Using Isotopic and Geochemical Tracers to Determine the Contribution of Glacier‐Snow Meltwater to Streamflow in a Partly Glacierized Alpine‐Gorge Catchment in Northeastern Qinghai‐Tibet Plateau

Abstract

Compared with arctic and subarctic catchments, our knowledge about the hydrological functions of glaciers and porous aquifers is still limited for the partly glacierized alpine‐gorge headwaters in the Qinghai‐Tibet Plateau. Here we examine the impact of glacial and groundwater storage on the variability of warm‐season (June to September) discharge from the Hulugou catchment, an alpine‐gorge headwater with 3% glacial coverage, by quantifying the timing and magnitude of contributions of glacier‐snow meltwater, baseflow, and rainwater to streamflow using a three‐component hydrograph separation model. It is found that baseflow was the largest component (55 ± 2%) of warm‐season streamflow while glacier‐snow meltwater also contributed significantly (30 ± 10%) despite of the very low glacial coverage. We suggest that the water flowing out of glaciers was mainly supplied by the melting short‐ and intermediate‐term storages (i.e., snow over glaciers), which led to the high meltwater contribution to streams during the warm season and the high peaks of meltwater discharge following heavy precipitation events. The porous aquifers in piedmont plain may serve as major reservoirs that store a growing body of groundwater during the warm season, which explains the general increasing trend of baseflow contribution during this period. The moraine and talus deposits in high mountains, by contrast, allow groundwater to pass through them quickly and therefore being responsible for the obvious responses of baseflow contribution amount to heavy rainfall events. Our findings suggest that small mountain glaciers and porous aquifers may play a greater role than expected in hydrological regulation in the alpine‐gorge catchments of northeastern Qinghai‐Tibet Plateau.

Effects of Mining Activities on the Release of Heavy Metals (HMs) in a Typical Mountain Headwater Region, the Qinghai-Tibet Plateau in China

“…This result also supported the conceptual model of the hydrologic process described in [ 6 , 12 ] indicating that precipitation reached the ground through a series of transport flows such as flow through the sediments, surface flow, and base flow entering the river [ 6 , 12 , 13 , 40 ]. Meltwater also infiltrated into the sediment aquifer and then through groundwater runoff discharge into river runoff [ 39 , 41 , 42 ].…”

Using hydrogeochemical data to trace groundwater flow paths in a cold alpine catchment

“…The mean annual precipitation is approximately 500 mm, with the majority occurring between June and September (Liu et al, ). The annual potential evaporation is approximately 1,100 mm (Chang et al, ; Ma et al, ), and the mean annual temperature is approximately −3.9°C (Ma et al, ).…”

“…The annual potential evaporation is approximately 1,100 mm (Chang et al, 2018;Ma et al, 2017), and the mean annual temperature is approximately −3.9°C (Ma et al, 2017).…”

Spatial Variation and Controlling Factors of H and O Isotopes in Lancang River Water, Southwest China

“…In the northeastern Qinghai-Tibet Plateau, in June-August, the δ 18 O content of glacier snowmelt water (from −9.51% to −11.69% ) was lower than those of stream water, rainwater, and baseflow, and the baseflow had the highest TDS content (ca. 402 mg/L) [49]. Therefore, we tried to estimate the inputs of groundwater and glacier meltwater on river water using stable isotopes.…”

“…It means that glaciers and ground ice in the permafrost zone melted more longitudinally. Moreover, precipitation or meltwater infiltrated into the active layer that may interact with surface water via lateral flow or overland flow [49,50]. In the upstream before the Zaduo County, the mean δ 2 H value of river water was −98.3% , and the mean TDS value was 600 mg/L.…”