The Physical Environment: Lake Peipsi and its Drainage Basin

Lake Peipsi (Chudskoe in Russian) is one of the largest European lakes with a surface area of 3500km2. Due to its shallow character (its depth does not exceed 15 m) together with anthropogenic activities in the river basin such as agriculture and settlements, it is sensitive to eutrophication problems (Nõges 1996) such as water blooms in summer and autumn caused by blue-green algae (cyanobacteria), and often accompanied by summer fish-kills. The drainage basin is part of the Baltic Sea drainage basin. Lake Peipsi discharges into the Narva River, which in turn has its outflow in the Gulf of Finland In this outline of geographical features, we will hereafter focus upon the Lake Peipsi drainage basin and disregard the Narva River basin. This chapter summarises the major physical features of the region, including: • The geographical features of Lake Peipsi and its drainage basin. • Assessments on the emissions and flows of nutrients from the drainage areas of Lake Peipsi, with main emphasis on the nutrients’ effects. • Assessments of the water quality and ecological status of the lake. The results from these assessments will be used as input to the methodological processes of translating the qualitative scenarios to quantitative ones (Chapter 5). This chapter should also be seen in relation to the social-economic and politicoadministrative features of the region that is given in the next chapter (Chapter 3).JRC.H.5-Rural, water and ecosystem resource