滨海地区地下水泄流研究进展     

李丹  王刚  丁丽娜  石磊 《化工矿产地质》2011,33(1):50-53

20世纪90年代以来出现的对滨海地下水的研究方式取得了有意义的结果.其中W.S.Moore通过对226Ra富集揭示了地下水对海岸水体大量补给的研究以及Jacob、Sun等关于潮夕动力地下水流法的研究对解决环境地质问题具有一定的意义.  相似文献   

基于水污染物通量的小流域生态补水研究     

石成春 《地质灾害与环境保护》2011,22(2):99-102

为改善水质环境,对福建省龙江中下流进行补水效果实验.根据控制断面测得的水质浓度和流量数据,计算水污染物通量.使用该通量评估污染负荷,计算生态补水量.所得污染物通量良好地反映出流域污染状况,实验效果显著,河流水质达到了国家规定标准.  相似文献   

Continual erosion of bare rocks after the Wenchuan earthquake and control strategies   总被引：1，自引：0，他引：1  

Zhaoyin Wang  Wenjing Shi  Dandan Liu 《Journal of Asian Earth Sciences》2011,40(4):915-925

The newly bared rocks created by the Wenchuan earthquake are undergoing continual intensive erosion in the form of detachment and movement of individual grains. Grain erosion is defined as the phenomenon of breaking down bare rocks under the action of insolation and temperature change, detachment of grains from the rockwalls by wind, flow down of grains on the slope under the action of gravity, and accumulation of grains at the toe of the mountain, forming a deposit fan. The Wenchuan earthquake, which occurred in Sichuan on May 12, 2008, caused thousands of avalanches and landslides and left scars on slopes and a huge area of bare rocks. Grain erosion causes flying stones, injured humans and resulted in numerous slope debris flows. The process of grain erosion and strategies to limit the erosion were studied by field investigations and field experiments. According to these field investigations and field studies, the most serious grain erosion occurs in spring and early summer when it is very dry. Rocks are broken down to grains under the action of insolation and temperature change. Then, wind blows the grains from the bare rock down slope. Experimental results showed that the amount of grains blown down by wind per area of rock surface per unit time is proportional to the fourth power of the wind speed. However, the size of the grains blown down by wind increases linearly with the wind speed. An experiment proved that grain erosion can be controlled with two moss species. Moss spores were mixed with clay suspension and splashed on bare rocks. The moss species germinated on the rock surface in one month and greened the bare rocks in two months. The moss layer protected the rocks from insolation and mitigated the effects of temperature change, thus effectively mitigated grain erosion.  相似文献   

Chemical and Strontium Isotopic Compositions of the Hanjiang Basin Rivers in China: Anthropogenic Impacts and Chemical Weathering   总被引：1，自引：0，他引：1  

Zhifang Xu  Chao Shi  Yang Tang  Hongyin Han 《Aquatic Geochemistry》2011,17(3):243-264

The Hanjiang River, the largest tributaries of the Changjiang (Yangtze) River, is the water source area of the Middle Route of China’s South-to-North Water Transfer Project. The chemical and strontium isotopic compositions of the river waters are determined with the main purpose of understanding the contribution of chemical weathering processes and anthropogenic inputs on river solutes, as well as the associated CO₂ consumption in the carbonate-dominated basin. The major ion compositions of the Hanjiang River waters are characterized by the dominance of Ca²⁺ and HCO₃ ⁻, followed by Mg²⁺ and SO₄ ²⁻. The increase in TDS and major anions (Cl⁻, NO₃ ⁻, and SO₄ ²⁻) concentrations from upstream to downstream is ascribed to both extensive influences from agriculture and domestic activities over the Hanjiang basin. The chemical and Sr isotopic analyses indicate that three major weathering sources (dolomite, limestone, and silicates) contribute to the total dissolved loads. The contributions of the different end-members to the dissolved load are calculated with the mass balance approach. The calculated results show that the dissolved load is dominated by carbonates weathering, the contribution of which accounts for about 79.4% for the Hanjiang River. The silicate weathering and anthropogenic contributions are approximately 12.3 and 6.87%, respectively. The total TDS fluxes from chemical weathering calculated for the water source area (the upper Hanjiang basin) and the whole Hanjiang basin are approximately 3.8 × 10⁶ and 6.1 × 10⁶ ton/year, respectively. The total chemical weathering (carbonate and silicate) rate for the Hanjiang basin is approximately 38.5 ton/km²/year or 18.6 mm/k year, which is higher than global mean values. The fluxes of CO₂ consumption by carbonate and silicate weathering are estimated to be 56.4 × 10⁹ and 12.9 × 10⁹ mol/year, respectively.  相似文献   

低渗透油藏CO2驱过程中含水率变化规律   总被引：1，自引：0，他引：1  

俞宏伟  杨思玉  李实  杨永智 《吉林大学学报(地球科学版)》2011,41(4):1028-1032,1047

通过国内外多个油田水驱后实施CO2驱的矿场实例研究,发现注入CO2后很多油井存在含水率下降的现象;这种现象发生在CO2驱的整个开发阶段,包括注气初期阶段CO2未到达生产井、生产井见气阶段以及高气油比阶段。重点讨论了生产井见气前的开发规律,在该阶段油藏内以油水两相渗流为主,不受三相渗流作用的影响。通过现场动态反应并结合室内细管和长岩心实验,揭示了CO2与油、水2种介质的相互作用,得到了两个结论:第一是始于低含水阶段的CO2驱过程中气体穿越地层水驱替地层油到达生产井;第二是始于高含水阶段的CO2驱替规律在不同级别低渗透岩心中的差异非常明显:对于特低渗岩心,CO2突破前的采出程度占CO2驱总采出程度的73.27%,CO2突破后的采出程度占26.73%,对于一般低渗岩心,CO2突破前的采出程度仅占CO2驱总采出程度的16.72%,而CO2突破后的采出程度占到了CO2驱总采出程度的83.28%。  相似文献   

滇东地区煤田构造格局与煤系赋存规律的研究   总被引：1，自引：0，他引：1  

陶志刚  曹代勇  李建  石显耀  林玉成  王坚 《中国煤炭地质》2011,(8):56-59

滇东地区位于特提斯和环太平洋构造体系的交接部位,煤田构造格局的总体特征是呈NNE向条带状展布。区内断层以NNE、NE向为主,受主要断裂影响,煤田在南北向呈带状,东西向呈段状展布,各煤矿区在平面上呈NE向带状分布。研究区煤系赋存受基底主干断裂的控制作用明显,变形强度由北向南逐渐增强,北部地区以褶皱构造为主,断层较少,煤层多保存于向斜构造中,保存较完整,煤层埋藏较深;南部受弥勒-师宗断裂带影响,断裂构造极为发育,对煤层破坏严重,煤系赋存不稳定。  相似文献   

http://www.sciencedirect.com/science/article/pii/S1674987111000752   总被引：2，自引：0，他引：2  

Jiansheng Shi  Zhao Wang  Zhaoji Zhang  Yuhong Fei  Yasong Li  Feng’e Zhang  Jingsheng Chen  Yong Qian 《地学前缘(英文版)》2011,2(4):593-598

A series of environmentalegeological problems have been caused by over-exploitation of deep groundwater (i.e., confined aquifer water) in the North China Plain. In order to better understand the status of deep groundwater over-exploitation and the resultant environmentalegeological problems on a regional scale, the over-exploitation of groundwater has been assessed by way of the groundwater exploitation potential coefficient (i.e., the ratio of exploitable amount of deep groundwater to current exploitation), cumulative land subsidence, and long-term average lowering rate of the groundwater table. There is a good correlation among the results calculated by the different methods. On a regional scale, deep groundwater has been over-exploited and there is no further exploitation potential under the current conditions. The groundwater exploitation degree index takes the exploitation in 2003 as the reference for the calculations, so the results mainly reflect the degree of current groundwater exploitation. The results of over-exploitation of deep groundwater obtained by land subsidence data and long-term average rate of depression of the water table mainly reflect environmentalegeological problems caused by exploitation of deep groundwater.  相似文献   

Numerical simulation of wave-induced currents combined with parabolic mild-slope equation in curvilinear coordinates     

崔雷  佟飞飞  石峰 《中国海洋工程》2011,25(3):457-468

Researches on breaking-induced currents by waves are summarized firstly in this paper. Then, a combined numerical model in orthogonal curvilinear coordinates is presented to simulate wave-induced current in areas with curved boundary or irregular coastline. The proposed wave-induced current model includes a nearshore current module established through orthogonal curvilinear transformation form of shallow water equations and a wave module based on the curvilinear parabolic approximation wave equation. The wave module actually serves as the driving force to provide the current module with required radiation stresses. The Crank-Nicolson finite difference scheme and the alternating directions implicit method are used to solve the wave and current module, respectively. The established surf zone currents model is validated by two numerical experiments about longshore currents and rip currents in basins with rip channel and breakwater. The numerical results are compared with the measured data and published numerical results.  相似文献   

Experimental researches on reflective and transmitting performances of quarter circular breakwater under regular and irregular waves   总被引：1，自引：1，他引：0  

史艳娇  吴米玲  蒋学炼  李炎保 《中国海洋工程》2011,25(3):469-478

A series of regular and irregular wave experiments are conducted to study the reflective and transmitting performances of quarter circular breakwater (QCB) in comparison with those of semi-circular breakwater (SCB). Based on regular wave tests, the reflection and transmission characteristics of QCB are analyzed and a few influencing factors are investigated. Then, the wave energy dissipation as wave passing over the breakwater is discussed based on the hydraulic coefficients of QCB and SCB. In irregular wave experiments, the reflection coefficients of QCB and their spectrums are studied. Finally, the comparisons between the experimental results and numerical simulations for QCB under regular and irregular wave conditions are presented.  相似文献   

Environmental capacity of chemical oxygen demand in the Bohai Sea: modeling and calculation     

赵喜喜  王修林  石晓勇  李克强  丁东生 《中国海洋湖沼学报》2011,29(1):46-52

A three-dimensional advection-diffusion model coupled with the degradation process is established for describing the transport of chemical oxygen demand (COD). Comparison of the simulated distribution of COD at the surface in the Bohai Sea in August, 2001 with field observations, shows that the model simulates the dataset reasonably well. The Laizhou Bay, Bohai Bay, and Liaodong Bay were contaminated heavily near shore. Based on the optimal discharge flux method, the Environmental Capacity (EC) and allocate...  相似文献