Magnitude of fluvial transport and rate of denudation in a non‐glacierised catchment in a polar zone, central spitsbergen

Abstract

Research into the magnitude of fluvial transport was carried out in the non‐glacierised polar ynamisk ekken catchment in the region of Petunia Bukta, in the central part of est pitsbergen. The study period included two ablation seasons (uly–ugust) in 2008 and 2009. The stream flows from the glacial cirque cutting the north‐western edge of the ordiekammen assif. The bedrock is composed of sedimentary rocks. The ynamisk ekken is periodic stream, mainly fed from snow cover from une to early eptember. The other components of the feeding in the ablation seasons are less effective precipitation and groundwater from the active layer of permafrost. Medium discharge was 27.4 dm3 s–1 ranging from 0.1 to 250.8 dm3 s–1. Average ionic composition of the water indicates the hydrogeochemical sulphate‐bicarbonate‐calcium type. A tendency of systematic increase in the proportion of sulphates and decreasing share of bicarbonate ions in the ionic composition of water during the ablation season was observed. This correlates with the gradual decrease in the discharge rate and the decrease of the meltwater in the stream feed. The proportion of geogenic components in the dissolved load material outflow from the catchment is 75%. It consists of mainly bicarbonates, sulphates and calcium, which are derived from the dissolving of limestone, gypsum and anhydrite. The average value of the chemical denudation was 0.35 t km–2 d–1 and the mechanical denudation 0.32 t km–2 d–1. The results are similar to those obtained in previous years, reflecting the relatively large stability of the polar environment.