Chemical Denudation in Sweden

Abstract

Many analyses of groundwater have been made by the Swedish Health authorities. Of those about 10,000 have been used for an attempt to map the geographic distribution of various substances. The factors analyzed are: Total amount of inorganic substances, Ca, Fe, Mn, NH4, SO4, Cl, NO3, HCO3, PO4, pH and oxidation by permanganate. It is found that the water of wells with a depth less than 2 m are more diluted than that of the deeper ones.

Scania and the plains of the later district have rich waters whereas the Highlands of Southern Sweden and the northern part of the country (Norrland) have water with a low salt content. Drilled wells are richer than the shallow ground water wells. The chemical denudation is much stronger than formerly calculated. One can estimate that the topmost metre of the soil has lost about 1/5 of its weight by denudation since the ice age. Great losses are also caused through the sewage waters which are carried away to the sea, by the burning of straw etc.

Very much may be done in order to stop or to counteract the chemical denudation. A well planned crop rotation, planning of a forest culture which improves the soil conditions, taking care of all affalls are some of the roads leading to a decreased chemical denudation of the soil.