【摘要】 以榆林市的遥感影像资料为依据,运用地学信息图谱的理论和方法,在RS和GIS的支持下,生成了榆林市1985—2000年的土地利用及生态价值变化图谱;在此基础上,对该区土地利用及生态价值的时空变化特征进行了分析,并作了土地生态风险动态评估。研究表明,研究期内,榆林市未利用地及水域面积减少,耕地、林地、草地及建设用地面积增加,其中草地增加最多;未利用地向草地流转及草地与耕地的相互转化占了全区土地利用类型总变动量的79.59%,其中,北6县以未利用地向草地及草地向耕地流转为主,南6县以草地向林地及耕地向草地转变为主;土地利用变化使该区生态价值总量增加了3.11%,其中,北6县占总增量的86.74%;榆林市土地生态风险降低,与土地生态价值的变化情况能够相互印证。更多还原

【Abstract】 Based on the remote sensing data and supported by RS and GIS,the land use/cover change(LUCC) images and the ecosystem services value(ESV) change images of Yulin City during 1985—2000 were constructed by using the theory of geographic information images.According to the research on above change images,the characteristics of LUCC and its ecological effects in the study area were analyzed.Results showed that the areas of water and unused land were decreased,while the areas of farmland,forest land,rangeland,and construction land were increased in the research period.Rangeland was found to be increased fastest.The main land use change category was the transformations from unused land to rangeland,from farmland to rangeland,and from rangeland to farmland,whose areas were 79.59% of the total change.The change of land use made the ESV of the research area increase from 9.84×109 yuan in 1985 to 1.01×1010 yuan in 2000.There was 86.74% of the total increased ESV in the northern six counties where the ESV was increased by 2.66×108 yuan,but there was only 13.26% of the total increased ESV in the southern six counties where the ESV was raised by 4.06×107 yuan.During the research period,the similar changes in ecosystem service value and ecological risk index show that the eco-environmental effect of the land use changes in Yulin City is positive,but the effectiveness of ecological construction is obviously imparted by the great change from rangeland to farmland.更多还原