长江干流岸带区域的土地利用变化特征分析

Land use change features of riparian zone along the Yangtze River mainstream

岸带区域国土空间的合理开发与保护,对于推动长江绿色生态廊道建设、维护长江流域生态安全发挥着重要作用。本文以2000—2010年为时间尺度,分析长江干流岸带区域的土地利用结构特征及其时空变化,并对比分析岸带5 km和10 km范围内土地利用变化差异,探讨不同岸带宽度范围内的土地利用格局变化,以期为构建岸带区域生态安全格局提供决策参考。研究结果表明:(1)长江干流岸带区域的土地利用开发强度明显大于流域平均水平,且越靠近水域强度越大,岸带5 km和10 km范围内的建设用地所占面积比例分别是流域的2.65和2.27倍;(2)上游岸带区域土地利用类型以林草地为主,自然生态系统保持较好;中游岸带区域的土地利用类型以耕地为主,所占面积比例在50%以上;下游岸带区域主要以耕地和建设用地分布为主,两者合计所占面积比例超过70%;(3)长江干流岸带区域的土地利用类型变化主要表现为建设用地所占面积比例的增加以及耕地所占面积比例的减少,且变化幅度以下游最大。

Rational development and protection of land space in riparian zone plays an important role in promoting the construction of the Yangtze River green ecological corridor and maintaining the ecological security of the Yangtze River Basin.In this study,land use structure features,as well as their spatial and temporal changes,in the riparian zone along the Yangtze River mainstream were analyzed from the year of 2000 to 2010.The variation of land use structure in riparian zone within 5 km and 10 km was contrastively analyzed.Furthermore,the changes of land use structures and patterns on different geographical scale in Yangtze River mainstream zone were discussed,in order to provide decision-making reference for the construction of ecological security pattern in riparian zone.According to the results,the intensity of land use in riparian zone along the Yangtze River mainstream was significantly larger than average values for the whole basin,and the closer to the water area,the larger the exploitation intensity would be.The percentage of the artificial surface area within the 5 km and 10 km of the riparian zone along Yangtze River mainstream were 2.65 and 2.27 times the average values those for the whole basin,respectively.The type of land use within the upper reaches of the Yangtze River mainstream zone was dominated by forest and grassland,with natural ecosystem in good condition.The type of land use within the middle reaches was mainly cultivated land,and the area proportion was more than 50%.Meanwhile,the distribution area of cultivated land and artificial surface accounted for more than 70%of the total lower reach area.The change of land use types in the mainstream of Yangtze River mainly behaved in the increase of land occupied by the artificial surface and the decrease of land occupied by cultivated land,and the largest variation range occurred in the lower reach.