Yinchuan Groundwater Quality Assessment And Nitrogen Pollution. Analysis

Evaluation of groundwater quality is very important in the protection of water resource. Once groundwater is polluted, it causes many hazards, among which, nitrogen pollution (mainly nitrate-N nitrite-N and ammonia-N which are called "3 nitrogen") can make the people who drink it be poisoned, have the Metamoraphic hemoglobin disease and even suffer from cancers and so on. In recent years, due to the rapid development of its industry and agriculture, groundwater of YinChuan city ,which includes YinChuan city itself ,HeLan and YongNing counties which are governed by YinChuan, is polluted in different degree, especially nitrogen pollution being the most serious. Because not only its groundwater is the unique source of water supply for industry and people's everyday life, but also at present no one studies nitrogen pollution specially, it is imperious that nitrogen pollution is analyzed and studied.In the article, beginning with physiognomy water , hydrogelogical condition, groundwater replenishment , runoff and discharge condition of the region of YinChuan,the author learns about the situation of groundwater hydrogeology, then the author evaluates the quality of groundwater by applying Fuzzy Integral Assessment Method. Due to accounting for the main factors that lead the environment quality of groundwater to decline and do harm to people, the author selects 9 evaluation factors such as sulphate, chloride and so on and 5-class evaluation standard according to the Quality Standard of Groundwater. The evaluation result that is calculated by programming shows that its quality of groundwater is very bad, more often than not, belonging to 4-class and 5-class water and nitrogen compounds such as ammonia, which mostly belongs to 5-class water, is one of the main contaminations. At last, on the basis of Fuzzy Integral Assessment, the author mainly analyze and study the current situation and cause of nitrogen pollution from the beginning of the forth chapter. According to the monitoring data of the quality of water from 1991 to 2000, the author analyze that its nitrogen pollution is caused by nitrogen compounds such as nitrite-N ,ammonia-N. What caused this phenomena? The author analyze and study it as the following aspects: the source of nitrogen contamination, the characters of nitrogen pollution and the types of its cause, affect of the factors of the environment hydrogeology, affect of the oxidation and reduction conditions on "3 nitrogen" transformation, affect of the content of iron and manganese on nitrogen pollution, affect of groundwater evaporation on the content of nitrogen and so on.