China
Africa
Explore chapters and articles related to this topic
Reservoir sedimentation
Published in Arved J. Raudkivi, Sedimentation, 2020
Reservoirs are man-made lakes created to store water during times of excess flow and supply it from storage when the demand exceeds the inflow. The equalization provided by the reservoir makes it possible to satisfy a higher continuous water demand than can be provided from the normally fluctuating river flow. In developing countries reservoirs serve mainly irrigation and hydro-power generation. In densely populated regions, like Central Europe, the reservoirs are predo-minently for multiple uses; apart from hydro-power, they serve for water supply, low flow augmentation, flood control, recreation and even navigation. The creation of a reservoir by damming the river(s) also leads to a ‘sudden’ imbalance of natural conditions in the immediate region. Such changes can also occur naturally, but these are rare and associated with catastrophic events, e.g. Lake Waikaremoana (New Zealand) was formed by a huge landslide a few thousand years ago. It covers about 54 km2 and is over 200 m deep.
Ecosensitive approaches to managing urban aquatic habitats and their integration with urban infrastructure
Published in Iwona Wagner, Jiri Marsalek, Pascal Breil, Aquatic Habitats in Sustainable Urban Water Management, 2014
Jiri Marsalek, Diederik Rousseau, Peter Van Der Steen, Sophie Bourguès, Matt Francey
Flood protection has been practised as a single-purpose water management measure for thousands of years, but increasing competition for water resources and conflicts among their uses has led to more holistic approaches in recent years. In the ecosystem approach, the flood management planning in catchments should be connected with land use planning (City of Cape Town, 2003) and should address not only flood defence, but also the protection of water resources, including fish habitats. Among the three possible approaches to flood management measures, i.e., living with floods, non-structural measures, and structural measures, only the third category exerts strong impacts on aquatic habitats. Structural measures reduce flood volumes and peaks by spatially distributed management measures serving to reduce runoff generation and structural measures including storage facilities, the enhancement of river bed flow capacity, and earthen platforms and polders in flood plains. All of these measures are designed to reduce flood volumes and peaks by storage and flow redistribution. Perhaps the largest impacts on habitat are caused by reservoirs, including the loss of land to water storage, loss of habitat, reduced biodiversity, interference with fish passage, the introduction of nuisance species and diseases, loss of land regeneration in flood plains, and the creation of new risks associated with potential dam failures.
Overview of Inland Aquatic Ecosystems and Their General Characteristics
Published in Sven E. Jørgensen, Jose Galizia Tundisi, Takako Matsumura Tundisi, Handbook of Inland Aquatic Ecosystem Management, 2012
Sven E. Jørgensen, Jose Galizia Tundisi, Takako Matsumura Tundisi
The construction and operation of large reservoirs in Brazil are illustrative examples of the impacts (positive and negative) of large artificial ecosystems on watersheds and rivers. Initially built with the purpose of producing hydroelectricity, these reservoirs are used for multiple activities such as energy production, navigation, irrigation, fisheries, recreation, tourism, and water for public supply. The multiple uses of the reservoirs’ waters require complex management operation, because it involves technology, optimization, and regulation of activities and control systems based on operational rules that should maintain water volumes and water levels and water quality in the reservoir and downstream of the dam. It includes furthermore protection and recovery of biodiversity. But the large dams built in Brazil had several positive impacts on the regional economy, supporting development by the generation of energy as well as providing opportunities for employment, diversification of economic activities, and better sanitation infrastructure. The main impacts of these reservoirs are (1) changes in the ecological services of the rivers, (2) reduction of biodiversity, (3) water quality degradation, and (4) changes in the hydrosocial cycle for the human population of the watershed. Table 1.6 shows the main, large Brazilian reservoirs and their characteristics.
Ecological security evaluation for Changtan Reservoir in Taizhou City, East China, based on the DPSIR model
Published in Human and Ecological Risk Assessment: An International Journal, 2023
Lingxi Li, Peiyue Li, Song He, Rui Duan, Fei Xu
As an important form of water resources, reservoirs are useful in flood control, aquacultural production, agricultural irrigation and power generation (Gunkel et al. 2018; Quinn et al. 2018). As a result, drinking water sources in some major cities in China gradually depend on reservoirs (Zhu et al. 2015; Li et al. 2018; Han et al. 2020). The construction of reservoirs brings important value to the development of modern agriculture and the effective use of ecological resources (Fowe et al. 2015; Chow et al. 2016). However, the ecological security of reservoirs is threatened by various factors. This makes the ecosystem of some reservoirs unbalanced. The common problems are eutrophication and soil erosion, thus affecting the water quality around the reservoir. It can seriously threaten human health (Naveedullah et al. 2016; Xu et al. 2016; Miao et al. 2020). The economic development and human activities around the reservoirs are the main factors affecting the ecological security, resulting in an ecological imbalance in the reservoir area (Banerjee et al. 2017).
The drawdown phase of dam decommissioning is a hot moment of gaseous carbon emissions from a temperate reservoir
Published in Inland Waters, 2022
Mabano Amani, Daniel von Schiller, Isabel Suárez, Miren Atristain, Arturo Elosegi, Rafael Marcé, Gonzalo García-Baquero, Biel Obrador
The Enobieta Reservoir is in the valley of Artikutza (Navarre, northern Iberian Peninsula), where human activities have been restricted since 1919, when the municipality of Donostia-San Sebastián bought the land to ensure the supply of high-quality drinking water. The mean annual air temperature is 12.2 °C with an average rainfall of 2064 mm yr−1 (average 1954–2019; Gobierno de Navarra 2019). The dam was constructed between 1947 and 1953 on the Enobieta Stream. The reservoir had an initial storage capacity of 2.66 hm3, length of 1.1 km, maximum depth of 25.5 m, a concrete dam height of 42 m, and an area of 0.14 km2. Geotechnical problems appeared during its construction, forcing a reduction in its storage capacity to 1.40 hm3, and the construction of a larger reservoir (Añarbe Reservoir, 43.8 hm3) downstream in 1976, after which Enobieta Reservoir was no longer used as a water supply facility (Larrañaga et al. 2019). In addition, Artikutza is part of the Natura 2000 Network and, since 2014, is a special conservation zone. The high conservation status of the valley and the structural instability of the dam led to a DD plan of the Enobieta Reservoir, a process that began in 2017 and extended through and 2019 (Supplemental Fig. S1). To date, the decommissioning has been partial; the reservoir has been completely emptied of water and the river runs freely through a hole in the dam, but the concrete structure of the dam (the physical structure retaining the water) is still standing.
Dominant factors influencing changes in the water quantity and quality in the Dianshi Reservoir, East China
Published in Human and Ecological Risk Assessment: An International Journal, 2022
Fengmei Su, Peiyue Li, Misbah Fida
Securing water environment safety in drinking water source areas is of crucial importance for maintaining human life and health as well as the ecological balance (He et al. 2022a, b). It has, therefore, become the top priority in ecological studies (Li et al. 2022; Cheng et al. 2020). As an important component of drinking water sources, reservoirs have become threatened by climate change, over-exploitation, pollution, and land degradation (Brookes et al. 2014; Weber et al. 2017). In the coastal areas of China, the surface water reservoir has a longer history of utilization than the groundwater reservoir. However, it is more vulnerable to external disturbance than the groundwater reservoir (Li and Wu 2019a, b), partly because the surface water quantity is influenced by climate variability and change (e.g., severe rainstorms, droughts, and cyclones) (Li et al. 2019a). In addition, without proper management, surface water quality may be more likely to be affected by pollution caused by human activities (Zhou et al. 2016; Li et al. 2017; Wu et al. 2017; Su et al. 2019, 2020). In recent decades, numerous studies have focused on the management of the reservoirs and the protection of their surrounding eco-environment (Naota et al. 2006; Li et al. 2019b).