High temperature in the city centers than its’ surroundings known as the Urban Heat Island (UHI) effect, which is causing discomfort to the urban dwellers in the summer time is gaining much attention around the world because the world is getting urbanized as it advances in technology. Alterations of surface area, improper urban planning, air pollution, etc. are causing this increasingly growing phenomenon and it is accountable for human discomfort, human casualties and decline of climate. In this paper, an attempt has been taken to review various measures to encounter UHI effect and the processes by which these strategies work is described with diagrams. Using high albedo materials and pavements, green vegetation and green roofs, urban planning, pervious pavements, shade trees and existence of water bodies in city areas are the potential UHI mitigation strategies on which discussion is done in this paper with their limitations. Green vegetation seems to be the most effective measure and other strategies can play a major role under proper condition.

Energy insufficiency is obstructing the socio-economic and industrial improvement of Bangladesh. Renewable energy contributes about 560 Megawatt (MW) of the total electricity production of 20,430 MW, which can be a sustainable solution to the demand-supply crisis. This paper, summarises the current energy situation of Bangladesh and examines the available renewable energy resources and their future prospect. It has been revealed that Bangladesh is heavily (62%) relying on natural gas although government has already taken steps to generate electricity from renewable energy sources. Current policies and legislations related to generation of renewable energy in Bangladesh have been discussed explicitly. Finally, some suggestions have been made to tackle the ongoing energy crisis in the country, in addition to the renewable energy.Abbreviations: GDP: Gross domestic product; RNPP: Rooppur Nuclear Power Plant; Tcf: Trillion cubic feet; IDCOL: Infrastructure development company limited; BPDB: Bangladesh Power Development Board: GS: Grameen Shakti; BWDB: Bangladesh Water Development Board: USD: United States Dollar; IPP: Independent power producer: BCAS: Bangladesh center for advanced studies; NWPGCL: North West Power Generation Company Limited: BCSIR: Bangladesh Council of Scientific and Industrial Research; EGCB: Electricity Generation Company of Bangladesh: WRA: Wind Resource Assessment; REB: Rural Electrification Board: BRAC: Bangladesh Rural Advancement Committee; kW: Kilowatt: PJ: Petajoules; MW: Megawatt: IFRAD: Institute for fuel research and Development; GWh: Gigawatt hours: ICS: Improved Cooking Stoves; MWh: Megawatt hours: DoE: Department of Environment; TWh: Trillion-watt hour: DLS: Department of Livestock Services; RPCL: Rural Power Company Limited: mmcfd: million cubic feet per day; APSCL: Ashugang Power Station Company Limited: BSCIC: Bangladesh Small & Cottage Industries Corporation (BSCIC); GOB: Government of Bangladesh: BADC: Bangladesh Agricultural Development Corporation; SREDA: Sustainable and Renewable Energy Development Authority: DIDA: Danish International Development Agency; LGED: Local Government Engineering Directorate: BAU: Bangladesh Agricultural University; NGO: Non-Governmental Organization: HBRI: Housing & Building Research Institute; IRENA: International Renewable energy Agency: : BARD: Bangladesh Academy for Rural Development; ETP: Electronic Traffic Pricing: BCCD: Bangladesh Commission for Christian Development; PV: Photovoltaic: BRRI: Bangladesh Rice Research Institute; SHS: Solar Home Systems: NDBMP: National Domestic Biogas and Manure Program; TOE: Tonne of oil equivalent: K/km: Kelvin/kilometer; LEAP: Long range Energy Alternative Planning

Floating Treatment Wetland (FTW) is a cost-effective and easy-to-retrofit device for stormwater treatment. Its treatment efficiency largely depends on the fraction of inflow entering FTW and the residence time within it. Thus hydrodynamics play a crucial role, which is affected by the design configurations of FTW and stormwater pond. Despite a spike in research on FTWs, very little is known about how various design configurations affect treatment efficiency by an FTW. Our study hypothesizes that relative positions of FTW geometry, FTW position and pond inlet-outlet have impact on the hydrodynamics and as a consequence, treatment efficiency. To explore these design features, we employed computational fluid dynamics (CFD) modeling conducted in ANSYS Fluent, validated by experimental data to examine the impact of the aforementioned design features. The results revealed that circular FTW geometry positioned near inlet coupled with center inlet-side outlet configuration achieved the highest removal (94.8%) for a non-dimensional removal rate of k_rt_HRT = 20 (k_r is the first order removal rate in per day, t_HRT is the nominal hydraulic residence time of the pond in days). Far side inlet-side outlet configuration performed the worst due to profound promotion of short-circuiting. FTW positioned near inlet performed better (61.8% mass removal on an average) than center (42.7%) and near outlet positions (54.1%) for k_rt_HRT = 20. Sensitivity analysis revealed that the treatment efficiency is most sensitive to inlet-outlet configurations. The design implications of this study will help practitioners achieving better water quality and ecological improvement goals.

Groundwater extraction for irrigation in Bangladesh has caused groundwater depletion, especially in the Northern region. As such, shifting reliance from groundwater to surface water is one of the solutions to mitigate this problem. This study aims at investigating the contribution of effective rainfall to the total consumptive use requirement of rice cultivated in Tanore, Rajshahi, in Bangladesh. The prospect of rainwater harvesting using ponds and its contribution to the consumptive use requirement of rice was also determined. Effective rainfall, temperature, monthly percentage of bright sunshine hours, and consumptive use factor for rice data were collected from Bangladesh Meteorological Department (BMD) and Barind Multipurpose Development Authority (BMDA). Blaney-Criddle method was used to calculate total consumptive use requirement of rice. Analysis results showed that from June to September, there is no requirement of irrigation due to high rainfall in this period. It was revealed that total consumptive use requirement of rice in Tanore averaged at 436 million m ³ of water between the period of 2005 and 2012. Effective rainfall contributed to about 38% of the total consumptive use in this period. It was also found that another 5% of the total consumptive use requirement could be supplied by rainwater harvesting using the ponds of Tanore.