The Catchment Of Karez Influenced By Pumping-well And Flood Storage

Karez,located in Turpan Region of Xinjiang,is a unique underground water diversion irrigation system in arid and semi-arid areas of China,which has an irreplaceable role in the production and life of local residents.At the same time,Karez is a valuable intangible cultural heritage of our country,with its unique value of culture,society and ecology.However,in recent years,with the use of a large number of pumping wells,the regional groundwater level continued to be declined,resulting in lower or even dry water flow.There is a sharp drop in the number of water wells,the protection of the Wells should not be delayed.Karez mainly uses the shallow groundwater.When the underground water level drops,the catchment capacity of Karez will be significantly decreased,or even broken flow.In this paper,the influence of the different position and pumping intensity on the catchment capacity of the Karez is discussed.Because of the water harvesting capacity of the Karez is obviously affected by the fluctuation of the groundwater level,based on the experience of the recharge of groundwater,this paper puts forward the flooding of the flood control dam in the alluvial fan area of Turpan area,and uses the GEOSTUDIO software to simulate the groundwater Infiltration process in alluvial fan area.Here are some research results:(1)The catching capacity of the Karez is affected by the location of the pumping wells.When the pumping well is laid in the upstream area of the culvert,the catching capacity of the Karez is reduced by 20% when the pumping capacity reaches 5000 m3/d.When the pumping well is located in the culvert area of the canal tunnel,under the same situation,the maximum water harvesting capacity of the well is 10%,which is half of the former reduction.(2)Different pumping intensity also has influence on the catchment of Karez.At the same location,change the pumping intensity of the pumping wells,the greater the pumping intensity,the Karez catchment is weaker.In the area of the culverts,the water collecting capacity of the pumping well is 1000 m3/d,and the pumping capacity is 5000 m3/d.The former is reduced by 2% compared to normal water catchment,while the latter is up to 10%.(3)The construction of flood dam can increase the local groundwater level effectively by flooding in the alluvial fan area.Through the simulation results,we can see that within 14.2 hours after the flood storage,the water inflows all underground.And there is a process of distribution of water resources after water is infiltrated into the ground due to the imbalance of groundwater level.The final groundwater is evenly distributed,and the groundwater level is raised by 13.5m.