For soil erosion modeling, determining sediment transport capacity (Tc) is essential because it plays a key role in sediment detachment, transport, and deposition research. This paper provides insights into the seasonal spatial distribution of sediment transport capacity, excess runoff depth in response to the distribution of precipitation, and land use at a watershed scale, using SCN Curve Number (CN) method, Remote Sensing (RS), and Geographic Information Systems (GIS). Spatial distribution in runoff production on hillslopes and sediment transport are explained. We integrated the effect of slope gradient in the curve number to model the landscape effect on sediment transport. The findings show that seasonal variation in sediment transport capacity is influenced by climate change. During June and October, the transport capacity is higher and coincides with channel areas in the Boubo watershed. Potential applications of this map may help the decision-maker to deal with problems associated with watershed development and management.

Land Use / Land Cover (LULC) changes has been progressive across the globe, causing the alteration and shifting of various land use/land cover features. These changes are caused by natural factors such as extreme environmental conditions, earthquakes, volcanic eruption, flooding and also human factors including agricultural expansion, urban and industrial development of infrastructure. The study combined spatial time series satellite data and field observations to observe the changes which have occurred in the land cover mapping between 1999 and 2007. Land cover features were categorized into Vegetation, Crop/farmland, Settlement, Bare land and Water body. Satellite imagery for the intervening period was used to assess the changes in LULC. LULC classes of Settlements and Bare land recorded an increase of 3.21%, and 33.1%, whereas Vegetation, Crop/farmland and Water decreased by 1.8%, 33% and 2.1% respectively. It was observed that the mean conversional change between 1999 and 2007 was 2148.55 hectares. A total land size of 9297.79 hectares did not undergo any change; conversion into Water body was 417.62 hectares, 7688.56 hectares was changed into Crop/farmland, 1137.76 hectares into Settlement, 337.17 hectares into Bare land, and 1161.65 hectares into Vegetation. It was also observed that the sharp increase in Settlement is as a result of rapid population growth and expansion of infrastructure.

Shipbreaking industry has turned out to be dominant sector in Bangladesh without considering the environmental issues. However, to date, extremely limited studies have been performed to monitor the air and noise level around shipbreaking sites of Bangladesh. This study is conducted to assess the air and noise level with associated health risk vicinity to selected shipbreaking areas of the country. Herein, data on various air pollutants, noise level, and meteorological factors were collected from six prominent shipbreaking yards in Chattogram. Findings of the research work revealed that some air quality parameters and noise level adjacent to shipbreaking areas are exceeded the permissible level set by the WHO. The values of Air Quality Index (AQI) is found in the unhealthy category for human health perspective. The average noise level was also recorded beyond the permissible limit in every sampling sites, following descending order: S3 > S4 > S5 > S6 > S1 > S2. From the statistical analysis, the authors explored that there are significant correlation with poor to strong (0.0.026 to 0.97) among the climatic parameters and air pollutants. Both particulate matters and AQI demonstrate a moderate correlation with the meteorological parameters (humidity and wind speed), and gaseous air pollutants (CO2 and TVOC) also have considerable correlations. The moderate correlation between AQI and noise level is also observed in this study. The authors recommended for effective control actions to alleviate the detrimental environmental pollution arises due to the consequences of shipbreaking activities for ensuring health safety of workers.

Polymesoda spp., which represent bivalves in the mangrove ecosystem, inhabit the mangrove forests of the Indo-Pacific region. They are edible bivalves consumed by inhabitants located around the mangrove forests in the region. The bivalves also have a cultural significance because their shells are used for religious ceremonies on the Yaeyama Islands in Japan. However, detailed studies of these bivalves is scarce and their biology is not well understood. We conducted this study in the mangrove forest along Urauchi River of Iriomote Island, Japan. The spatial distribution patterns of the bivalves and the forest floor environment were surveyed. We used 75 large (10m2 quadrat) plots to survey plant species and above-ground root density, and small (1m2 quadrat) plots to count the number of bivalves and measure median particle diameter, sediment temperature and Oxygen Reduction Potential (ORP) in each large plot. In addition, the relationships between these forest floor environmental factors and the spatial distribution patterns of the bivalves were analyzed. Polymesoda spp. was present in 34 plots. Bruguiera gymnorhiza was dominant in 79.4% of plots. A correlation between the distribution and median particle diameter and ORP and sediment temperature was not found. In 94% of the plots, the above-ground root density was over 50% of the large plot. The relationships between the spatial distribution patterns of the bivalves and plant species and the above-ground root density were revealed.

Construction sites are often blamed for dengue outbreaks in surrounding localities. The environment is suitable for immature mosquitoes to develop without predators and the convenience of female mosquitoes to feed on the exposed construction workers. The purposes of this study were to identify the species of mosquitoes present at construction sites and the types of their preferred breeding habitats, and also to determine the vertical distribution of the mosquitoes. Nineteen construction sites in the Federal Territory of Kuala Lumpur were cross-sectionally surveyed for the presence of immature mosquitoes in 2018. All water-holding containers were inspected for the presence of immature mosquitoes. Types of water-holding containers were recorded and counted. The number of immature mosquitoes was counted from each positive container and then transferred to the laboratory for species identification. A total of 1,643 immature mosquitoes were collected, comprising 1,287 larvae and 356 pupae. Aedes aegypti immature was the most abundant mosquito species (76%), followed by Culex quinquefasciatus (19%), and the Aedes albopictus (5%). The most productive breeding sites were flooded floors, drains, plastic containers, elevator shafts, water drums, and pails. We discovered that the immature mosquitoes were most abundant from the ground floor to the second floor, with Ae. aegypti immature could disperse up to the thirteenth floor. This study has provided useful information to the health department regarding the preferred breeding habitats of vector mosquitoes at construction sites. Consequently, it contributes to effective and efficient vector prevention and control measures, thus saving time and manpower.