Feb 20, 2012

Statistical Downscaling Method of Global Climate Model

General Circulation Models (GCMs) suggest that rising concentrations of greenhouse gases will have significant implications for climate at global and regional scales. GCMs are restricted in their usefulness for local impact studies by their coarse spatial resolution (typically of the order 50,000 km2) and inability to resolve important sub–grid scale features such as clouds and topography. So, downscaling techniques are used to bridge the spatial and temporal resolution gaps between what climate modelers are currently able to provide and what impact assessors require.
Downscaling Method

Feb 14, 2012

Impounding Reservoir: Feasibility & Case Study

Bangladesh is situated in the downstream position of few major rivers. As a reason, River borne problem are very frequent here. Flood, drought, salinity intrusion in coastal region and climate change impact is seriously threatening the water resources of Bangladesh. Economic activity of Bangladesh is vastly based on whether surface water or ground water. Surface water is mainly used as fish farming, navigation etc. Surface water as drinking water is begun to be used in limited scale due to the increasing rate of pollution. Ground water is hugely used in irrigation, drinking water supply etc. But due to excessive use of ground water and (in some region) slow recharge rate, ground water is depleting drastically. Impounding rain water in those areas are useful. Impounding Reservoir is a reservoir with outlets controlled by gates that release stored surface water as needed in a dry season; may also store water for domestic or industrial use or for flood control. It is also known as storage reservoir. 

Feb 6, 2012

Alternate Water Source Investigation in Barind Tract

Figure 1: Barind Tract 
Barind Tract is situated in the north western part of Bangladesh. It is a semi arid region. Soil structure is different in this region. This is the largest Pleistocene physiographic unit in the whole Bangladesh floodplain. It covers an area of about 7,770 km2. It has long been recognised as a unit of old alluvium, which differs from the surrounding floodplains. This physiographic unit is bounded by the Karatoya river to the east, the Mahananda river to the west, and the northern bank of the Ganges River to the South. A lower fault scarp marks the eastern edge of the Barind Tract, and the Little Jamuna River (Jamuneshwari), Atrai River and Lower Punarbhaba rivers occupy fault troughs. The western part of this unit has been tilted up; parts of the western edge are more than 15 m higher than the rest of the tract and the adjoining Mahananda floodplain. The southern part of the main eastern block of the Barind Tract is tilted down towards the southwest and passes under lower Atrai basin sediments in the south. 

Feb 2, 2012

Conservation of Water Resources in Little Feni River in Noakhali Coastal Region

Figure 1: Position of Musapur Regulator and Closure
Conventional source of water for drinking is either surface water or groundwater. Perennial rivers, reservoirs, lakes and ponds are the surface water source, while underground aquifer is the groundwater source. Both of the sources have limitations like water availability, water quality environment, physical locations, hydrogeology, salinity etc. Water availability, local bio diversity, flora fauna in the coastal region Noakhali district is now facing severe threat due to excessive salinity intrusion. There was a ragulator in ‘Kazirhat’ to confront the salinity intrusion. Due to this regulator, a huge land mass is reclaimed in the downstream of the Little Feni River. To ensure the security of this reclaimed region a new regulator is constructed in Musapur union. The main objective was to establish a control structure in a diversion channel of the Little Feni River and close Little Feni River. For this reason, after constructing a regulator on a diversion channel of the Little Feni River near Musapur Union, authority demolish the regulator at Kazirhat due to its poor condition. But the closure of the Little Feni River is yet to construct. For this reason, the local flood plain area namely Bashurhat, Sonagazi, Daganbhuiyan are very susceptible to tidal flow and salinity intrusion. This phenomenon makes ‘Musapur Regulator’ redundant.