Evaluation To Groundwater Exceed Area Of Daqing Western Region

Water is the source of life and the indispensable material basis ofhuman existence and sustainable development of the society. Groundwateris an important component of water resources of China and occupy 1/3 ofthe total water resources. Nearly 70% of the population drink groundwaterand groundwater has a wide distribution, big storage capacity, strongregulation capacity, and relatively stable water quality and quantity, a highdegree of supply, low investment and quick results. Therefore, thegroundwater is an important drinking water sources, but also play animportant role in the building of national economic development.Daqing is an energy base of China and an area of water shortage.Therefore, since the early 60s of last century to the mid-70s, groundwateris mainly taken as a major source of water supply in oil field development.In the two hydrogeological units divided by Daqing and Changyuan supplywell numbers is up to 125 . In concentration exploitation area thegroundwater has already formed large areas of cone of depression and thegroundwater level in the center of cone of depression in west area wasdropped from the buried depth of 9m in the early of exploitation to 48.73min 1998 the groundwater level in the center of cone of depression in eastarea was dropped from the buried depth of 10m in the early of exploitationto 53.92m in 1992. Over the years, relevant departments had approved thefunnel area through drawing funnel with east-west, north-south profile ofthe methods, and used the static value of the funnel area for many years,didn't delineat funnel-shaped zone of annual changes in the scope and didn't study the problems of groundwater overdraft area in the center of thefunnel.In this paper, the quantity of groundwater in Daqing area is calculatedthrough analyzing the regional overview of the study area, thecharacteristics of regional geological, hydrological and hydrogeologyparameters, which supplies that the quantity of total annual recharge is15.168×108m~3/a in phreatic water and the quantity of ateral recharge is2.033×108m~3/a in confined water. The Balance method, Average ClothWells method and numerical method is selected to comparative analysisthe groundwater allowable withdrawal of the study area and the finallydetermined that the groundwater allowable withdrawal of the study area is6.183×108m3/a. Then, the area and intensity of groundwaterover-exploitation in study area is evaluated according the principle ofdivision of the groundwater overdraft area detemined by overdraft ofgroundwater areas in Heilongjiang Province and evaluation of thetechnical details of the survey (for trial implementation). The results showthat the western Daqing groundwater overdraft distribution area are 9.72 ~145.47 km~2, the average years of overdraft distribution area is 59.25 km~2;The eastern overdraft distribution area are 246.98-745.38km~2, theaverage years of overdraft distribution area is 492.81 km~2; The seriousoverdraft distribution area are 29.35-176.54 km~2, over the years anaverage is 97.27 km~2. Finally, the paper determine the western regionMingshui and Taikang mixed mining program by introducing the mixedfield test results of water samples.The establishment of mathematical model of groundwater flow in thispaper is the basis to overdrafted zone evaluation. In the model, Daqingregion is divided into 688 triangular elements and 383 nodes throughanalyzing the geographical and regional hydrogeology conditions, and the time step of the model is 30 days. The model take the groundwater levelflow field in January 1986 as the initial flow field, then run and calculatethe water balance for the study area. The model verification is donethrough comparing the measured water level and modeled water level.After verification, the proposed numerical model of the groundwater flowis reliable and the groundwater resources of the west area of Daqing can besimulated by the model.Finally, combined with the western region of Daqing status and socialdevelopment situation, combined mining method is discussed in thispaper ,and two methods are suggested.