The Study On Groundwater Recharge Programs In Alluvial Fan Of Hutuo River

The north China plain has a large population and its economy is developed,however, its water resources quantity is small. The north China plain faces seriousresources and environment problems, especially the available water decreasesdramatically, the water shortage is more and more serious. Therefore, we adopt thetechnique of artificial recharge of groundwater in this area to introduce the excess ofsurface water into the underground aquifer, which is one of the effective methods ofrecharging groundwater resources.This paper choses the typical area of the alluvial sector of Hutuo River in thenorth China plain as the study area, in this area, old channels are well developed andthe lithology is coarse which makes their strong storage capacity, further more,excessive mining caused landing funnel and so on, all these conditions provide thehuge groundwater recharge water storage capacity. Available recharge water in thestudy area include water from Huangbizhuang reservoir, water in Shijin canal andSouth-North Water Transfer Project water supply. Take the water level in the5to7months in1977in the history as the limit water level of artificial recharge ofgroundwater. Using the difference between the water level at the end of2009and thelimit of high water level analyzed the regulation storage capacity of study area is74.54×108m3by mapgis spatial overlay technology.On the base of the existing numericalmodel of groundwater flow of the alluvialsector of Hutuo River, the changes of groundwater level and storage under theconditions of4recharge schemes are provided,simulation time of flow predictionmodel is2010to2020. Combined with the existing potential recharge facilities andwater sources conditions,4recharge schemes are provided: river channel recharge,sand and gravel pit recharge, recharge well injection and Shijiazhuang Cityexploitation control plan. By2020compared with no recharge average level ofunconfined aquifer groundwater increased1.231meters,1.081meters,0.017meters,2.357meters; confined aquifer underground water level rose by0.187meters,1.027meters,0.027meters,0.678meters. The accumulation of groundwater reservoir variables respectively increased by6.10million cubic meters and49.6million cubicmeters and0.02million cubic meters and11.78million cubic meters. Visibleconclusion can be drew that recharge can effectively increase water quantity inaquifer, and the south-north water transfer project is of great significance to improvethe Shijiazhuang funnel of groundwater depression and the variable negative balanceof groundwater storage for a long time.Establish theoptimal management model of groundwater and solve it by bygenetic algorithm, the solution shows that until the end of2020the funnel area ofShijiazhuang has recovered obviously under the condition of making the four rechargeschemes and the exploitation control in the downtown all in operation, undergroundwater level rise in the overall, compared with water level of no recharge case andnormal production, maximumunconfined aquifer water level rising is36meters, thearea of the rise of ground water level that is greater than2m is2392km2，accountingfor88.2%of the whole area in the study area, and the influence area increased by1389k㎡compared with the floe prediction model; the confined aquifer water levelalso get a sharp rise up to16m. By the year2020, the cumulative storage variablerose respectively from-33.56×108m3to-11.72×108m3and-10.51×108m3for flowmodel and optimal model, and the ground water resources amount increased21.84×108m3and23.05×108m3. All the above shows that optimal management model can beefficient to obtain the optimal recharge scheme.