Identifying the trend of precipitation changes in Kavir-e Miqan basin

Miqan wetland is a natural hole formed between Zagros and Central (Markazi) Iran mountain ranges. This wetland is expanded in the center of this basin and in the heart of Markazi province. In Iran comprehensive water plan, this basin is classified under 7-1-5 study code. The basin covers an area of 5514 km² and its average annual precipitation is about 280 mm. This basin has experienced lots of fluctuations in precipitation, so that it spent a low rainfall period during the 60s. In order to investigate the system of precipitation changes in this basin, monthly precipitation data was exploited from weather stations and was transformed into zone data using Kringing interpolation method and a cell size of 5*5. Finally, 220 cells covered the basin boundaries and a data matrix of 220*12 was obtained. In order to identify precipitation changes, standard scores of the monthly precipitations’ time series were calculated and Mann-Kendall non parametric trend test was applied. Results indicate the presence of a trend in the basin’s precipitation in March, July, September and October.