Nitrogen Contents And Variation Rules Of Shallow Groundwater In Chengdu Area

Groundwater is a very important resource. If the groundwater was polluted, it will renew hardly. Chengdu area is lies in the east of Chengdu plain. It has some characteristics, including three aspects following: shallow burial groundwater, close connection with surface water and easy polluted.Nitrogen pollution is a general pollution. It can case hard hazard to human health. Though the problem of nitrogen pollution was noticed, it is't do some special researchs in Chengdu area. So, it is important and necessary to do some research about shallow groundwater in this area.According to the reality conditions of nitrogen pollution, combining with the hydrogeologic condition, through the analysis of groundwater quality data about twenty years, research the transfer and transformation of nitrogen in Chengdu shallow groundwater and regress influencing factors. It can be find that the shallow groundwater pollutions of nitrogen in Chengdu area are mainly cased by point source. The pollutions by city sanitary waste and rubbish are lightened. The space distribution of nitrogen contents has the feature of non-uniform. The contents of nitrogen are reduced sharply. The modes of groundwater recharge, runoff, drainage, aquifar type, the depth of groundwater exposure and groundwater hydrochemical characteristic influenced the transfer and transformation of nitrogen. In the study procedure, find Fe³⁺ and Mn²⁺ is the key factor which influence the tranfer and transformation of nitrogen. There have some primary Fe³⁺ and Mn²⁺ in aquifar. This condition takes advantage of alleviates nitrogen diffusion. In sum, the contents of NO₃^- and polluted areas are small. The influence to wter quality is lightness. The pollution is concentrate in the region of groundwater outoff. The influence and pollution areas of NO₂^-, NH₄⁺ are greater relatively. The pollutions are concentrate in population compact district. It must pay attention to these conductions.