宁夏黄河流域土地利用时空变化特征分析

Spatio-Temporal Dynamic Changes of Land Use in Ningxia Yellow River Valley

在RS和GIS技术的支持下,基于多期Landsat-TM卫星遥感影像,对宁夏黄河流域1985-2010年间的土地利用时空变化特征进行分析.结果表明:1)在1985-2010年间流域主导土地利用类型是草地和耕地;面积呈增加变化的是林地、水域、建设用地和耕地,呈减少变化的是草地和未利用地,变化最剧烈的是建设用地.2)不同土地类型间的转移变化主要体现在草地向耕地、未利用地向草地和耕地以及耕地向建设用地和草地的转变.3)1985-2000年和2000-2010年两个时段综合土地利用动态度分别为0.26%和0.56%,空间分布差异明显,动态度较大的区域均分布在流域北部和中东部,后期强度和范围也均明显强于前期.4)流域土地利用变化的热点地区在1985-2000年有4个,2000-2010年增加到9个,主要是耕地和建设用地增加变化的热点,均分布于流域中部和北部.5)在流域土地利用变化中,自然因素制约着不同土地利用类型的分布和转变,而人为因素对其变化起到直接的推动作用,因此要充分考虑各种人为和自然因素,合理地对未来土地进行开发利用.

Land-use/land-cover changes （LUCC） are considered to be the major driving force for changes of the function and structure of the ecosystem. Based on remote sensing and Geographic Information System techniques, multi-temporal Landsat data were used to investigate LUCC in the Ningxia Yellow River Val- ley, which is a part of the Yellow River Basin and accounts for the most areas of Ningxia Hui Autonomous Region. The results obtained are as follows. 1） The dominant land use types were grassland and farmland during 1985--2010. The area of woodland, water, construction land, and farmland increased more or less, and the grassland and unused land decreased. 2） The significant shift changes from the transfer matrix were grassland to farmland, unused land to grassland and farmland, and farmland to construction land and grassland. 3） The integrated dynamic degree of the whole valley was 0.26% during 1985--2010 and 0.56% during 2000--2010. The spatial difference of integrated dynamic degree showed that the intensity of land use change was more obvious in the northern and central valley. And both the intensity and scope in change in the second period （2000--2010） increased compared with the first period （1985--2000）. 4） There were four hot spots of dynamic changes in land use from 1985 to 2000, and nine from 2000 to 2010, and all of them were distributed in the northern and central areas of the valley. 5） Natural factors are important to the distribution and changes of land use. However, human activities have the decisive impact on the tempo- ral and spatial change of land use in Ningxia Yellow River Valley.