Impacts of environmental flow controls on the water table and groundwater chemistry in the Ejina Delta,northwestern China     

Ping Wang  Jingjie Yu  Yichi Zhang  Guobin Fu  Leilei Min  Fei Ao 《Environmental Earth Sciences》2011,64(1):15-24

The impacts of environmental flow controls on the water table and chemistry of groundwater in the Ejina Delta, an arid inland river basin in northwest China, were investigated with field observations in 2001 and 2009. The results indicate that the shallow groundwater level rose by 0–2 m in the upper reaches of the east tributary of the Heihe River and in the areas of Saihantaolai—Dalaikubu during the period of environmental flow controls. The chemical constituents of the groundwater show a distinct spatial heterogeneity with the total dissolved solids (TDS) in the groundwater increasing from the periphery towards the depocenter of the Ejina Basin. In addition, the rate of groundwater cycling in the south of the Ejina Delta increased, and the mineralization of groundwater declined, while the overall mineralization and salinity increased in the northern regions, especially in the depocenter of the Ejina Basin. Since shallow groundwater is important to the ecology of arid regions, and because understanding the changes in the shallow groundwater environment (groundwater level and hydrochemistry) in response to environmental flow controls is essential for the sustainable improvement of the ecological environment, the results of this paper can be used as a reference for watershed water resources planning and management to help maintain the health and proper function of rivers in arid regions.  相似文献   

霍尔果斯背斜深井井身结构优化设计          下载免费PDF全文

刘奥  曹光福  谢建安  陈松平  辛小亮 《探矿工程》2018,45(2):26-29

霍尔果斯背斜受山前构造的影响,存在地质情况复杂、倾角大、多套压力体系并存以及泥岩含量高等问题,在钻进过程中复杂事故频发,严重制约了该地区油气勘探开发的进程。通过对完钻井的测井资料、地破实验数据、钻井复杂等资料的分析,确定必封点位置,形成适合霍尔果斯背斜深探井的四开井身结构,并针对安集海河组复杂事故率高的情况,采用高密度油基钻井液抑制泥岩水化,从而实现安全钻进。优化后的井身结构在霍尔果斯背斜深探井H11井进行了应用,首次实现了在安集海河组、紫泥泉子组两套压力系统下进行套打,历时5.5 d钻穿“死亡之海”安集海河组,未出现井漏现象,取得了良好的应用效果。优化后的井身结构在H11井的成功应用,不仅为该地区深探井的井身结构设计提供依据,也为该地区后续常规井的四开转三开井身结构提供了指导。  相似文献   

西藏嘎拉勒夕卡岩型铜金矿白云母~(40)Ar-~(39)Ar年龄及其地质意义     

汪傲  赵元艺  许虹  卢伟  郭硕 《地质通报》2014,33(7):1008-1014

西藏嘎拉勒夕卡岩型铜金矿床中铜的资源量达到中型规模,金的资源量达到大型规模。在系统的野外地质调查基础上,选取矿床夕卡岩中保存极好的白云母,测得40Ar-39Ar年龄为91.48Ma±0.68Ma,代表矿床成矿年龄,表明矿床为燕山运动晚期的产物。结合区域地质资料认为,在拉萨地块中北部,成矿年龄约为90Ma的夕卡岩型—斑岩型矿床集中分布在措勤—申扎岩浆弧上;在早白垩世班公湖—怒江洋盆闭合后,狮泉河—永珠—纳木错—嘉黎蛇绿混杂带(Slainajap带)上的弧后盆地和弧间盆地演化成了一系列小洋盆,这些小洋盆的演化与中拉萨地块北部成矿年龄约为90Ma的夕卡岩—斑岩型矿床的形成有更直接的关系。今后宜加大在措勤—申扎岩浆弧上寻找成矿年龄约为90Ma的夕卡岩—斑岩型矿床的力度。  相似文献   

Impacts of relative sea level rise on the shoreface deposition,Shuidong Bay,South China   总被引：2，自引：1，他引：1  

Xiaoling Zhang  Zhijun Dai  Ao Chu  Jinzhou Du 《Environmental Earth Sciences》2014,71(8):3503-3515

The influence of relative sea level rise on shoreface deposition helps to elucidate changes in beach and nearshore geomorphology in response to different forcing factors. In this study, two sets of sediment samples, one from 1982 and one from 2004, from the Shuidong Bay of South China were analyzed to determine the changes in shoreface depositions. An EOF (Empirical orthogonal function) method was used to examine how these depositions changed based on the relative sea level rise. The results show that shoreface sediments of Shuidong Bay are mainly composed of sand. Fine-grained sediments are distributed in the lower shoreface/offshore area, and coarse-grained sediments are mainly found in the upper shoreface/nearshore area. Due to the altered hydrological forcing caused by relative sea level rise, the sand fraction in sediments increased from 84.7 % in 1982 to over 90 % in 2004, and the clay and silt fractions decreased from 11.8 % in 1982 to 5.6 % in 2004. Grain-size parameters in sediments in 2004 became coarser, slightly more well sorted, less skewed and had lower kurtosis than those in 1982. In addition, the shoreface deposition of Shuidong in 1982 and 2004 is distinctly different: a polarized mode was described by the first eigenfunctions, and a homogenized mode was described by the second eigenfunctions. The former means that the sediment components developed towards the two opposite poles, undergoing both coarsening and refining processes. The second mode indicates that the secondary variation in sediment components was mostly in the three intermediate-grained sand components. In the future, the Shuidong Bay shoreface may be subjected to even further erosion because of increases in the energy of the environment resulting from rapid relative sea level rise.  相似文献   

Study of the comprehensive risk analysis of dam-break flooding based on the numerical simulation of flood routing. Part I: model development     

Ruirui Sun  Xiaoling Wang  Zhengyin Zhou  Xuefei Ao  Xiaopei Sun  Mingrui Song 《Natural Hazards》2014,73(3):1547-1568

Dam-break floods have been of increasing concern to safety engineers and decision makers. The presence of complex terrain in inundation areas multiplies the simulation difficulty of flood routing. In previous studies, representing the flood routing parameters empirically does not reflect the characteristics of flood routing, which strongly influences the accurate assessment of the dam-break consequences. The basis for carrying out dangerous reservoir reinforcement is just engineering safety, without considering the actual situation of downstream areas. In this study, a comprehensive risk analysis of the dam-break flood was implemented based on the numerical simulation of flood routing. First, coupled with the volume of fluid method, a three-dimensional k–? turbulence mathematical model was developed for flood routing in complex inundation areas. Then, based on the flow parameters obtained through computational fluid dynamics modeling, the attribute measure methodology was used for the evaluation of consequences combined with the calculation of the dam-break consequences (loss of life, economic loss, social and environmental influence). Furthermore, a methodology containing the combined weight method and the technique for order performance by similarity to ideal solution method was proposed for risk ranking of dangerous reservoirs due to its logical consideration of scalar values that simultaneously account for both the best and worst alternatives. Finally, a sensitivity analysis was performed to provide information about the stability of risk ranking. The aforementioned model and methodology are applied to a case involving five reservoirs in the Haihe River Basin in China for Part II of this study.  相似文献   

Study of the comprehensive risk analysis of dam-break flooding based on the numerical simulation of flood routing. Part II: Model application and results     

Zhengyin Zhou  Xiaoling Wang  Ruirui Sun  Xuefei Ao  Xiaopei Sun  Mingrui Song 《Natural Hazards》2014,72(2):675-700

The present model and methodology described in Part I of this work are applied to perform a comprehensive risk analysis of the dam-break flood of five reservoirs in the Haihe River Basin, China. The results indicate that the three-dimensional numerical simulation considering complex terrain can reflect the characteristics of flood routing and the three-dimensional phenomena. Based on the simulation results, it can be concluded that the risk grades of the consequences induced by a gradual or instantaneous dam break of the Dongwushi reservoir are extremely serious, as determined through the attribute synthetic approach. The results obtained from ranking the risk by the technique for order performance by similarity to ideal solution method are that the Dongwushi reservoir has the most serious consequences when the dam breaks followed by the Lincheng reservoir, the Miaogong reservoir and the Yunzhou reservoir, and the Youyi reservoir has the least severe consequences. Though the ranking of the relatively comprehensive risk coincides with that of the consequences, the dam safety measured by the dam failure probability plays an important role in ranking the risk. A sensitivity analysis is performed by individually increasing the weight of each criterion by 20 %, and the ranking order is not changed, suggesting that the evaluation model is reasonable, stable and reliable.  相似文献   

Bootstrap aggregating approach to short-term load forecasting using meteorological parameters for demand side management in the North-Eastern Region of India     

Sarkar  Dipu  Ao  Taliakum  Gunturi  Sravan Kumar 《Theoretical and Applied Climatology》2022,148(3-4):1111-1125

Theoretical and Applied Climatology - Electricity is an essential commodity that must be generated in response to demand. Hydroelectric power plants, fossil fuels, nuclear energy, and wind energy...  相似文献   

构造附加动力对煤变质过程的影响          下载免费PDF全文

敖卫华  黄文辉  唐修义  陈萍 《地质科学》2012,47(2):517-529

本文从固体力学、构造物理化学的角度分析了煤岩所受应力的来源、性质以及应力在煤变质过程中的影响方式。作者在前人研究基础上,阐述了构造动力影响过程中煤岩能量的转换形式,分析了应力在烟煤分子团聚过程中的影响。研究认为,煤岩所受的各种应力(压应力、拉应力、剪应力)为地层压力与构造动力所造成的附加内力。这种附加内力可以分解为构造附加静水压力与偏应力两部分。构造附加静水压力主要影响煤岩的物理性质,如孔隙度、颗粒性质与瓦斯吸附特征,并对煤的化学煤化过程有缓慢促进作用。偏应力主要使煤岩发生变形和位移。煤化过程中,由构造运动所产生的动能转化为各种形式的热能、表面能、弹性变形能以及声、光、电、磁等形态能量。  相似文献   

使用CTMAB改良剂改良天然膨胀土的试验研究   总被引：2，自引：0，他引：2  

王保田  任骜  张福海  施建坤 《岩土力学》2009,30(Z2):39-42

CTMAB是一种新型的有机阳离子表面活性剂,采用CTMAB对天然膨胀土进行了化学改良试验研究,探讨了其改良机制和改良效果。试验结果表明：经过改良剂改良后的膨胀土与原状土相比,其塑性和膨胀性得到了明显降低,水稳定性有了显著提高,在经过不同次数的反复溶漓后,土样仍具有一定的强度。说明了CTMAB对膨胀土的工程性质有一定的改善作用。该成果已申请获得了国家发明专利。  相似文献   

湖北省蒲圻县(赤壁)幅1:50 000环境地质调查数据集          下载免费PDF全文

张傲  邵长生  王岑  杨艳林  路韬 《中国地质》2019,46(S2):50-59

依托自然资源部中国地质调查局部署的"长江中游城市群咸宁-岳阳和南昌-怀化段高铁沿线1：50 000环境地质调查"项目,开展了蒲圻县幅1：50 000环境地质调查。本数据集采取水文地质调查、岩溶地面塌陷调查、水文地质钻探、水质测试分析等方法而形成。数据集包含73个泉水调查点、7个矿泉水测试分析结果、1个岩溶地面塌陷点、7个岩溶洞穴点、10个水文钻孔等5方面数据。其中泉水调查成果包括泉点的分布位置、野外水质检测指标、泉水成因等;矿泉水分析结果为针对区内泉点及水文钻孔所取水样进行室内测试,达到矿泉水标准的测试结果;岩溶地面塌陷数据主要包括岩溶地面塌陷的位置、塌陷坑特征、地质背景、塌陷后状态等信息;岩溶洞穴调查成果包括洞穴点的位置、洞穴发育特征、开发利用情况等信息;钻孔基本情况数据为钻孔位置信息、孔径、孔深等信息。数据集为赤壁市城镇规划建设,土地安全利用,优质地质资源开发提供重要的地质数据源支撑。  相似文献