咸阳市漆水河防洪工程洪水计算

在漆水河流域自然状况勘查及洪水调查的基础上,分析了龙岩寺、好寺河水文站洪水系列的可靠性、代表性,经过适线,求得了羊毛湾水库坝址不同频率的洪水成果,为工程兴建提供了资料依据。     

Delayed influence of dam storage and discharge on the determination of seasonal proliferations of Microcystis aeruginosa and Stephanodiscus hantzschii in a regulated river system of the lower Nakdong River (South Korea)

This study presents the relationship between the dam hydrology and phytoplankton proliferations in a regulated river system in East Asia. A long-term ecological study reveals that multi-purpose dam regulation on river flow in the Nakdong River (South Korea) affects proliferating patterns of phytoplankton, especially during summer (June-August) and winter (December-next February) as Microcystis aeruginosa and Stephanodiscus hantzschii, respectively, dominate each season by over 80%. Eutrophication was observed in the lower Nakdong River (South Korea) (mean+/-standard deviation: nitrate-N, 2.8+/-0.9 mg L(-1); phosphate-P, 40.3+/-31.3 microg L(-1); chlorophyll a, 45.2+/-84.9 microg L(-1); n=449), and the limnological characteristics responded to climatic variations such as monsoon and summer typhoons. The river basin experiences concentrated rainfall during the rainy season (June-September, over ca. 60% of total annual rainfall). Correlation and cross-correlation for time-delayed relationship revealed the hydrological environments (i.e., quantity of dam storage and discharge) had significantly negative relationship with the population dynamics of the two bloom-forming species for up to the next 2 years. S. hantzschii had clearer relationship with dam storage and discharge, which might be due to the seasonality exhibited by the species. The results support the necessity of "smart flow control" which may enable destruction of bloom formation by the two species with an adequate pulse of discharge generated by upstream dams in the far-east Asian river systems. This would increase the efficiency of water resource management system.     

The Watershed Architecture of the Mekong River Basin

In this project, I suggest an alternative, speculative future in counterpoint to the recent construction and planned development of large-scale, water-based infrastructural transformations in Southeast Asia. Critical of massive hydropower dam constructions that tend to prioritize certain interests over others, I question the future viability of such actions when weighed in the context of possible negative effects that such dams may have across the entire river basin. Additionally, the current forecast of climate change stressors, especially in regards to freshwater availability, positions the future of the basin as uncertain. The focus of this essay is part of my multiyear project titled “Way Beyond Bigness: The Need for a Watershed Architecture,” which studies the Mekong, Mississippi, and Rhine River Basins in relation to water-based infrastructure and design challenges.     

Causes of seasonal flooding in flood plains: a case of Makurdi,Northern Nigeria

This study assessed several factors and their implication for flooding in Makurdi which is located in the flood plains of the River Benue. The annual rainfall of Makurdi between 1979 and 2008 was analysed for annual totals, intensity, frequency, peak periods and trend to demonstrate propensity to cause flooding while records on relief, water table, urbanisation and the river Benue were examined for their contribution. This study has identified amongst other things that areas of low relief in Makurdi are susceptible to seasonal flooding between June and October annually. The study also identified the causes of floods and factors which intensify floods in Makurdi town. Heavy, intense rainfall and the River Benue spilling its banks are the major causes of floods in Makurdi town. Other factors which intensify flooding in Makurdi town include its low relief, high water table, urbanisation and human activities.     

金沙江虎跳峡河段河床深厚覆盖层成因及工程意义

 虎跳峡河段具备建设金沙江中游龙头水库的地形、地质条件,开发效益十分显著。本河段河床覆盖层深厚,最深达250 m,在深厚的覆盖层上建设高坝大库技术难度大,研究河床覆盖层的成因和探讨深厚覆盖层建高坝的可行性对本河段水电开发方案坝址比选意义重大。通过大量的地质调查、勘探、岩土测试等勘察成果,揭示了本河段河床深厚覆盖层的成因：本河段主要受新构造运动的影响,区域垂直升降活动明显,形成了滇西北地区有名的古龙蟠断陷盆地,东侧的玉龙山在中更新世以来不断抬升,龙蟠盆地相对下降并陆续接受各种类型的沉积,河床最终形成了现今的深厚覆盖层。本河段水电开发较典型的比选坝址有8处,其中位于虎跳峡大峡谷地段的下峡口、上峡口2个坝址的河床覆盖层相对较浅(厚40～50 m),坝基处理较容易;上游河段石鼓、红岩、上江3个坝址河床覆盖层最为深厚(厚172～250 m),根据目前世界筑坝技术水平,大坝只宜座落在覆盖层上,坝高最低为250 m级水平,修建高土石坝技术均达到甚至超过世界前沿水平;龙蟠、塔城、其宗3个坝址河床覆盖层深度相当(厚100 m左右),覆盖层全挖或利用方案的大坝规模均已接近甚至达到当前国内外大坝建设的最高水平,筑坝技术需深入研究。结果对研究金沙江河谷发育史以及今后类似工程坝址比选均具有重要的科学和参考价值。     

A Survey Of Health Effects Of Air Pollution On Peasant Farmers In Benue State,Nigeria

This paper examines the health effects due to air pollution on peasant farmers in Benue State, Nigeria. The study is based on the review of epidemiological data collected from clinics and hospitals in the State. The diseases found to be prevalent in the study area include allergic asthma, pulmonary tuberculosis, pneumonia, upper respiratory tract infection (URTI), chronic bronchitis and visual impairment. The ambient air quality in the state is far worse than national and international ambient air quality standards. This gives an indication of a strong correlation between the diseases and the air pollutants. The environmental impact matrices of the patients versus diseases indicate that pollution is already affecting the quality of life and productivity of the people. Since agriculture is the principal occupation of Nigerians, accounting for about 60% of employment, a case is made for an intensification of environmental education, especially among the rural farmers.     

Biomonitoring of the genotoxic potential (micronucleus assay) and detoxifying activity (EROD induction) in the River Dadou (France), using the amphibian Xenopus laevis

Within the framework of a general survey of the water quality of the river Dadou (Tarn, France), different physico-chemical parameters were measured and an inventory of the fish population was made along the water course, around the Rassisse dam. With the aim of monitoring the potential genotoxic effects and the detoxifying activities induced in organisms exposed to the river water, two in vivo bioassays were performed in laboratory experiments, using larvae of the amphibian Xenopus laevis. The first was the micronucleus test, using red blood cells, and the second the assay of ethoxyresorufin-O-deethylase (EROD) induction in the liver of exposed animals. Eight water samples were taken from the river and at outlet points from the two major industrial activities of the studied section of the water course: a spar-fluor mine and a water treatment plant. Genotoxic impact and EROD induction were measured in the larvae. The effluent of the filter-washing process from the water treatment plant was found to be particularly genotoxic, even after dilution in pure reconstituted water, but no particular genotoxicity was found, either in Dadou river water, or in the effluents from the mine. On the other hand, most of the water samples tested produced a clear induction of EROD activity compared to the level of enzymatic activity found in the liver of larvae reared in the river water sampled upstream of the industrial activities. These results were interpreted taking into account (i) the high concentrations of pollutants (fluorine and manganese) measured in the river water, (ii) the very low population levels inventoried in the downstream section of the river and (iii) the possible interactions between the substances present in the river water, particularly the classical EROD inducers PAHs and PCBs.     

基于线性文化遗产视域下的湖南沅水流域古镇保护研究

本研究在线性文化遗产保护的背景下,追寻历史踪迹,感悟沅水流域古镇的神韵,思考和保护沅水流域古镇的方法。在湖南沅水流域古镇的调查研究报告的基础上,指出该流域古镇保护存在：主导经济模式不明确、新旧城建设矛盾激化和缺乏线性文化遗产整体保护的科学观等问题。因此,根据沅水流域地貌环境相似、流域经济相通、多民族文化共融以及文化资源分布集中的特点,该文提出建立沅水流域遗产管理机构、遗产评估体系、遗产分层保护框架、遗产管理条例等保护措施,以期形成科学有效的沅水流域古镇保护体系,同时为其他流域文化遗产保护工作作出探索性的示范研究。     

修建在砂砾岩地基上的拱坝应力分析

在砂砾岩基础上修建拱坝，坝体的垂直方向和顺河向变形是否过大，是关系到拱坝安全甚至能否修建的重要因素。砂砾岩受力变形有两个特点：一是在较低应力条件下，仍有较大的不可恢复变形；二是不同应力条件下，岩石的切线变形模量不同。通过分析现场原位变形试验，构造出能够反应出砂砾岩受力变形特点的非线性本构模型，并应用到实际工程中，分析其对坝体变形、应力的影响，可为工程规划和设计提供一定的参考依据。     

地震力与共振动水压力综合作用下冰碛堰塞坝失稳机制研究

 小型库湖中地震产生的水体共振现象是一直被忽视的问题。在我国帕隆藏布流域,即使是小型堰塞湖溃决,仍可能因灾害链效应而形成大灾,但有关地震力与共振产生的动水压力综合作用下的冰碛堰塞湖溃坝机制研究尚属空白。利用大型振动台实验揭示地震动水压力的分布规律;结合弹簧模型,提出水体共振时最大地震动水压力的经验公式;基于极限平衡理论,采用拟动力方法模拟地震力,建立地震振动与共振动水压力综合作用下堰塞坝的整体稳定性分析模型;以川藏铁路拟经帕隆藏布流域为例,比较考虑和不考虑水体共振下35个冰碛堰塞坝的整体稳定性,对小型冰碛堰塞湖溃决进行危险性评估。该研究为小型库湖地震溃决风险预测增加了新认识。     

Geomorphological impacts of Inanda Dam on the Mgeni estuary, north of Durban, South Africa)

 Completed in 1988 at a site some 32 km from the Mgeni river mouth, the Inanda Dam may have influenced bed load transport and deposition. The aims of this study were to ascertain whether the dam had affected fluvial sediment delivery to the lower channel, whether the sediment characteristics and bedform of the estuary had been modified and, within this context, to predict the likely effects of continued sand mining on the Mgeni estuary. Re-examination of estuarine cross sections originally surveyed prior to dam completion, comparison of present estuarine sediment characteristics with those of pre-dam sediments and a bottom survey of the Inanda Dam itself were key elements in the analysis. Mean annual discharge of the Mgeni river has reduced by 4% since dam construction and changes in discharge regime caused by the water release policy resulted in an increase in competent discharge events. Retention of sediment behind the dam wall had led to reduction in available downstream sediment. Sediment volume in the estuary had not changed significantly since 1989, although sediment calibre is now much finer. These changes will probably signal the end of sand mining in the lower river and will ultimately cause the estuary to deepen as residual pre-dam sediment is flushed through and not replaced by new material from upstream. Since Mgeni sediment is a source of material for natural beach nourishment, it is likely that beaches will become narrower. Received: 20 November 1999 · Accepted: 3 April 2000     

Climate-change impacts on hydrology and nutrients in a Danish lowland river basin

The Mike 11-TRANS modelling system was applied to the lowland Gjern river basin in Denmark to assess climate-change impacts on hydrology and nitrogen retention processes in watercourses, lakes and riparian wetlands. Nutrient losses from land to surface waters were assessed using statistical models incorporating the effect of changed hydrology. Climate-change was predicted by the ECHAM4/OPYC General Circulation Model (IPCC A2 scenario) dynamically downscaled by the Danish HIRHAM regional climate model (25 km grid) for two time slices: 1961-1990 (control) and 2071-2100 (scenario). HIRHAM predicts an increase in mean annual precipitation of 47 mm (5%) and an increase in mean annual air temperature of 3.2 degrees C (43%). The HIRHAM predictions were used as external forcings to the rainfall-runoff model NAM, which was set up and run for 6 subcatchments within and for the entire, Gjern river basin. Mean annual runoff from the river basin increases 27 mm (7.5%, p<0.05) when comparing the scenario to the control. Larger changes, however, were found regarding the extremes; runoff during the wettest year in the 30-year period increased by 58 mm (12.3%). The seasonal pattern is expected to change with significantly higher runoff during winter. Summer runoff is expected to increase in predominantly groundwater fed streams and decrease in streams with a low base-flow index. The modelled change in the seasonal hydrological pattern is most pronounced in first- or second-order streams draining loamy catchments, which currently have a low base-flow during the summer period. Reductions of 40-70% in summer runoff are predicted for this stream type. A statistical nutrient loss model was developed for simulating the impact of changed hydrology on diffuse nutrient losses (i.e. losses from land to surface waters) and applied to the river basin. The simulated mean annual changes in TN loads in a loamy and a sandy subcatchment were, respectively, +2.3 kg N ha(-1) (8.5%) and +1.6 kg N ha(-1) (6.9%). The rainfall-runoff model and the nutrient loss model were chained with Mike 11-TRANS to simulate the combined effects of climate-change on hydrology, nutrient losses and nitrogen retention processes at the scale of the river basin. The mean annual TN export from the river basin increased from the control to the scenario period by 7.7%. Even though an increase in nitrogen retention in the river system of 4.2% was simulated in the scenario period, an increased in-stream TN export resulted because of the simulated increase in the diffuse TN transfer from the land to the surface-waters.     

Regionalization of water quality in the upper fraser river basin, British Columbia

Uniformity of water quality in the Upper Fraser River basin was examined using cluster analysis. Substantial variations in water quality exist within the basin. These differences are largely related to the geology of the watersheds. Differences in water quality were more pronounced among the tributaries than along the mainstem of the Fraser River. The mainstem of the river could be considered to have three distinct reaches where water quality properties were relatively constant. Cluster analysis was a useful technique for establishing similarities and differences for both the tributaries and the mainstem stations. Some limitations of water quality data and the methods used are discussed. The diversity of water quality found to exist within this basin suggests that uniform criteria or objectives cannot be applied to the basin as a whole, but may be applied to smaller units.     

Influence of deep seated discontinuities on the left slope of Jinping I Hydropower Station and its stability analysis

This paper presents a case history detailing the development of cracks within a rock mass up to 350 m from the steeply incised valley slopes of the Yalong river in South West China, where the Jinping I dam is being constructed. The cracks have opened along previous tectonic structural features such that they penetrate further into the rock mass in the metasandstones and slates than in the marble. The presence of these cracks significantly reduces the stability of the near surface rock mass, requiring major excavation at the dam abutment. Analysis has indicated that the most appropriate way of stabilizing the slopes before the dam is constructed is by grout-infilled, specially constructed galleries which extend 60–80 m from the freshly excavated abutment.     

Impact on hydrodynamics of the estuarine region of Mahadayi (Mandovi) river due to change in flow pattern

A proposal to construct a dam on the river Mahadayi (Mandovi) for power generation would change the hydrodynamics of the estuarine stretch of the river. Using DYNHYD, the hydrodynamic model of WASP developed by the USEPA, several space and time dependent parameters were estimated in the stretch of approximately 80 km from the mouth of the river close to Panaji City up to the village of Sonali. The model was calibrated through the observed and predicted salinity values at various segments for summer and monsoon flows in the river. The channel flow variations in the river and estuarine zone, as well as flow velocities, effect on salinity have been predicted for pre‐ and post‐project scenarios. The natural variation in the river flow during a year was from 1.3 cum/s to 824 cum/ s. In the post project scenario, the variation ranged from 18.3 cum/s to 724 cum/s, respectively. The results indicated that predicted impact of salinity changes in the estuarine portion of the river Mandovi will be marginal. A stretch of about 12.5 km from Usgaon Pali village to Amone village may change from mesohaline to oligohaline during summer due to the construction of the dam.     

Three-dimensional seismic response analysis of a concrete-faced rockfill dam on overburden layers

Reasonable seismic response analysis of a high rockfill dam is of great engineering significance in guiding its design and ensuring its seismic safety during operation, especially of a concrete-faced rockfill dam (CFRD) on overburden layers. The three-dimensional seismic behavior of the Miaojiaba CFRD is simulated and analyzed by the finite element method (FEM). The results indicate that: 1) the amplification coefficient along the dam axis gradually increases with the altitude, and reaches maximum at the dam crest; 2) the vertical residual deformation mainly exhibits downwards and reaches maximum near the dam crest; 3) the earthquake significantly aggravates the deformation of peripheral joints; 4) the impounding condition and overburden characteristics have great effects on the dam’s seismic response.     

An integration of aeromagnetic and electrical resistivity methods in dam site investigation

Aeromagnetic map (Katsina-Ala sheet 272 S.E.) and the electrical resistivity sounding data obtained along eight traverses, from two sites, across the Katsina-Ala river were examined with the principal aim of defining depths to the bedrock, bedrock relief, geologic structures and the nature of the superficial deposit. The purpose of this exercise was the selection of probable axis for a hydroelectric power dam. The aeomagnetic map shows the basement rocks trending roughly NE-SW. This trend correlates with the 40°–45° strike of foliation measurements made on the rock outcrops along the river channel. A network of cross cutting lineaments suspected to be fault/fractures trending approximately NE/SW and NW/SE was delineated from the magnetic map. The depths to the bedrock estimated from depth sounding data at site I generally vary from 1–53.1 m. Depths to the bedrock estimated at site II range from 1.9–19.5 m. The superficial deposit varies from clay to sandy clay. clayey sand (with boulders in places), sand and laterite. The bedrock relief is relatively flat and gently undulating along most of the traverses with an overall dip towards the river channel. Except for the relatively high overburden thicknesses, two traverses at site I and one traverse at site II are probable, axes for a major and minor dam respectively.     

水电站运行对宝成线路基边坡稳定性影响评价

针对宝成铁路部分地段沿嘉陵江右岸前进,荷叶坝水电站的蓄水运行易导致水库塌岸等问题,从边坡地层岩性、地质构造、边坡形态、库水位变化、水库淤积等方面对铁路路基的稳定性进行分析,并对其进行了分段评价,提出了路基边坡的防护措施。     

Modelling the impacts of Combined Sewer Overflows on the river Seine water quality

To achieve the objectives of the European Water Framework Directive (EWFD), the Seine basin Water Authority has constructed a number of prospective scenarios forecasting the impact of planned investments in water quality. Paris and its suburbs were given special attention because of their impact on the river Seine. Paris sewer system and overflow control is of major concern in future management plans. The composition and fate of the urban effluents have been characterized through numerous in situ samplings, laboratory experiments and modelling studies. The PROSE model was especially designed to simulate the impact on the river of both permanent dry-weather effluents and of highly transient Combined Sewer Overflow (CSO). It was also used to represent the impact of Paris at large spatial and temporal scales. In addition to immediate effects on oxygen levels, heavy particulate organic matter loads that settle downstream of the outlets contribute to permanent oxygen consumption. Until the late 90s, the 50 km long reach of the Seine inside Paris was permanently affected by high oxygen consumption accounting for 112% of the flux upstream of the city. 20% of this demand resulted from CSO. However, the oxygenation of the system is strong due to high phytoplankton activity. As expected, the model results predict a reduction of both permanent dry-weather effluents and CSOs in the future that will greatly improve the oxygen levels (concentrations higher than 7.3 mgO(2) L(-1), 90% of the time instead of 4.0 mgO(2) L(-1) in the late 90s). The main conclusion is that, given the spatial and temporal extent of the impact of many CSOs, water quality models should take into account the CSOs in order to be reliable.