城市景观格局动态及空间自相关研究——以郑州白沙组团为例

Study on the Dynamic Characteristics and Spatial Autocorrelation of Landscape Pattern of Baisha District in Zhengzhou

新型城镇化背景下,大都市区的城市融合区域成为发展重点,其景观格局动态研究具有重要意义.基于遥感影像,应用景观指数、空间统计学、网格分析法等方法,分析了2007-2018年郑州白沙组团景观格局时空变化及空间自相关动态特征.研究表明:(1)整体景观破碎化加剧,多样性提升,连通性降低.斑块面积比中农用地虽然保持最大值,但减小幅度最大,建设用地增长较快,绿地和水体增幅不大;(2)总体上各指数的Global Moran’s I都大于0,景观多样性、景观破碎度及农用地、交通用地的空间正相关性随时间增强. 2018年1.5 km×1.5 km尺度上景观破碎化和多样性的空间正相关性较高,高值区聚集现象突出;0.5 km×0.5 km尺度上水体的空间正相关性最高,绿地的高值聚集区域较多;(3)聚集特征逐渐呈南北差异:南部建设用地的斑块面积比、交通用地的斑块面积比和绿地的斑块面积比(PLAND)、边缘密度(ED)、景观破碎度(SPLIT)和景观多样性(SHDI)指数高值区聚集,是景观整合与重构的主场地,北部逐渐成为农用地集约发展地,蔓延度(CONTAG)指数高值区聚集;(4)规划政策等人为因素驱动着景观格局的改变,研究区存在绿地、水体发展滞后、景观破碎化区域广等问题,建议南部要加强绿色网络体系的发展,北部要提高农用地保护水平,禁止建设用地无限制扩张.

Under the background of new urbanization, the metropolitan urban integration areas have become the key development areas. The study of the dynamic characteristics of landscape pattern in the urban integration area is of great significance. Based on remote sensing imageries, landscape indexes, spatial statistics, grid analysis and other methods were applied to explore the spatio-temporal evolution and spatial autocorrelation of the landscape pattern of Baisha District in Zhengzhou from 2007 to 2018. The results were as follows.(1) The overall landscape fragmentation was intensified, the landscape diversity was increased, and the landscape connectivity was decreased. The PLAND(Percentage of Landscape Types) of agricultural land maintained the maximum value, but its decrease was the largest. The PLAND of construction land grew rapidly, while the increases of green land and water body were small.(2) On the whole, the Global Moran’s I value of each landscape pattern index was greater than 0. The positive spatial correlations of SHDI(Shannon’s Diversity Index), SPLIT(Splitting Index) and the PLAND of agricultural land and traffic land were increased with time. In 2018, on the scale of 1.5 km×1.5 km, the positive spatial correlations of landscape fragmentation and diversity were relatively high, and their region aggregation phenomena of high-value were prominent, and on the scale of 0.5 km×0.5 km, the positive spatial correlation of the water body was the highest, and there were more high-value aggregation areas of green land.(3) The aggregation characteristics gradually showed a north-south difference: The high-value areas of SPLIT, SHDI and the PLAND of construction land and traffic land gathered in the south, which was the main site for landscape integration and reconstruction, while the north gradually became an intensive agricultural land development area, with high-value concentration areas of CONTAG(Contagion Index).(4) The change of landscape pattern was mainly driven by human factors such as planning policy. The study area had the problems of wide areas of landscape fragmentation and lagging development of green land and water body. It was suggested that the south should strengthen the development of the green network system, and the north should improve the protection level of agricultural land and prohibit the unlimited expansion of construction land.