Southwest Coastal Region Of Bangladesh Research Articles

Hydro-Meteorological Trends in Southwest Coastal Bangladesh: Perspectives of Climate Change and Human Interventions

The southwest coastal region of Bangladesh, being under tidal influence and dependent on sweet water supplies from upstream, has a unique brackish water ecosystem. The region, having vast low-lying areas enclosed by man-made polders, is considered to be highly vulnerable to climate change induced hazards. In this study, linear trends in hydro-climatic variables, such as temperature, rainfall, sunshine, humidity, sweet water inflow and tidal water level in the region are assessed using secondary data and following both parametric and nonparametric statistical techniques. Correlation between the sweet water flow from the Gorai River, a major distributary of the Ganges River, and the salinity level in the Rupsa-Pasur River near Khulna, a southern metropolis, is also investigated. The results reveal that the temperature in the Khulna region is increasing at a significant rate, particularly in recent years. The number of extremely cold nights is decreasing and the heat index is increasing. The sunshine duration has a decreasing trend and the humidity has an increasing trend. Rainfall is increasing in terms of both magnitude and number of rainy days. However, the annual maximum rainfall and the number of days with high intensity rainfall have remained almost static. The annual maximum tidal high water level is increasing and the annual minimum low water level is decreasing at a rate of 7 - 18 mm and 4 - 8 mm per year, respectively. There is a negative correlation between the Gorai flow and the river water salinity around Khulna. Dredging of the Gorai during 1998-2001 resulted in an improvement of the salinity situation in the Khulna region. The variation in water salinity, tidal water level and sweet water flows in different time periods indicates that the human interventions through upstream diversion and coastal polders have contributed more in hydro-morphological changes in the southwest than the climate change. However, there are some evidences of climate change in the meteorological variables at Khulna.

Evaluating pond sand filter as sustainable drinking water supplier in the Southwest coastal region of Bangladesh

This study investigates existing water supply scenario, and evaluates the performance of pond sand filter (PSF) in meeting drinking water demand of Dacope Upazila in southwest coastal Bangladesh. Questionnaire survey to the villagers reveals that PSF is the major drinking water sources (38 %) of the study area followed by tubewells (30.4 %), rainwater harvesting (RWH) systems (12.6 %), ponds (10.3 %) and others (8.7 %). The spot test and laboratory analysis show that odour, colour, pH, dissolved oxygen, hardness, calcium, magnesium, nitrate, sulphate and phosphate of the PSFs water meet Bangladesh standard. The efficiency of PSF in reducing total dissolved solids (TDS) (15 %) and potassium (8.2 %) is not enough to meet the standard of 20 % PSFs for TDS and one-third PSFs for potassium. The study proves that PSF is unable to remove coliform bacteria by 100 % from highly contaminated water. Hence, disinfection should be adopted before distribution to ensure safe drinking water. Majority of the PSF’s users (80 %) are either partially satisfied or dissatisfied with the existing system. The beneficiary’s willingness to pay for drinking water technologies seems that the combination of PSF and RWH could ensure sustainable drinking water in coastal region of Bangladesh.

Social supremacy and its role in local level disaster mitigation planning in Bangladesh

PurposeThis paper aims to discuss issues related to disaster mitigation planning provisions in Bangladesh, one of the most disaster‐prone countries in Asia. It seeks to concentrate on the issues related to the role of local groups in establishing cyclone shelters.Design/methodology/approachIn February 2008, a field study was conducted in the Southwest coastal region of Bangladesh. Combining the most recent empirical data, the location of cyclone shelters and the social supremacy structure are explored in this paper. Vulnerability due to infrastructure is defined here on the basis of available infrastructural facilities i.e. cyclone shelters, by using catchment area analysis in the geographical information system (GIS) software ArcGIS. The paper bases its argument on the assumption that the location of an infrastructure item like a cyclone shelter is dependent on the influential and motivational power of local elites and not on the necessity of the deprived people. Vulnerability, from this perspective, is interpreted in this study as a result of socio‐political supremacy in establishing cyclone shelters in coastal regions of Bangladesh.FindingsThe results indicate that locally supreme groups are located the closest to the cyclone shelter and may control local‐level disaster mitigation planning.Research limitations/implicationsThe paper outlines the “social supremacy” concept based on one rural union and the communication rationalities of the general people. Both describe the ways of identification, the social spectrum of public interests as well as the decision‐making process in rural Bangladesh.Originality/valueThe paper contains valuable information regarding rural society and its socio‐political structure as well as planning problems in coastal Bangladesh.

Characterization of water quality in shrimp ponds of different sizes and with different management regimes using multivariate statistical analysis

Coastal shrimp aquaculture in Bangladesh is mostly practiced in an agricultural unit called a Gher, which is a special type of agricultural field with elevated surrounding embankments/borders situated by the side of a river that is used to grow rice in winter and shrimp in summer. Ghers of different sizes are managed in different ways. An on-farm project was carried out to study the effects of Gher size and their related management practices on water quality, shrimp production and the economic returns of shrimp farming in the Southwest coastal region of Bangladesh. We present here the results of this project with respect to water quality as explored through factor analysis, which was applied as a way to understand the nature and extent of the effects of different variables. For the majority of the variables and factors, one-half to two-thirds of their variability was explained by changes over time (months), and a further one-quarter to one-third was explained by Gher size and associated management practices. The alternating dry/monsoon season and water management practices determined long-term and large-scale (annual) water exchange in the Ghers that mainly affected processes related to live and dead particles suspended in the water column. Processes related to decomposition and nitrification were more dependent on short-term (days) water circulation in the Ghers, which is turn was reliant on the time span between the exchanges of water in the Ghers and river. Our results show that improved management leads to higher natural and shrimp productivity in the smaller Ghers and strongly support the argument put forward by the policy makers and scientific community in Bangladesh that the smaller the Gher, the better they can be managed and the better the possibility of increased shrimp survival and production.

Glutinous Rice (<i>Oryza sativa</i> L.) Cultivars Grown on Coastal Soils of Bangladesh

The experiment describes the patterns of plant height, days required for booting, heading and flowering, sterility (%), grain yield, straw yield and harvest index of three glutinous rice (Oryza sativa L.) cultivars namely, Pushbiruine, Kathalibiruine and Pakbiruine grown in the coastal saline soils of South West Bangladesh. The experiment was carried out in a Randomize Complete Block Design (RCBD) during aman season, 2003 at the experimental land of Khulna University, Khulna. The obtained results suggest that Kathalbiruine had better plant growth, considerable booting, heading and flowering periods, higher grain yield and harvest index than Pushbiruine and Pakbiruine. Thus Kathalbiruine may be considered as a potential candidate for cultivation in South-West Coastal Region of Bangladesh. Keywords: Coastal Bangladesh; glutinous rice and urea DOI: 10.3329/agric.v8i2.7580 The Agriculturists 8(2): 74-79 (2010)