基于AHP-GIS的西北干旱区聚落选址适宜性评价研究以吐鲁番市为例

[目的]西北干旱区存在自然环境劣势,其聚落的分布直接影响着土地利用的集约程度,因此构建干旱区聚落选址适宜性评价体系具有重要的现实意义。[方法]文章采用层次分析法(AHP)确定各评价因子的权重,利用GIS技术及评价模型研究聚落选址适宜性分布,为其规划建设提供科学依据。[结果]裸地(61.46%)和草地(30.09%)是研究区主要景观。吐鲁番市聚落选址空间分为极适宜区、高适宜区、中适宜区、低适宜区和不适宜区5个类型,聚落中适宜区及以上所占比例仅为26.8%;极适宜区(4.09%)主要分布在吐鲁番盆地中部的博格达山南部地带;高适宜区(6.39%)分布在极适宜区周围的河谷边缘地带以及部分丘陵缓坡区;中适宜区(16.32%)分布在地形起伏较大区域,同时受盐碱地影响,植被覆盖度较低、生态系统结构较差;低适宜区(40.49%)分布在盐碱地以及山区裸岩,植被稀疏、生态环境差;不适宜区(32.71%)集中连片分布在盆地南北端,生态条件更恶劣。[结论]由于特殊的地质地貌条件的制约,吐鲁番市聚落选址空间适宜性较低,因此城市聚落选址建设中应充分结合当地土地利用现状和发展需求,科学布局,实现聚落选址适宜区土地的集约利用。

STUDY ON THE SUITABILITY EVALUATION OF SETTLEMENT LOCATION IN NORTHWEST ARID REGION BASED ON AHP-GISA CASE STUDY OF TURPAN CITY

Northwest arid area inevitably occur natural environment disadvantages. Consequently the distribution of settlements directly affects the intensity of land use. Therefore, it is of vital practical significance to construct an evaluation system for the suitability of settlement site selection in the arid area. Analytic Hierarchy Process (AHP) was applied to determine the weight of each evaluation factor, and GIS technology was combined with evaluation model to determine the distribution of suitability of settlement site choice, so as to provide scientific reference for its planning and construction. Bare land (61.46%) and grassland (30.09%) were the main landscapes background in the study area. The settlement site selection space in Turpan could be divided into five types: extremely suitable area, high suitable area, moderate suitable area, low suitable area and unsuitable area. The proportion of moderate suitable area or above was only 26.8%. The extremely suitable area (4.09%) was mainly distributed in the central part of Turpan Basin and the southern Bogda Mountains. The high suitable area (6.39%) was distributed in the valley edge and part of hilly gentle slope area around the extremely suitable area. The moderate suitable area (16.32%) was distributed in the region with large relief, and was affected by saline-alkali, low vegetation coverage and poor ecosystem structure. The low suitable area (40.49%) was distributed in saline-alkali and bare rock in mountainous area, with sparse vegetation and poor ecological environment. The unsuitable area (32.71%) was concentrated and contiguous in the northern and southern ends of the basin, and the ecologsical basis was worse. So, due to the restriction of unique geological and geomorphic conditions, the spatial suitability of settlement site selection in Turpan is low. Therefore, the construction of urban settlement site selection should be fully combined, the current situation and development needs of local land use. Scientifically layout should be made to realize the intensive use of suitable area of settlement site selection.