基于空间核密度的新型城镇化实验区农村居民点变化研究——以天津市蓟州区为例

THE CHANGES IN RURAL SETTLEMENT OF A NEW-TYPE URBANIZATION EXPERIMENTAL AREA BASED ON SPATIAL KERNEL DENSITY ANALYSIS——A CASE STUDY OF JIZHOU DISTRICT IN TIANJIN MUNICIPALITY

[目的]天津市蓟州区于2016年被列为第一批国家新型城镇化综合试点地区,深入分析天津市蓟州区改革开放以来农村居民点的演变过程及其特征,能够为该地区新型城镇化政策的制定和实施提供参考。[方法]文章利用1980年、2000年和2015年3期蓟州区土地利用数据,通过计算土地利用转移矩阵,分析了蓟州区1980~2000年和2000~2015年两个时期土地利用变化情况;采用景观格局指数法,对蓟州区农村居民点斑块空间分布特征进行定量分析;采用空间核密度估计法对3个年份农村居民点进行密度计算,通过对比研究区各期核密度值变化,分析1980~2015年农村居民点的变化特征。[结果]1980~2000年蓟州区农村居民点规模整体变化较小,城乡、工矿、居民用地增加了3 140.2hm^2,其主要来源为耕地。农村居民点斑块数量有所减少,但农村居民点平均斑块面积有所增加,农村居民点变化主要集中在离城区较近的中部平原地区;2000~2015年蓟州区农村居民点整体上有较大发展,城乡、工矿、居民用地增加4 823.6hm2,其主要来源为耕地、林地和草地3种地类,农村居民点斑块数量和面积加权平均形状指数明显增大,聚集度降低,研究区内景观趋向破碎化,居民点分布更为分散。北方山区发展十分突出,受当地重点发展农村特色旅游政策的影响,北方山区农村居民点变化较大,居民点数量增加,规模扩张明显。[结论]在未来新型城镇化发展的过程中,官庄镇、下营镇等新形成的高核密度值全新居民点组团,可以优先考虑作为新型城镇化建设的重点区域。

Jizhou District of Tianjin municipality was selected as the comprehensive pilot area of national new-type urbanization in the first batch in 2016. To analyze the process and characteristics of rural settlement evolution in Jizhou since the launch of Reform and Opening-up Policy can provide references for the formulation and implementation of the new-type urbanization policy in the region. This paper calculated two land use transfer matrixes in Jizhou using the land use data in 1980,2000 and 2015. The landscape pattern index method was adopted to quantitatively analyze the spatial distribution characteristics of rural settlement patches. The kernel density estimation method was utilized to calculate the kernel density values of rural settlement in 1980,2000 and 2015. Then the change characteristics were analyzed. The results showed that the changes of rural settlement in Jizhou were small from 1980 to 2000. The construction land increased by 3 140. 2 hm^2,due to the conversion from cultivated land. The number of rural settlement patches decreased while the average patch size increased. The changed rural settlements were mainly distributed in middle plain which was close to urban areas. From 2000 to 2015,the rural settlements in Jizhou changed significantly. The construction land increased by 4 823. 6 hm^2,and sourced from cultivated land,woodland and grassland. The number of patch and the Area-Weighted Mean Shape Index of rural settlements increased significantly while the Aggregation Index decreased. The landscape was more fragmented compared to the previous period. In addition,the distribution of settlements became more dispersed. The expansion of rural settlements in the northern mountainous areas was prominent. Affected by the local policy of developing rural tourism,the rural settlements in the northern mountainous areas changed significantly featured with the expansion of numbers and scales. In the future when developing new-type urbanization,some new developed rural settlement groups with high kernel density values such as Guanzhuang town and Xiaying town,were suggested to be planned as the key areas for new-type urbanization.