2022特枯年洞庭湖区洲滩面积变化特性分析  

Analysis on beach and flat area change characteristics in Dongting Lake area in 2022 extreme dry year

作　　者：郭小虎[1] 刘亚[1] 陈栋[1] GUO Xiaohu;LIU Ya;CHEN Dong(Key Laboratory of River and Lake Management and Flood Control in the Middle and Lower Reaches of the Yangtze River of MWR,Changjiang River Scientific Research Institute,Wuhan 430010,China)

机构地区：[1]长江科学院水利部长江中下游河湖治理与防洪重点实验室,湖北武汉430010

出　　处：《人民长江》2023年第2期43-48,共6页Yangtze River

基　　金：国家自然科学基金长江水科学研究联合基金项目(U2240206,U2240224);水沙科学与水灾害防治湖南省重点实验室开放基金(2021SS01)。

摘　　要：2022年洞庭湖出现了“汛期反枯”的罕见现象,湖区水文情势发生较大改变,直接导致汛期洞庭湖区洲滩大面积提前出露,从而对洲滩湿地环境产生不利的影响。基于此,根据最新实测资料研究了2022年湖区洲滩面积变化特征,初步分析了其变化对湿地环境的影响,并取得了以下主要认识:(1)2022年1~6月城陵矶站水位一般高于2003~2021年同期水位值,7月份开始城陵矶站水位持续走低,水位由7月初的30.40 m下降至9月30日的19.43 m;(2)除10月上旬城陵矶站水位抬高外,其他月份该站水位基本变化不大;(3)与2013~2021年相比,2022年7~11月份湖区洲滩面积分别增加了340,680,860,660 km^(2)及510 km^(2);(4)湖区洲滩面积不断增大引起苔草类和芦苇群落生物量不断向水深区域增加,导致沉水植被的生存空间急剧缩小,不利于耐旱能力较差的植物生长繁殖与以鱼类、沉水类植物为食的鸟类捕食,同时一旦来年汛期水量较大,将有可能导致东方田鼠暴发。In 2022,a rare phenomenon of‘drought in flood season’occurred in the Dongting Lake.The hydrological situation in the lake area changed greatly,which advanced the exposure of large beaches and flats in Dongting Lake area,exerting a certain adverse impact on the beach wetland environment.Based on this,according to the latest measured data,the change characteristics of the beach area in the flood season of the lake area in 2022 were studied,and the impact of its changes on the wetland environment was analyzed.The following main understandings were obtained:The water level of Chenglingji Station from January to June 2022 was generally higher than that of the same period from 2003 to 2021.The water level of Chenglingji Station had continued to decline since July,and the water level had decreased from 30.4 m in early July to 19.43 m on September 30.In addition to the water level of Chenglingji Station in early October,the water level of the station had little change in other months.Compared with the same periods from 2013 to 2021,the beaches areas in the lake area increased by 340,680,860,660,510 km^(2)in each month from July to November 2022.The continuous increase of the beach area in the lake area had driven the Carex and Phragmites to the deep water area,resulting in a sharp decrease of the living space of submerged vegetation,which is not conducive to the growth and reproduction of plants with poor drought tolerance and the predation of birds feeding on fish and submerged plants.At the same time,once the water volume in the next flood season is large,it may lead to the outbreak of Microtus fortis.

关 键 词：洲滩面积 湿地环境 特枯年 汛期反枯 洞庭湖 

分 类 号：TV147[水利工程—水力学及河流动力学]