Sediment Monitoring Protocols for Churia Originating River Systems
The rivers in Nepal can be broadly classified into three types depending on their sources and discharge. The first type (e.g. Mahakali, Karnali, Gandaki, Koshi etc.) originates in the Himalaya and carries snow-fed flows with significant discharge even in dry season. The second type originates in the Midlands or the Mahabharat Range and is fed by precipitation as well as groundwater regeneration. Babai, West Rapti, Tinau, Bagmati, Kamala, Kankai etc. fall under this type. Apart from these two types, there are large numbers of non-perennial rivers having many ephemeral tributaries originating from Churia range for example Ratu, Khando, Gagan, Lothar, Lakhandehi, etc.
Churia ranges can be classified into three formations: i) Lower, ii) Middle and iii) Upper Churias. The Lower Churia consists of hard sandstone with conglomerates containing pebbles of clay and shale, whereas the Upper Churia is composed of coarse conglomerates, sands, girt and clay. The region is highly influenced by specific climate patterns of intense rainfall, weak geology and excessive human activities leading to mass wasting and sediment transport towards low land.