hamzeh saeediyan; Hamid Reza Moradi; Sadat Feiznia; nader Bahramifar
Abstract
Acidic rainfall is one of the complications of industry life that a point of view geographically in recent years spread widely and the attention of many researchers has been found. These rains have significant effects on the different ecosystems of earth. In this study, in order to investigate the sensitivity ...
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Acidic rainfall is one of the complications of industry life that a point of view geographically in recent years spread widely and the attention of many researchers has been found. These rains have significant effects on the different ecosystems of earth. In this study, in order to investigate the sensitivity of erosion and sediment yield of Gachsaran Formation to acidic rainfall and its density change, parts of the Kuhe Gach watershed area in Izeh Township are selected with the area of 1202 hectares. This investigation in order to determine productivity runoff and sediment in 8 points and with 3 replicates in Gachsaran formation in different intensities 1, 1/25 mm in min and in the intensities of distilled water and 4, 5 acidic water in four aspects of northern, southern, eastern, western with using kamphorst rain simulator was done. In order to analyze statistical was used SPSS and EXCEL packages. The highest of runoff and sediment rates in Gachsaran formation in 1, 1/25 mm in min are related to 4 acidic rainfalls. The rainfall of 5 acidic also runoff and sediment are more than the rain of distilled water. The infiltration rates in rainfall different intensities also showed a significant difference.
M. Padyab; S. Feiznia
Abstract
Importance of sediment storage has been expressed as being higher than that of water in floodwater spreading networks. To determine the contribution of each geological formation in sediment input of Gachsaran Floodwater Spreading Station after 12 years of flood spreading, sediment sampling was conducted ...
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Importance of sediment storage has been expressed as being higher than that of water in floodwater spreading networks. To determine the contribution of each geological formation in sediment input of Gachsaran Floodwater Spreading Station after 12 years of flood spreading, sediment sampling was conducted in 16 points and 0-15 cm depth of the field. Using dry sieve analysis, all samples were analyzed for granolumetry. To determine mineralogical composition of sediments, particles on 150 and lower than 62 micron sieves were used. The lithology of formations was identified using geologic maps. The mineralogical composition of samples was also compared with lithological units of upstream watershed. Then percentages of share of each lithological unit in sediment production were determined. By considering the area of each lithological unit, weighted percentage of share of each unit was calculated. The results showed that Pabdeh-Gurpi formations with 55.3 % of the sediment input, has had the most contribution in the production of the largest particle size of 150-300 micrometers, followed by Kazhdomi formation with 14.1% share, Ilam-Sarvak formations with 13.1 % share, Khami formation with 10.8 % and Asmari formation with 6.5% share in the sediment production, respectively. With regard to the particles size less than 62 micrometers, Pabdeh-Gurpi formations with 80% of input sediment, had the largest contribution in the production of these particles. By using erosion control measures and storing sediments of streams on Pabdeh-Gurpi formations, 80% of very fine sediments (less than 62 microns) and 50% of fine sediments (150-300 micrometers) will be decreased.