Weihe River Water Environment Trends And The Poor Degree Of Hydration,

Water resources is the foundational natural resource and the strategic economical resources. Meanwhile it is the main restriction factor of economical development and ecology construction for the west of China. Guang zhong region in Weihe River basin with comparably developed economy science education and superiority location, is the key region in western development. But under the dual affection of climatic change and human activity, in Weihe River there are some problems such as water resources' shortage water pollution silt siltation and so on, which becomes one of the most difficult rivers to deal with. In order to rebuild eco-Weihe River ensure water resources to use sustainably, restore Weihe River healthy, promotes region economy and society to develop well and fast, it is necessary to research some water environment problems about Weihe River.Based on runoff and sediment dates of Huaxian hydrologic station from 1935 to 2006, and also water quality dates of thirteen important sections along the Weihe River in Shaanxi Province, this article first comprehensively analyses change rules of water environment of Weihe River through trend analysis and wavelet analysis, and second has an evaluation for runoff sediment and water quality of Weihe River, and designs a model of judging the degree of water poverty, then apply this model into Weihe River, finally suggests rebuilding eco-Weihe River. The main conclusions are as follows:(1)in all runoff and sediment of Weihe River decrease obviously by trend and Hurst index analysis, and the former decrease faster than the latter, which is bad for water utilize, but in the later some years runoff maybe increase, meanwhile the abruptly change year is 1985 for runoff and 1997 for sediment by M-K monitor. Runoff changes bigger than sediment every year, runoff concentrates on July～October and sediment also concentrates on July～September for the distribution in a year. Runoff and sediment can be obviously divided into two stages through anomaly change and wavelet analysis, the first stage is that runoff is abundant and sediment is more before 1970s, since 1970s both runoff and sediment have decreased, this is the second stage. The periodic of runoff is 24 years, and 23 years for sediment, meanwhile main periodic of sediment is two or three years.(2) From 1991 to 2006 most years runoff is little, and sediment is more in 1990s and decrease in recent years. Water quality is good in Lin jiacun and Chang Xingqiao section, other sections all belong to below the fifth class which is very bad. At the beginning of 1990s the degree of water pollution is relatively low, at the beginning of this century water pollution degree reaches the seriousness, for other time it is in serious condition. The evaluation result of water poverty is that it doesn't happen to water poverty in 2003, the degree of water poverty is weak in 1993 and 2005, in 2004 and 2006 the degree of water poverty is medium, and in the 1994 1996 1997 and 2002 four years the degree is extreme and other years are intensive. As a whole the degree of water poverty is serious from the middle of 1990s to the beginning of this century, the degree seems to decrease in recent years. Because runoff will decrease and water quality can't become good in short time, water poverty of Weihe River will still last even become worse.(3)According to the trend of runoff and sediment and the degree of water poverty for WeiheRiver this article gives an effective method——rebuild eco-Weihe River to improve waterenvironment and solve the water poverty problem: change the sense of govern river, make use of natural to restore Weihe River healthy; save water resource and build some transfer water project to ensure runoff doesn't flow; strengthen the peed of decrease pollution and improve water quality of Weihe River step by step; need other methods in management polity and so on.