Wang, Fushun; Maberly, Stephen C.; Wang, Baoli; Liang, Xia. 2018. Effects of dams on riverinebiogeochemicalcycling and ecology [in special issue: Effects of dams on river biogeochemistry and ecology] Inland Waters, 8 (2). 130-140. https://doi.org/10.1080/20442041.2018.1469335
flow and ecology of the river permanently until then. Moreover, removal of dams can lead to floods in the plain areas as due to removal of dams, sludge flows down to the plains. Moreover, these dams are corroded because of the mud flowing down into the dams from the hilly areas. This has reduced the life of Bhakra Dam in India from 88 years to 47 years whereas that of Hirakund from 110 years to 35 years.Dams can also increase or decrease the temperature of the rivers thus killing the marine life in the rivers and around it. Some canals and other water bodies emerge from dams. The soil in these canals is degraded due to dams. As a result of which fluoride, calcium and other minerals get imbalanced in the soil. Which, through crops lead to gastrointestinal diseases, goitre etc in humans.
set of international actors, interdependencies and ecological impacts necessitates a broad theoretical framework . This research uses the conceptual framework of the ‘Political Ecology of the Asian Drivers’. The political ecology framework  is used as a basis for analysing the implications caused by the varied forms of control over the access to natural resources such as water and energy [10, 32, 38] to highlight governance issues and the unequal distribution of costs and benefits associated with environmental change brought by human intervention, in this case by large infrastructure development. Large energy infrastructures such as dams have profound effects on the society-environment relationships. Large dams are most of the time associated with land enclosures for infrastructure development, resettlement of the local population and environmental impacts. Power relations between different actors embedded in social and political interests of large dams’ construction can influence society-environment interactions in different ways, such as access to resources, assessment and mitigation of the impacts. To analyse power relations and their influence on society-environment interactions associated with large dams development, we combine the political ecology framework with the ‘Asian Drivers’ framework. The Asian Drivers framework developed by Humphrey and Messner , Schmitz , and Kaplinsky and Messner  assesses China’s direct and indirect impacts as a Rising Power and its channels of interaction with low and middle income countries. In each of these channels - aid, trade, investment, global governance, individuals/migrants and environment – there will be a mixture of complementary and competitive economic impacts and positive and negative impacts in relation to society and the environment . Urban et al.  advanced the Asian Drivers Framework further by addressing the motives, actors and beneficiaries in addition to impacts to analyse how, why and with which impacts Chinese actors engage in low and middle income countries (Table 1).
Many studies have looked at the effects of dams on the downstream rivers. Comprehensive reviews are given by (for example) Brandt (2000), Petts & Gurnell (2005) and Beck & Basson (2003). Dams alter the geomorphology and ecology of the rivers downstream through the reduction of total flows (due to evaporation and abstraction), through the altering of natural flow patterns (almost always reducing the magnitude of frequent floods, and often increasing the dry-season low flows), and through the trapping of sediments and nutrients. The downstream impacts are highly dependent on dam operation as well as the dam capacity- to-inflow ratio. Alterations to the downstream river include changes in channel width, channel depth, bed material composition, sediment concentrations, channel slope, bed form (eg. ripples or dunes), plan form (i.e. channel patterns: straight, meandering or braided), and riparian vegetation. These changes in turn affect the riverineecology.
Despite the abundance of articles, various scholars state that many research gaps remain in the literature, amongst others the leading anthropologist Michael Cernea of the World Bank (Cernea, 2004b; Tilt, Braun, & He, 2009; Vanclay, 2002). One of the main weaknesses in the literature is the assessment of the social impacts of dams. Most authors depend on “Inductive, ‘thick description’ and qualitative research approach focused on the resettlement area”, and fail to delineate or assess their social impact research (Kirchherr & Charles, 2016, p. 102). A reason for the authors engaging in social impact research without a framework, is the complexity of dams’ social impact. A myriad of social impacts occur during the design, construction and operational phase over various dimensions. The impact of dams are more complicated and comprehensive than of other infrastructure projects, because of the multitude of purposes dams serve (Kirchherr et al., 2016). Scholars often do not possess the resources to comprehensively study all the social impacts, particular components are focused upon.
Water molecules are made of hydrogen and oxygen atoms. Hydrogen and oxygen are nutrients that organisms need. Clearly there is no problem obtaining these nutrients in aquatic ecosystems. However, they are sometimes in short supply in terrestrial ecosystems. The cycling of water in nature involves both aquatic and terrestrial ecosystems and the air above them. Let’s see how this
Exercise performance in the heat has been shown to decline when the level of dehydration during exercise reaches as little as two percent of the body weight loss (25). In this study, subjects lost 2.6 ± 0.5 % and 2.8± 0.5% body weight as a result of exercise with H and P trials respectively, which would have affected their performance. These values indicated that both H and P drinks produced the same effect on body weight loss and hence similar performance effects.
the selected percentile levels or a simple multiple of the parameter standard deviations for the natural or pre-impact hydrologic regime. The management objectives are to attain the targeted range at the same frequency as occurred in the natural or pre-impact flow regime, evaluate the effects of dams and sluices on river flow regime, and set management targets. For example, attainment of the RVA target range defined by the 25th and 75th percentile values of a particular parameter would be expected in only 50% of years. To quantify the hydrologic alteration, Richter et al. (1998) divided the ranges of hydrologic alteration into three classes of equal range: 0%–33% (L) represents little or no alteration, 34%–67% (M) represents moderate alteration, and 68%–100% (H) represents a high degree of alteration.
Using a 300 m transect of monitoring wells from the plantation-forested lowland to an estuary, we examined groundwater physico-chemical conditions and the abundances of cultivable Fe- (and Mn-, S-) oxidizing and reducing bacteria in the shallow aquifer. We specifically focused on a group of neutrophilic Fe(II)-oxidizing bacteria which have recently been found ubiquitous in surface and subsurface waters encompassing the catchment study area (Lin et al., 2012). The objectives were to identify environmentally significant functional bacterial groups contributing to biogeochemical processes in this estuary-adjacent ecosystem, and to evaluate implications for groundwater Fe (and Mn, S) cycling and potential water quality impacts.
While hydroelectric dams contribute to atmospheric preservation, they still present much concern. Whether these benefits outweigh the concerns is controversial, debatable, and a contributing factor to many international political disputes. The main problem is address- ing the issues that arise between States given the applicable interna- tional environmental law. While one State may determine that the advantages of a particular hydroelectric dam outweighs the potential disadvantages, another nation, also affected by the potential dam, may not agree. The possibility for this scenario is quite likely since nearly fifty percent of Earth’s land surface (not including Antarctica) and sixty percent of all fresh water are part of transboundary water
With the fast development of nanotechnology the po- tential risks of NP exposure to human health is expanding. A wide variety of consumer products already contain a varying array of nanomaterials including health and fitness products, targeting pharmaceuticals, cosmetics, antibac- terial clothes, home and garden products, electronics and computers, and paints. Therefore, chances for exposure to engineered nanomaterials are increasing for the public as well as for individuals in the occupational environment. Inhalation is one potential route of exposure and can occur during manufacturing, accidental release of mate- rials, use of consumer products or medical applications. Even though it is a small percentage of the population, the most vulnerable and sensitive group to the adverse effects of NP exposure are pregnant women and their developing fetuses. However, there is limited information about the effects of exposure to nanomaterials during pregnancy. The risk of these materials is not only related to the man- ufactured quantities and the probability of exposure but also on the reactivity and potency to biological systems, including the immune system . Increased inflammation during pregnancy (including production of a number of pro-inflammatory cytokines) may negatively influence the normal fetal development and may have negative postna- tal consequences.
Abstract. One of the methods in limiting tensile stresses in arch dams and removing stress concentrations at the dam-foundation interface is setting the dam body on a concrete saddle called a Pulvino. In the present study, the eects of Pulvino and peripheral joints on the static behavior and seismic performance of arch dams are investigated. Dez Dam with a height of 203 m was selected as a case study and all contraction joints of the dam body were modeled using the discrete crack approach based on as-built drawings. Also, the surrounding rock was modeled as a mass-less medium tied to Pulvino. The dam-reservoir- foundation system was analyzed under static loads accounting for stage construction eects, hydrostatic and thermal loads. The provided numerical model was then excited using near- and far-eld earthquake ground motion. It was found that modeling the peripheral joint between the saddle and the main dam body changes the direction of principal stresses and their distribution patterns, and the safety of the system is improved. In addition, over stressed surfaces on the faces of the dam body decreased in comparison with the model without a peripheral joint.
The effects of human-induced climate change have been the focus of a vast amount of scientific studies over the last decades. Typically, a multitude of different approaches are used, amongst them laboratory studies (e.g. Fang et al. 2005; Fierer et al. 2005; Bradford et al. 2008a; Liu et al. 2009a), long-term observations and inventory studies (e.g. Giardina & Ryan 2000; Bellamy et al. 2005; Luyssaert et al. 2007; Bond-Lamberty & Thomson 2010), environmental gradient studies (e.g. Bird et al. 2004; Loomis et al. 2006; Wynn et al. 2006; Oberbauer et al. 2007; Heckman et al. 2009; Girardin et al. 2010; Thomas et al. 2010; Ostonen et al. 2011), global change manipulation experiments (e.g. Oechel et al. 1994; Oren et al. 2001; Melillo et al. 2002; Neff et al. 2002; Loya et al. 2003; Mack et al. 2004; Dukes et al. 2005; Körner et al. 2005), or ecosystem modeling studies (e.g. Cannell & Thornley 1998; Eliasson et al. 2005; Knorr et al. 2005b; Pepper et al. 2005; Esser et al. 2011). An increased understanding and better estimation of the magnitude and direction of ecosystem responses, derived from such experiments, will increase the accuracy of model structures, and be highly relevant for the validation of these models.
Freshwater wetlands are among the most ecologically and economically valuable ecosystems in the world due to their ability to provide ecosystem services such as habitat for migratory waterfowl (Zedler and Kercher, 2005), nutrient cycling (Aerts et al., 1999; DeAngelis et al., 2010), and carbon storage (Costanza et al., 1997; Chmura et al., 2003; Kayranli et al., 2010). Carbon storage is a vital service provided by wetlands, with an estimated 830 Tg yr -1 sequestered globally (DeDeyn et al., 2008; Kayranli et al., 2010). Urban and agricultural development is threatening wetlands, resulting in the need for creation and restoration of wetlands. However, created wetlands tend to have lower species diversity and unstable
Performance criteria or specifications of acceptable damage under SEE ground motions are poorly defined and considering these in safety evaluations requires considerable engineering judgment. Basically, it must be shown that after the SEE the damaged dam can still retain the reservoir water. How can such damage be defined? So far very little work has been done in this area of dam safety assessment. Unlike the seismic hazard assessment which has been tackled by a large number of earth scientists, few engineers may be able to contribute to the damage assessment, mainly due to the lack of dams, which have experienced very strong ground shaking.