Identification of sand and dust storm source areas in Iran

Abstract

Sand and dust storms (SDS) are common phenomena in arid and semi-arid areas. In recent years, SDS frequencies and intensities have increased significantly in Iran. A research on SDS sources is important for understanding the mechanisms of dust generation and assessing its socio-economic and environmental impacts. In this paper, we developed a new approach to identify SDS source areas in Iran using a combination of nine related datasets, namely drought events, temperature, precipitation, location of sandy soils, SDS frequency, human-induced soil degradation (HISD), human influence index (HII), rain use efficiency (RUE) and net primary productivity (NPP) loss. To identify SDS source areas, we firstly normalized these datasets under uniform criteria including layer reprojection using Lambert conformal conic projection, data conversion from shapefile to raster, Min-Max Normalization with data range from 0 to 1, and data interpolation by Kriging and images resampling (resolution of 1 km). After that, a score map for the possibility of SDS sources was generated through overlaying multiple datasets under average weight allocation criterion, in which each item obtained weight equally. In the score map, the higher the score, the more possible a specific area could be regarded as SDS source area. Exceptions mostly came from large cities, like Tehran and Isfahan. As a result, final SDS source areas were mapped out, and Al-Howizeh/Al-Azim marshes and Sistan Basin were identified as main SDS source areas in Iran. The SDS source area in Al-Howizeh/Al-Azim marshes still keeps expanding. In addition, Al-Howizeh/Al-Azim marshes are now suffering rapid land degradation due to natural and human-induced factors and might totally vanish in the near future. Sistan Basin also demonstrates the impacts of soil degradation and wind erosion. With appropriate intensity, duration, wind speed and altitude of the dust storms, sand particles uplifting from this area might have developed into extreme dust storms, especially during the summer.Keywords: sand and dust storm; weight allocation criterion; Kriging interpolation; score map; Al-Howizeh/Al-Azim marshes; Sistan Basin Citation: CAO Hui, LIU Jian, WANG Guizhou, YANG Guang, LUO Lei. 2015. Identification of sand and dust storm source areas in

Simulation of mineral dust aerosols in southwestern iran through numerical prediction models

“…The persistence of this specific area of intense dust activity is suggesting that locations in this area are especially appropriate for dust generation. The results of mean monthly AI distribution for the last 11 years are confirmed in who identified Sand and Dust Storms source regions in Iran (see Figures and in ) showing that, regions which are located in South‐ West of Iran are possible local sand and dust storm origins . Comparing the mean monthly AI distribution with top soil layer wetness and surface skin temperature in the warm and cold periods for all 11 years shows a good agreement.…”

“…Also, the surface skin temperature experienced a considerable increase during warm period especially in July which led to a notable reduction of top soil layer moisture. It can be seen in Figures 4 and 5 1 and 3 in [35]) showing that, regions which are located in South-West of Iran are possible local sand and dust storm origins [24]. Comparing the mean monthly AI distribution with top soil layer wetness and surface skin temperature in the warm and cold periods for all 11 years shows a good agreement.…”

Dimming in Iran since the 2000s and the potential underlying causes

“…A more precise look through the long‐term mean annual and monthly values and also the time series of CC shows that a great proportion of ASR S at the station Ahvaz originates from CSR S which may vary as a result of increase/decrease in the amount of aerosols. Recent studies with respect to aerosols show that dust and sand storms are frequent in the southwest of Iran (Cao et al, ; Sarraf et al, ; Middleton, ) and the highest amounts of aerosols is mostly observed during summer (Maleki et al, ). This is mainly caused by sand and dust storms blowing from eastern Syria and Iraq (Shahsavani et al, ; Amanollahi et al, ), in addition to the dust activities originating from severe soil degradation in the Hoor‐Al‐Howizeh/Al‐Azim marshes, which is mainly located in the Khuzestan province, in the southwest of Iran (Cao et al, ) and has dried up as a consequence of several factors such as droughts, climate change, dam construction projects, etc.…”

Impacts of Chemical and Synoptic Processes on Summer Tropospheric Ozone Trend in North China

“…where c ′ is the normalized time series parameter and c min and c max are the minimum and maximum values in the series, respectively [38]. Some large-scale dynamics influence the tropospheric O 3 such as the quasibiennial oscillation (QBO) and the El Niño-Southern Oscillation (ENSO) related to the dynamical processes leading to a modulation of the stratospheric circulation and of the stratospheric-tropospheric exchanges (STE).…”