The Impact of Human Activities on Flood Trends in the Semi-Arid Climate of Cheliff Basin,Algeria

Water Resources - Algeria shares similarities with other countries of the world facing destructive floods. The need to understand changes in the intensity, frequency and severity of floods is...     

Runoff of Russian Rivers under Current and Projected Climate Change: a Review 2. Climate Change Impact on the Water Regime of Russian Rivers in the XXI Century

Water Resources - The present overview is the second part of the article “Runoff of Russian Rivers Under Current and Projected Climate Change: A Review,” which focuses on modern...     

Impact of Possible Climate Change on Extreme Annual Runoff from River Basins Located in Different Regions of the Globe

Water Resources - For 11 large river basins (the Rhine, Tagus, Ganges, Lena, Upper Yellow, Upper Yangtze, Niger, Mackenzie, Upper Mississippi, Upper Amazon and Darling) located on different...     

Assessment of Climate Change Impact on the Gharesou River Basin Using SWAT Hydrological Model

The evaluation of climate change and its side effects on the hydrological processes of the basin can increasingly help in dealing with the challenges that water resource managers and planners face in future courses. These side effects are investigated using the simulation of hydrological processes with the help of physical rainfall‐runoff model. Hydrological models provide a framework for examining the relationship between climate and water resources. This research aims at the investigation of the effect of climate change on the runoff of Gharesou, which is one of the main branches of the “Karkheh” River in Iran during the periods 2040–2069. To achieve this, the distributed hydrological model Soil and Water Assessment Tool (SWAT) – a model that is sensitive to the changes in land, water, and climate – has been used with the aim of evaluating the impact of climate change on the hydrology of the Gharesou Basin. For this reason, first, the continuous distributed model of rainfall‐runoff SWAT for the period 1971–2000 has been calibrated and validated. Next, with the aim of evaluating the impact of climate change and global warming on the basin hydrology for the period 2040–2069, HadCM3‐AR4 global climate model data under the A2 scenario – from the SRES scenario set‐haves been downscaled. Eventually, the downscaled climate data haves been introduced in the SWAT model, and the future runoff changes have been studied. The results showed that the temperature increases in most of the months, and the precipitation rate exhibits a change in the range of ±30%. Moreover, the produced runoff in this period changes from ?90 to 120% during different months.     

The Impact of Human Activities on Freshwater Aquatic Systems

The roles of oxygen and its activated species (superoxide radicals, hydrogen peroxide, hydroxyl radicals), as well as that of sulfur compounds, are considered in relation to biological quality and the self-cleaning capacity of freshwater aquatic systems. The effects on the aquatic redox-processes are discussed in terms of atmospheric fallout of sulfur compounds, bottom sediment composition, and input of wastewaters containing reducing substances. It is shown that the totality of anthropogenic influences, and/or unfavourable natural geochemical conditions, as well as climatic effects in a region can increase the significance of one-electron transfer processes in bio-geochemical cycles of oxygen, sulfur and manganese, compared with the significance of two-electron transfer processes. The resulting, reactive intermediate products of one-electron transfer processes are very important with respect to the composition and properties of aquatic systems. Examples are given of practical applications of wastewater treatment, using hydrogen peroxide and UV-irradiation, and of regulation of consumers’ activities which affect natural waters.     

Steric Sea-Level Change and its Impact on the Gravity Field caused by Global Climate Change

It is sometimes assumed that steric sea-level variations do not produce a gravity signal as no net mass change, thus no change of ocean bottom pressure is associated with it. Analyzing the output of two CO₂ emission scenarios over a period of 2000 years in terms of steric sea-level changes, we try to quantify the gravitational effect of steric sea-level variations. The first scenario, computed with version 2.6 of the Earth System Climate Model developed at the University of Victoria, Canada (UVic ESCM), is implemented with a linear CO₂ increase of 1% of the initial concentration of 365 ppm and shows a globally averaged steric effect of 5.2 m after 2000 years. In the second scenario, computed with UVic ESCM version 2.7, the CO₂ concentration increases quasi-exponentially to a level of 3011 ppm and is hold fixed afterwards. The corresponding globally averaged steric effect in the first 2000 years is 2.3 m. We show, due to the (vertical) redistribution of ocean water masses (expansion or contraction), the steric effect results also in a small change in the Earth’s gravity field compared to usually larger changes associated with net mass changes. Maximum effects for computation points located on the initial ocean surface can be found in scenario 1, with the effect on gravitational attraction and potential ranging from 0.0 to −0.7·10⁻⁵ m s⁻² and −3·10⁻³ to 6·10⁻³ m² s⁻², respectively. As expected, the effect is not zero but negligible for practical applications.     

Assessment of Anthropogenic Impact on River Basins in Southern Kuzbass Mining Areas

The total pollution caused by spreading and fallout of atmospheric aerosols in river catchment areas of a coal-mining region is estimated. The contribution of the emission produced by a coal mine to the total fallout in the territory is assessed. Different types of water pollution in the coal-mining region are analyzed, the principal pollutants are identified, and their contribution to river water quality is assessed.     

Effect of Present-Day Climate Changes and Agricultural Activities on Spring Overland Runoff in Forest-Steppe and Steppe Regions of the Russian Plain

Space and time analysis of the formation of spring overland runoff in forest-steppe and steppe regions of the Russian Plain has been carried out. It has been shown that, in addition to zonal climate conditions, its distribution over the area is largely determined by the agricultural load on river catchment areas, primarily, the structure of agricultural lands—the proportions of areas under winter tillage and consolidated tillage. The character of overland runoff response to present-day climate changes and agricultural activity has been identified, and quantitative estimates have been given to the manifold hydrological role of these factors.     

Hydrological Response of Runoff to Climate Change of Typical Tributaries in Ebinur Lake Basin of Xinjiang

In recent years, the natural hydrology behaviors were greatly influenced by climate change. The relation between runoff and climate change are always the core of scientific hydrological study in arid region. This paper presents a multi-variate time series controlled auto-regressive (CAR) model based on hydrological and climatic data of typical tributaries Jinghe River in Ebinur Lake Basin of Xinjiang covering the period from 1957 to 2012. The aim is to study the climate change and its effects on runoff of the Jinghe River, Northwest China. The results showed the following: the runoff of the Jinghe River was unevenly distributed and has obvious seasonal changes throughout the year. It was concentrated in summer and has along dry season with less runoff. The monthly maximum river runoff was from June to September and accounted for 74% of annual runoff. The river runoff increased since the 1980s till the 1990s; in the 21st century there was a trend of decreasing. The oscillatory period of annual runoff series in the Jinghe River Basin was 21a and 13a, and these periods were more obvious, followed by 32a and 9a. The oscillation with a time scale of 21a and 13a was a fulltimed domain. The MRE is 6.54%, the MAE is 0.84 × 10⁸ m³, and the RMSE is 0.039. The CAR model passed the F-test and residual test, and the change trend of calculated and measured values of annual runoff is consistence, which means that the model was reasonable.     

土—结构相互作用对煤矿采动损伤建筑的抗震性能影响分析

为了探讨土—结构相互作用对煤矿采动损伤建筑地震动力破坏的影响,基于损伤力学和能量耗散理论,研究采动区土—基础—上部结构的协同作用,通过建立考虑土—结构相互作用的煤矿采动损伤建筑的动力学方程,重点分析了煤矿采动损害影响下的建筑物地震动力灾变演化过程。计算结果表明:土—结构的相互作用对煤矿采动建筑的地震动力响应影响较大,不考虑土—结构相互作用是偏于安全的;煤矿采动作用明显改变了建筑物的结构动力特性,建筑结构的薄弱层位置改变明显、塑性铰和层损伤分布规律发生改变,严重降低了建筑物的抗震性能,对于煤矿采动区建筑应当开展安全损伤评估工作,以保证矿区工程建设的安全性和可靠性。     

The Runoff Declining Process and Water Quality in Songhuajiang River Catchment,China under Global Climatic Change

The runoff in Songhuajiang River catchment has experienced a decreasing trend during the second half of the 20th century. Serially complete daily rainfall data of 42 rainfall stations from 1959 to 2002 and daily runoff data of five meteorological stations from 1953 to 2005 were obtained. The Mann–Kendall trend test and the sequential version of Mann–Kendall test were employed in this study to test the monthly and annual trends for both rainfall and runoff, to determine the start point of abrupt runoff declining, and to identify the main driving factors of runoff decline. The results showed an insignificant increasing trend in rainfall but a significant decreasing trend in runoff in the catchment. For the five meteorological stations, abrupt runoff decline occurred during 1957–1963 and the middle 1990s. Through Mann–Kendall comparisons for the area‐rainfall and runoff for the two decreasing periods, human activity, rather than climatic change, is identified as the main driving factor of runoff decline. Analysis of land use/cover shows that farmland is most related with runoff decline among all the land use/cover change in Nenjiang catchment. From 1986 to 1995, the area of farmland increased rapidly from 6.99 to 7.61 million hm². Hydraulic engineering has a significant influence on the runoff decline in the second Songhuajiang catchment. Many large‐scale reservoirs and hydropower stations have been built in the upstream of the Second Songhuajiang and lead to the runoff decline. Nenjiang and the Second Songhuajiang are the two sources of mainstream of Songhuajiang. Decreased runoff in these two sub‐catchments then results in runoff decrease in mainstream of Songhuajiang catchment. It is, therefore, concluded that high percent agricultural land and hydraulic engineering are the most probable driving factors of runoff decline in Songhuajiang River catchment, China.     

流域土地利用/覆被变化的水文效应及洪水响应

干旱与洪涝灾害已成为全球关心的重大问题.土地利用/覆被变化影响雨水的截留、下渗、蒸发等水文要素及其产汇流过程,并进而影响流域出口断面的流量过程,加大流域洪涝灾害发生的频率和强度.深入研究土地利用/覆被变化对洪涝灾害的影响,对于社会经济可持续发展具重要意义.通过分析和总结已进行的有关流域土地利用/覆被变化的水文效应及洪水响应研究工作进展,讨论了其研究内容、方法及现有工作的不足之处.     

Impacts of Coal Mining on the Aboveground Vegetation and Soil Quality: A Case Study of Qinxin Coal Mine in Shanxi Province,China

The exploitation and utilization of coal resources have been lasting for thousands of years, resulting in a series of ecological environmental problems in China. So far, the mining area has changed into severe and typical damaged ecosystem locally and globally. The coal exploitation history is long in Shanxi province, but goafs are distributed widely. In this study, we addressed this point and took a coal mine, located in Shanxi province where the coal mining has a long exploitation history with goaf densely distributed, as an example. The growth patterns of above ground plant communities, succession characteristics of vegetation community and soil quality characters in the goafs, which could provide theoretical basis for the sustainable development of coal resources and ecological reconstruction in this region, have been studied.     

Hydrogeochemical Processes and Quality Assessment of Groundwater in Sulin Mining Area,Northern Anhui Province,China

Water Resources - In mining areas, coal production, agriculture, and drinking use had increased the demand for fresh groundwater. It was essential to obtain a deeper understanding of the...     

矿震和水库地震等非天然地震的公共服务需求调查研究

采矿、水库蓄水等人类活动可能伴随地震的发生,其突发性和破坏性会对公共安全、社会稳定和经济发展带来威胁。本文围绕国内外矿震、水库地震等非天然地震事件的公共服务需求和相关部门的应急处置措施进行调研分析,发现对于不同类型的地震,公共服务需求存在差异,归纳得到以下针对地震部门和相关单位的应急处置对策建议：震前,完善和落实应急预案,提升建（构）筑物抗震设防等级,规范相关企业行为;震时,判别地震类型并核准地震信息,多部门联动开展应急响应,完善灾情收集渠道;震后,注重科普宣传和舆论疏导。平震结合,多方协调,可有效应对非天然地震事件,维护社会稳定和谐。     

Surface Water Contamination by Uranium Mining/Milling Activities in Northern Guangdong Province,China

The northern region of Guangdong Province, China, has suffered from the extensive mining/milling of uranium for several decades. In this study, surface waters in the region were analyzed by inductively coupled plasma optical emission spectrometry (ICP‐OES) for the concentrations of uranium (U), thorium (Th), and non‐radioactive metals (Fe, Mn, Mg, Li, Co, Cu, Ni, and Zn). Results showed highly elevated concentrations of the studied radionuclides and metals in the discharged effluents and the tailing seepage of the U mining/milling sites. Radionuclide and heavy metal concentrations were also observed to be overall enhanced in the recipient stream that collected the discharged effluents from the industrial site, compared to the control streams, and rivers with no impacts from the U mining/milling sites. They displayed significant spatial variations and a general decrease downstream away from upper point‐source discharges of the industrial site. In addition, obvious positive correlations were found between U and Th, Fe, Zn, Li, and Co (R² > 0.93, n = 28) in the studied water samples, which suggest for an identical source and transport pathway of these elements. In combination with present surface water chemistry and chemical compositions of uraniferous minerals, the elevation of the analyzed elements in the recipient stream most likely arose from the liquid effluents, processing water, and acid drainage from the U mining/milling facilities. The dispersion of radionuclides and hazardous metals is actually limited to a small area at present, but some potential risk should not be negligible for local ecosystem. The results indicate that environmental remediation work is required to implement and future cleaner production technology should be oriented to avoid wide dispersion of radioactivity and non‐radioactive hazards in U mining/milling sites.