【作者】 朱继鹏；

【导师】 高甲荣；

【作者基本信息】 北京林业大学 ， 水土保持与荒漠化防治， 2006， 硕士

【摘要】 本文通过对晋西黄土区的自然、社会经济及水源涵养状况进行调查分析的基础上,采用层次分析法和灰色关联法,通过对林冠层、枯落物层和林下土壤层的水文功能比较,对流域水源涵养林的植被配置进行分析,确定流域各植被类型的最优配置比例。与现有林分状况进行比较,提出林分改造建议。首先,对流域的水环境特征进行总结和分析。包括研究区降雨的年内分布规律,研究区降雨的年际分布规律和研究区暴雨特征分析。研究区属暖温带大陆气候,春季干旱多风,十年九春旱,夏季气温较高, 6、7、8三个月约占全年降水量的80.6%。年际降水量以平均21.9mm(10a)-1的速度连续性递减。降雨量为10～30mm的降雨是当地主要的降雨形式,这种降雨如果雨强达到一定程度,将是产生地表径流的主要降雨形式。其次,对不同森林植被的林冠层、枯落物层和林下土壤层的水文功能进行比较和评价。按林分的不同,分为针叶林、阔叶林、混交林、灌木林和经济林,利用标准径流小区的观测数据,对每一层次进行单独评价,并对林冠截留量做了预测模型。利用上述数据资料,对林分郁闭度、林冠持水量、枯落物厚度、枯落物最大持水力、土壤非毛管孔隙度、土壤最大拦蓄量与地表径流系数的灰色关联度进行灰色关联法分析。影响因子参数的灰色关联度大小依次为:土壤最大拦蓄量>林冠持水量>林分郁闭度>土壤非毛管孔隙度>枯落物厚度>枯落物最大持水力。最后,对水源涵养林植被空间结构进行配置。此处采用层次分析法。以获取最佳的水源涵养功能作为植被类型结构优化的最终目标,第一层。水源涵养优劣主要取决于林地枯落物的拦蓄降水、土壤的储水和林冠层截留降水三个方面,即第二层。合理的植被类型结构组成是实现总目标的措施层,即第三层。按照分析方法,构造判断矩阵,进行层次单排序和层次总排序,得出流域最优的各植被类型配置比例。即针叶林面积比例为值为0.164;阔叶林面积比例为0.159;混交林面积比例为0.336;灌木林面积比例为0.275;经济林面积比例为0.066。更多还原

【Abstract】 The social ,natural and economical conditions of loess plateau in western Shanxi province are investigated.The analytic hierarchy process and grey system theory have been applied to the analysis of the hydrologic functions of forest canopy, litter and soil layers.Based on the study of vegetation disposition of water and soil conservation forests, the optimum structure of forest type in this catchment is established.Compared to the current forests condition, the rational suggestions for forest stand are discussed.Firstly, the water environment character of the watershed is summarized and analysed.It includes the distribution trend of monthly precipitation in a year and annual amount of precipitation and the storm character analysis in the area. The area belongs to warm temperate zone continental climate , the arid and windy climate in spring and the high tempetature in summer. Rainfall occurring in June, July and August accounts for 80.6% of the total in a year.A continuous decreasing tendency ,with a linear-change-rate-21.9mm(10a)-1 ,during 1950s-1990s could be detected . The amount of precipitation between 10mm to 30mm is the principal rainfall type in the area, and surface runoff is produced under the condition of precipitation more than 30mm.Secondly, the hydrologiacal functions of forest canopy, litter and soil layers for different forest vegetations are compared and assessed. Based on the observation data through runoff plots, function of conservation water of different forsets stands, including conifer,hard wood, mixed forest, shrub, economical forest are evaluated. On the basis of the grey related result, six factors including forest canopy density, canopy water-holding ability, litter height, litter water-holding ability, soil non-capillary porosity, soil water-holding ability have been selected as the indexes to assess the water conservation function. The relation according to the grey correlative degree : soil water-holding ability > canopy water-holding ability >forest canopy density> soil non-capillary porosity> litter height>litter water-holding ability.At last, using analytic hierarchy process, the spatial disposition of forest of water and soil conservation is established. Water conservation function is the final object, which is objective level; the hydrological functions of forest canopy, litter and soil layers determining function of conservation water is strategic level; rational vegetation structure更多还原