基于夜间灯光数据的甘青宁城市扩展及其建成区植被变化特征

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 基于夜间灯光数据的甘青宁城市扩展及其建成区植被变化特征 DOI: 10.5846/stxb202005141227 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 甘肃农业大学大学生创新创业计划项目（202102045）；国家自然科学基金青年项目（41907406）；甘肃农业大学科技创新基金（GAU-KYQD-2018-23） Characteristics of urban expansion and vegetation change in built-up areas of Gan-Qing-Ning based on nighttime light data Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:开展针对黄河上游甘青宁地区城市建成区空间发展模式及其植被变化特征的研究，可为构建科学合理的城市发展体系、维护区域生态安全屏障提供重要的参考依据。以DMSP/OLS和统计数据为基础，运用统计数据比较法提取了甘青宁地区21座地级市（州）的城市建成区边界，并从城市空间扩展特征、扩展速度、动态度、紧凑度和重心迁移5个方面对城市扩展特征进行分析；在此基础上，引入SPOT/VEGETATION NDVI数据，以年均NDVI作为表征城市建成区植被状况的指标，从NDVI总和、均值、比值及其变化量、年际变化率及其变化百分率和稳定性5个方面对研究区2002-2013年城市建成区的植被变化进行研究。结果表明：1）采用统计数据比较法提取获得的研究区城市建成区精度较高，误差率在6.7%以内；2）城市用地围绕河西走廊及黄河上游地区形成不连续的"几"字型空间形态，并具有点状、线状和面状3种不同的分布模式；3）城市扩展年均速及动态度大体呈上升趋势，且2010-2013年的城市扩展速度（4.53 km2/a）是2006-2010年的2倍；4）除酒泉、海西、白银、天水、石嘴山和兰州外，其他城市建成区紧凑度指数均较高；5）城市重心在第一（2002-2006）和第二阶段（2006-2010）均向北发生迁移，在第三阶段（2010-2013）则向南发生迁移；6）城市建成区NDVI总和随建成区面积的增加呈上升趋势；7）城市建成区植被整体呈向好趋势，从NDVI均值看，2002-2006年植被状况变差，而2006-2013年又有所改善，且NDVI均值分布具有明显的空间差异，中西部地区普遍小于东部；从NDVI年际变化率和变化百分率来看，各城市建成区均大于外围背景区；8）城市建成区植被状况普遍较背景区差，且2002-2013年近4/7的城市建成区NDVI比值及其变化量均呈下降趋势；9）城市建成区植被稳定性普遍较差，半数以上城市的变异系数在12年间均有不同程度的增加。 Abstract:Carrying out research on the spatial development pattern and vegetation change characteristics of urban built-up areas in the Gan-Qing-Ning region on the upper reaches of the Yellow River can provide an important reference for building a scientific and reasonable urban development system and maintaining regional ecological security barriers. Based on DMSP/OLS and statistical data, this paper extracted the urban built-up area boundaries of 21 prefecture-level cities (prefectures) in Gan-Qing-Ning region by using statistical data comparison method, and analyzed the urban expansion characteristics from five aspects:urban spatial expansion characteristics, expansion speed, dynamic degree, compactness and center of gravity transfer. On this basis, the SPOT/VEGETATION NDVI (Normalized Difference Vegetation Index) data was introduced, and the annual average NDVI was used as an indicator to represent the vegetation status in urban built-up areas. The vegetation change of urban built-up areas in the study area from 2002 to 2013 was studied from five aspects:sum, mean, ratio and its change amount, interannual change rate, percentage and stability of NDVI. The results showed that:1) As one of the effective methods to extract urban built-up area, the statistical data comparison method had high accuracy in our study area, and the error rate was within 6.7%. 2) The urban land formed a discontinuous spatial pattern of "几" around the Hexi Corridor and the upper reaches of the Yellow River, and had three different distribution patterns:point, line and plane. 3) The annual average rate and dynamic degree of urban expansion showed an upward trend, and the rate of urban expansion during 2010-2013 (4.53 km2/a) was twice as high as that during 2006-2010. 4) Except for Jiuquan, Haixi, Baiyin, Tianshui, Shizuishan and Lanzhou, the compactness index of other urban build-up areas was relatively high. 5) In the first stage (2002-2006) and the second stage (2006-2010), the center of gravity shifted northward, and in the third stage (2010-2013), the center of gravity shifted southward. 6) The total NDVI of urban built-up area increased with the increase of built-up area. 7) The vegetation in urban built-up areas showed a positive trend on the whole. From the perspective of the mean NDVI, the vegetation condition got worse from 2002 to 2006, and improved from 2006 to 2013. Moreover, the mean NDVI distribution showed obvious spatial differences, and the central and western regions were generally smaller than the eastern ones. From the perspective of the interannual variation rate and percentage of NDVI, the built-up area of each city was larger than the peripheral background area. 8) The vegetation status in urban built-up areas was generally worse than that in background areas, and the NDVI ratio and its variation in nearly 4/7 urban built-up areas showed a downward trend from 2002 to 2013. 9) Vegetation stability in urban built-up areas was poor, and the variation coefficients of more than half of the cities increased to varying degrees in the past 12 years. 参考文献 相似文献 引证文献