Since The Ming Sea Henan Department Of Water Environmental Changes Research

Based on data and findings got from historical literatures and maps, field investigation, toponymy and surface features studies, the author has restored, in its utmost particularity and elaboration, the evolution of the southern part of the Haihe River water system (hereafter referred as "the Sub-System") since the Ming dynasty; and, according to certain justified principles, the author has also achieved a most possibly accurate location of historical watercourses eroded during the migrations. These watercourses have been plotted on digital maps.Then, characteristics and regular patterns are found out after a detailed analysis for the evolution of the Hutuo River, the Zhanghe River, the DaLu Ze and the Ningjin Po lakes, with two of them being most significant. On the one hand, during the Ming and Qing dynasties, a general trend can be observed that the sub-system was structurally less stable, and it suffered shrinkage in water resources, multiplication in water problems, and degradation in water environment. Specifically, the Hutuo River and Zhanghe River migrated more frequently, and Dalu Ze lake split into two moors at late Ming dynasty or early Qing dynasty, which died out at late Qing dynasty. On the other hand, even though Hutuo River and Zhanghe River migrated very frequently, their inundated areas, major watercourses, and locations of bank breach respectively have their own features, out of which regular patterns can be concluded.Impacts of sandy rivers on water and edaphic environments vary significantly according to the surface features of the areas in question. Both Hutuo and Zhanghe are sandy, and their frequent migrations have caused changes in water environment of the affected areas. Their migrations cause changes in the structure of water system, which results in changes in the quality of water environment. A comprehensive analysis and evaluation reveals the internal relation between the water system structure and the water environment of the valley—taking into account of the then conditions, and under the premise that climate conditions are relatively constant in the time window, the former is the determining factor of the later.Centering on water system structure, this study explores and evaluates the causes of water environment changes happened to the sub-system. First of all, it sorts out all kinds of measures adopted to harness the water environment, and their results and sequences. This leads to the conclusion that these measures are characteristic of a Let-It-Be philosophy. Thus, it rules out that hydraulic engineering has significant impacts on the water system structure. Furthermore, it searches for the factors contributing to the...