以坦桑尼亚首位城市达累斯萨拉姆2002、2007和2012年土地利用分类数据为基础，结合实地调研，运用扇形分析和同心圆分析等方法，以及用地增长弹性系数、扩展强度指数、紧凑度、分形维数等指标，研究达累斯萨拉姆近年来城市蔓延的总体态势和空间格局特征。研究结果表明：1）2002—2012年间达累斯萨拉姆城市蔓延特征明显，蔓延程度较高，蔓延速度不断加快，主要表现为非正式聚落不断增长情况下的城乡混合发展，侵占的土地类型主要为裸地，其次为植被；2）2002—2007年城市建成区主要沿交通干道以及在市中心周边进行轴线式蔓延，2007—2012年主要在交通干道间及城市边缘地区进行填充式蔓延，城市空间形态由指状向团块状演变；3）城市蔓延方向性明显，向西北、西、西南和东南扩展较多，东南方向成为新的扩展热点，且表现出明显的距离衰减特征；4）城市蔓延主要受到人口与经济增长、交通条件改善、政策变化及土地制度缺陷等因素的影响，其中交通设施起到重要的空间引导作用。
Based on the land-use classification data (2002, 2007, and 2012) and field investigation, the pattern and influence factors of the urban sprawl of Dar es Salaam were studied. Sector analysis, concentric circle analysis, elasticity ratio of urban land growth, and expansion intensity index were employed in the analysis. The results are showed as follows. 1) The sprawl of Dar es Salaam was characterized by high expansion degrees and increasing expansion speeds from 2002 to 2012, which presented the rapid urban-rural mixed development accompanied by the continuous growing of informal settlements. The occupied lands during the expansion were mainly bare lands and vegetation. 2) The built-up areas mainly spread along the arterial roads and around the city center from 2002 to 2007, while the spread was characterized by filling the open areas between arterial roads or along the urban edges from 2007 to 2012. Therefore, the urban space-form evolved from finger-like to block-shaped. 3) The built-up areas spread mainly towards northwest, west, southwest, and southeast, and the southeast of the city became an important area of spreading. Furthermore, the urban sprawl showed a significant distance attenuation feature. 4) The urban sprawl of Dar es Salaam was mainly affected by the growth of the population and economy, the improvement of traffic conditions, the policy changes, and the land tenure system. Transportation facilities played an important role in guiding the spatial expansion pattern.
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