Study on land use pattern change and its causes

Land use of Sylhet has changed gradually. This is found from the field survey that in 1970 the area was dominated by marshy land [645.33 katha], vacant land [430.88 katha] and crop land [336.17 katha]. By 1988 there was no university in the area. Residential area also increased. It covered 39.11% of total study area. Now in 2007 there is a radical change noticed in the area in comparison with 1988. Population has increased and accordingly residential area has also increased. Now it covers about 58.71% of the study area. A survey was conducted to judge the view of the old residents of the area about the change of the land use pattern. The impacts of land use changes are desertification, climate changes and hill cutting. Improper lands use like removal of vegetal cover brings about marked changes in the local climate of Sylhet. Deforestation changes rainfall, temperature, wind speed etc. It was observed that rainfall pattern; atmospheric window of Sylhet has been changed significantly within last ten years

Regression analysis of ground water quality data of Sunamganj district, Bangladesh

Ground water samples from different Upazilas of Sunamganj District have been analyzed for drinking and irrigation purposes. Correlation coefficients among different parameters were determined. An attempt has been made to develop linear regression equations to predict the concentration of water quality constituents having significant correlation coefficients with electrical conductivity [EC]. Calcium and EC; Bicarbonate and EC are highly correlated but not perfect. Our findings show that calcium, nitrate, and bicarbonate are significantly related with electrical conductivity at 1% level of significance. Except for the total dissolved solid, all other variables are significant at a conventional level [i.e. 5%] with expected sign. The usefulness of these linear regression equations in predicting the ground water quality is an approach, which can be applied in any other locations

Assessment of ground water quality in Sunamganj of Bangladesh

In this study, groundwater quality in Sunamganj of Bangladesh was studied based on different indices for irrigation and drinking uses. Samples were investigated for sodium absorption ratio, soluble sodium percentage, residual sodium carbonate, electrical conductance, magnesium adsorption ratio, Kelly's ratio, total hardness, permeability index, residual sodium bi-carbonate to investigate the ionic toxicity. From the analytical result, it was revealed that the values of Sodium Adsorption Ratio indicate that ground water of the area falls under the category of low sodium hazard. So, there was neither salinity nor toxicity problem of irrigation water, so that ground water can safely be used for long-term irrigation. Average total hardness of the samples in the study area was in the range of between 215 mg/L at Tahirpur and 48250 mg/L at Bishamvarpur. At Bishamvarpur, the water was found very hard. Average total hardness of the samples was in the range of between 215 mg/L at Tahirpur and 48250 mg/L at Bishamvarpur. At Bishamvarpur, the water was found very hard. It was shown based on GIS analysis that the groundwater quality in Zone-1 could be categorized of [excellent] class, supporting the high suitability for irrigation. In Zone-2 and Zone-3, the groundwater quality was categorized as [risky] and [poor] respectively. The study has also made clear that GIS-based methodology can be used effectively for ground water quality mapping even in small catchments

Sustainable approach of solid waste management of small urban area: case for Habibganj municipality in Bangladesh

Existing solid waste management system of Habibganj municipality [pourashava] of Bangladesh was studied. A total of 234 households were surveyed. Solid waste generation rate was found to be 0.36 kg/cap/day. Household waste disposal was one of the main problems across the city. Among the different options of waste disposal, 21.4% and 23.9% respondents generally threw their wastes into nearby ponds and drains, respectively. About 14.5% of the sampled households discarded their wastes in their respective compound and only 12% households used bins supplied by the municipality. About 10.7% households disposed their garbage on the roadside. Lack of awareness, lack of dustbins, and improper maintenance of drainage system and lack of drainage facilities were the main reasons of the current inadequacy of the management system as reported by 183 [78%] respondents. The result indicate that for a 200 MT capacity composting plant, safe distance will be about 800 m from the disposal site in terms of odorous impact, while 500 m for health impact. In this study, a sustainable management system of solid waste disposal is suggested for the Habibganj municipal area

Study on traffic noise level of Sylhet by multiple regression analysis associated with health hazards

The study reports the level of traffic-induced noise pollution in Sylhet City. For this purpose noise levels have been measured at thirty-seven major locations of the city from 7 am to 11 pm during the working days. It was observed that at all the locations the level of noise remains far above the acceptable limit for all the time. The noise level on the main road near residential area, hospital area and educational area were above the recommended level [65dBA]. It was found that the predictive equations are in 60-70% correlated with the measured noise level. The study suggests that vulnerable institutions like school and hospital should be located about 60m away from the roadside unless any special arrangement to alleviate sound is used

Unplanned urbanization: assessment through calculation of environmental degradation index

Urbanization is an inevitable phenomena for the country like Bangladesh. The push and pull factors help to migrate people from rural area to urban area. As a result haphazard and unplanned urbanization create environmental degradation. Survey data reveals that inadequate solid waste disposal services, lack of adequate public water supply, traffic congestion, water logging, air pollution, noise pollution, hill cutting are the main problems in the city area. Concentration of dust as well as SOx, NOx exceeded the allowable limit at the selected points. Groundwater level of Sylhet city has a considerable lowering over the last few decades. It has lowered from 3380 mm below ground in 1982 to 7880 mm below ground. Sylhet is located in highly seismic risk zone but most of the buildings and other structures in this area are constructed without considering earthquake risk. Environmental degradation index was calculated based on economical condition of the country