Land Degradation Characteristics in Hebei-Inner Mongolia Contiguous Area in the Farming-pastoral Zone of China from 1990 to 2010
1990 年至2010 年农牧交错带冀蒙接壤区土地退化特点及影响因素分析

Contiguous area of Hebei-Inner Mongolia is located in the middle part of econtone between farming and animal husbandry of northern China. Based on Landsat-TM data, statistical data and field survey data, quantitative transition and spatial variation in the process of land use change from 1990-2010 in contiguous area of Hebei-Inner Mongolia were analyzed with the PCC method and land quality assessment in this paper. Although more concerns were given to the change characteristics of land with different quality grades before and after implementation of the policy of Conversion of Cropland to Forest and Grassland, the research also probed into the major driving forces of ecological deterioration. The results show that: 1) The year of 2000 is a major turning point of local ecological condition. The overall ecological environment deteriorated gradually before 2000, which is demonstrated by shrinkage of woodland, grassland and water area, while ecological restoration took place after 2000, which is supported by gradual improvement of woodland and grassland. However, in some parts of the study area, surfacewater keeps shrinking and the ecological environment deteriorates seriously; 2) Land deterioration is relatively concentrative: degraded lands are mainly distributed in some areas of Shangyi, Zhangbei, Taipusiqi from 1990 to 2000, while in some areas of Zhangbei, Shangyi and Zhenglanqi from 2000 to 2010; 3) Before 2000, land degradation mainly occurred in the high quality land, but after 2000, the rate of degradation increased rapidly in the land of medium quality; 4) Excessive human activities, such as water consumption of agriculture and industry, is the main reason for degradation of arable land and grassland and water exhaustion. Based on the above findings, the paper suggests that in order to reverse the trend of ecological degradation, the study area should carry out the policy of returning farmland to grassland or forest continuously, and implement reasonable and detailed water use plan to make reasonable arrangements for agricultural production activities.