基于遥感和GIS的新疆绿洲城市扩展时空动态变化分析

以新疆16座城市为研究对象, 运用多时相卫星遥感资料, 利用遥感和GIS技术提取城市的空间特征信息, 并通过城市扩展强度、扩展速率以及城市空间形态紧凑度和分形维数等指标定量分析了1990-2010年以来新疆城市扩展时空动态变化的过程和特征. 结果表明: 新疆城市的空间分布由其独特的自然环境和绿洲经济所决定, 许多城市的发展依托于绿洲, 城镇的形成具有"亲水性"的特点, 由于新疆地域辽阔, 交通干线附近往往形成城镇相对集中的城市带或城市群. 南北疆城市之间在扩展速度及强度上存在较明显的差异, 位于北疆天山北坡经济带上的城市大多属于扩展速度相对较快、扩展强度相对较大的扩张类型, 而南疆城市的扩展速度则相对较慢、扩展强度也相对较小.通过对城市紧凑度和分维数变化的分析发现, 新疆城市平均紧凑度呈下降趋势, 而分形维数呈增长的趋势, 说明整体上新疆城市空间结构有趋于松散化的趋势, 城市的空间结构不够合理, 有待改善.

Analysis of the Spatial-Temporal Dynamic Changes of Urban Expansion in Oasis of Xinjiang Based on RS and GIS

Using multi-temporal satellite remote sensing data and GIS technology, urban spatial information was extracted. Using of urban expansion intensity, urban growth rate and compactness and fractal dimension index of the urban spatial form, the processes and features of Xinjiang urban spatial-temporal dynamic changes during 1990-2010 was analyzed. The following main conclusions can be drawn: 1) The cities of Xinjiang have the dependence on unique natural environment and oasis economy, which decide the spatial distribution of cities. Development of many cities depends on oasis, characterized by a hydrophilic. Due to vast territory, urban zones or urban agglomerations are relatively concentrated near the traffic trunk. 2) There are obvious differences in the propagation speed and strength between South and North Xinjiang. In North Xinjiang, the cities in the economic zone on the northern slopes of the Tianshan Mountains have more fast expansion speed and more high expansion intensity, while in South Xinjiang the cities have slower expansion speed and low expansion intensity. 3) Analysis of the changes in compactness and fractal dimension of Xinjiang cities finds that average compactness is decreasing, while the fractal dimension is increasing, which indicate that the spatial structure of cities is loosing and the urban spatial structure is unreasonable. It is necessary to be improved.