Browsing by Author "Silva, T.M."

Now showing 1 - 3 of 3

Changing Crop Pattern in Central Highlands of Sri Lanka; Reasons and Consequences (A Case Study of Aranayaka Samasara Mountain area)
(19th Conference on Postgraduate Research, International Postgraduate Research Conference 2018, Faculty of Graduate Studies,University of Kelaniya, Sri Lanka, 2018) Silva, T.M.; Sakalasooriya, N.
The case study discusses changing crop pattern in central highlands of Sri Lanka and the case focused to Aranayaka Samasara mountain area. Especially it has drastically been changed the ecosystems of central highlands without concerning the land condition and their consequences. Disasters, which have been occurred in central highlands, have also been increased with the intensity and the number of disasters and Aranayaka landslide, which was occurred on 17 May 2016, is one of the best evidence. The case study paid attention about three crops as Tea, Rubber and Home Gardens. The main objective of the study is to identify the pattern of crop changes in the study area. There are two specific objectives as find out reasons and consequences reference to the crop pattern changes. This case study proves the significance of cropland management of hilly areas in Sri Lanka The study found the cropland pattern of the area had changed within last 50 years of period. The area encompassed by major Tea and Home Gardens with minor Rubber lands. Apart from that, the area had exposed to the excessive land preparation, and took very limited remedies as application for the conservation of slopes plus extreme land uses denoted near steep slopes of the area as remain poor land management system. When concluding with all above results the changes of crop pattern has changed without concerning the fragile environment of the area and just concern short-term benefits from the harvest of the croplands. The major consequence due to this crop pattern change is, the area has exposed to disaster as landslide and made unstable banks. These results were taken by applying both cartographical and ground level analysis. Cartographical analysis based on land covers in 1956, 1981, 1992, 2012 and 2016. Arc Map 10.1 used as a Geographic Information System (GIS) tool and relevant Geoprocessing techniques were applied. The ground level analysis verifies the story of cartographic contrast changes
Impact of Land Cover Changes on Steep Slopes in Central Highlands for Accelerating the Landslides in Sri Lanka: An Experience from Aranayaka Landslide
(4th International Conference on Social Sciences 2018, Research Centre for Social Sciences, Faculty of Social Sciences, University of Kelaniya, Sri Lanka, 2018) Silva, T.M.; Dr. Sakalasooriya, N.
This paper discusses the nature of the impact of land cover changes which has been occurred in Central Highlands in intensifying the landslides. The land cover on the steep slopes in Central Highlands of Sri Lanka has been drastically changed and it has accelerated the landslides. Consequently, the intensity and the number of occurrences of landslides have also been increased. Aranayaka landslide, which occurred on 17 May 2016, is one of the best evidence in this regard. The main objective of the study is to reveal the major land cover changes which occurred as a result of human activities in Aranayaka area. This case study proves the significance of land use cover management of the steep slopes in hilly areas of a tropical country like Sri Lanka. The study found land cover changes occurred during the last 50 years on steep slopes of the area encompassed by economic land covers with high land preparation, and minor level applied slopes conservation methods. Apart from that, extreme land use was evident near steep slopes of the area. When considering these results, it is clear that most of the human-induced requirements for a landslide has been fulfilled and the situation created a risk of landslides which became a reality. These results were taken from applied both cartographical and ground level analysis. Cartographical analysis based on 1956, 1981,1992,2012,2016 steep slopes land covers. The steep slopes demarcated more than 60% regarding Land use and Policy Planning Department (LUPPD) and three common suitable land covers for all studied years ad Tea, Home Garden (Economic Land covers - ELC) and Natural Forest (Natural Land cover – NLC) were taken into consideration. Arc Map 10.1 used as a Geographic Information System (GIS) tool and relevant Geoprocessing techniques were applied. The ground level analysis verifies the story of cartographic contrast changes and suitable statistical approaches were also applied for the appropriate outcome. The statistical analysis tool is SPSS 22
The Potential of Use Slope Gradient as a Criterion for Demarcating Agro Ecological Zones of Wet Zone, Sri Lanka: With Special Reference to Kegalle District
(International Postgraduate Research Conference 2019, Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2019) Silva, T.M.; Sakalasooriya, N.
This study is focused to introduce the importance of slope gradient for existing criterion for demarcating agro ecological zones of the Wet Climatic Zone (WCZ). The case is special reference to Kegalle District. There are 46 agro ecological zones in Sri Lanka and those defines with considering similar climatic variations, soil condition as a major factor and beyond this stage, it has been concerned elevation regarded from the mean sea level (MSL). Then focus either level of precipitation and spatial changes or soil types when constant level precipitation with vary of soil types. This zonation is the major decision of agriculture; it is a major economic activity, which is majority of local population engaged. Apart from that, commercial and domestic agriculture is the backbone for cultural aspects of traditions Sri Lankan society. Agriculture is playing a key role of land use activities with dynamic scenarios plus unplanned land use and land cover changes are key roles to enhance disaster risk specially the WC. Consequently, there is essential to apply better land use practices including agriculture for the disaster risk reduction. This study points out that the slope gradient is an important factor for demarcating agro ecological zones in WCZ and the study recommends for applying micro level implementation for agriculture decision-making to risk areas of WCZ. Kegalle District is a one of high disaster risk district for landslide with identified risky and dynamic land use practices. The study based on spatial analysis with the secondary data collected from Land use and Policy Planning Department (LUPPD) and Department of Survey, Sri Lanka. Then, applied relevant geospatial techniques to manipulate the data for the research purpose. Selected manmade agriculture (MMALs) land covers in 1998 and 2016 as tea, home garden and rubber cultivation were concerned in whole Kegalle District. Arc Map 10.1 is the main Geographic Information System (GIS) for apply relevant Geoprocessing techniques. Couple of slope gradients selected here according to the LUPPD as 30 – 60% gradient use under proper soil conservation methods and more than 60% slope gradient keep with natural vegetation. The results show the MMALs has temporal changes with drastically increasing even in the slopes of more than 60% within last 50 years of period. This situation alarming to consider the slope gradient use as a criterion for demarcating agro ecological zones of WCZ with relevant conditions