【作者】 谢红霞；

【导师】 李锐；

【作者基本信息】 陕西师范大学 ， 地图学与地理信息系统， 2008， 博士

【摘要】 黄土高原作为中华民族的摇篮和华夏文明的发祥地，由于土地资源的不合理利用，使得水土流失、植被退化等生态问题突出，成为了我国乃至世界上水土流失最严重、环境最脆弱的地区之一。新中国成立后，国家对黄土高原地区投入了大量的人力、物力开展水土流失治理和相关的科学研究工作。经过多年治理，该地区水土流失和生态环境发生了极大的变化。如何基于土壤侵蚀研究成果并应用3S技术分析水土流失和环境变化的时空特征和差异，区分自然因子和人为因子对水土流失和生态环境的影响，成为决策者和科研工作者共同关注的问题。虽然目前泥沙、径流观测站能提供一些径流、泥沙数据，但这些数据反映的是观测站控制区域的整体状况，而且是气候和水土保持措施共同作用下的结果，既难以真正反映水土保持措施产生的效应，也难以从中了解控制区内水土流失的空间差异。基于此，本研究以国家973项目一中国主要水蚀区土壤侵蚀过程与调控研究(项目编号：2007CB407200)为依托，选择地处陕北黄土高原丘陵沟壑区中部，气候上跨温暖半湿润气候区和温和半湿润区，植被跨暖温性森林地带、暖温性森林草原地带和暖温性典型草原地带，地貌包含黄土梁峁状丘陵沟谷、河流阶地和黄土宽梁残塬沟谷，水土流失严重、治理时间长治理力度大，且有了一定研究基础的延河流域作为研究区，旨在探讨一种基于GIS与专业模型的区域水土保持环境效应评价方法，为大规模土保持和环境建设提供科学依据。本研究以水土保持学、土壤学，水文学，生态学，生态经济学等有关理论为基础，分析了影响土壤侵蚀的自然与人为因素的时空变化，计算了1986至2006年区域土壤侵蚀量和径流量，探讨了区域水土保持环境效应评价的方法，建立了区域水土保持环境效应评价模型，并利用该模型评价了延河流域1986年以来实施水土保持措施对环境的影响，取得了以下成果：(1)建立了延河流域水土保持时空数据场景库。以野外调查数据、遥感数据、管理部门及农户调查数据、已有地图数据、文字材料为数据源，通过数据融合，建立了包括区域降水、径流、植被、地形、土壤、水土保持措施等的水土保持时空场景数据库。(2)针对中国土壤侵蚀方程(CSLE)提出了基于GIS的区域水土保持工程措施因子的定量标识方法。在其他条件相同情况下区域有工程措施和无工程措施土壤侵蚀量的比值定义为区域水土保持工程措施因子。考虑到研究区面积大实地调查水土保持不可能，而TM影像上也无法获得措施数据，以乡镇为单位收集水土保持工程措施数据，但收集的数据缺乏其准确空间信息，拟将工程措施的减少侵蚀效果平摊到拥有空间信息的乡镇单元来计算水土保持工程措施因子，从而获得水土保持工程措施因子图，计算公式为：S=(1-S_t/×α)(1-S_d/s×β)(3)基于GIS计算了延河流域各土壤侵蚀的影响因子、径流量和侵蚀量。利用本研究提出的水土保持工程措施因子的计算方法和筛选出的适合本区的其他影响因子计算方法，分别计算了降雨侵蚀力、土壤可蚀性因子值、平均坡度坡长因子值、植被覆盖因子值、耕作措施因子值、工程措施因子值。应用中国土壤侵蚀方程(CSLE)和径流系数法计算了不同治理状态下土壤侵蚀量和径流量。并生成了各因子值、土壤侵蚀和径流的有关图件。各个图件的最终输出格式为栅格数据，栅格大小为25m，投影采用统一采用ALBERS等面积双标准纬线圆锥投影。(4)完成了对延河流域生态服务价值的测算。利用生态服务价值测算模型和延河流域气候、土壤、地形、土地利用等数据，基于GIS测算了延河流域不同治理状态下的生态服务价值，编制了延河流域生态服务价值图。(5)探讨了区域水土保持环境效应定量评价方法。考虑到水土保持措施的实施改变了流域下垫面状况，也改变了生态系统的结构和功能，本研究从水土保持措施实施对水圈、土圈、大气圈和生物圈的影响出发，选择了水土保持措施实施后水、土、有机物、碳氧变化来评价区域水土保持环境效应，由于水、土、有机物、碳氧不能直接相加，引入了生态服务价值概念，这样既能进行不同生态系统同一项生态系统服务功能的比较，也能将某一生态系统的各单项服务功能综合起来。基于生态服务价值提出了水土保持环境效应指数及其计算模型，并以1986年为治理初期，模拟了1997年和2006年在治理初期和末期条件下生态服务价值，1997年和2006年延河流域水土保持环境效应指数为106．55和110．24，表明水土保持实施后对环境的影响是积极的，改善了流域的环境。水土保持环境效应指数为治理初期状态下的生态服务价值和治理末期状态下生态服务价值的比值，治理初期状态下水土保持环境效应指数定义为100，计算模型为：本研究在以下两个方面有一定的创新：(1)提出了基于GIS的区域水土保持工程措施因子定量标识与计算方法：(2)探讨了区域水土保持环境效应定量评价方法。更多还原

【Abstract】 The Loess Plateau, located in the middle reaches of the Yellow River, is the cradle of Chinese civilization. It is well known in the world for its deep loess deposits and serious soil erosion. Due to the unreasonable land use, this region has become one of the places with fragile eco-system. People in this region have struggled long and hard against soil and water loss. The government has increasingly paid attention to the region, especially in the past 50 years. A lot of efforts have been used to prevent soil and water loss. As a result, the conditions of soil erosion and environment have changed greatly.The common issues that policy makers and scientific researchers concerned are how to analyze the spatio-temporal characters and difference of soil loss and how to distinguish the impacts on environment from natural effects and human being. Though hydrologic observation stations can supply some data of runoff and sediment at present, the data just can reflect the overall situation of area observed by station and the effects of climate and soil conservation together. It could not tell the impacts on environment from soil and water conservation. In this paper we choose Yanhe Basin as research area to develop a method for assessing impacts of soil and water conservation on environment using GIS technology and professional model in order to supply scientific base for massive work of soil and water conservation and environment construction. The research is supported by the Program 973. Yanhe Basin is very representative for its special situation, such as climate including two kinds of climate type, three types of geomorphology, serious soil erosion, long-term action to prevent soil erosion and some research achievements.Based on involved scientific theory of soil and water conservation, soil science, hydrology, ecology and ecological economics, this research analyzed spatio-temporal changes of natural and human activity factors that affected soil erosion, calculated soil loss and runoff of Yanhe Basin from 1986 to 2006, brought forward the model of assessing impacts of soil and water conservation on environment and used this model to assess the impacts of soil and water conservation on environment. The main results are as following.(1) To establish the spatio-temporal-scenic database of Yanhe Basin. The database mainly consists of precipitation, runoff, vegetation cover, land use, topography map, DEM, soil, thematic maps, remote sensing image, field landscape pictures, and investigated data of practices of soil and water conservation.(2) To develop a method to quantify regional engineering practice factor of soil and water conservation in order to use the Chinese Soil Loss Equation (CSLE). The regional engineering practice factor of soil and water conservation was defined as the ratio of soil loss with engineering practice to without engineering practice when other situation was the same. We collected engineering practice data with township as unit because it’s impossible to get engineering practice data by fieldwork for such a large area and we can’t get information of engineering practice by TM image. However the collected data of engineering practice had no spatial information and we planned to average the impacts of engineering practice to the whole collected unit with spatial information to get the map of regional engineering practice factor. The equation is as follows.(3) To calculate all factors of soil erosion and the loss of soil and runoff. The factors include rainfall erosivity, soil erodibility, slope length and slope steepness factors, biological measure factor, engineering measure factor and tillage measure factor. It also simulated to calculate runoff and soil loss in the beginning year of soil and water conservation. All the results had the corresponding maps with the same projection and the same grid size.(4) To calculate the ecological value of different years in different state of soil and water conservation based on GIS with the data of climate, soil, topography and land use and obtained all the map of Yanhe Basin.(5) To develop a method for quantitatively assessing the impacts of soil and water conservation on environment. Practices of soil and water conservation changed the situation of the earth surface of this basin and also changed the structure and function of eco-system. This research chose one kind of ecological service respectively from hydrosphere, soil sphere, biology sphere and atmosphere to assess impacts of soil and water conservation on environment according the progress of ecological service research. However the ecological service can’t be added together for different dimensions, it was necessary to use the concept of ecological service value to make them with the same dimension. Index of impacts on environment from soil and water, which was ratio of ecological service value of the end state to the beginning state of soil and water conservation, was put forward based on ecological service value. This index is 106.55 and 110.24 in 1997 and 2006 respectively and could reflect that soil and water conservation improved the quality of environment. The equation of calculating this index is as follows.Main new progresses: (1) To develop a method of assessing impacts of soil and water conservation on environment. (2) To develop a method to quantify the regional engineering practice factor of soil and water conservation.更多还原