Atmospheric, weathering and biological contributions in the chemical signature of stream water: the upper Iskar Reka watershed, Bulgaria

作者：Gassama Nathalie^*; Violette Sophie

来源：Hydrological Sciences Journal, 2012, 57(3): 535-546.

DOI：10.1080/02626667.2012.665609

• surface waters
• geochemical study
• subalpine zone
• weathering contribution
• atmospheric contribution

The chemical signature of stream water is influenced by several factors: atmospheric input, weathering of bedrock and soils, biological uptake, soil storage, and decomposition of organic matter. The importance of weathering and biological activity, according to season, can be assessed by subtracting atmospheric input. In the upper Iskar Reka watershed, Bulgaria, results show that Na and Ca are mainly exported out of the basin (weathering is dominant), while nitrate and sulphate are consumed/stored. The behaviour of K suggests that biological activity is dominated by vegetation uptake in spring and by bacterial activity in autumn. In summer, the weathering load of Mg is compensated by reactions with clays. The low nutrient input from weathering due to low reserves in the soil may lead to a biomass production closely linked to a rapid internal cycle and also to a relative sensitivity of the ecosystem to any change in vegetation cover and atmospheric input.

• 出版日期2012