Browsing by Author "Keerthi, T"

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    Assessment of rehabilitation options for environmental impacts of abandoned mines
    (Department of Earth Resources Engineering, University of Moratuwa, 2021-12) Kavirathne, SR; Udayanga, RI; Keerthi, T; Gunawardana, ADTJ; Chaminda, SP; Jayawardena, CL; Dissanayake, DMDOK; Jayawardena, CL
    The quarries which are abandoned ceasing operations without a proper closure plan cause negative impacts on the environment and also risk for the health and safety of society and the economy. This research focused on the environmental aspects that are affected by abandoned quarries and a sustainable methodology to design future land use. The objective of this research is to introduce a quarry rehabilitation method that is effective and has a positive impact on the environment, and applicable for abandoned quarries in Sri Lanka. In this respect, the district of Colombo has been chosen due to its importance in social and economic aspects. The research was conducted by identifying abandoned quarries through remote sensing and geographic information system technique (RS & GIS) analysis of satellite images of the concerned area. Prioritised two quarries among identified quarries for further analysis and suggested possible rehabilitation options. According to the land use analysis around the two quarries, the better rehabilitation option is to transform the lands into a vegetation area.
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    Enhancing operational strategies in water reservoir management through satellite imagery: analysing temporal anomalies in water surface variations for climate adaptation under seasonal changes
    (Business Research Unit (BRU), 2024) Madhurshan, R; Dhananjaya, KIK; Keerthi, T; Dassanayake, SM; Chao, Z
    Climate change variations have significant adverse impacts on water resources, particularly in regions where the water supply is primarily dependent on reservoir systems. For efficient management of water resources, it is essential to comprehend the dynamics of reservoir water levels and climate-driven anomalies. Quantitatively appraising the water budget is crucial for enhancing socio-economic water and energy demands. Analyzing fluctuations in water levels and cyclic patterns of drought seasons due to climate change can significantly aid in the pre-planning and managing reservoir systems. This study aims to enhance water reservoir management by using satellite imagery to identify drought periods through surface water area analysis. With the fusion of Landsat 8 and Sentinel-1 data, this research focuses on mapping water surface changes at the Victoria Lake reservoir, Sri Lanka, using the Normalized Difference Water Index (NDWI) from 2018 to 2023. Both satellite data were acquired and subsequently processed on the Google Earth Engine platform (GEE). The resulting maps were created using ArcMap desktop software. The correlation coefficient observed between Landsat 8 and Sentinel-1 NDWI area measurements is 0.771, indicating a strong relationship between the two datasets. This high correlation underscores the reliability of using both sources to comprehensively analyze water surface area. Factors such as sensor calibration, atmospheric conditions, and data processing techniques can affect recorded values and correlations. Results revealed a cyclic pattern in water levels, with a notable trough in March 2019, followed by a significant drop lasting until March 2022, and another rapid decline observed within the subsequent year. Integrating satellite imagery in monitoring and decision-making processes offers a valuable tool for addressing the challenges of water and energy management under climate anomalies.