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During their flow through an area, the streams are used to erode, transport and re-deposit sediments in the number of cycles following the climatic variation in an area. This cycle in turn affect the chemistry of these sediments and hence the geochemical study of these sediments helps to understand the palaeo-climate, source-area weathering and provenance of the study area. In order to understand the geochemical classification of sediments, palaeo-climate, source-area weathering and provenance for stream sediments of the Eastern Ghats Mobile Belt (EGMB), 364 stream sediment samples were collected from the area around Daringbadi, Kandhamal district, Odisha, India and analyzed for major oxides, trace elements and rare earth elements. These sediments are geochemically classified as shaly and wacke type, moderately mature and derived through the high intensity of weathering of source rock under warm and humid climatic condition. The positive correlation between Al2O3 and Fe2O3, MnO, and MgO, indicates multiple sources for sediment and these oxides are associated with clay minerals. The discrimination function diagram suggests a felsic igneous as well as quartzo-sedimentary provenance for these sediments whereas the ratio of Al2O3/TiO2 and concentration of V-Ni-Th suggest a felsic igneous source rock. The high concentration of LREE, slight enrichment of HREE and negative Eu anomaly indicate terrestrial or continental crust source rock. Hence the source rock for these sediments are granite gneiss, charnokite and khondalite present in and around Daringbadi area. [ABSTRACT FROM AUTHOR]

• Hydrology and sediment supply in regulated Godavari R., India simulated using SWAT. • Simulations illustrate importance of reservoirs in distributed hydrologic modelling. • Geomorphic stability index computed from pre/post- dam flow and sediment transport. • Observed incision is related to the simulated geomorphic stability index. • Climate change could move rivers below existing dams toward states of net erosion. Long-term geomorphic evolution of rivers depends both on the amount of sediment supply and on the river's ability to transport that sediment. Climate change is anticipated to change flow frequency distributions and sediment yield and could thus alter the geomorphic trajectory of many regulated rivers. We aim to examine the possible geomorphic response of the upper Godavari River, India, to climate change using two well-accepted metrics: the frequency of the sediment-transporting flows (T*) and the ratio of the sediment flux below and above a dam (S*). Soil and Water Assessment Tool (SWAT) was used to simulate streamflow and sediment yield in the basin. We calibrated and validated the model using SWAT-CUP for pre- (1971–75) and post-dam (1976–81) conditions downstream of Jayakwadi dam. The model performance was good (NS value > 0.6 for discharge and PBIAS < ± 10 for sediment) with low uncertainty (p-factor > 0.6 and r-factor <1) and it improved significantly by factoring the operation of the reservoirs into the simulation. We ran the model for 10 years consecutively in the pre and post-dam states for baseline (1971–81) and future (2090–99) climate conditions derived from NEX-GDDP climate projections (Emission scenario RCP 8.5 & 4.5). A linear relationship between T*/S* and observed erosion (m) below the dam provided the basis for estimating the amount of erosion associated with future climate states. Our simulations show substantially larger T* below the dam site in 40% of the 2090s scenarios relative to the baseline conditions. These could be associated with 4–6 times the erosion compared to the baseline. Severe erosion is indicated only under RCP 8.5. Simulations suggest that amplified peak releases from dams in the future could lead to greater downstream erosion potential. [ABSTRACT FROM AUTHOR]