石羊河流域中下游近40a地下水位动态特征分析

Dynamic Variation of Groundwater Level in the Middle-Lower Reaches of Shiyanghe River Basin for Nearly 40 Years

石羊河流域位于河西走廊东部,是中国西北最发达的经济区域,也是甘肃省内水资源最紧张、用水矛盾最尖锐、生态环境不断恶化的地区之一。依据河西走廊石羊河流域中下游64个观测点1977~2015年地下水位观测点时间序列观测资料,在深入阐述研究区地下水位季节性及多年动态特征、类型和平面分布规律的基础上,利用Kendall秩次相关系数和Hurst指数分别分析了研究区地下水位的趋势性和持续性特征。根据计算数据,分析了研究区域地下水位下降的原因。结果表明：石羊河流域平原地带绿洲区和绿洲区外围地下水位的趋势性和持续性各不相同,地下水位的年均值与月均值都通过了显著性检验,呈不断的下降趋势,绿洲区地下水位下降幅度、下降趋势大于绿洲区外围,并具有较强的持续性,且绿洲区地下水位下降的持续性比绿洲区外围更强。

Located in the eastern part of the Hexi Corridor,the Shiyang river basin is the most economically developed region in the whole northwest region.However,the water shortage,contradiction and continuous deterioration of environment are also concentratedin this area.According to the time series observation data from 64 observation points during 1977-2015 in the middle and lower reaches of Shiyang River Basin in Hexi Corridor,the seasonal variation,dynamic changes,types and plane distributions over years of the groundwater level in study area have been elaborated.And then,the characteristics of tendency and sustainability of the groundwater level have been analyzed through using Kendall rank correlation coefficient and Hurst exponent.Finally,the reason of the decline of groundwater level has been explained by computed data.The results indicate that both the tendency and sustainability of groundwater level in the plains aredifferent the ones in oasis areas and corresponding peripheral areas,with effectively verified annual and month averages.The groundwater level in oasis areas owes greater decrease amplitude and rate and duration than that in peripheral areas.