A Coastal reservoir is a type of reservoir to store fresh water in a dammed area of a coastal sea near a river delta. Saemanguem in South Korea, Marina Barrage in Singapore, Qingcaosha in China, Plover Cove in Hong Kong, Zuiderzee Works and Delta Works in the Netherlands, and Thanneermukkom Bund in India are a few existing coastal reservoirs. [1] [2]
Unlike land-based water reservoirs, there is no land submergence in the case of coastal reservoirs. [3] [4] They store water without disturbing land use by replacing standing salt water of the sea area by fresh water from a river. [3] The coastal reservoir area is separated from the sea by building earth dikes, e.g. by dredging. Fresh water from these reservoirs can be used for irrigation, drinking water and industrial purposes. Sometimes the reservoirs are used for flood control and land reclamation. The social and environmental impacts of coastal reservoirs are often negligible compared to land-based water reservoirs. [3] The construction costs are a few times less than the costs of land-based reservoirs since there is no expenditure for acquiring the vast land area, the submerged immovable properties and the rehabilitation of displaced people. [3] The sea side of the coastal reservoir can also be used for locating a deep sea harbor.
It is technically and economically feasible to construct man-made freshwater coastal reservoirs up to 20 meters depth from the coastline. Excess water from the high rainfall regions needs to be collected in the coastal reservoir. The fresh water from a coastal reservoir can be used to irrigate coastal desert lands. [5]
The following are proposed projects:
A coastal reservoir project can also create adequate capacity Pumped-storage hydroelectricity potential to store the electricity generated by variable renewable energy sources and ensure adequate round-the-clock electricity supply. [6] Due to irrigation, lands which are not available for cultivation and forestry can be turned into a habitat with copious greenery with enhanced carbon storage in the topsoil which would contribute in mitigating the global warming process. With the advent of cheap renewable energy like solar and wind power, the availability of energy sources is not an ongoing issue but water availability is still a major issue that can be solved by coastal reservoirs to a major extent. [9]
Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater and fresh water together, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root brak. Certain human activities can produce brackish water, in particular civil engineering projects such as dikes and the flooding of coastal marshland to produce brackish water pools for freshwater prawn farming. Brackish water is also the primary waste product of the salinity gradient power process. Because brackish water is hostile to the growth of most terrestrial plant species, without appropriate management it is damaging to the environment.
Morocco is the northwesternmost country which spans from the Mediterranean Sea and Atlantic Ocean on the north and the west respectively, into large mountainous areas in the interior, to the Sahara desert in the far south. Morocco is a Northern African country, located in the extreme northwest of Africa on the edge of continental Europe. The Strait of Gibraltar separates Spain from Morocco with a 13 kilometres (8.1 mi) span of water. Morocco borders the North Atlantic Ocean to the west, and the western Mediterranean Sea to the north, and has borders with Algeria and disputed Western Sahara.
At 824,292 km2 (318,261 sq mi), Namibia is the world's thirty-fourth largest country. After Mongolia, Namibia is the second least densely populated country in the world. Namibia got its name from the Namib desert that stretches along the coast of the Atlantic. It is also known for its wildlife.
Spain is a country located in southwestern Europe occupying most of the Iberian Peninsula. It also includes a small exclave inside France called Llívia, as well as the Balearic Islands in the Mediterranean, the Canary Islands in the Atlantic Ocean 108 km (67 mi) off northwest Africa, and five places of sovereignty on and off the coast of North Africa: Ceuta, Melilla, Islas Chafarinas, Peñón de Alhucemas, and Peñón de Vélez de la Gomera.
Water extraction is the process of taking water from any source, either temporarily or permanently, for flood control or to obtain water for, for example, irrigation. The extracted water could also be used as drinking water after suitable treatment.
Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the water table. Groundwater is recharged from the surface; it may discharge from the surface naturally at springs and seeps, and can form oases or wetlands. Groundwater is also often withdrawn for agricultural, municipal, and industrial use by constructing and operating extraction wells. The study of the distribution and movement of groundwater is hydrogeology, also called groundwater hydrology.
Saltwater intrusion is the movement of saline water into freshwater aquifers, which can lead to groundwater quality degradation, including drinking water sources, and other consequences. Saltwater intrusion can naturally occur in coastal aquifers, owing to the hydraulic connection between groundwater and seawater. Because saline water has a higher mineral content than freshwater, it is denser and has a higher water pressure. As a result, saltwater can push inland beneath the freshwater. In other topologies, submarine groundwater discharge can push fresh water into saltwater.
The Indian rivers interlinking project is a proposed large-scale civil engineering project that aims to effectively manage water resources in India by linking Indian rivers by a network of reservoirs and canals to enhance irrigation and groundwater recharge, reduce persistent floods in some parts and water shortages in other parts of India. India accounts for 18% of the world population and about 4% of the world's water resources. One of the solutions to solve the country's water woes is to link the rivers and lakes.
The ongoing pollution of the Ganges, the largest river in the Indian subcontinent, poses a significant threat to human health and the environment. The river, which is severely polluted with human waste and industrial contaminants, provides water to about 40% of India's population across 11 states, serving an estimated population of 500 million people, more than any other river in the world.
Surface water is water located on top of land, forming terrestrial waterbodies, and may also be referred to as blue water, opposed to the seawater and waterbodies like the ocean.
Water resources in India includes information on precipitation, surface and groundwater storage and hydropower potential. India experiences an average precipitation of 1,170 millimetres (46 in) per year, or about 4,000 cubic kilometres (960 cu mi) of rains annually or about 1,720 cubic metres (61,000 cu ft) of fresh water per person every year. India accounts for 18% of the world's population and about 4% of the world's water resources. One of the proposed solutions to solve the country's water woes is the Indian rivers interlinking project. Some 80 percent of its area experiences rains of 750 millimetres (30 in) or more a year. However, this rain is not uniform in time or geography. Most of the rains occur during its monsoon seasons, with the northeast and north receiving far more rain than India's west and south. Other than rains, the melting of snow over the Himalayas after the winter season feeds the northern rivers to varying degrees. The southern rivers, however, experience more flow variability over the year. For the Himalayan basin, this leads to flooding in some months and water scarcity in others. Despite an extensive river system, safe clean drinking water as well as irrigation water supplies for sustainable agriculture are in shortage across India, in part because it has, as yet, harnessed a small fraction of its available and recoverable surface water resource. India harnessed 761 cubic kilometres (183 cu mi) (20 percent) of its water resources in 2010, part of which came from unsustainable use of groundwater. Of the water it withdrew from its rivers and groundwater wells, India dedicated about 688 cubic kilometres (165 cu mi) to irrigation, 56 cubic kilometres (13 cu mi) to municipal and drinking water applications and 17 cubic kilometres (4.1 cu mi) to industry.
Peak water is a concept that underlines the growing constraints on the availability, quality, and use of freshwater resources. Peak water was defined in 2010 by Peter Gleick and Meena Palaniappan. They distinguish between peak renewable, peak non-renewable, and peak ecological water to demonstrate the fact that although there is a vast amount of water on the planet, sustainably managed water is becoming scarce.
A seawater greenhouse is a greenhouse structure that enables the growth of crops and the production of fresh water in arid regions which constitute about one third of the Earth's land area. This in response to global water scarcity, peak water and soil becoming salted. The system uses seawater and solar energy, and has a similar structure to the pad-and-fan greenhouse, but with additional evaporators and condensers. The seawater is pumped into the greenhouse to create a cool and humid environment, the optimal conditions for the cultivation of temperate crops. The freshwater is produced in a condensed state created by the solar desalination principle, which removes salt and impurities. Finally, the remaining humidified air is expelled from the greenhouse and used to improve growing conditions for outdoor plants.
Interbasin transfer or transbasin diversion are terms used to describe man-made conveyance schemes which move water from one river basin where it is available, to another basin where water is less available or could be utilized better for human development. The purpose of such water resource engineering schemes can be to alleviate water shortages in the receiving basin, to generate electricity, or both. Rarely, as in the case of the Glory River which diverted water from the Tigris to Euphrates River in modern Iraq, interbasin transfers have been undertaken for political purposes. While ancient water supply examples exist, the first modern developments were undertaken in the 19th century in Australia, India and the United States, feeding large cities such as Denver and Los Angeles. Since the 20th century many more similar projects have followed in other countries, including Israel and China, and contributions to the Green Revolution in India and hydropower development in Canada.
The Kalpasar Project or the Gulf of Khambhat Development Project envisages building a 30 km dam across the Gulf of Khambat in India for establishing a huge fresh water coastal reservoir for irrigation, drinking and industrial purposes. The project with 30 km sea dam will have the capacity to store 10 billion cubic meters fresh water, equating to 25% of Gujarat’s average annual rainwater flow, from the rivers like Narmada, Mahi, Dhadhar, Sabarmati, Limbdi-Bhagovo, and two other minor rivers. A 10 lane road link will also be set up over the dam, greatly reducing the distance between Saurashtra and South Gujarat. The project, which will create world's largest freshwater lake in marine environment, will cost INR90,000 crore or US$12.75 billion excluding the cost of tidal power plant. Project entails construction of the main "Kalpasar dam" across Gulf of Khambat and another Bhadbhut barrage on Narmada river, as well as a canal connecting the two.
India is 5th globally for installed hydroelectric power capacity. As of 31 March 2020, India's installed utility-scale hydroelectric capacity was 46,000 MW, or 12.3% of its total utility power generation capacity. Additional smaller hydroelectric power units with a total capacity of 4,683 MW have been installed. India's hydroelectric power potential is estimated at 148,700 MW at 60% load factor. In the fiscal year 2019–20, the total hydroelectric power generated in India was 156 TWh with an average capacity factor of 38.71%.
The Polavaram Project is an under construction multi-purpose irrigation project on the Godavari River in the Eluru District and East Godavari District in Andhra Pradesh. The project has been accorded National project status by the Central Government of India. Its reservoir back water spreads up to the Dummugudem Anicut and approx 115 km on Sabari River side. Thus back water spreads into parts of Chhattisgarh and Odisha States. It gives major boost to tourism sector in Godavari Districts as the reservoir covers the famous Papikonda National Park, Polavaram hydro electric project (HEP) and National Waterway 4 are under construction on left side of the river. It is located 40 km to the upstream of Sir Arthur Cotton Barrage in Rajamahendravaram City and 25 km from Rajahmundry Airport.
Coastal sediment supply is the transport of sediment to the beach environment by both fluvial and aeolian transport. While aeolian transport plays a role in the overall sedimentary budget for the coastal environment, it is paled in comparison to the fluvial supply which makes up 95% of sediment entering the ocean. When sediment reaches the coast it is then entrained by longshore drift and littoral cells until it is accreted upon the beach or dunes.
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include non-salty mineral-rich waters such as chalybeate springs. Fresh water may encompass frozen and meltwater in ice sheets, ice caps, glaciers, snowfields and icebergs, natural precipitations such as rainfall, snowfall, hail/sleet and graupel, and surface runoffs that form inland bodies of water such as wetlands, ponds, lakes, rivers, streams, as well as groundwater contained in aquifers, subterranean rivers and lakes. Fresh water is the water resource that is of the most and immediate use to humans.
Coastal Hydrogeology is a branch of Hydrogeology that focuses on the movement and the chemical properties of groundwater in coastal areas. Coastal Hydrogeology studies the interaction between fresh groundwater and seawater, including seawater intrusion, sea level induced groundwater level fluctuation, submarine groundwater discharge, human activities and groundwater management in coastal areas.
