国家蓄滞洪区土地利用变化及国内外典型案例分析

Land use variations of national flood storage and detention areas and typical case analysis in domestic and abroad

蓄滞洪区是我国防御流域性洪水的一项重要水利工程,目前,我国设立了98处总面积达34 261 km^2的国家级蓄滞洪区及若干地方蓄滞洪区。为了解国家蓄滞洪区近20年来的土地开发建设情况,利用2000年与2018年土地利用数据,分析国家蓄滞洪区近20年来的土地利用变化及建设用地增加情况,选择国内两个开发较为典型的蓄滞洪区进行土地利用变化及行蓄洪容量等的影响分析,同时以日本渡良濑滞洪区为国外典型案例分析研究其建设管理模式。研究结果表明,我国国家级蓄滞洪区近20年来土地利用具有明显的突出变化,其中耕地减少明显,减少约99 515 hm^2,建设用地增加突出,增加了约95 257 hm^2;从流域看,海河流域蓄滞洪区的建设用地增加最多,约为62 727 hm^2,其次是长江流域和黄河流域,分别约为18 355 hm^2和6 450 hm^2;在占蓄滞洪区面积的百分率上也是海河流域建设用地增加的百分比最多,为5.73%。两个典型蓄滞洪区的分析结果表明,蓄滞洪区建设用地增加,只要合理规划、开发,蓄滞洪区的蓄洪容量也是有潜力可挖的,但无序的开发建设,可能会增加蓄洪的洪灾损失,从而影响蓄滞洪区启用。从国外典型蓄滞洪区的分析研究也可发现,通过科学、合理、有序地规划建设,蓄滞洪区不仅能无争议地自然分蓄洪水,而且还能兼具排沥、净水、生态、景观、旅游、娱乐等多种功能的综合利用,而我国蓄滞洪区在这些方面总体上还有不足。研究成果可为加强我国蓄滞洪区的建设管理提供有益的参考和借鉴。

The construction of flood storage and detention areas is one of the important and fundamental hydraulic engineering for river basin floods prevention in China.At present,98 national flood storage and detention areas,with a total area of 34261 km2,have been established,as well as a number of local flood storage and detention ar⁃eas.In order to understand the conditions of land development and constructions of the national flood storage and detention areas in the past 20 years,the land use data collected both in 2000 and 2018 are employed to analyze the land use changes and construction land increases in the national flood storage and detention areas.In addition,two typical flood storage and detention areas are selected to analyze the impacts of the land use changes and the flood storage capacities.The Watarase flood detention area in Japan as a typical case abroad is chosen to analyze the elaborated construction and management mode.The results show that the national flood storage and detention areas have significant variations in land use during last 20 years with significantly reduced farmlands(about 99515 hm2)and increased construction lands(about 95257 hm2).The Haihe River Basin has the largest increase in construction land(about 62727 hm2),followed by the Yangtze River Basin(about 18355 hm2)and the Yellow River Basin(about 6450 hm2).The largest increase percentage of the construction land area is the Haihe River Basin(5.73%).The analysis results of the two typical flood storage and detention areas show that the flood storage capacity still has the potential to be exploited as long as the increased construction lands are well planned.Howev⁃er,the disordered development and construction may increase the flood loss caused by flood storage,which will af⁃fect the use of flood storage and detention areas.According to the analysis of the Watarase flood detention area in Japan,if the flood detention area is planned and constructed scientifically,reasonably and orderly,it can not only store floods naturally without dispute,but also have multiple functions such as drainage,water purification,ecolo⁃gy,landscape,tourism and entertainment.However,the flood storage and detention areas in China are still insuffi⁃cient in these aspects.The research results in this paper can provide a useful reference for strengthening the con⁃struction and management of flood storage and detention areas in China.