基于GIS和RS的德令哈市城市扩展研究

借助RS和GIS技术，对德令哈市1989年TM影像数据、1999年ETM影像数据和2009年土地利用现状图进行分析处理，采用人机交互目视解译法提取德令哈市建成区边界图，并将3个时期的建成区范围图叠加；然后从城市扩展强度、重心坐标转移、紧凑度指数、分形维数指数以及城市扩展弹性系数等角度对德令哈市建成区的空间扩展状况进行分析；结果显示:1989—1999年、1999—2009年这两个阶段，德令哈市建成区的面积都在增加，但是1999—2009年，建成区面积的扩展速度和强度都大于1989—1999年；建成区重心坐标第一阶段向西北方向偏移，第二阶段向南偏移，紧凑度指数偏小，并逐渐减小，分形维数指数比合理值1.12大很多，城市空间演变形态趋于复杂；城市扩展弹性系数偏大，并有上升趋势，城市人口增加与城区面积扩展不协调。德令哈市在未来的发展中，需要注重城市内部建设用地填充，合理控制外延扩展规模，尽力确保城市形态紧凑发展。

Study on Construction Land Extension of Delhi City Based on GIS and RS

With the help of RS and GIS, the remote sensing image of 1989 TM, 1999 ETM and the land-use pattern of 2009 in Delhi City were analyzed and treated, the information about scope of built-up of this city was extracted by the method of visual interpretation of human-computer interaction, and the maps of the built-up area of the three periods were overlaid. Then, the status of spatial expansion of built-up area in Delhi City was analyzed based on the intensity of urban expansion, transfer of the center of gravity, compact index, fractal dimension index and urban expansion coefficient of elasticity. The results showed that both the area of Delhi built-up area in the two stages were increasing, however, the rate and intensity of expansion of the built-up area was greater from 1999 to 2009 than that from 1989 to 1999. The center of gravity of the built-up area offset to the northwest, the compact index was too little, and gradually reduced, the fractal dimension index was much lager than the reasonable value of 1.12, the morphology of urban spatial evolution became more complex. The urban expansion coefficient of elasticity was too large, and there was an upward trend, the increase of urban population and the expansion of urban area were inconsistent. As for the development of Delhi City in the future, it will be needed to focus on internal urban construction land planning, the reasonable control of the extension and expansion of the scale, it will also be needed to ensure the compact development of the urban pattern.