What are Sinkholes? Sinkholes are ground-surface depressions that result when a subterranean void weakens support of the overlying earth. Why are Sinkholes a Concern for Inspectors? They threaten water supplies by draining unfiltered water from streams, lakes, and wetlands directly into aquifers. They kill and injure people. A person can be harmed when stepping into an existing sinkhole or when the ground beneath gives way during a sinkhole’s collapse. Sinkholes can cause structural damage and instability under buildings, roads and bridges. Repairing them after collapse is expensive and requires specialized knowledge. The underlying cause of the sinkhole must be addressed first, or the repair may prove to be only temporary. Formation Natural sinkholes are formed when sub-surface rock dissolves to create underground cavities. They are most often found where the rock below the land surface is limestone, dolo...
Bangladesh is situated at the unique juxtaposition of the composite, sprawling, interlinked Ganges-Brahmaputra-Meghna (GMB) river systems, the second largest river system in the world, which drains an area of 1,086,000 square kilometers from China, Nepal, India, and Bangladesh. Because of this unique geophysical location, the country has been endowed with rich biological diversity, hosting a rich variety of species that superbly evolved to populate the ecosystems of the country. However, due to the various pressures of a growing population (with an already existing base of 145 million people), development interventions, gaps in policy and legislation, and conflicting institutional mandates, 95% of Bangladesh’s natural forests and 50% of its freshwater wetlands are lost or degraded. Bangladesh now has among the smallest areas of protected and intact forest in the world, consisting of 1.4% of its landmass. Many terrestrial wildlife species have been lost during the last 100 years. In addition, the World Conservation Union (IUCN) in 2000 classified 40% of Bangladesh’s freshwater fish species as threatened with national extinction.
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