Moniruzzaman Moniruzzaman

Solar energy may also be used by individuals as a hybrid solution—that is, one that combines grid and solar power—to provide a steady supply of electricity in the event of a power outage. This study aimed explore the mode of solar home system (SHS) purchasing, daily usage, impacts and satisfaction level of community dwellers in Singair sub-district of Manikganj, Bangladesh. A total of 120 solar home system user households were randomly selected and surveyed using a semi-structured questionnaire. This study revealed that households have been purchasing SHSs with their direct income, loans from NGOs and banks, and borrowed money from relatives and neighbours. The systems are widely used by the user households (>5 hours/day by 53% households). Results highlighted several reported benefits of SHSs in the study area, including improvements in children’s education (96%), household productivity (84%), living standard (84%), communication (82%), entertainment (76%), and social interactions (62%). Besides, this study explored a high level of satisfaction regarding the use, acceptance, and effectiveness of SHSs in the study area. This study mainly focused on the social benefits and user satisfaction of SHSs. Future research can focus on comprehensive social-economic-environmental benefits as well as demand based user satisfaction.

The impact of land use on water quality is becoming a global concern due to the increasing demand for freshwater. This study aimed to assess the effects of land use and land cover (LULC) on the surface water quality of the Buriganga, Dhaleshwari, Meghna, and Padma river system in Bangladesh. To determine the state of water, water samples were collected from twelve locations in the Buriganga, Dhaleshwari, Meghna, and Padma rivers during the winter season of 2015 and collected samples were analysed for seven water quality indicators: pH, temperature (Temp.), conductivity (Cond.), dissolved oxygen (DO), biological oxygen demand (BOD), nitrate nitrogen (NO₃-N), and soluble reactive phosphorus (SRP) for assessing water quality (WQ). Additionally, same-period satellite imagery (Landsat-8) was utilised to classify the LULC using the object-based image analysis (OBIA) technique. The overall accuracy assessment and kappa co-efficient value of post-classified images were 92% and 0.89, respectively. In this research, the root mean squared water quality index (RMS-WQI) model was used to determine the WQ status, and satellite imagery was utilised to classify LULC types. Most of the WQs were found within the ECR guideline level for surface water. The RMS-WQI result showed that the “fair” status of water quality found in all sampling sites ranges from 66.50 to 79.08, and the water quality is satisfactory. Four types of LULC were categorised in the study area mainly comprised of agricultural land (37.33%), followed by built-up area (24.76%), vegetation (9.5%), and water bodies (28.41%). Finally, the Principal component analysis (PCA) techniques were used to find out significant WQ indicators and the correlation matrix revealed that WQ had a substantial positive correlation with agricultural land (r = 0.68, P < 0.01) and a significant negative association with the built-up area (r = − 0.94, P < 0.01). To the best of the authors’ knowledge, this is the first attempt in Bangladesh to assess the impact of LULC on the water quality along the longitudinal gradient of a vast river system. Hence, we believe that the findings of this study can support planners and environmentalists to plan and design landscapes and protect the river environment.