基于夜间灯光遥感数据的汶川地震重灾区恢复状态评估

Condition assessment of recovery status in Wenchuan Earthquake severely-stricken areas based on night light remote sensing data

汶川地震对灾区社会经济产生深远影响,我国采取前所未有的措施进行恢复重建。本文基于地震重灾区灯光指数对灾区恢复状态开展分析,评估Ⅶ度及以上烈度区内各市县的宏观恢复状况。运用幂数拟合技术对灯光指数数据DMSP-OLS与NPP-VIIRS进行数据整合,解决因卫星与传感器参数差异产生的数据匹配问题,将灯光指数时间可用性扩长为1992年至2019年。以城市规模指数与增长率为主要指标,评估汶川地震灾区恢复状态。研究结果表明,汶川地震重灾区外部援建快速发展历经3年,之后灾区内各市县进入3~6年自我调节适应期,平均恢复期为8年。15个重灾市县中,约80%震后十年灯光水平恢复到震前水平及以上;部分重灾县因灾区外部大力投入建设得益而快速发展,其灯光指数远超震前水平。然而,震后灾区恢复状况存在较大差异,从灯光指数和发展指标来看,少数市县恢复状况仍不乐观。

A series of unprecedented measures have been taken to restore and rebuild in China in respect of the far-reaching influence on society and economy by Wenchuan earthquake.In this paper,the recovery status of the earthquake-stricken areas was analyzed based on the corresponding light index.For cities and counties with intensity of seven degree or above,the macro recovery status was assessed.Light index data DMSP-OLS and NPP-VIIRS were integrated by fitting technology of powerful number,so as to solve the data matching problem caused by parameter difference between satellites and sensors.The validity of light index was extended,lasting from 1992 to2012.With city size index and growth rate as the main indicators,the recovery status in Wenchuan earthquake-stricken areas was assessed.The research results proved that these cities and counties went through a threeto six-year self-adjustment period after the three-year rapid development with external assistance.The recovery phase was around 8 years in average.Among 15 severely-afflicted cities and counties,nearly 80%of them recovered the light index to the status before the earthquake in a decade.Some of them developed rapidly owing to external investment in construction,so the light index was far beyond the one before the earthquake.However,there were huge differences in the post-earthquake recovery status.The recovery status for a few cities and counties was still not optimistic in terms of light index and development indicators.