关键词: 湖泊水位特征; 湖泊面积; 遥感影像; 水文学方法; 归一化差值法; 围湖垦殖; 枞阳闸; 菜子湖; 安徽省;

Abstract: The change of water level in the gate-controlled shallow lakes connecting with Yangtze River is of great significance to the steady transition of aquatic ecosystem.It is crucial to study the root cause of water level change by investigating the phenomenon and its response to factors such as lake inflowing runoff,sluice regulation,river-lake relation and human activities.Thus,the Caizi Lake,a typical gate-controlled shallow lake connecting with Yangtze River in the middle and lower reaches of the Yangtze River,was selected as the object of study.Based on the measured water level data from 2002 to 2016 of four stations named Chefuling Station,upper Zongyang Sluice Station,lower Zongyang Sluice Station and Anqing Station in Caizi Lake Area,combined with remote sensing images,lake area reclamation situation and river flow data,we analyzed the response relationship between the characteristics of Caizi Lake water level change and the reclamation,sluices scheduling and the Yangtze River water level fluctuation.The results showed that the annual average water level of Chefuling Station,which directly represents the water level characteristics of the lake area,was the highest and was increasing year by year.During a year,the water level fluctuation of Caizi Lake showed obvious characteristics of flood and dry water level variation in a unimodal shape.The runoff into the lake was a major controlling factor to the fluctuation process of the water level during the flood and dry seasons,but the water level fluctuation process obviously lagged behind the inflow process.The influence of Zongyang Sluice on the water level in the lake area was mainly reflected in maintaining the relatively stable change process of the water level in the lake area.Influenced by the regulation of the Zongyang Sluice and the fluctuation of the Yangtze River water level,the water level in the lake area was lower than that in the Yangtze River main stream in the flood season,while the water level in the dry season was relatively stable and higher than that in the Yangtze River main stream in dry season.Under the dual influence of natural sedimentation and reclamation,the sensitivity of the water area change to the water level change in the Caizi Lake showed significant differences during the flood seasons and dry seasons.

Key words: characteristics of water level change; lake area; remote sensing images; hydrological method; normalized difference method; lake reclamation; Zongyang Sluice; Caizi Lake; Anhui Province;