Civil Insight: A Technical Magazine Volume 3 | Page 21

Civil Insight (2019) 21-28 Civil Insight: A Technical Magazine Forest Mapping in Roshi and Melamchi Watersheds 1,* Santosh Chaudhary, 2 Rajiv Giri, 2 Govinda Baniya, 3 Suman Shrestha, 4 Kumud Raj Kafle, 5 Bim Prasad Shrestha 1 Lecturer, Department of Civil Engineering, Kathmandu University, Nepal, [email protected] 2 Alumnus, BE in Civil Engineering (Class of 2017), Kathmandu University, Nepal 3 Assistant Professor, Department of Civil Engineering, Kathmandu University, Nepal 4 Associate Professor, Department of Environmental Science and Engineering, Kathmandu University, Nepal 5 Professor, Department of Mechanical Engineering, Kathmandu University, Nepal Abstract A watershed is the area of land where all of the water on the land flows to a common point, such as a reservoir, a bay or any point along a stream channel. The land cover on earth has been continuously changing due to different human activities. This necessitates the need of systematized classification of vital areas to obtain information on their spatial distribution. Forest mapping is one such method to gathering information for forest conservation and conducting related analyses and researches. For the purpose of forest mapping in Melamchi and Roshi watersheds, satellite data (Landsat 8) and ArcGIS software were used. Supervised classification was performed for the preparation of Land Use Land Cover (LULC) map of Melamchi and Roshi watersheds. The visual image interpretation of the satellite data was done and the analysis indicated that out of total area, forest occupied 45% in Melamchi watershed and 50 % in Roshi watershed. Further, the results were compared with the statistics prepared by ICIMOD for verification. Hence, the study of the watersheds emphasizes the requirement of proper management of forest area in the coming days to preserve the wildlife as well as natural water resources. Keywords: Watershed, Forest mapping, Land Use Land Cover (LULC) 1) Introduction The Roshi watershed is situated in the western part of Kavrepalanchok district in the middle hills of Nepal. These hills are located between the High Mountains on the Northern part and the Low Flatlands Terai on the Southern part of the country. The Roshi watershed covers an area of 15,335ha and its altitude varies between 1420m to 2820m above sea level. The climate is monsoonal with dry season normally spanning from November to May and rainy season from June to October. The Roshi watershed was selected for this research for two principal reasons. First, the watershed is reasonably a representative of the middle hills: land use, population densities, forest types, and forestry- related issues in the area are typical for the middle-hills region. Therefore, the results of this study are expected to provide information applicable to other parts of the middle hills. Second, Roshi was one of the pioneer areas for community forestry implementation in Nepal. As such, the effects of community forestry on land use should be more pronounced in Roshi than in other districts with more recent implementation (Gautam, Webb, & Eiumnoh, 2002). Regarding Melamchi watershed, the Melamchi River originates from the Jugal Himal range at an elevation of 5,875m and joins the Indrawati River at Melamchi Pul Bazar at 940m elevation. The total length of the Melamchi River is 41km and the total catchment area is 330sq.km. The river flows southwards and widens towards the downstream. Melamchi River receives a number of tributaries, thus augmenting the discharge of the river. *Corresponding Author Email address: [email protected] (Santosh Chaudhary) Submitted on October 12, 2019; Accepted on December 7, 2019 21