成渝经济区近20年城市扩展研究——基于DMSP/OLS夜间灯光数据

Research on the Urban Expansion in Chengdu-Chongqing Economic Zone Based on DMSP/OLS Nighttime Light Data in Recent 20 years

【目的】研究成渝经济区城市扩展基本状况以及未来城市可能的发展方向。【方法】采用1992—2012年DMSP/OLS夜间灯光数据,运用"影像自校正方法"和"动态阈值法"对城市扩展数据进行提取,采用重心偏移相关指数、灯光指数和城市化相关指数以及指数聚类分析等方法对成渝经济区近20年来城市扩展情况进行分析。【结果】结果表明:1)灯光数据提取误差在4%以内;2)成渝经济区扩展区在1997—2007年的增加面积比例最小,同时期四川部分增加比例下滑,重庆部分持续上升;3)成渝经济区城市区重心在1992—2012年时期向东南方向波动变化,四川部分城市区/扩展区重心均先靠向成都市区然后向绵阳方向转移,重庆部分城市化区/扩展区重心位置沿东北方向较快移动;4)成渝经济区近20年来城市发展以第i类为主,四川部分城市化呈现出加速提升—持续加速—减速提升—加速提升的态势,重庆部分城市化呈现出加速提升—减速提升—加速提升—持续加速的态势。【结论】成渝经济区呈现以成都市和重庆市为两极向外不断扩展的趋势,是一种非良性发展,应注重多极化发展。采用DMSP/OLS夜间灯光数据对成渝经济区城市扩展进行分析结果较好,对充分了解区域内城市化区域发展类型有较好的参考价值。

[Purposes]It aims to analyze the urbanization process and understand the trends of urban development of ChengduChongqing economic zone.[Methods]DMSP/OLS nighttime light data from 1992 to 2012 and the Statistical Yearbook from 1992 to2012 are used in this study.The use of ＂First denoising and further divided＂ ideas to extract the optimal threshold lights data.In order to analysis and research urbanization expansion situation about Chengdu-Chongqing economic zone,and use urbanization change types,gravity shift index,night index,urbanization index and cluster analysis to resolve it.[Findings]Firstly,the extraction error was 0 to 0.04 with this method.Secondly,during the 1997 to 2007 period,the expansion area＇s increase speed was the least in the Sichuan and Chongqing region.Meanwhile,the increase speed was decreased in Sichuan section and increased in Chongqing section.Tertiary,during the 1992 to 2012 period,the gravity of whole urbanization area was fluctuation in the southeast.At the meantime,the gravity of urbanization area and expansion area in Sichuan section was move to Chengdu first and turn to Mianyang later,the gravity was fluctuation in the northeast and the move speed was faster.Fourth,in recent 20 years,the i type of urban development was main style in Sichuan and Chongqing region,Chongqing was belong to the ii type in 2002 and Sichuan was belong to the iii type in 2007.The increases rate of urbanization development was different in each region in each period.[Conclusions]The economic development too focused on urban area of Chongqing and Chengdu,and is a non-benign development model.It should focus on multipolar development and enhance the urbanization level of the underdeveloped regions such as Western Sichuan and Northeast Chongqing.This study results have good reference value for urbanization development research about intra-regional and interregional,and it have a good significance to urbanization development decisions.