Investigating and predicting climate changes in JazMurian basin

Gradual changes in climate systems and patterns such as temperature, humidity, cloudiness, and wind and precipitation patterns affect type of climate in different areas. The climate of lagoons is especially sensitive and easily affected by climate changes. Critical ecosystems of lagoons protect biodiversity and have various tourism, economical, ecological, environmental and social values. Located in JazMurian basin, JazMurian wetland is frequently affected by wet years and droughts. However, repeated droughts and loss of freshwater have resulted in the wetland drying out. The dried out water body not only affects plant and animal life, but also acts as a dust emission center.

Three scenarios of emission (A2, A1B, B1) in medium-term (2046-2065) and long-term (2080-2100) are used in the present study to evaluate climate changes in JazMurian basin. Related data have been collected from Iranshahr synoptic station in the east and JiroftMianDeh in the west during 1990-2010 statistical period. The output of HADCM3 model has been downscaled using LARS-WG statistical model and minimum/maximum temperature, and monthly precipitation of the synoptic stations were analyzed.

Evaluation of LARS-WG model proved that monthly and annual average of minimum and maximum temperature in all modeling scenarios are higher than the observation period. The highest and lowest temperature increase will occur in A2 (business as usual) and B1 (the most environmental) scenarios. The highest increase in monthly average of maximum temperature will occur in Iranshahr station during the long-term A2 scenario (4.3 for maximum temperature in April and 4.6 for minimum temperature in May). In Iranshahr station, the highest increase in monthly average of maximum temperature predicted for the medium-term A2 scenario will equal 2.5 ° in April. In both scenarios, the lowest increase in monthly average of maximum temperature in Iranshahr will occur in October.According to all scenarios, precipitation will decrease in January and December. An increase in precipitation is recorded during March and October in Iranshahr station, and during February in Jiroft. Thus, changes will mainly occur in Mediterranean winter precipitation in thestudy area, while negligible changes will occur in monsoon precipitation during summer. Precipitation modeling shows higher precipitation fluctuation in long-term scenario compared to the basic statistical period. Long-term A 1B and B1 scenarios have predicted a small increase in precipitation of both stations compared to the basic statistical period. A2 scenario has shown a small decrease in precipitation during the same period. Modelling based on B1 scenario has indicated that the region will experience a higher increase in precipitation in long-term future (2080-2100) compared to the medium-term future (2046-2065), while the other two scenarios have predicted a lower increase in precipitation of the same period. Medium-term B1 scenario has predicted a lower annual precipitation average compared to the observation period. Results indicated that in accordance with the B1 scenario, Iran will experience the lowest level of precipitation during the 21 century in the medium-term period.

Investigating various meteorological parameters in western and eastern borders of JazMorian basin has predicted 1.5° to 2.1° increase in average temperature during the future 50 years, and 2.4° to 3.9° increase in average temperature during the future 100 years. Moreover, results indicated that changes will mostly occur in winter precipitation, and summer time changes will be negligible. All things considered, all scenarios have predicted lower precipitation for eastern parts of JazMurian compared to the western parts.