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To date, meteoric characterization of a mountain catchment was done based on the isotopic composition of river discharge only. However, a sampling location in a river channel represents a basin averaged estimation of regional precipitation. Therefore, the isotopic composition of its discharge may not capture the meteorological processes active along different elevation transects. Additionally, if a catchment is fed by both snow and rainfall, the river water may not necessarily capture the proportionality of the total precipitation, as rainfall will immediately join the river whereas snow will melt gradually around the year. In this study, for the first time, we have made an Isoscape model on the ArcGIS platform for surface runoff using the isotopic composition of meteoric reservoirs and remotely sensed environmental parameters. Towards this, we have identified the processes and factors which are controlling the isotopic composition of meteoric reservoirs by multi-regression models. We have observed that the isotopic lapse rate in each meteoric reservoir varies non-uniformly w.r.t elevation. Sublimation, catchment vegetation, the temperature difference between day and night, type of clouds and insolation play a significant role in controlling the isotopic composition of meteoric reservoirs.
Developing an isoscape for surface runoff in a mountain region and understanding its implications is the premise for the hydropool model. Our approach examines the variability in Isotopic Lapse Rate in a mountain basin and its importance in paleoreconstruction. However, the success of the approach lies in the systematic sampling of surface waters from lower-order streams, accounting for different meteoric fractions in a basin, covering a wide altitudinal range and tracking the spatial variation in meteorological variables such as snow cover, diurnal temperature range, evapotranspiration, cloud cover, and solar radiation. |