【作者】 赵静；

【导师】 万力； 王旭升；

【作者基本信息】 中国地质大学（北京） ， 地下水科学与工程， 2010， 博士

【摘要】 黑河流域作为我国西北地区典型的内陆河流域,以其特殊的寒区水文过程、复杂的陆地水文循环过程、省际水事矛盾、脆弱的生态环境等诸多科学与热点问题受到广泛关注。其水资源形成于上游山区,开发利用于中游灌溉绿洲,耗散于下游巨大的蒸发中,具有鲜明的分区特征。由于大规模的、长时期的水资源开发,黑河流域已经成为人类干预再造地表水、土壤水和地下水的综合试验场,形成自然-人工复合型的水循环系统。本文从黑河流域上游、中游、下游的特点出发,通过模型设计和数值模拟分别阐述了上、中、下游的水循环模式及其对人类活动的响应。上游祁连山区是黑河流域的产流区。除黑河干流研究程度较高外,仍有众多子流域因观测资料缺乏而进展微弱。本文在对祁连山区数字地形识别的基础上,运用流域水量平衡原理,对祁连山黑河流域20多个子流域的降水-径流关系进行了统计,提出多年平均状态下估算出山径流量的统计模型。该统计模型中,各子流域的年蒸发系数与其年降水量成幂函数关系;进一步研究表明,年蒸发系数从统计意义上又可表述为年降水量与年水面蒸发量比值的双曲函数。在假设月蒸发系数和年蒸发系数具有相同函数表达式的基础上,对黑河干流地区设计了TANK流域水文模型。通过模拟可知,黑河干流地区年降水量的38%用于产流,直接地表径流、融雪径流、地下径流对出山径流的贡献分别为52%、11%、37%。本文以黑河干流中游地区即张掖盆地为研究对象,在定性分析其地表水、地下水相互转化特征的基础上,提出张掖盆地年水均衡模型,定量解释了地表水与地下水之间的相互转化。年水均衡模型中包含一个非线性的河道渗漏模型,该模型充分考虑了河道水量适时变化条件下的河道渗漏行为以及灌溉引水对河道渗漏的影响。从地下水动力学角度出发,通过分析典型观测孔水位与高崖断面(黑河干流河道上的重要控制断面)基流量的关系,提出基于地下水观测的高崖断面月径流模型,模型参数少、精度较高,基本反映了高崖断面径流量的变化特征。张掖盆地地下水补给区的包气带厚度普遍较厚,厚层包气带的存在,影响地下水补给的时间和数量,通过简化的数值模拟得出张掖盆地厚层包气带中入渗-补给转化过程的总体特征,在此基础上提出简化的地下水补给模型,并将其应用到张掖盆地月水均衡模型的设计中。基于张掖盆地出口断面正义峡月径流过程的不同模拟方案,提出两种月水均衡模型,详细刻画了张掖盆地地表水-地下水相互转化的各个环节与细节。下游地区水循环特征以垂向的蒸发蒸腾为主。地下水位的高低决定着植被的生长状况与演替,而地下水则主要接受黑河河水的补给,构成了河流-地下水-植被相互反馈、相互制约的生态链条。结合黑河调水的新形势,在分析黑河下游地质、水文地质条件的基础上,采用Visual Modfolw 4.0建立黑河下游盆地地下水模型,模拟分析了调水前后生态耗水区的变化。结果显示,生态耗水区较调水前明显增大,生态状况趋于好转。根据中、下游模型结果,深入分析了人类活动对黑河流域中下游水循环过程的影响。灌溉回归水需要在厚层包气带中平均运移长达5个月之久,才能到达潜水面,会引起地下水的二次补给;灌溉引水量对中游水循环过程的影响具有双重性,表现为正义峡流量与灌溉引水比例(灌溉引水量与河流径流量之比)呈很强的负相关,而与灌溉引水量呈弱的正相关。在限制灌溉引水增加的条件下,采用渠系防渗能有效减少地表水的渗漏。黑河调水工程实施后,中游地区除黑河干流沿岸有局部区域地下水位呈上升趋势外,其他大部地区地下水位呈下降趋势;下游地区受入境河水量的增加,地下水位普遍呈上升趋势。更多还原

【Abstract】 Heihe River Basin is the most typical inland river basin in northwest China. Extensive attentions have been paid to its so many scientific and hot research issues, such as its specific hydrological processes in cold regions, complicated terrestrial water cycle processes, water affairs conflicts between provinces, fragile eco-environment problems, and so on. Its water resources, characterized by distinct regional features, is generated in mountain areas of the upper reaches; and then it is developed and utilized in the irrigated oases of the middle reaches; finally it is disappeared in the huge evapotranspiration of the lower reaches. Due to the large-scale and long-term developments of water resources, Heihe River Basin has became to a synthetical test site where human activities intervene and transform the relationships between surface water, soil water and groundwater. Based on the different characters of the upper, middle, and lower reaches of Heihe River Basin, this paper separately explains their terrestrial water cycle schemes and their responses to human activities by designing several models and numerical simulations.The upper reach at Qilian Mountain is the only runoff generating area of Heihe River Bain. Enough attention is paid to the main stream; many sub-basins of Heihe River catchment at Qilian Mountain are lack of enough concern because of limited observation data. Based on identifying the digital terrain of Qilian Mountain, the relationship of precipitation and runoff at more than 20 sub-basins is statistically analyzed from the view of average water balance, and then a statistical model used to estimate the runoff at the basin outlet under long-term average conditions is put forward. In this statistic model, the ratio of evapotranspiration to evaporation can be described as a power function of precipitation. By further study, the annual evaporation coefficient can be statistically described as a hyperbolic function of the ratio of annual precipitation to annual evaporation. In this paper, it is assumed that the monthly evaporation coefficient has the same function format with the annual evaporation coefficient. Based on this assumption, a kind of TANK Model is designed to simulate the monthly runoff processes for mountainous region of Heihe Mainstream River. 38 percent of annual precipitation is used to generate runoff, which contains directly surface runoff, snowmelt runoff and sub-surface runoff and their contributions to runoff are separately 52 percent, 11 percent, and 37 percent through the simulation. By selecting Zhangye Basin as the study area and based on the qualitative analysis of the interactions between surface water and groundwater in Zhangye Basin, an annual water balance model is put forward to explain quantificationally the mutual transformation between all kinds of resource. This annual water balance model contains a non-linear stream channel leakage model which emphasizes the leakage behavior of stream channel under the condition of stream flow timely changing and human activities. From the principle of groundwater dynamics and according to analyzing the relationship between groundwater levels in typical observation wells and the base flow of Gaoya cross-section (very important cross-section on the Heihe Mainstream River), a kind of monthly runoff model based on the observed groundwater level for Gaoya cross-section is brought forward. This model has fewer parameters and higher model accuracy and basically represents the variation mechanism of Gaoya cross-section. In the recharge area of groundwater of Zhangye Basin, thick vadose zone is widespread distributed under the ground surface, which effects on the time and amount of the recharge of groundwater. Simplified numerical model are carried out to investigate the general behaviors of leakage-recharge conversion through a thick vadose zone, and then a simple groundwater recharge model is presented. Two different schemes for simulating the runoff of Zhengyi Gorge are taken into account, combining with above simple recharge model, two monthly water balance model for Zhangye Basin are proposed, which can describe every details of the transformation process between surface water and groundwater.The water cycle in the lower reaches is characterized by vertical evapotranspiration. The growth and succession of vegetation are controlled by the level of groundwater, and the leakage from Heihe River channel is the main recharge component for groundwater. So, river, groundwater, vegetation, which feedback and confine each other, compose an integral ecological chain. After analyzing the geological and hydrogeological conditions of the lower reaches, considering the new situation of water allocation of the Heihe River, a groundwater model is set up to simulate the variation of the ecological water consumption area before and after the implement of water allocation by the software Visual Modfolw 4.0. It is shown that the area of ecological water consumption is significantly enlarged after water allocation, which predicts the vegetation will turn to be better.Based on the results calculated by the models developed for the middle and lower reaches, the effects of human activities on the water cycle processes are analyzed deeply. Irrigation return water needs approximate 5 months to arrive the groundwater level, which can contribute to the second recharge event for groundwater. The effects of the irrigation water diversion on the water cycle processes in the middle reaches have double nature. On hand, the runoff of Zhengyi Gorge is strongly negatively correlated with the ratio of the amount of the irrigation water diversion to the runoff of Yingluo Gorge. On the other hand, it is weakly positively correlated with the amount of the irrigation water diversion. Under the condition of confining the amount of the irrigation water diversion, the increment of the conveyance efficiency of canal water can decrease the leakages from surface water efficiently. After the implement of the water allocate of the Heihe River, for the middle reaches, except some local areas having an uptrend in the groundwater levels, the rest areas have a downtrend in the groundwater levels. For the lower reaches, the groundwater levels rise widespread due to the increment of leakages from the Heihe River.更多还原