Freshwater animals are vanishing faster than those on land or at sea. But captive-breeding programs hold out hope.

As Egypt celebrates the 50th anniversary of the start of the construction of the Aswan High Dam, some scientists say that this wonder of engineering is contributing to an environmental catastrophe that could force millions of its citizens to abandon the lush, fertile delta. The worst of these is coastal erosion and subsidence, the compacting of the delta soil.

The Lam Phra Phloeng dam was constructed in 1963 and is located in the Nakhon Ratchasima province. The dam has severely reduced water level caused by deforestation and agriculture at the upper land. Sediment cores were collected using a gravity corer. The 210 Pb activities were measured using alpha and gamma spectrometry and sedimentation rates were determined.

The comparative assessment of morphologic runoff and annual silt load from micro-watersheds can help in establishing relationships between these parameters with objectives of controlling runoff, conservation of soil, reduction of reservoir silt load and enhanced groundwater resources in the micro-watersheds.

Erosion is a natural geomorphic process occurring continually over the earth

The Brahmaputra Valley region has a unique landscape, with the Brahmaputra River and other rivulets running between the parallel hill ranges. The valley gets flooded during the monsoons, which deposit a large amount of silt and debris on the riverbeds.

Coastal ecosystems are sensitive to changes in the quantity and lability of terrigenous dissolved organic matter (DOM) delivered by rivers. The lability of DOM is thought to decrease with age, but this view stems from work in watersheds where terrestrial plant and soil sources dominate streamwater DOM.

To measure impact of ecological change in Chittagon Hill Tracts after the installation od dam Kaptai in 1955 on siltation, Bangladesh Water Development Board has conducted siltation study several times from 1978.