胡实　熊黑钢　朱忠鹏

摘要利用多期Landsat MSS/TM数据对1992～1999、1999～2007和2007～2011年3个时段的北京市9个有代表性区县的不透水面变化特征进行分析。结果表明：经过近20年的发展，北京市各区县因为各种历史原因和所处的位置不同，向不透水面转化的地类存在着区位差异和动态特征。就面积而言：新增不透水面主要集中在发展新区的昌平、通州和顺义，其在各时期新增不透水面总和及增长率均远远超过拓展区的海淀、朝阳、丰台和石景山。早期各区县不透水面增加面积和速度均比较小，中期则大大增加，后期增加速度都有所放缓。不透水面比例显示：拓展区各区县的不透水面占各地类的比例从一开始（1992年）与耕地、绿地不相上下到后来逐渐占优（2007年），再到全部超过50%（2011年），占绝对优势，表明其用地结构却发生了质的变化，农业功能已很小。新区各区县不透水面比例虽然各时期均不断上升，但始终以耕地和绿地为主要用地类型。从不透水面来源看：1992～1999年，发展新区各区县是以耕地为不透水面主要来源；拓展区各区县则是以绿地和耕地转化为主要方式。1999～2007年，各区县由耕地转化所占比例都有所上升。2007～2011年，只有新区的区县仍以耕地为不透水面增加的主要来源，耕地和绿地转化为不透水面的趋势有所控制，城市生态环境保护政策的效果初步显现。

关键词不透水面；转移矩阵；动态变化特征；北京各区县

中图分类号S271；P237；P951文献标识码

A文章编号0517-6611（2015）07-237-04

Dynamic Characteristics of the Impervious Surface Changing in Different Districts in Beijing

HU Shi1， XIONG Hei-gang1，2*， ZHU Zhong-peng1 （1. Key Laboratory of Oasis Ecology of Ministry of Education， College of Resource and Environment Sciences， Xinjiang University， Urumqi， Xinjiang 830046. 2. College of Applied Arts and Science of Beijing Union University， Beijing 100191）

Abstract By using different periods of Landsat MSS/TM imagery， an analysis has been done， which is about three times of impervious surfaces dynamic character in nine representative counties in Beijing. The result suggested that after the nearly 20 years of development， the classification transformed into the impervious surface has regional difference and dynamic characteristics because of various historical reasons and position. In terms of area， the newly increased impervious surface mainly concentrated in the developing new counties， including Changping， Tongzhou and Shunyi， their growth rate and the sum of the impervious surface was far beyond the expanding area like Haidian， Chaoyang， Fengtai and Shijingshan. Early in each district， the increasing area and the speed of impervious surface was relatively quite small， all of them became greatly accelerating In the middle and finally slowed down in the late. The impervious surface percentage in the classification showed that the proportion in the expanding area was roughly the same with the cultivated land and green space at the beginning（1992） and became dominant（2007）. Then it became overwhelming and exceed 50% in the whole area（2011）. This situation indicated that the land-use structure had changed in quality and the function of agriculture has shrunk a lot. Although the proportion of impervious surface in the new district were on the rise in each period， the farmland and green space were the majority in the land-use types. As to the source of the impervious surface， the new district depended on the cultivated land and the expanding area derived from the green space and the farmland from 1992 to 1999. In the stage from 1999 to 2007， the cultivated land conversion percentage has all risen in each county. When it comes to the last period， only the new district depended on the cultivated land as the source of the impervious surface. The trend that farmland and green area were transformed into the impervious surface has been controlled and the policy of ecological environment protection in city initially appeared.

Key words Impervious surface； Transition matrix； Dynamic characteristic； District of Beijing

近20年来，随着我国改革开放的深入和经济的大发展，城市化进程不断改变着地表下垫面的状态。……