Flood Control In The Lower Reaches Of The Haihe River Since The Song Dynasty

In the historical period,the downstream area of the Haihe River basin in which Duliu is located was affected by natural and human activities,and the flood disaster occurred frequently.Before Song,the Duliu area was far from the administrative center,and the river was in a laissez-faire state.During the Northern Song Dynasty,the single stream,located on the border between Song and Liao began to attract the attention of the rulers,and built a Tangyu defense line from the east to the west of Duliu.The deep-seated consideration behind the three back-flow disputes surrounding the Yellow River diversion was that the Yellow River flew north would silt the hard-working Tangyu defense line,so that the defense of Northern Song Dynasty would be in danger when facing the Liao and Jin cavalry.Based on this,during the Northern Song Dynasty,the water conservancy construction in the single stream and surrounding areas served its overall military defense in the northern border.During the Jin and Yuan period,the Haihe River as a whole was included in the scope of rule,and the river and lake depressions in the single-stream area were to be undertaken by shipping functions,and its water conservancy construction and river dredging were for the service of transportation.From the Ming to the middle of Qing Dynasty,the population of the north proliferated rapidly and the pressure of transportation increased greatly,at the same time,the climate fluctuated,the flooding was more frequent in little ice age of the Ming and Qing Dynasties,the water transport of grain to the capital was not smooth in Jingzhao district and Zhili province,and the authorities paid attention to the Zhili province Tuntian.However,affected by natural conditions,drought and flooding were not frequent,and the cultivation of land and cultivation were totally dependent on water conservancy.Therefore,from the Ming to the middle of the Qing Dynasty,in addition to maintaining the smooth flow of transport,it is also necessary to ensure the irrigation of Tuntian through the construction of water conservancy projects and dredging of river ditches.In the middle and late of Qing Dynasty,with the collecting silver instead of tribute grain,the establishment of interregional trade system and the rise of maritime transportation,the function of canal transportation in the south area of Duliu gradually weakened.After the opening of the city,Tianjin became an important base for foreign powers to dump goods,plunder raw materials and export capital in China,and in a short period of several decades,it was transformed from a transit terminal into the largest trading port and financial center in northern China.But the current situation of frequent flooding in the lower reaches of the Haihe River basin centered on Tianjin hasnot been fundamentally improved,and the authority had been in the face of internal and external problems,leaving no time to take into account the water conservancy construction in the Tianjin and Jinghai area.Since the Republic of China,the economy and society had further developed compared with the late Qing Dynasty,but it also meant that the damage and losses caused by the flooding have intensified.In the face of frequent flooding,the authority began to start to deal with the construction of a number of water conservancy projects,to a certain extent to alleviate the threat of flooding in the Jinjing area under pressure from all sides.However,due to the current turmoil,lack of funds,failed to completely cure the Haihe river.After the founding of the People`s Republic of China,under the call of Chairman Mao,as the landmark project of the radical cure Haihe River,the construction of the Duliujian River began in1951,put hundreds of thousands of military and civilian,was officially completed in 1953,and after many expansions and reinforcements,the Haihe River was finally completely cured.