## 3 Results and Discussion
### Implications of Climate Change on Sediment Yield  
The sediment cycle in the Nagavali and Vamsadhara watersheds exhibits a strong correlation with streamflow and precipitation patterns. The mean peak sediment yield followed the mean peak streamflow patterns. During the 40-year baseline period (1975-2014), the average annual sediment yield was 6.68 t/ha/yr in the Nagavali watershed and 7.3 t/ha/yr in the Vamsadhara watershed. Table 5 presents the percentage change in sediment yield predicted by climate models for the near future (2022-2060) and far future (2061-2100) compared to the historical sediment yield (1975-2014). The percentage change in the sediment yield of different models under all scenarios followed the percentage change in streamflow patterns over both watersheds. In the near future, the Warm-Wet model shows the highest overestimation of sediment yield under the SSP370 and SSP585 scenarios. The Average  
Figure 6: Projected mean monthly streamflow for the Nagavali and Vamsadhara watersheds under three different scenarios: SSP245, SSP370, and SSP585. Panel (**a**) shows the Nagavali watershed and panel (**b**) shows the Vamsadhara watershed. model exhibits the highest overestimation in the Nagavali watershed, while the Cold-Wet model shows the highest overestimation in the Vamsadhara watershed under the SSP245 scenario. In the far future, the Warm-Wet and Cold-Wet models consistently show the highest overestimation of sediment yield under all scenarios. According to Figures 4 and 7, the historical and future sediment yield peaks under all scenarios align with streamflow peaks, indicating a strong correlation between these variables. However, the specific timing and intensity of monthly sediment yield values varied among the climate models. These findings highlight the uncertainties in predicting sediment yield under future climate scenarios and the importance of considering multiple climate models to capture the range of possible outcomes. Understanding sediment yield dynamics is crucial for effective watershed management, as increased sediment yield can negatively impact soil properties, reservoir capacity, and water quality. Reservoirs estimated the average sediment trapping efficiency under IMD data over the Nagavali and Vamsadhara watersheds to be 85.14% and 62.1%, respectively, during  
Figure 7: Projected mean monthly sediment yield for the Nagavali and Vamsadhara watersheds under three different scenarios: SSP245, SSP370, and SSP585. Panel (**a**) displays the Nagavali watershed and panel (**b**) displays the Vamsadhara watershed. a 40-year period (1975-2014). The sediment trapping efficiency, which is the ability of a reservoir to retain or trap sediment that flows into it from upstream areas, instead of allowing the sediment to continue downstream, in the Nagavali and Vamsadhara watersheds ranged from 78% to 88.21% and 61.56% to 64.3%, respectively, according to climate models. It will range from 71% to 88.5% and 61.5% to 65.43% in the near future, and from 61.26% to 86.34% and 61% to 64% in the far future over the Nagavali and Vamsadhara watersheds, respectively. In general, trap efficiency decreases with age because silt deposition reduces reservoir capacity. Future periods in both watersheds are expected to report lower sediment trapping efficiency than historical periods, while wetter models will have lower sediment trapping efficiency than drier models. According to a report by the Central Water Commission (CWC, 2020), many Indian reservoirs were reducing their storage capacity at a rate of 1% per year due to sedimentation. In order to save reservoir capacities, agricultural areas, and water quality in these basins, water and soil management methods must be planned and implemented.