Analysis of internal and external dust contributions and their spatial-temporal changes in Kerman province

Dust particles originating from internal and external sources have adverse effects on public health and the environment. Considering the unknown contribution of the mentioned resources to dust production, it is very important to investigate this issue in different regions of Iran. In addition, the analysis of spatial and temporal changes of events with different origins can be an effective step toward identifying areas more sensitive to the phenomenon of wind erosion and reducing the risks caused by its occurrence in the affected areas. The present study was conducted considering the mentioned topics as the main objectives. For this purpose, internal (codes 07-09, 98 and 30-35) and external (code 06) dust phenomenon statistics recorded in 11 synoptic stations of Kerman province in the common time frame of 2002-2020 were used. After calculating the frequency of events, the contribution of internal and external dust sources in different regions of Kerman province was determined. Using the classified map of the dust events occurrence frequency and Mann-Kendall test were respectively analyzed their spatial and temporal changes. The results showed that in the three cities of Jiroft, Anar, and Sirjan, the contribution of external events was higher than other regions of the province, about 80%, 53.8%, and 53.2%, respectively. The contribution of internal events in Shahrbabak, Rafsanjan, Shahdad, and Baft was more than 73% and in Zarand, Kerman, Bam and Kohnuj more than 52%. On average, the share of internal and external events in Kerman province was estimated to be 60.6% and 39.4%, respectively. The spatial distribution pattern of internal and external dusts showed that Bam and Jiroft were the most sensitive areas to wind erosion in the study period. In the study period, the events originating inside and outside the station in Shahdad and Zarand had a significantly increasing trend. A significant increasing trend of events with internal origin was observed in Kohnouj, Rafsanjan and Anar, and an increasing trend of dust originating outside the station was also observed in Sirjan (Z>+1.96).