基于水资源分区的黄河流域土地利用变化对人类活动的响应

Response of land use change to human activities in the Yellow River Basin based on water resources division

在分析黄河流域1980-2015年土地利用面积变化的基础上,基于水资源二级分区,采用土地利用变化重要性指数(Ci)、土地利用变化面积比例(D)、林草植被变化指数(R)三个指标分析8个子区域土地利用变化的方向和程度;然后针对1980-1990年、1990-2000年、2000-2010年、2010-2015年四个时期,采用单一土地利用动态度、综合土地利用动态度及土地利用程度研究各分区的土地利用变化速度与程度。结果表明:与1980年相比,城乡工矿居民用地与水域面积变化最为显著。8个分区的土地利用变化面积比例均在20%左右,相互之间差异不大。在单一土地利用类型变化方面,沙漠及未利用地、水域和城市及工矿用地变化速度明显,其余三种土地利用类型由于面积基数较大,变化速度相对较小,但是变化面积很大。从各时期看,2010-2015年变化速度最大,并且大致呈现随时间推移变化速度逐渐增大的特征。在综合土地利用变化的速度方面,8个分区基本呈现出逐渐增大的趋势,上游龙羊峡以上增加最为明显。

Land use change analysis at different periods has been very helpful for resource management and essential trends detection through time. In order to understand the changes of land use, we examine the level of land use and the strength of human activities on land use in the Yellow River Basin in recent years. Based on the analysis of the change of land use area in the study area, according to secondary divisions of water resources, importance index of land use change(Ci), proportion of land use change area(D) and vegetation index of forest and grassland(R) were used to analyze the direction and degree of land use change in eight regions of Yellow River Basin during 1980-2015. It is found that land use in this basin underwent significant changes in the 35 years. The intensity of land changes in the Hekouzhen-Longmen section of the Yellow River Basin was the most intense. Although the degree of change in the eight sub-regions was relatively small, the absolute change area was large. The speed and degree of land use change were studied in four periods of 1980-1990, 1990-2000, 2000-2010 and 2010-2015 by using single land use dynamic degree, comprehensive land use dynamic degree and land use degree. The results showed that compared with 1980, the area of built-up land and water changed significantly. By analyzing the rate of single land use change in different periods, the rate of desert and unused land, water and urban and rural industrial and residential land changed significantly. The other three types of land use were not noticeable because of larger base area. In terms of the study periods, the change rate during 2010-2015 was the highest, and presented an increasing trend over time. Through the analysis of land use change rate, there was an increasing trend in all the eight regions;however the increasing trend in Longyangxia region was the most obvious. Except Longyangxia and Huayuankou water resources divisions, the comprehensive index of land use degree in the entire Yellow River basin ranged from –2 to 2 from 1980 to 2015, indicating that the comprehensive level of land use in each division did not change much in this period. From this perspective, human activities have less impact on land use. The reason for this result is that the entire area of the Yellow River Basin is too large, and the areas with intense human activities are only distributed in densely populated towns and plains. In the 35-year period, human activities did not have a profound impact on forests, grasslands, and deserts.