THE CLIMATE CHANGE IMPACT ON THE MESTA RIVER BASIN RUNOFF

The paper presents an attempt for assessment of the Climate Change impact on the Mesta river runoff (cross section Hadji Dimovo) using HBV mathematical model. The used version is developed for the project “Climate Change and Energy Production”, a Nordic project aimed at evaluating the impacts of climate change on the water resources. The HBV model has a simple vegetation parameterisation including interception, temperature and evapotranspiration calculations, lake evaporation, lake routing, glacier mass balance simulation, special functions for climate change simulations etc. The HBV model can be classified as a semi-distributed conceptual model. The main input variables used in this report are the average monthly temperature, monthly totals of the precipitation, the potential evapotranspiration and the monthly discharges. The River Mesta flows from North to South up to the Aegean Sea. Two different Climate Change scenarios are used (HadCM2 and ECHM4). The calculations are for years 2025, 2050 and 2100 using 30 years base period (1961 – 1990). The obtained results are promising and they show the potential possibility for the HBV model use to assess the climate change impact on the elements of hydrological cycle for the Bulgarian river basins using monthly data. he Bulgarian river basins using monthly data