Study On The Evolution Of Groundwater In Yanbian Area

There is strong strength of the economic uplift belt and the first area of the opening in Changjitu development pilot area. And the area will accelerate the development of the revitalization of Jilin. It has very important strategic significance for deepening development in the Tumen River area. The groundwater plays an irreplaceable role in agriculture, industry and life. Meanwhile, the studies of Yanbian area of groundwater is rate, especially system, regional. Therefore, in order to provide advices about groundwater, it is necessary to understand what the groundwater dynamic, evolution and hydrochemical characteristics, and so on.It is based on “1-50000 hydrogeological atlas compile” from water conservancy science research institute in Jilin(project number: 3R214N941425). There are following researches.1. There is a calculation and analysis on groundwater resources about spatial distribution and time evolution characteristics in Yanbian area. Compare the space distribution of groundwater flow in each basin, though the statistical analysis of groundwater flow in Yanbian. The long-term trends and cycles of groundwater flow in Yanbian are amalyzed using the accumulative anomaly, M-K inspection, harmonic analysis, double cumulative curve. At the same time, comparing with the long-time trend and periodic change of flow and that of precipitation shows groundwater recharge mainly comes from atmospheric precipitation recharge in Yanbian. There is a huge change in the correlation of long-term ternd and periodic change in groundwater resources and precipitation, because of influence of human mining.2. Though collection of the geological and hydrogeological conditions, classify the groundwater dynamic type to analyze groundwater dynamic type relation with atmospheric precipitation and artificial mining, and the evolution of dynamic in nearly 20 years. The depth trend and cycle component of quaternary groundwater, tertiary fissure groundwater, basalt fissure groundwater are compared with precipitation. Predict groundwater depth by ARIMA time series model. Prediction result shows ARIMA is suitable for less artificial minig or regularly.3. The characteristics of the evolution of groundwater quality in Yanbian was analyzed by ion equivalent ratio of groundwater. There is not a big change about quaternary groundwater though statistical analysis of chemical composition of groundwater in Yanbian in 1994, 1997, 2004. The variation coefficient of NO2-, K+, NO3- is the largest, shows invariably in the space position, may be because of the influence of human activity to make the local pollution and caused by the variation coefficient is bigger. Pearson correlation coefficient method is used to analyze the relationship between each component, using the factor analysis method to classify chemical composition analysis of groundwater. The groundwater composition can be divided into two categories collectively, category1 is mainly derived from the original geological environment, is to control the groundwater characteristics of main reason; category2 due to the influence of human, mainly agricultural fertilizer and life pollution to groundwater.There is an evaluation about quaternary and other groundwater by groundwater environment quality present situation appraisal and the evaluation of groundwater pollution of quaternary. From Quaternary groundwater individual components evaluation results, over-limit ratio of p H, total hardness, total soluble solids, sulfate, chloride is not big, over-limit ratio of nitrate and nitrite is bigger, overweight components in 2004 significantly more than in 1994. From the point of pollution index evaluation, most of the components of pollution is lighter, and nitrate, nitrite which is very high. The comprehensive pollution index is greatly influenced by the NO2 and NO3, distribution and evaluation result is the same. Human activities have closely regional pollution. TDS in Yanji basin clastic rock, bedrock antu region, Dunhua basalt groundwater is not greater than 0.5g/L, total hardness is generally not more than 300 mg/L. Other common components are also small. Exceed the ammonia nitrogen, nitrate content.