River water quality is a key concern as it is used for drinking and domestic purpose, irrigation and aquatic life including fish and fisheries. The Jamuna River is one of the most prominent central rivers in Bangladesh as well as it represents the tapestries line of our riverine country. The river can play a vital role to contribute social economic structure of development as a developing country like Bangladesh. The study was conducted to assess the physical and chemical water quality parameters of Jamuna River. The water samples were collected in plastic container of 2 liters capacity from five different geographic locations along the river in 2012-2013 during both dry and wet season. And 25 numbers of samples were collected from surface and 2 feet below from the surface of water at different selective sampling points. A number of physiochemical water quality parameters including Temperature, pH, EC, TDS, DO, BOD, COD, Nitrate (NO 2-and NO 3-), Ammonia, Sulphates, Chlorides, and Calcium were measured in laboratory base analysis. The mean value of such respective parameters in both season were compared with the water quality standards as set by the EQS guideline, ADB, and the guideline of Department of Environment (DoE) in Bangladesh.

The study deals with the assessment of water quality parameters including pH, DO, BOD, temperature, TDS, EC, transparency, hardness, and alkalinity of the Turag River in Tongi, Gazipur, Bangladesh. The physicochemical parameters of water were investigated for 3 points in the Turag River through experimental methods. The river water was black in color and the odor was bad which indicate that the water is polluted and dangerous for aquatic ecosystem and human health. The temperature of water was within an average value of 28.39 o C which indicates standard temperature (20 to 30 o C) for aquatic medium. The average value of pH was 6.83, which indicates that the value was within the standard limits (6.5 to 8.0) for aquatic organisms. The values of DO water were within the range of 0.6 to 3.9 ppm with an average value of 2.25 ppm indicating low DO value from standard level (4.0 to 6.0 ppm for domestic and 5.0 ppm for fish culture). The values of BOD were within the average value of 1.15 ppm indicating lower condition compared to standard value of BOD (6.0 ppm for fish culture and 10.0 ppm for irrigation). The average value of TDS was 340.86 ppm which indicates low TDS condition. The EC values were ranged from 35 to150 µS/cm with an average value of 56.30 µS/cm which indicates lower condition than the standard value. The average value of transparency was 28.39 cm. The average value of hardness was 106.79 ppm which indicates near to the standard level. The average alkalinity was 237.66 ppm indicating very lower condition than the standard limit (2000 ppm for irrigation). From this investigation, it is recommended that the water quality of the Turag River is beyond the acceptable limit. So, effective measures should be taken to reduce the level of pollution and mitigate the existing aquatic environmental problems of the Turag River.

This study assessed the extent and trend of landuse/cover change in three selected area of Dhaka city, Bangladesh. This paper examined the use of GIS and Remote Sensing in mapping Land Use/Land Cover in Dhaka city of Landsat imageries of 1960, 2000 and 2014 were downloaded from the Landsat website and to detect the changes that has taken place in this status between these periods. Remote sensing and GIS based software (ILWIS) were used to produce and analysis the land use maps and least square method was functioned to identify the trend of land use change in the study areas. The images were analyzed using unsupervised classification approach in ILWIS 4.1 environment. The present study expressed the experiences of unplanned land use change in Dhaka city. And it is found that the study area follows the pattern of urbanization without planned development. Consequently, the pattern of unplanned land use change in Dhaka city will make it a haphazard city in World.DOI: http://dx.doi.org/10.3329/jesnr.v7i2.22217 J. Environ. Sci. & Natural Resources, 7(2): 105-109 2014

Abstract:The tea industry of Bangladesh is one of the most important foreign exchange earner and source of income. Sylhet, the northeastern divisional city of Bangladesh, is the major tea-producing region of the country. For this reason the study area was selected in Sylhet district to assess the pattern and causes of fluctuation on tea leaf production in selected tea Estates and the impact of micro-climate change on the productivity of tea leaf. The yield of tea is greatly influenced by microclimatic parameter of a region especially rainfall, temperature. Scanty rainfall causes irreparable losses because irrigation is seldom used on tea plantations. On the other hand, heavy rains erode top soil and wash away fertilizers and other chemicals. An analysis of the results of field experiments with weather data shows that increase highest tea leaf production per hectare lies on 4000mm to 4600mm rainfall. Heavy or scanty or delayed rainfall adversely affected the growth and yield of tea. It is observed that tea leaf production is slightly increased with increase in total annual rainfall. The temperature and humidity have no direct effect on tea leaf production. It may largely depend on soil quality and solar radiation. Loobacherra tea estate produces high amount (1838.70 kg) of tea leaf per unit area, on the other hand, Lackatoorah tea estate produce lowest amount (682.31 kg) of tea leaf. Further study is needed to identify the cause of variation of tea leaf production in different tea estate. Awareness should be rise on micro-climate change amongst the planter, estates and worker groups for the maximum production of tea leaf.

An experiment was conducted at the field laboratory of Department of Environmental Science, Bangladesh Agricultural University, Mymensingh to study the textural influence on surface and subsurface soil temperatures under various conditions. The experiment consisted of four types of soil (red, sandy, clay and peat). Observations were made at three conditions viz. bare, moist and vegetation cover. Sandy soil at bare condition showed the highest surface temperature followed by peat, red and clay soils. Sand surface produced nearly 10ºC higher values than from clay soil at around midday hours. In four types of soils, the amplitude of the daily surface temperature wave decreased in the order sand > peat > red > clay at bare dry condition. In case of subsurface temperature observed at 10 cm depth, red, clay and peat soils showed insignificant differences. Soil surface temperatures of 4 types soils under moisture condition at around mid days showed similar pattern as in dry condition i.e. sand > peat > red > clay. Soil subsurface temperatures of 4 types soils under moisture condition at around mid days showed similar pattern as in surface temperature. Among three conditions, sandy soil emitted highest long wave radiation ) at bare condition. The long wave radiation emitted by the surface was lower when the soil was wet and has vegetation cover. Air temperature positively correlated with soil temperature.