Browsing by Author "Chandrasekara, C.M.K.N.K."

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Cause and Effect Analysis of Impacts of Land Cover Changes on Belihuloya Mini-Catchment Area
(Postgraduate Institute of Science Research Congress, Sri Lanka., 2024) Gunathilake, K.L.W.I.; Jayawardhana, D.T.; Chandrasekara, C.M.K.N.K.
The rapid expansion of human activities has significantly transformed landscapes, leading to major impacts on water resources and ecosystem health. This study comprehensively assessed the transformations within the Belihuloya mini catchment, focusing on the effects of land use and land cover changes. The primary objectives included identifying changes, analyzing trends, and evaluating human perceptions of the impacts on the mini catchment. The study utilised remotely sensed data from 1959, 1988, 2000, and 2020 to assess land use and cover changes over time. A questionnaire survey was conducted among 60 randomly selected households across six Grama Niladhari Divisions within the catchment area. Correlation-based pair-wise analysis, paired t-test analysis, vulnerability value calculation, and interpolation mapping were employed to interpret the data. A cause-and-effect analysis was conducted using the Drivers-Pressures-State-Impacts-Responses (DPSIR) framework. The results revealed significant changes in land cover and use over the study period. Forest cover decreased dramatically, from 80% in 1959 to 33% in 1988, primarily due to the expansion of paddy fields and home gardens. Nine major driving forces were identified, highlighting the pressures on the natural environment and wildlife from land and forest clearance for construction. High-altitude areas surrounding the young Belihuloya river faces significant risk due to rapid land use changes, threatening the river's energy flow. The southern region, including Sabaragamuwa University and the Samanalawewa reservoir, is equally vulnerable, potentially compromising the mini-catchment's health. The findings underscore the urgent need for conservation efforts and informed land management practices to mitigate adverse impacts on the mini-catchment ecosystem and ensure sustainable development for future generations.
The influence of ecological green villages project on ecosystem services
(Department of Geography, University of Kelaniya, Sri Lanka., 2020) Wijesinghe, I.C.S.; Chandrasekara, C.M.K.N.K.
Increasing the population in developing countries will increase the demand for food. The human population has changed ecosystems more rapidly and extensively than in any comparable period in human history, to meet rapidly increasing demands for food, fresh water, and fuel. To meet the challenges of demand for food, enhancing agricultural productivity is essential. Therefore, the usage of chemical fertilizers was increased. Sri Lanka is identified as one of the nations with higher consumption of chemical fertilizers among the South Asian countries. Chemical fertilizers dramatically deteriorate the quality of food, water, soil and air of the particular environment. As a remedy to those problems ecological green villages program was introduced by the department of export agriculture of Sri Lanka in 2017, to promote the concept of organic agriculture. At present, there are about 15 green villages in Sri Lanka. One such program is being implemented in the Kurunegala district as the “Indulgodakanda organic crops village” with 41 farmers. The recommendation of the organic certificate is given only for their organic lands. Their other lands which are not belonging to the project are cultivated with chemical fertilizers. The present study aimed compares the impact to ecosystem services by considering the land belongs to the eco-green village of Indulgodakanda and chemical agriculture land not belonging to the project. The Shannon diversity index and the scale of diversity index were used to achieve the aim. Thereby the diversity of crop species at the beginning of the project in 2017 and two years after the commencement of the project in 2019 were compared. During the commencement of the project, there was a high Shannon diversity index value for 26 chemically cultivated lands out of 41 lands. However, 2 years later the Shannon diversity index values were increased in 33 organic lands. The highest diversity value of the organic agriculture land was 2.06 while the same chemical agriculture land reveals 1.75. After 2 years alpha diversity of the organic lands were increased up to 10 and 7. However, the beta value was used to study the diversity of crops between organically and chemically cultivated lands. According to the above results, this project helped to increase the diversity in organic lands than the chemically cultivated lands.
The Spatial concentration of human-peacock conflict
(Department of Geography, University of Kelaniya, Sri Lanka., 2020) Rajapaksha, R.L.N.; Chandrasekara, C.M.K.N.K.
Human-wildlife conflict is harmfully affecting the wellbeing of both people and animals. Human – peacock conflict in the wet zone of Sri Lanka is increasing at present and yet the information on this conflict is limited. Therefore, the main aim of this study was to investigate the spatial concentration of peacock habitats and the areas where impairment created by peacock species. Matara Divisional secretariat Division in Matara district was selected as the study area. A field survey has been carried out to identify the absolute locations (latitudes and longitudes) of peacock habitats and the affected areas. A handheld Garmin e Trex 10 GPS recorder was used to record the geographic coordinates of the locations. A total of 849 locations were recorded, including 511 peacock habitats and 338 effected areas by the peacock. Kernel Density estimation was used as the main tool for hot spot identification. Two separate estimations were carried out to identify concentrations of habitats and affected areas. The analysis of data was accomplished, through the integrated use of Arc GIS 10.1 software packages along with Microsoft Excel analytical tool. Maps and graphs have been prepared in visualizing the results of the analysis. The results reviled that the peacock habitats and effected areas were in two different locations. Peacock habitats were widely spared in areas where tree species occur like Albesiya, Attoniya, and Hora. Further tea lands also identified as where peacocks prefer to stay. The bird stays those places between 6.30 pm to 7.30 am of the following day. The affected areas depend on the food availability for peacocks. The birds used to be at those locations from 7.30 am to 6.30 pm Lack of predators for peacock, not destroying the eggs, lack of layers of plants due to crop cultivation, snakes in farm oil plantations are the most common pull factors for peacocks to come to the villages.
Suggest Land use and land cover changes of Udawalawe National park and their possible influence on the carrying capacity of elephants (Elephas maximus maximus) of the park.
(Department of Geography, University of Kelaniya, Sri Lanka., 2020) Hemachandra, I.V.D.; Chandrasekara, C.M.K.N.K.; Dayawansa, P.N.
Habitat loss is considered a crucial factor that influences the dispersion of animals. Anthropogenic changes in land use and land cover patterns are known to impact the carrying capacity of elephants. Udawalawe National Park (UNP) was established in 1972 to protect the catchment of the Udawalawe Reservoir and maintaining the carrying capacity (K) of its flagship species elephant (Elephas maximus maximus) by minimizing habitat loss due to land clearance and cultivations by villagers. Despite this, the vegetation cover of UNP has changed over time resulting in poor wellbeing of elephants at present. The present study was carried out to identify the temporal changes in land use and land cover of UNP from 1966 to 2018. Topographic maps 1966 and 1985 produced by the survey department of Sri Lanka and the interpreted data were converted into digital format by screen digitizing. Satellite imageries downloaded from the Google Earth website for 2018 of the area were used for the study. Satellite imageries were geometrically rectified to Kandawala_Ceylon_Belt_Meters to allocate a common coordinate system for all images, and on-screen visual interpretation followed by screen digitization was performed to identify and extract LULC categories. The LULC layers were in vector format and were subsetted into the boundary of the UNP area using ArcGIS 10.1 software. Land extents of each land use category about each year were calculated using Arc GIS 10.1 software. Thick forests had occupied the highest land cover at 54.23% in 1966 while total anthropogenic activities had only 11.79%. By 1985, thick forests have reduced to 2.86%. Grassland patches at the North-western end that had occupied 6.03% of the park have been lost to chena, scrub, forest, and thick forest, from 1966 to 1985. Scrub areas had gradually increased and reached up to 55.54% of the total area in 1985. Total anthropogenic land use has increased to 16.38% during the same period. The current geographic occupation of the park has 26.23% scrub, 24.99% thick forests and 23.89% of anthropogenic land use. The results revealed that human encroachment of UNP has dramatically increased from its Gazetted boundary due to natural succession. When vegetation thickness increases within the park from succession, elephants tend to avoid such areas. Thick vegetation will reduce the K of elephants and result in poor wellbeing of elephants. If the trending land-use changes continue, elephants will tend to move out from UNP, thus intensifying Human- Elephant Conflict.