【作者】 郑爱勤；

【导师】 王文科；

【作者基本信息】 西安科技大学 ， 地质工程， 2013， 博士

【摘要】 渭河是黄河的最大支流，是陕西的母亲河，对陕西省的社会经济发展起着举足轻重的作用。近年来因受人类活动和自然因素的双重影响，渭河河川基流量呈现大幅度下降趋势，枯水期河流生态基流得不到保障。由于河川基流是构成地表径流的重要组成部分，基流量衰减，意味着地下水对河水的保障能力减弱，从而导致河川径流量减少，诱发湖泊萎缩、河流断流等一系列生态环境负效应。因此，开展渭河关中段地下水对河流生态基础流量保障研究，对维护健康的渭河具有重要的理论意义和实用价值。本文以国家科技重大专项“渭河水污染防治专项技术研究与示范”的子课题三“渭河关中段生态基流保障技术研究”为依托，以系统理论为指导，紧紧围绕保障渭河关中段生态基流的目标，从河水与地下水的转化关系入手，以基流分割、数理统计和数值模拟为手段，开展地下水对河流生态基流的保障研究，主要成果如下：(1)系统分析了河川基流与河流生态基流的概念、特征及其影响因素，指出在枯水季节河川基流量在河流生态基流量中占有极其重要的地位，这表明增加枯水季节河川基量是保障河流生态基流的重要举措。(2)在资料收集和野外调查的基础上，编制了渭河流域河水与地下水转化关系图，渭河流域95%以上的地区为地下水排泄补给河流。渭河流域关中段，秦岭山前冲洪积扇中后部和渭南-潼关段干流，河流补给地下水；其余地段均为地下水排泄补给河流。(3)通过BFI基流分割和M-K趋势分析，近60年来渭河关中段干流和支流的径流量和基流量总体呈现波动下降趋势，通过R/S分析，得出渭河关中段河川基流量未来仍为下降趋势；在年内枯水季节地下水对河流径流量的贡献达85%以上；20世纪60年代以前降雨是影响基流的变化起的主要因素，90年代以来随着人为活动的加剧，对河川基流的影响较大。(4)渭河流域关中段，丰水年和平水年河流生态基流基本可以得到保障；枯水年和特枯年，河流生态基流量出现不同程度的亏损，亏损程度为：林家村断面>魏家堡断面>咸阳断面>华县断面，在河流生态基流亏损的时段，河川基流量占河流径流总量的90%以上。因此，枯水期地下水对河流生态基流量发挥着重要作用。(5)渭河关中段在丰水年及平水年，地下水基本能够满足河流的生态基流量；在枯水年及特枯年的枯水期，除了华县站地下水能够满足河流生态基流量外，林家村、魏家堡及咸阳站地下水对河流生态基流的贡献在0.6?0.8之间。(6)为了增强地下水对河流生态基流的保障程度，提出了地下水合理开采和雨洪地下调蓄的保障措施。①以渭河关中段河流生态基流保障为目标，以区域生态环境良性发展为约束条件，构建区域水文地质概念模型和地下水流数值模型，计算出保障河流生态基流条件下林家村-魏家堡、魏家堡-咸阳、咸阳-华县等断面的地下水开发阈值分别为1.78xl08m3/a，7.43><108m3/a，13.01><108m3/a。②根据研究区地质、水文地质和气象水文等条件，提出秦岭山前洪积扇洪水地下储存模式、山间河谷型洪水地下调蓄模式、傍河水源地洪水地下调蓄模式和城市雨洪地下储存模式，共可增加地下水储存量2.7xl08m3/a。③在区域地下水合理开采和多种水源地下储存的共同作用下，地下水对河流生态基流的保障程度为66%。上述研究成果，对于指导渭河流域生态基流保障和水资源合理开发具有重要的理论意义和实际利用价值，也为西北干旱半干旱地区重污染缺水河流的生态基流保障提供了示范作用。更多还原

【Abstract】 Weihe River is the largest tributary of the Yellow River which is the mother river ofShaanxi Province.lt plays an important role in the socio-economic development. In recentyears, Weihe River base lfow showed a signiifcant downward trend because of the impact ofhuman activities and natural factors. Especially, the river ecological base lfow can not beguaranteed in dry season. However, it is an important part of surface runoff. Its attenuationmeans groundwater weaken the protection of the river. These result decreasing in river runoff,shrinking lakes, drying up rivers and a series of ecological environment negative effects.Therefore，this study carryed on groundwater protection of the river ecosystem base lfow inGuanzhong section of Weihe rive.That plays an important role on theoretical signiifcance andpractical value in maintaining healthy to Weihe River.This stdudy was based on the major projects of the National Science and Technology of“ecological base lfow security technology research in the Weihe River basin Guanzhongsection It is the third topic of" the Weihe River water pollution prevention and control ofspecial technology research and demonstration". This study takes Weihe River ecological baselfow as a main target, guided by system theory. It was starting from the conversion betweenriver water and groundwater. Base on methods of the river base lfow separation, mathematicalstatistics and numerical simulation, the researchcarries out the study of groundwater protectionof the river ecological base lfow and the main results are as follows:(l)By analyzing the concept，characteristics and influencing factors of the river base lfowand ecological base lfow, the study points out that the river base lfow occupies an extremelyimportant position in river ecological base lfow in dry season. In the same time, it indicatesthat increasing the amount of river base lfow in dry season is an important way to safeguardriver ecological base flow. (2)0nthe base of the data collection and ifeld investigation, the transformation diagrambetween river water and groundwater is compiled in Weihe River basin. It shows groundwaterrecharge rivers happenes at more than95%region in Weihe River basin. The region of riverrecharge groundwater is back in the diluvial fan of QinLing mountain and Weinan toTongguan section in Guanzhong segment of Weihe River basin.The rest region is groundwaterrecharge rivers.(3)Throughthe analysis of the BFI (base lfow index), Mann-Kenndal and R/S(RescaledRange Analysis), the research shows that the river base lfow appears fluctuation downwardtrend in Weihe River Guanzhong section in recent60years. Since the1990s，the stream lfowand the river base lfow have been keeping downward trend obviously. The river base lfowaccounts for more than85%of the river runoff in dry season.(4)Inwet year and median water year, the river ecological base lfow can be guaranteedbasically in Guanzhong segment of Weihe River basin. In dry year and particular dry year, theriver ecological base lfow appeares different degree of loss，that is the Linjia village section>Weijia fort section〉Xianyang section>Huaxian county section. In the period of the riverecological base lfow losses，the river base lfow accounts for more than90%of the river runoffamount. As a result, groundwater plays an important role in the river ecological base flow.(5)Inwet year and average year, the groundwater can meet the river ecological base lfowin Guanzhong section of Weihe river basin. In dry season of dry year, the contribution value ofthe groundwater to the river ecological base lfow is between0.6and0.8in Weijia andxianyang station. However, Huaxian station groundwater can satisyf the river ecological baselfow during this period.(6)Inorder to strengthen the groundwater protection degree of the river ecological baselfow，the study puts forward the reasonable exploitation of groundwater and rain lfood ofunderground sotrage system technology.①Aiming at protect the river ecological base lfow in Weihe River Guanzhong section,and taking regional ecological environment development as constraint conditions, the researchstructure the regional hydrogeology conceptual model and groundwater lfow numericalmodel.lt calculates that groundwater development threshold in Linjia village-Weijia fortsection, Weijia fort-Xianyang section, Xianyang-Huaxian county section, is respectively1.78xl08m3/a,7.43><10sm3/a，13.01xl08m3/a.②According to the conditions of geology, hydrological geology and meteorologyhydrology in study area, the reseach puts forward groundwater storage mode: before theQinling mountain diluvial fan, the mountain valley, alongside the river water source and urban rain lfood storage pattern. Under these regulation mode，groundwater can increase the storagecapacity by2.7X108m3/a.③Under the combination effect of area groundwater rational exploitation and a variety ofwater stored underground, the level of groundwater protection to the river ecological base lfowis66%.The research has important theoretical signiifcance and practical use value for theguidance to the Weihe River ecological base lfow protection and rational development ofwater resources. Further more it provides a demonstrate in river ecological base lfowprotection of the northwest arid and semi-arid regions，where the river is severely polluted andwater resource is poor.更多还原