Chemical pollution monitoring of river Pinios in the Mediterranean climatic region

Abstract

The impact of climate change and human activities on the fluctuation of chemical and physico‐chemical parameters along the river Pinios as well as on their seasonal variation are presented. High temperatures, from June to August, cause a restriction of the water flow, an enhancement of nutrient concentration with the subsequent increase of eutrophication. This process leads to the accumulation of organic matter and the depletion of the dissolved oxygen in the water. High concentrations of nutrients were observed first in winter, caused by leaching of fertilisers from terrestrial systems after heavy rainfall, later during the warm months due to the decrease of water flow of the river and at last in autumn when plant organisms began to decompose. The intensive algal and macrophyte productivity (spring, summer) results in severe depletion of nutrients. The conductivity is also high during the warm period. C.O.D. display abrupt fluctuations in the seasonal variation during the year. Among the studied areas along the river Pinios the most heavily polluted were near the cities of Tricala and Larissa where sewage and industrial discharges occur.