Mechanism Of Groundwater Response To Climate Change In Guanzhong Basin

Under the background of climate warming in the world and the national, the change ofgroundwater response to climate has became the leading edge and hot spot. Most scholarshave studied for groundwater dynamic and climate change in arid regions, but contrary toresearching in the relationship of the groundwater and climate in arid and semiarid regions.Sogroundwater responsed to climate change in Guanzhong basin has the important meaning.This paper lined with Guanzhong basin’s groundwater responsed to the climate as themain line, using the walvet analysis temperature and rainfall’s cycles in study area andforecasting tendency of temperature and rainfall in the future. According to the undergroundwater level and rainfall data, groundwater levels of analysis on the fluctuation characteristicsof various elements. Using the gray theory of methods and comprehensive index weightedmethods，systematic analyzing climate change the correlations and human activity. Andcombined with numerical simulation results, forecasting the flow field of groundwaterresponsed to climate in the extreme weather. The following conclusions can be concluded:(1) The annual temperature rises in steady tendency from1951to2010year. Thetemperature oscillation periods separately have19to20years and32to34years two scales.The temperature will drop in the2010year later. The rainfall oscillation periods respectivelyare3years,9years,16years,28years. Rainfall falls after2009year.(2) Dynamic groundwater level is caused by the topography and geomorphologymeteorological、hydrology and artificial factors. From1984to2008, diving water leveldeclined and the rate of uneven distribution of space. The dropping rate of level ofgroundwater is maximum in Loess Platform region, the minimum rate is in the river valley.Change of groundwater embedded depth of no.070is the maximum in the Fengxiang county.Average annual decline rate is1.25m/a, The valley of underground water depth transformeris relatively small, level fell at a rate of0.03m/a or so.(3) Central to different parts of the basin groundwater on climate change the maininfluence factors relevance analysis1.The rainfall and artificial exploited are the main factors to the groundwater level decline of Baoji, Xian, Xianyang and Weinan regions. Yieldes of Baoji, Weinan and Xianareas are the dominant factors to deep underground water level, the rainfall of Xianyang areais the dominant factors.2. The change of the groundwater temperature in Xianyang and Xian area groundwatertemperature and rainfall buried underground water level (correlation coefficient>0.6) allhave close relationship, the result of joint action by three Xian area buried depth ofgroundwater levels influence is the dominant factors of groundwater water temperaturechanges, annual rainfall is Xianyang groundwater water temperature changes leading factors.(4) Human activity intensity was calculated to be28%,37%,35%in1980’s,1990’s and2000-2008year respectively, which indicated that the most human activity intensity waspresent in1990’s. The groundwater of Guanzhong is mainly influenced by the climate.(5) Using groundwater flow numerical simulation, predicting underground water flowfield changes in different climate conditions. In a wet year, the groundwater levels showdifferent rise in different degree. Groundwater level obviously rises in the loess tableland, thehighest rising water level appeared in Liquan－Fengxiang loess tableland area. Due to risingwater level, the region appeared in abundant surface water in Liquan－Fengxiang loesstableland area. The lowest rising water level appeared in Xian-Huayin low terraces, increasingbetween1and5meters. In a low flow year, groundwater level is significantly decline indifferent degrees. The biggest reducing water appeared in the in Liquan－Fengxiang floodproduct sector, the biggest reduced to25meters. The groundwater decline between1and5meters in Xian-Huayin low down smaller terrace.Paper finally central Guanzhong basin under different climate groundwater reasonable useand self-control countermeasures, putting forward some reasonable suggestions.