清乾隆朝京南永定河湿地恢复

清代乾隆年间,在京南小平原永定河及淀泊治理中,一改康雍以来"束水攻沙"策略,采取人工引水出堤等调节径流的办法,修筑并不断改造与维护河湖湿地,使河水散漫流淌,将泥沙沉淀于河岸周围四野荒滩,以防御河水挟带泥沙淤塞河流尾闾淀泊及洪水期间危及居民田舍。这一策略效果较好。此间折射出日益尖锐的人水矛盾。人占水地,加大了永定河治理的成本与难度。

The Wetland Restoration of the Yongding River in the Jingnan Plain during the Qianlong Reign

The approach to managing the Yongding River and lakes in the Jingnan plain in Kangxi and Yongzheng periods stressed allowing the river to carry silt. However, during the Qianlong reign, the approach was changed to regulate the runoff, such as pumping water out of the river embankment by artificial measures, in order to maintain the river and lake wetlands. The methods applied in Qianlong reign made the river water fl ow freely, so that the silt carried by the river could deposit in the fl oodplain outside the embankments. These changes in river management obtained good results because it prevented the river-borne silt from blocking the lake in the river way and thereby prevented fl oods that could destroy the people’s villages. The change of the theory and practice of managing the Yongding River suggested an increasingly serious confl ict between humans and water resources. Over time human activity made the management of Yongding River more difficult.