Earth observation satellite data-based assessment of wetland dynamics in the Kashmir Himalaya.

Earth observation (EO) technology offers enormous opportunities to assess the magnitude and patterns of spatial variability in wetlands over time. This study aims to assess the spatial and temporal changes in the wetlands of the Kashmir valley using multiple remote sensing satellite data products, Geographic Information System (GIS), and field observations. Moreover, role of major factors operating at different time scales including regional geology, climate, and human activities in driving the wetland change is presented. The dynamics of the wetlands are illustrated in the occurrence, seasonality, and recurrence of surface water, land cover transitions and loss patterns particularly for the period from 1984 to 2021. Constituting about 3% (495 Km2) of the total area, substantial and variable patterns of seasonal and annual changes are exhibited by the wetlands. The main transitions of the water surface reveal that 2% of the area has changed from permanent to seasonal; 8% is lost; 15% is new seasonal; 0.12% is permanently lost; and 0.3% is new permanent. About 22% of the area reveals increase in the intensity of water surface occurrence, whereas 44% shows no change, and 34% exhibits decrease. Bathymetric analysis suggests that the average depth of the wetlands ranges between 0.6 and 16.6 m. In general, alpine wetlands are relatively deeper and mostly static in their structure whereas those in the floodplain are shallow, fragmented, and showing signs of depletion during the assessment period. The results of this assessment will inform the policy on conservation and sustainability of wetlands in the Kashmir Himalaya.

Complementary use of multi-model climate ensemble and Bayesian model averaging for projecting river hydrology in the Himalaya.

Considering the sensitivity and importance of water resources in the Himalayan uplands, this study intended to assess the hydrological responses to climate change in the Jhelum basin. Representative concentration pathway (RCP)-based projections from six dynamically downscaled global circulation models (GCMs) were bias-corrected for developing the climatic projections over the twenty-first century. The uncertainty associated with GCM outputs was addressed by using multi-model ensemble projections developed through Bayesian model averaging (BMA) technique. The assessment reveals that compared to the baseline (1980-2010) values, the annual mean maximum temperature in the basin will rise by 0.41-2.31 °C and 0.63-4.82 °C, and the mean minimum temperature will increase by 1.39-2.37 °C and 2.14-4.34 °C under RCP4.5 and RCP8.5, respectively. While precipitation is expected to decrease by 7.2-4.57% and 4.75-2.47% under RCP4.5 and RCP8.5, correspondingly. BMA ensemble projections were coupled with the Soil and Water Assessment Tool (SWAT) to simulate the future hydrological scenarios of the drainage basin. With the changing climate, the discharge of rivers in the Jhelum basin is expected to witness reductions by about 23-37% for RCP4.5 and 19-46% for RCP8.5. Moreover, the water yield of the basin may also exhibit decreases of 17-25% for RCP4.5 and 18-42% for RCP8.5. The projected scenarios are likely to cause water stress, affect the availability of water for diverse uses, and trigger transboundary water-sharing-related conflicts. The impact of climate change on discharge demands early attention for the formulation of mitigation and adaptive measures at the regional level and beyond.

Assessment of trends in climatic extremes from observational data in the Kashmir basin, NW Himalaya.

The present study aims to assess the recent changes and trends in the extreme climate indices in the Kashmir basin using the observational records from 1980 to 2016. The extreme climate indices were computed using the ClimPACT2 software and a total of 39 indices were selected for the analysis having particular utility to various sectors like agriculture, water resources, energy consumption, and human health. Besides adopting the station scale analysis, regional averages were computed for each index. In terms of the mean climatology, an increase has been observed in the annual mean temperature with a magnitude of 0.024 °C/year. Further, differential warming patterns have been observed in the mean maximum and minimum temperatures with mean maximum temperature revealing higher increases than mean minimum temperature. On the other hand, the annual precipitation shows a decrease over most of the region, and the decreases are more pronouncing in the higher altitudes. The trend analysis of the extreme indices reveals that in consonance with the rising temperature there has been an increase in the warm temperatures and decrease in the cold temperatures across the Kashmir basin. Furthermore, our analysis suggests a decrease in the extreme precipitation events. The drought indices viz., Standardised Precipitation Index (SPI), and Standardised Precipitation Evapotranspiration Index (SPEI) manifest decreasing trends with the tendency towards drier regimes implying the need for better water resource management in the region under changing climate.