湖南省水库洪水调蓄能力时空分异研究

Temporal and spatial differentiation of reservoirs and flood regulation abilities in Hunan Province

建立湖南省水库空间数据库,运用核函数密度估计法来分析湖南省水库工程的时空演化规律;选取防洪库容作为水库洪水调蓄能力评估指标,来研究湖南省水库洪水调蓄能力的时空分异特征。结果表明:①湖南省水库数量众多,总库容为514.12亿m^(3),其中小型水库数量占比高达97.0%,大部分建于20世纪50~70年代,21世纪以来则以大中型水库工程建设为主。②水库分布与地形地貌特征密切相关,主要分布于海拔50~1000 m之间的丘陵、岗地和山间盆地。③全省水库防洪库容106.00亿m^(3),洪水调蓄以大型水库为主,其防洪库容占比接近70.0%;从空间分布格局来看,沅江流域水库洪水调蓄能力最强,防洪库容占比接近40.0%,位于湘西北的怀化市、张家界市和常德市防洪库容占比超过50%。④不同时期的水库洪水调蓄能力各异,20世纪90年代和70年代是水库洪水调蓄能力提升最大的时期,期间防洪库容增加占比分别为28.1%和18.3%;20世纪80年代处于水库工程建设低潮期,防洪库容增加占比仅为3.4%。

A spatial database of reservoirs in Hunan Province is established,and the spatial-temporal evolution laws of reservoirs are analyzed by kernel density method.The flood control storage capacity is selected as an evaluation index of reservoir flood regulation and storage capacity to studying the spatial-temporal variation characteristics of reservoir flood regulation and storage capacities in Hunan Province.The results show that:①There are a large number of reservoirs in Hunan Province,with a total storage capacity of 51.412 billion m^(3),of which small reservoirs accounts for 97%.Most of them were built in the 1950s to 1970s,and since the 21st century,the constructions are mainly focused on large and medium-sized reservoir projects.②The distribution of the reservoirs is closely related to the topographic and landform features,mainly in hilly region,mound around the Dongting Lake and intermountain basins with the altitude of 50~1000 m.③The flood control storage capacity of all the reservoirs in Hunan Province is 10.6 billion m^(3),the flood regulation and storage is dominated by large reservoirs accounting for nearly 70%.From the perspective of spatial distribution pattern,the flood control capacity of reservoirs in Yuanjiang Basin is the strongest,accounting for nearly 40% of the total storage.The flood control capacity of reservoirs in Huaihua,Zhangjiajie and Changde City,located in the northwest of Hunan Province,accounts for more than 50% of the total storage.④The reservoir flood regulation and storage capacity was improved most significantly in the 1990s and 1970s,with an proportions of increment storage capacity of 28.1% and 18.3% respectively.In the low tide period of reservoir construction in 1980s,the proportions of increment storage capacity accounted for only 3.4%.