干旱区扬水灌溉对区域地下水动态特征的影响分析

Analysis on impact from pumping irrigation on dynamic characteristics of regional groundwater in arid area

受季节性人工灌溉的影响,干旱扬水灌区不同运移带的地下水具有独特的时空动态特性。以甘肃省景电一期灌区为研究区,利用其1982-2011年地下水位实时监测数据,分析灌区地下水时空变化规律,探索干旱扬黄灌区不同地下水运动带的地下水动态特性。研究表明,灌区内的潜水汇聚带与潜水运移带年际地下水位具有明显的上升趋势,地势比较低洼的潜水汇聚带甚至出现地下水出露现象,而灌溉水入渗带与潜水排泄带地下水位处于相对平衡状态;灌区内不同地下水运动带年内的地下水位变化过程具有显著差异性,这种差异主要是受灌溉过程及区域局部开采共同作用影响;灌区地下水空间动态以自西南向东北运移为主。

By taking the phase I Project of Jingtaichuan Electric Pumping Irrigation District in Gansu Province as the study area,the spatio-temporal changing law of the groundwater within the irrigation district is analyzed herein in accordance with the realtime monitoring data of the groundwater therein,and then the dynamic characteristics of the groundwater in various groundwater movement zones in the Yellow River pumping irrigation district in arid area are explored as well. The study shows that the interannual groundwater levels of both the groundwater accumulation zone and the groundwater movement zone within the irrigation district have the trends of obvious rising,and even the phenomena of outcrops of ground water occur in the groundwater accumulation zone within those low-lying areas,while the groundwater level is in an relative equilibrium state for both the irrigation infiltration zone and the groundwater discharge zone. The changing processes of the groundwater levels in various groundwater movement zones have significant discrepancies,which are mainly impacted by the common effect from the irrigation process and the local groundwater exploitation,furthermore,the spatial dynamic state of the groundwater within the irrigation district shows a movement mainly from the Southwest to the Northeast.