基于长时间序列的洞庭湖面积变化与气候响应关系研究

Study on the response relationship between the area change and climate of Dongting lake based on a long time series

洞庭湖是长江中下游最大的调蓄湖泊,它的存在对调节湖区周边气候具有重要的作用,同时气候也会反作用于湖泊。为研究洞庭湖水体面积变化与气候变化之间的响应机制,利用1989—2018年洞庭湖水体面积长序列数据分析其时空演变特征,并研究水体面积变化与气候要素的响应关系。结果表明,洞庭湖水体面积月际波动明显,月平均面积7月最大,1月最小。30年间洞庭湖水体面积总体处于缩减趋势,水体年最大面积和年内面积变化有减小趋势。对30年间洞庭湖水体面积与气温、降水量的分析可知,洞庭湖水体面积的变化与周边气候条件在长期演变过程中存在显著相关性,但短期内的相关性不显著;湖泊水体面积的变化导致湖区周边温度上升速率高于湖南省乃至全国的平均上升速率。

Dongting lake is the largest reserve lake in the middle and lower reaches of the Yangtze river.It plays an important role in regulating the surrounding climate of the lake,and the climate also reacts on the lake.In order to study the response mechanism be⁃tween the area change of Dongting lake and climate change,the long sequence data of water area of Dongting lake from 1989 to 2018 was used to analyze the spatio-temporal evolution characteristics of water area of Dongting lake,and the relationship between the change of water area and climate factors was studied.The results showed that the area of Dongting lake fluctuated significantly,with the largest monthly average area in July and the smallest in January.In recent 30 years,the water area of Dongting lake was in a gener⁃al shrinking trend,and the annual maximum lake area and area change had a decreasing trend.According to the analysis of the lake area of nearly 30a with temperature and precipitation,the change of the water area of Dongting lake had a significant correlation with the surrounding climate conditions in the long-term evolution process,but the correlation was not significant in the short term.The change of lake area caused the temperature around the lake area to rise faster than the average rise rate of Hunan province and even the whole country.