Relief morphology and sediment management of the Upper Jiadhal River Basin, Arunachal Pradesh and Assam, North-East India

An environmental geographical study involves the relief aspects of the geographical unit. Relief analysis of a geographical unit includes relative relief, slope gradient, steepness, and drainage characteristics. The study area selected for the study is a part of the upper Jiadhal drainage basin consisting of 370.63 sq. km of area. It is a young river system (6th order) with lots of sediment carrying capacity and intensive flood frequencies. In this study, the relief morphology of the upper Jiadhal basin is undertaken observing its unique characteristic of large sediment supply causing flood problems in lower basin areas. Open source Landsat: L5135041_041200901113_MTL, TA6RFR_A012986-20,190,901 data from Bhuvan (ISRO) was accessed by ArcGIS tools. It focused that the upper catchment is more influential by environmental problems rather than human except deforestation activities, as there is very less settlement due to no communication route to the interior catchments of the basin. The mainstream of Sido occupies forth (4th) order stream, Sika and Siri are of fifth (5th) order and Jia of sixth (6th) order stream contained to drain the lower basin. The results revel that, the landscape is prone to erosion mainly due to physical and climatic factors and prominently dominated by human intervention due to agro-forestry and could be mitigated with certain specific measures on a location basis including structural engineering measures and watershed management techniques in the degraded areas for the sustainability of the basin. The early studies in this region include the lower basin of the river system, due to inaccessibility. The area is newly demarcated to a different administrative district of Arunachal Pradesh (Lower Siang) and thus in near future more anthropogenic activities would active in the upper catchment, which may influence the environment stability. So the upper catchment management would be a prime concern for the environmentalist in near future.