ارزيابي ريسك تراز درياچه اروميه و تاثير تغيير اقليم بر آن

Risk Assessment of the Orumieh Lake Water Level and the Impact of Climate Change on It

According to IPCC1 global average temperature ha increased during the last century and it is anticipated that this trend will continue during the new century. Unfortunately, it is expected that climate change will have negative impacts on countries with spatial position the same as ours. Therefore, it is important to more seriously consider this phenomenon and its impacts. This research work is aimed at investigating the impact of climate change on the water level of Orumieh Lake, as the most important interior water body. For this, the lake level fluctuations were simulated based on historical data using ANNs2 technique with discharge, evaporation and rainfall as inputs. Then based on available data of HadCM3 AOGCM3 and SRES4 scenarios (A2 and B2), the discharge, evaporation and rainfall data were simulated from 2006 to 2099 for the study area. Application of the designed ANNs model and simulated data illustrated the possible changes in the lake water level due to climate change. Furthermore, the risk curves of the lake level for the 10 to 50 years return periods were developed and compared with those of the present situation. The results indicated that climate change will have significant decreasing impact on the lake water level. While the average lake water level was 1276.21 m.s.I.e during 1971-2000, it will fall 1.73 m and 0.63 m based on A2 and B2 scenarios, respectively. Also, the risks will increase in a confrontation with extreme low water level conditions of the lake.