International Journal of Ocean and Coastal Engineering

Mangaluru coast belt spreads about 22 Kms with Arabian Sea in the West and the Western Ghats in the East. Coastal anthropogenic activities such as disposal of untreated or partially treated sewage and industrial effluents and their possible impacts hinder the coastal environment. Huge amount of pollution load from the major industries located nearby are discharged into the sea directly or through the west flowing rivers of the area i.e. Gurupura and Nethravathi. Due to this, the soil properties also get affected. The preliminary study was carried out at the study area by considering surface water samples, i.e. stream water, river water, sea water and also soil samples to study the physicochemical characteristics. The study reveals that most of the surface water samples have low dissolved oxygen concentration and are high in BOD, COD, TDS, Electrical Conductivity (EC) and Chlorides Concentration. Very low dissolved oxygen concentration was observed in the Gurupura–Nethravathi Estuary point. With respect to fertility of the soil, most of the soil samples were below the normal range for the various parameters.

In this paper, the tsunami risk in the west coast of Japan is introduced. Especially, the inundation risk in Osaka city is discussed. Three visor gates are installed at the mouths of main rivers in the city. The gates are mainly installed to prevent the storm surge due to typhoons but they are effective to reduce the tsunami height at the mouth point of river. Though the gates are necessary to prevent the tsunami inundation, the stability against tsunami forces is not enough because the gates were constructed in 1960s. Therefore, the removable breakwater is now under consideration to reduce the tsunami force. The hydraulic experiment was carried out in order to investigate the applicability of the removable breakwater. The reduction rate by the breakwater was derived from the experiment.

In general, people like to live near the coast because of a better aesthetical pleasing living environment, access to a variety of recreational activities and more job opportunities. Consequently, more than 50% of the world’s population live within 200km of the coast, and ¾ of the world’s megacities are situated by the shore. Significant pressure on land, water supply, waste management and other infrastructures appear in these coastal cities. India, which hosts one-sixth of the world’s population is looking for strategies to manage India’s coastal cities, water, land and human resources. This paper reviews China’s experience in water resources development for coastal cities. China’s coastal economic corridor (CEC) contributes 60% of the national GDP, which needs plentiful water supply to sustain its coastal cities. The present investigation shows that India has better natural conditions to develop its CEC. Among the coastal infrastructures, coastal reservoirs (i.e., CRs) should be the priority, which nourishes the coastal prosperity. This paper also discusses the feasibility of water–oil exchange project between India and Persian Gulf countries.

Australia is the driest country in the world, and the lower Murray–Darling Basin and Adelaide have experienced extreme water scarcity crisis, especially during the Millennium Drought (2000–2010). Many counter measures have been proposed or implemented like desalination plants and water buyback, etc., some progress has been made, but far away from a complete solution. Different from existing measures, this research aims at using coastal reservoir technology to shift from upstream water development to downstream development, in order to solve a series of water supply and ecological environment problems by redesigning a coastal reservoir in the downstream area. It is suggested that high-quality water is stored in a “coastal reservoir” inside the Alexandrina Lake for Adelaide’s water supply. The lake water outside the “coastal reservoir” is used for agricultural development. A preliminary feasibility study was conducted in terms of water quantity and water quality, river’s environmental flow and agricultural output. The results show that if a small size (550–630GL) coastal reservoir was created inside the Lake Alexandrina in the mouth of Murray River, the Adelaide’s water supply could be secured and its water quality be improved even during droughts like the Millennium Drought. Besides, if the agricultural development is concentrated around the lake, its water demand can be fully met from the lake, rather than the river, thus the agricultural development has little negative impacts on the river’s ecosystem, it is a win-win solution for agricultural development and river ecosystem. It is suggested that Australian government should provide stimulus package for upstream farmers to relocate to areas around the lake.