Change Of Lakes In Hangjiahu Region In Ming And Qing Dynasties

At present,there are 2693 lakes in China with the area greater than lkm2.Their total area is 81414.6km2.The water storage capacity of the freshwater lake is 22.49 billion cubic meters,accounting for only 8%of China's total land water resources,only 0.17%of the world's total freshwater lake resources.The total amount of lake resources showed a downward trend in recent decades.In history,China was a lakes rich country,and now is different.There were ten famous Great Lakes in history,Daye Lake,Dalu Lake,Yangyu Lake,Mengzhu Lake,Yunmeng Lake and so on.Now,in addition to Taihu Lake,other lakes are disappeared.Some of the areas that seem to be very dry today have had many lakes in history,such as Guanzhong Plain,Taiyuan Basin,Haihe River Plain,and the lower reaches of the Yellow River.The Hangjiahu Region is located in the northern part of Zhejiang Province,in the south of Taihu Lake,east of Tianmu Mountain.Here is the southern margin of Taihu Lake water network,including Hangzhou,Jiaxing,Huzhou three jurisdictions.At the southeast edge of the eastern plains of China,there are plenty of rivers and lakes in Hangjiahu Region,the water utilization here is very high.Hangjiahu area dominated by small lakes,most of the lake area is less than 2km2.Some large lakes have disappeared in history.This paper chooses Ming and Qing dynasties as the main research period,use local history information as research material.By comparing the results with the present situation,we can get the following conclusions:1)The number of large lakes has continued to decline since Ming and Qing dynasties,small lakes gradually become rivers.2)The number of lakes that disappeared in historical period was more than recorded.On the one hand most of the ports of Taihu Lake were silted up during Ming and Qing Dynasties,and the river network is seriously blocked too.On the other hand we can see this evolving trend elearly form the redueingand merging process of Hebosuo,anorganization for levying piseatorial taxes.3)Lake changes are affected by climate change,drought and flood disasters are also one of the influencing factors.These conditions have exacerbated the demise of the lake.4)Since the Ming and Qing dynasties to the early days of the founding,the lake in Hangjiahu area has been showing a trend of disappearance.With the continuous development of society in recent decades,the use of lakes is becoming more and more diverse,lake changes tend to be stable.