱性进行定量评价,以制订该区域水土保持生态修复策略。结果表明:在选取的7个用于评价淮河流域沂蒙山区不同土地利用类型水土保持生态脆弱性的指标中,土壤侵蚀面积比例权重最大,为0.4412;其次为土层厚度,权重为0.225 2;再次为地表枯落物量,权重为0.1505,这3个指标是评价沂蒙山区不同土地利用类型生态脆弱性的重要指标。不同土地利用类型的生态脆弱性评价结果表明:经济林生态脆弱度为0.7295,属于中等脆弱类型,脆弱度等级为二级;耕地和疏幼林地脆弱度等级也较高,分别为0.565 8和0.5672,属于一般脆弱,脆弱等级为三级;草地生态脆弱度为0.415 4,具有潜在脆弱性;有林地脆弱度仅有0.1834,属于不脆弱等级。因此,沂蒙山区经济林的水土流失综合治理应引起高度重视。

AHP analysis of soil and water conservation ecological fragility assessment in Yimeng Mountain Area of Huaihe River Valley

Using analytic hierarchy process（AHP） method,the ecological fragility of different land-use types,such as forest land,farmland,grassland and bare land in Yimeng Mountain Area of Huaihe River Valley,was studied by selecting some indices that could represent quantatively the ecological characteristics of vegetation,landform and physiognomy,ground property and soil condition of each land-use type in Yimeng Mountain Area,to make the strategy of soil and water conservation for this area.Results show that the weight of soil erosion area ratio is the largest in all selected indices,which is 0.4412.The second is the thickness of humus layer,which is 0.2252.The third is litter thickness of ground surface,which is 0.1505.In all land-use types of Yimeng Mountain Area,the ecological fragility degree of economic forest land is largest（0.7295,located between 0.60-0.75）,belonging to middle fragility class.The fragility degree of farmland and thining-young forestland is larger,which is 0.5658 and 0.5672 respectively,located between 0.45-0.60,belonging to general fragility class.And the fragility degree of grassland is 0.4154（0.45）,belonging to potential fragility class.The fragility degree of ecological forest land is only 0.1834,belonging to non-fragility class.So,the soil loss control of economic forest should be paid more attention.