黑河流域土地退化分类研究(英文)

Classification of Land Degradation in the Heihe River Basin, Northwestern China

黑河流域位于我国的西北内陆干旱区。人类不合理利用水资源造成的土地退化,已成为黑河流域一个非常严重的生态问题。土地荒漠化是该流域最典型和最严重的土地退化形式。对该流域土地退化的空间分布、特点、退化面积等方面还没有较为详细的研究,因此探讨这个问题就显得非常重要。文章通过最新的遥感影像资料(2000年),在分析已有的研究成果的基础上,结合野外调查,利用遥感和地理信息系统(GIS)技术,初步分析了黑河流域土地退化的情况。研究结果表明,黑河流域土地退化主要有5种类型,即:水土流失、干旱化、植被退化、盐渍化和沙漠化。土地退化面积达29971.91 km2 ,占整个流域面积的23.06%;其中,水土流失主要分布在祁连山的南部山区,面积为5747.68 km2,占整个流域土地退化面积的19.18%,主要是由于过度开垦和放牧造成的;由于人类活动的影响,造成水资源在时空上的重新分配而导致的干旱化土地主要分布在山前部分冲、洪积平原的河流沿岸附近,其面积为1369.96 km2, 占整个流域土地退化面积的4.57%;盐渍化土地是该流域土地退化的主要类型之一,面积为10591.82 km2, 占整个流域土地退化面积的35.34%,分布在流域的低地、冲积扇的边缘等位置,主要是由于干旱的气候条件造成的;沙化土地,包括流动沙丘(地)。

Land degradation in the Heihe river basin in arid inland of northwestern China, is a very serious ecological problem mainly owing to the misuse of water resources. The most typical and serious form of land degradation in the basin is desertification. However, in the region, the precise characteristics of land degradation, such as the distribution, degree, area, are unknown. So understanding the current status, classification and spatial distribution of land degradation in the Heihe river basin is very important. Based on the data obtained through field investigation and Landsat TM (Thematic Mapper) imagery of July 2000, this present study outlined, interpreted several types, the status and spatial distribution of land degradation in the Heihe river basin, that is, water erosion in the southern mountains, desertified sandy land near the oases, aridization in the low reaches, salinization at the bottomlands. The total area of land degradation in the study area is 29971.91 km2, making up 23.06% of the entire land in the Heihe river basin.