Pollutant deposition via snowpack in the context of granite buffering capacity, Western Sudetes, Poland

摘要

At the end of each analyzed winter season, the cores of the snowpack profile were collected in the phase of maximum snow water equivalent and a few days later during long spring thaw. Comparison between pH and snow water equivalent allowed to calculate the load of hydrogen ion in the whole snowpack profile. To obtain detailed recognition of the structure of released load of pollutants, the results of determination of chemical composition of snowpack for winter season 2005/2006 are also included. The release of pollutants from snow and their real penetration into soil, ground and surface waters take place during thaw episodes. The initial results indicate however, that the first portions of water penetrating from snow into ground may bring a huge pollutant load and it depends on the amount of snowpack water storage and Total Inorganic Ionic Content value. During one week of continuous ablation in snow season 2005/2006, total load of H+ accumulated in snowpack show 40% decrease (it means: 16,4 mMoles m~(-2)). The fastest removal via the first portions of melting water occurred in case of H~+, (NO_3)~-, (SO_4)~(2-) and Mg~(2+), which is in contrast with much smaller removal rate of Na~+, Cl~- and (NH_4)~+. Such mechanism is responsible for significant acidification of soil and water ecosystems because granite bedrock is able to buffer only 20-30 mMoles m~(-2) of H+ within the whole year. The rate of pollutant deposition released from snowpack is closely related to the number and depth of thaw episodes. It means that the most intense acidification of soil and water ecosystems occurs at areas with deep snowpack during spring thaw events. The growth of snowpack during winter, maximum height and water storage change significantly from one year to another, however the basic mechanisms related to the additional environmental acidification under the influence of snow ablation at the end of each winter season are similar.