Document Type : Original Article

Author

Faculty of Natural Resource, University of Zabol, Zabol, Iran

Abstract

In order to determine the source and critical areas of wind Erosion, Sistan Plain, IRIFR-E.A method was applied. According to geomorphological investigations, the studied area consists of the following two main units namely: Pediment with 1 type and 8 geomorphological facies, and playa with 2 types of flatland and desert type that includes 9 geomorphological facies. On the basis of sediment, the facies in piedmont were divided into 3 groups so that, 2 facies (1-1-4, 1-1-3) have sediment delivery by 500-1500 tons/km²/y while, 4 facies (1-1-2, 1-1-8, 1-1-11) have 1500-6000 tons/km²/y sediment delivery, and 3 facies of covered pediment (1-1-5, 1-1-6, 1-1-7) have more than 6000 tons/km²/y sediment delivery. Therefore, the mean sediment delivery of piedmont (covered pediment type) is about 5500-39000 tons/km²/y. In playa unit, four facies (2-1-4, 2-1-5, 2-1-6 and 2-1-8) have 500-1500 tons/km²/y sediment load and three facies (1-1-2, 2-1-3, 2-1-7) carry 1500-6000 tons/km²/y, and two facies (2-1-2, 2-2-1) have more than 6000 tons/km²/y sediment load and total sediment load is 8000-30000 tons/km²/y. Morphoscopic study and investigation of the relationship between sediment grain diameter (D) and transport distance in 18 cases, it was shown that all samples except of one, transport distance is 5-20 km. Therefore the source of sediment is close to the sedimentation area. Dominant and erosive winds in the study area are from North and NW. Also due to drought, the erosive winds carry a considerable amount of sand especially during the summer and spring seasons and it has been intensified considering that, Hamoon and Hirman Rivers are dry.

Keywords

- Ekhtesasi, M. R. 1996. Finding the source of sand dunes in Yazd-Ardakan plain. Institute of Forests and Rangelands Researches, 139 p.
- Natural Resources Ministration of Sistan and Baluchestan, and Sand Consolidation and Desertification Office of Forests, Rangelands and Watershed Management Organization of Iran. 2002. Scheme of identification of wind erosion critical areas and its practical priorities. 127 p.
- Meteorological data of synoptic station in Zabol.
- Khosravi, A. 1995. Wind morphodynamic and forms resulted from it in Kashan region, Science Faculty, Beheshti University.
- Khosravi, M. 1989. Adverse bioclimatic caused by natural factors in Sistan plain. Quarterly of Geographic Researches, 13.
- Zabol University, 1999. Windmills of Sistan. 22 p.
- Refahi, H. 2004. Wind erosion and its control. Tehran University Press. 2418, 3rd edition.
- PBO, 2000. Statistics of Sistan and Baluchestan Province, 404 p.
- Saligheh, M. 2003. Attention to wind in constructing physical body of Zabol City. Journal of Geography and Development, 2.
- Consulting Engineers of Iran, 2005. Integrated studies of desertification and wind erosion of Sistan plain. Desertification researches, 144 p.
11- Goudie A. 2000. Dust storms٫ arid zone Geomorphology٫418-420
12- Goudie A. warren A. jones .k, cook r.1987. The character and possible origions of aeolation of the wahiba sand sea٫ Oman geogtaphical Journal٫V153٫231-256.
13- Lindsey, D.A, William, H., Langer, Bradly, s. V.G. 2007. using pebble lithology and roundness to interpret gravel provenance in piedmont fluvial systems of the rocky mountains, sedimentary Geology, 199:223-232.
14- Muhs,  D.R, Geomorphological & geochemical evidence for the source of
sand in Algodones dunes, (eds Tchakerian, W .P. ) pp., 37-75 Chapman & Hall, 1995.
15- Nick ling, W. G., and Neumann, C. M. 1988. Recent investigations of airflow and sediment transport over desert dunes",In: Aeolian Environment, Sediment & Land forms, (eds Goudie. A.S., Livingeston, L. and Stokes, S.)
16- Novalan, D., Hardiman, M., and Gill, T .2007. Asynoptic climatology of blowing dust events in elpaso, Texas from 1932-2005.
17- Piksen, M . J . P . M and Goossens, D .2005 . the Role of wind and splash erosion in inland drift- sand areas in the Nether lands. Geomorphology 88 (2007) 179-192.
18- Pye, K. and Sherwin, D. 1999. "Loess", In: Aeolian Environment, Sediments & landforms, ( eds Goudie, A.S.,Livingeston, I.and Stokes, S.) pp. 213-239, j. Wiely & Sons.