基于GIS的北京市城乡景观格局梯度时空变化研究

利用遥感和GIS的技术手段,对1990年和2000年北京市的土地利用数据进行了景观格局指数计算及景观梯度分析和时空变化分析,从而得出了北京市10年间城市化过程中土地利用景观结构变化特征和城乡景观的梯度变化的时空特点.结果表明,1990年和2000年北京市景观以林地和耕地为主,城镇用地总面积大量增加,2000年其总面积和农村居民点景观面积差别很小,北京的城市化水平已经达到较高程度.城镇用地景观沿样带分布呈典型的"凸"字形,城镇用地比例随距离市中心距离的增大而逐渐减小,城市化过程在10年间继续向郊区推进,向北扩张强度大于向南.城区范围不断扩大,中心城区聚集性大幅度增大,城乡交错带的景观斑块密度增大,景观破碎程度加剧,是景观格局变化最剧烈的区域.利用景观格局指数在样带上的梯度分布和其随时间的变化来分析城市发展特点、模式是一种研究城市化过程的重要手段.

A gradient analysis of spatiotemporal changes of urban landscape pattern in Beijing metropolitan region by GIS

From the gradient spatiotemporal landscape pattern analysis using the landscape metrics based on the 1990 and 2000 land use data of Beijing metropolitan region,we achieved the affirmative and informative conclusions on the characteristics of Beijing's landscape structure change pattern and the land use spatiotemporal change pattern in the ten years.Forest and cultivated land were the most two dominant landscape types,but the urban land expanded largely from 1990 to 2000 and the total area of urban land was almost the same as rural settlement which indicated that the urbanization level of Beijing had reached to a high level.The urban land proportion decreased as the distance from the city center increased and urban areas expanded to the suburban areas in the ten years.The urbanization degree was higher to the north direction than to the south.The cultivated land area decreased in all blocks in the transects and the edge areas of the city were the most dynamic area and they were more separated and fragmented.Combining landscape metrics with gradient analysis from a temporal angle is a robust and efficient method to study the landscape pattern change in the process of urbanization.