Research On The Assessment And Reasonable Development Of Groundwater Resources In Zhaoyuan County,Heilongjiang Province

Zhaoyuan County is famous known as National commodity grain base county that it’sabundant of grain, animal husbandry, fisheries and oil in Heilongjiang Province. With the rapiddevelopment of social economy, the contradiction in supply and demand of regional waterresource becomes increasingly obvious which makes it a higher level for reasonable exploitationand use of groundwater in study area. As it demanded, make assessments and analysis of thegroundwater in Zhaoyuan County to provide a scientific basis for groundwater exploitation anduse.Based on the meteorological, hydrological, geological and hydrogeological data collected instudy area, make clear of distributions characteristics of groundwater aquifer, hydraulic, dynamicand cycling characteristics; The groundwater flow numerical simulation model is founded viaGMS (Groundwater Modeling System) software, at the same time, combined the approachingdemand of groundwater project in Zhaoyuan County to predict the changing law of groundwaterlevel and thus provide the rational plans for groundwater exploitation and use. By the studiesabove, the mainly conclusions are derived:(1) According to the geological and hydrogeological data in study area, it is known thatgroundwater aquifers in Zhaoyuan County include two parts. One is unconfined aquifer made ofHaerbin group, the other is confined aquifer made of Baitushan group, Taikang group and Daangroup; based on the analysis of hydrogeological condition, the source of groundwater recharge inthe county mainly comes from precipitation, irrigation, lateral runoff,etc. The main discharge isevaporation of shallow groundwater, lateral runoff, artificial exploitation, etc.(2) In accordance with monitoring of groundwater quality, most of the groundwaterhydrochemical type in Zhaoyuan County is HCO3-Na·Ca, part is HCO3-Ca·Mg; as drinkingwater, components which exceeds the standard in the groundwater are ferrum, manganese,chloride, sulfate, total dissolved solids, total hardness, ammonia nitrogen and so on. Ferrum andmanganese seriously exceed, ammonia nitrogen takes second place; the evaluation of agricultureirrigation water indicates that the groundwater is quite safe for agriculture irrigation; thecomprehensive water quality evaluation shows that ferrum and manganese are seriouslyexceeding the standard and groundwater quality in Fuxing and Chaodeng village is on a better level. On the other side, Behetai, Daxing, Fuqiang, Minyi village and Maoxing county’s is worth.The rest all belongs to extreme worst quality; in order to avoid the problem of entirety anddiscontinuity in index hierarchy during traditional comprehensive assessment, use graycorrelation degree assessment method based on entropy weight to evaluate the characteristics ofthe groundwater equality in study area. The result shows that this method is more accurate.(3) According to the hydrogeological conditions in Zhaoyuan County, foundhydrogeological concept model and mathematical model in study area. Make use of GMSsoftware to set up groundwater flow numerical simulation model. Identification period is fromJay1st,2008to Jay1st,2009. Verification period is from Jay1st,2009to Jay1st,2010. Thenmake calibration of hydrogeological parameters, and the fitting effect between groundwater flowgradient field and drawdown velocity field is good enough to satisfy the demand of numericalsimulation. It is declared that the model can reflect basic characteristics of regional groundwaterflow well and can be used to predict the variation of groundwater level in the future; at the sametime, sensitive analysis of the model shows that precipitation infiltration coefficient has the mosteffect on calculated water level of the whole groundwater system.(4) Combining water demand planning of Zhaoyuan County in the future, predict thedynamic of regional groundwater level during2010to2020by utilizing the founded regionalgroundwater numerical simulation model. The result shows: unconfined water level is relativelylow because of water shortage over the years, so during the forecast period, it displays escalatingfirst and stabilizing following and the level rising rate is increasing with the increase ofprecipitation. But the excessively exploitation near Toutai County causes partial groundwaterdepression cone. Due to the centralized exploitation positions of regional confined water andunreasonable distribution of drilling wells, regional confined water level shows as decreasingtrend and water head descent rate is increasing with the increase of groundwater exploitationquantity. And the groundwater depression cone has appeared near Zhaoyuan County andChaodeng village; according to the comparative analysis of the prediction of agriculturewater-saving irrigation plans, it shows that there is larger water-saving space for agricultureirrigation groundwater resource in study area, and water-saving irrigation cannot only guaranteethe regional water demand, but also observably improve regional groundwater environment andrelieve the formation and expanding of the groundwater depression cone. (5) Agriculture irrigation is the main mining way of groundwater in Zhaoyuan County, souse water-saving irrigation can guarantee regional agriculture water demand, and at the sametime, it can relieve the formation and expanding of the groundwater depression cone; moreover,the pressure of regional water demand can be relieved by taking full advantage of the abundantsurface water resource, building surface water abstraction works, etc. And achieve sustainableutilization of regional groundwater resource.