ESTIMATING POTENTIAL EROSION IN PRESPA LAKE BASIN

Prespa Basin is part of a complex Prespa-Ohri-River Drini located on the southwest of Balkan Peninsula. The land use in the Prespa region is very diverse comprising of forest, pasture and intensive agricultural land. The Prespa basin region is characterized by complex geological and tectonic structures with predominantly calcareous rocks and to a lesser extend magmatic rocks. Many types of deposits such as alluvial, fluvioglacial, proluvial, organogenic-marsh and diluvial sediments occur in the valley, especially at the riverbeds with varying depths between 100 and 200m. The diverse land uses and pressure on the natural resources have increased the risk of degradation of the quality of the water and the biodiversity. Accelerated erosion rates pose a real threat to the existence of the lakes due to sedimentation and nutrient overload which could lead to increased biological oxygen demands (BOD) and hypoxia. The mean erosivity from the Climate stations was 3044 Mj mm ha-1 hr-1 and was significantly higher (p-value = 0.0008) compared to the WoldClim data with a value of 2591 Mj mm ha-1 hr-1. The reduction of sediment loss could potentially reduce the risk of Prespa Basin lakes to be polluted with chemicals and nutrients that would harm the ecological diversity of the lake and threaten other natural resources in the area.