Assessment of channel migration of Koshi River in Nepal using remote sensing and GIS

River channel shifting involves the lateral migration of an alluvial river channel across its floodplain. High planform dynamics are a distinctive feature of the Koshi river, particularly in the lower stretches as a result of recurring floods. In this research, the dynamics of channel planform and shifting through systematic analysis and interpretation of diverse channel configurations using multidate Landsat TM 5 images (1999 and 2009) and Sentinel-2A image (2019) of the Koshi River from Chatara to the Nepal-India border has been studied. Remote sensing techniques and GIS environment was used for change analysis based on the satellite imageries. The channel shifting was determined by assessing and estimating the transient changes in the planform from the temporal satellite data. The results indicated that the Koshi River is highly braided over the stretch of 48 km south from Chatara. It can be easily visualized that the southern section of the river has more river stretch and braiding than the northern section. Between 1999 and 2019, the area of the water channel is reduced by 24.08 km2 whereas, the channel bars have increased by 68.08 km2. The river was observed having experienced a clear shift of the channel toward the west in recent years. The average annual rate of shifting was estimated to be 21.6 m year−1 towards the west and 0.8 m year−1 towards the east, with the overall expansion of the river flood plains. This study can be utilized for developing integrated sustainable river and land management plans in the Koshi basin and support future researches on relevant topics

Pinus roxburghii stand dynamics at a heavily impacted site in Nepal: Research through an educational fieldweek

The fieldweek associated with the 4th Asian Dendrochronological Association Conference was an excellent opportunity for education, networking, and research. The participants and group leaders worked together for five days in an area that was new to some of the group leaders and new to some of the participants which enabled us to learn about forest ecology around Kathmandu and Nagarkot, Nepal. The fieldweek was an excellent networking opportunity and the group leaders and participants bonded which strengthened international research in dendrochronology and continues to foster new research collaborations. All of the group leaders and participants had the opportunity to learn about tree-ring formation in Pinus roxburghii at 1500 masl elevation, to explore its wood anatomy, and to examine specific research questions in our field area. In the end we developed a better understanding of the stand-age structure of a stand of trees in Nagarkot, explored the erosion history from exposed roots, and investigated tree health issues on closely related sites. We found that P. roxburghii poses some dating issues with false and micro rings at this elevation, but we were still able to develop a tree-ring chronology from this species and make preliminary assessments of stand dynamics and health

Pinus roxburghii stand dynamics at a heavily impacted site in Nepal: Research through an educational fieldweek

The fieldweek associated with the 4th Asian Dendrochronological Association Conference was an excellent opportunity for education, networking, and research. The participants and group leaders worked together for five days in an area that was new to some of the group leaders and new to some of the participants which enabled us to learn about forest ecology around Kathmandu and Nagarkot, Nepal. The fieldweek was an excellent networking opportunity and the group leaders and participants bonded which strengthened international research in dendrochronology and continues to foster new research collaborations. All of the group leaders and participants had the opportunity to learn about tree-ring formation in Pinus roxburghii at 1500 masl elevation, to explore its wood anatomy, and to examine specific research questions in our field area. In the end we developed a better understanding of the stand-age structure of a stand of trees in Nagarkot, explored the erosion history from exposed roots, and investigated tree health issues on closely related sites. We found that P. roxburghii poses some dating issues with false and micro rings at this elevation, but we were still able to develop a tree-ring chronology from this species and make preliminary assessments of stand dynamics and health. (C) 2016 Elsevier GmbH. All rights reserved