玛纳斯河下游灌区地下水埋深变化特征及成因分析

Changing Characteristics and Influencing Causes of Groundwater Depth in Irrigation Areas in the Lower Reaches of the Manas River

根据新疆玛纳斯河下游莫索湾灌区具有代表性的14个长期观测井多年(1998—2010年)地下水位数据,运用水量均衡法和Mann-Kendall突变检验法分析了灌区地下水埋深动态特征及成因。结果表明,研究区除147团地下水埋深略有减小外,其他各区地下水埋深均呈增大趋势,其中150团地下水埋深增大最为明显。灌区地下水埋深变化存在时空差异,并且在2004年之后的不同年份出现了变化趋势转折,其根本原因是受到了灌溉入渗和地下水开采的影响。灌区地下水埋深年际、年内变化基本都呈现出人工-自然双重影响下的变化特征,年内变化最为明显,且不同区域影响地下水位变化的主次因素有所不同。总体而言,人类活动已经成为玛纳斯河下游灌区地下水埋深变化的主要驱动力,其次是自然因素,其中灌溉入渗、地下水开采和潜水蒸发是影响研究区地下水埋深变化的主要因素。

Based on the groundwater table observation data during 1998—2010from the typical 14 longterm observation wells in the Mosuowan irrigation district in the Lower Reaches of the Manas River,Xinjiang,the changing characteristics and influencing causes of groundwater depth were analyzed by the means of the water balance method and Mann-Kendall method.The results showed that the groundwater depth of147 farm decreased slightly,while the groundwater depth of other districts increased,and the groundwater depth increased in 150 farm the most obviously.There was temporal and spatial differences for the variation of groundwater depth in irrigation area,and whose trend turning point appeared after 2004,which was influenced by irrigation infiltration and groundwater exploitation essentially.The variations of annual and inter-annual groundwater depth showed the changing characteristics under the double influence of artificialnatural,the variation of inter-annual was the most obvious,and the primary and secondary factors that resulted in the variation of groundwater table were different in different areas.In general,human activities became the main driving force for the change of groundwater depth in irrigation areas in the lower reaches of the Manas River,the second was the natural factors,among all of them,irrigation infiltration,groundwater exploitation and phreatic evaporation were the main factors affecting the change of groundwater depth in the study area.