黄土丘陵沟壑区乡村聚落分布格局特征与类型

Distribution pattern characteristic and type classification of rural settlements in loess hilly-gully region

为了进一步深化乡村聚落微观研究,为新时期新农村建设提供基础支撑,该文利用延安市宝塔区2015年Google earth遥感影像,运用探索性空间数据分析模型与格网分析法,定量分析了延安市宝塔区乡村聚落的空间分异特征,并基于多维组合特征划分了乡村聚落类型。结果表明:1)乡村聚落空间整体上呈集聚分布模式,且分布密度北高南低,密度大于5个/km2的聚落斑块,主要在桥沟镇和川口乡以北;聚落规模存在高值集聚特征,空间分布呈"Y"型结构;乡村聚落分布随高程、坡度变化呈正态分布,且81.42%的乡村聚落斑块最临近道路距离小于500 m,59.7%的乡村聚落斑块耕作半径为700~800 m;聚落形状指数受不同等级道路影响较大,高值区主要沿国道和省道分布,低值区主要分布在三、四级油路和砂石路。2)蟠龙川样带内聚落格局特征受地形与耕地资源影响较大,210国道沿线聚落格局受经济发展水平影响较大。3)基于多维特征组合矩阵将乡村聚落布局划分为9类,小规模-劣势区-集中分布和小规模-劣势区-离散分布是主要问题区。乡村聚落优化应立足于不同类型、因地制宜、分区推进,主要问题区实施优先整治战略,保障生态安全。

Rural settlements constitute the spatial area of region＇s production, livelihood and ecology. Therefore, it is necessary to study rural settlements＇ spatial distribution pattern for optimizing the town-villages construction pattern. In this paper, we aimed to improve the microcosmic study of rural settlements and provided theoretical support for the construction of new harmonioussocial society in the countryside. Based on the Google earth satellite images of Baota District in Yanan city in 2015, we obtained the rural settlements feature, arable land feature, road feature, and the river feature after geometric correction, coordinate registration, visual interpretation and vectorization. Then we conducted a quantitative analysis of the rural settlements＇ spatial distribution differentiation in Baota District using exploratory spatial data analysis model and geography grids analysis method, and identified the regional types basing on multi-dimensional characteristics. The results showedthat, 1） in the spatial distribution aspect, rural settlements in Baota District were characterized by obvious cluster spatial distribution mode, which was shown in the variable density of rural settlements. The density of rural settlements in northern area was higher than that in southern area, and the density higher than five per square kilometers mainly distributed in the north area of Qiaogou town and Chuankou town. In the scale aspect, rural settlements in Baota District showed an obvious spatial cluster distribution mode, and were in a ＂Y＂ structure. In the location aspect, rural settlements presented a normal distribution pattern along with the variations of elevation and slope. In the shape aspect, rural settlements had a low complexity in shape and most were stripe type. The shape index was also infected by the road level. The high shape index value distributed along the national level road and provincial level road, the low shape index value distributed along the lower level road; 2） the location of rural settlements closely related to the transportation, 81.42% of the rural settlements were approaching the main road less than 500m. And the location of rural settlements was also affected by the arable land, 59.7% of the rural settlements＇ farming radius distributed between 700 and 800 meters; 3） the characteristics of the rural settlements distribution pattern in the typical ditch area were influenced by the topographic factors, and the variation of rural settlements scale showed a multi-center characteristic. The distribution pattern of the rural settlements along the National HighwayNo. 210 was greatly affected by economic factors; and 4） based on the multidimensional feature combination matrix, the rural settlements were divided into nine types. The small scale-disadvantage location-aggregation distribution and small scale-disadvantage location-discrete distribution were the main problem areas. The spatial optimization of town-village was a complex and systematic engineering, and it was the first step to analyze the spatial distribution pattern of different area for rural settlements remediation and town-village spatial structure optimization. These results showed that rural settlements optimization should be based on different types, according to local conditions, and the main problem area should be the priority; the multi-center and equidistant distribution characteristics of gully settlements could be used to guide the rural settlements optimization and protect the security of ecology.