本研究以2004年上海市青浦区为研究范围,基于GIS技术构建格网体系,提取1918年和1978年2份军用地形图中的湖荡面积、河网密度、河流长度等指标,比对两者相关指数的分布状况和变化程度发现1918-1978年本区河网密化最主要的原因在于开挖新渠的同时大量保留地表原有水体。通过本个案研究总结出大河三角洲历史河网面貌的复原方法包括图形资料实测情况判断、实际分辨率分析、误差来源探讨、调校误差、格网体系构建等步骤。
This study set Qingpu,Shanghai as target,grid system was constructed based on GIS.Lakes and bogs area,drainage density,drainage length,etc be recorded in 1918 and 1978 military maps were extracted.The indexes show the main reason of this change is new channels construction while the old being maintained.Survey of the old atlas,scale studying,source of errors,adjustment and grid construction,etc are the measures of reconstructing big river delta drainage structure in history.