Abolgassem Amir Ahmadi; Maliheh Mohammadnia; Negar Golshani
Volume 2, Issue 3 , January 2017, , Pages 21-42
Abstract
Methods used for identification, separation and prioritization of flood prone areas generally consider the basin as a whole, or as regional regardless of the physical borders of the basin or the sub-basin. Hnnenjan Zrchshmh basin is located in Shahreza in Esfahan province. Every year, floods inflict ...
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Methods used for identification, separation and prioritization of flood prone areas generally consider the basin as a whole, or as regional regardless of the physical borders of the basin or the sub-basin. Hnnenjan Zrchshmh basin is located in Shahreza in Esfahan province. Every year, floods inflict considerable damage to large areas of its lands, rivers and orchards. Identifying and predicting the flood volume of these basins which undoubtedly condition the downstream areas and identifying the priorities and sensitivity of the sub-basins for flood control programs, is of great necessity. This study uses hydrological simulation method via HEC-HMS software to reconstruct and evaluate the routing flood hydrographs in the basin and analyze the sensitivity of flood discharges with respect to the parameters of the watershed in addition to CN, slope and area of each sub-basin in its logical extension. Calculation of the results in this study show that the kind of sub-basin participation in output flood are not necessarily proportional to the peak and that the sub-basins with high peak are not necessarily more effective in sealing the watershed outlet. Therefore, for any flood control operation or reduction of the peak flows in the watershed outlet, the effect of each basin after routing of the main channels must be determined. Then according to the share they have in the output seal, they should be prioritized and divided. Implementing the individual omission method of basins in the Hunejan Zrchshmh basin model with HEC-HMS software it was determined that the S13 sub-basin has the most and the S3 has the least decreasing effect on the output peak flow of the basin. Furthermore, increased CN in sub-basins S13-S5-S11-S12-S10-S15-S6 have increased the peak flow. Sub-basins S12-S13-S5-S10 showed greater sensitivity to changes in the area. Also the slope increase in the sub-basins S2, S4, S5, S7, S10, S12, S13, S15, S16, S17, S21, S22, and S24 has had a direct impact on the increase in peak flow output, having the reverse effect on other sub-basins.
Asghar Asgari Moghaddam; Ataollah Nadiri; Vahid Pakniya
Volume 3, Issue 8 , December 2016, , Pages 21-52
Abstract
Received: 2015.06.08 Accepted: 2016.10.29 Asghar Asghari Moghaddam[1]* Ataollah Nadiri[2] Vahid Pakniya[3] Abstract Bostan Abad plain is located in East Azerbaijan province, North West of Iran. Groundwater resources of the plain supply significant portion of the drinking and agricultural water demands ...
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Received: 2015.06.08 Accepted: 2016.10.29 Asghar Asghari Moghaddam[1]* Ataollah Nadiri[2] Vahid Pakniya[3] Abstract Bostan Abad plain is located in East Azerbaijan province, North West of Iran. Groundwater resources of the plain supply significant portion of the drinking and agricultural water demands of the area, as a result, protection of these resources from contamination is an important task. Therefore, for assessing of the aquifer vulnerability, DRASTIC and SINTACS models were used in GIS software setting. The plain vulnerability maps for each model, according to data layers including depth of water table, net recharge rate, aquifer media, soil media, topography, VA-dose zone media and hydraulic conductivity were prepared. The final map of aquifer vulnerability with five zone of vulnerability from very low to high is produced. DRASTIC and SINTACS index were calculated from 61 to188 and 92 to 202 respectively. The sensitivity analysis was determined by a single parameter that the vadose zone media has the most significant impact on the vulnerability index. The distribution of nitrate ions concentrations were used for the models verification. The adaptation nitrate layer and zoning map of vulnerability for both models showed that the areas with high concentration of nitrates are coincided with high potential vulnerability areas. The correlation coefficient of 0.75 between DRASTIC model and nitrate layer were obtained. For preparing the contamination risk map of groundwater, the land use layer was overlapped to DRASTIC vulnerability map. The results of overlapping maps showed that 31.33 percent of the total area of land used for agriculture is high potential vulnerable area. According to the final maps of vulnerability for both models the central and northwestern parts of the plain contains the highest contamination potential in the area. [1]- Professor, Dept. of Earth Science, University of Tabriz (Corresponding Autor), Email:moghaddam@tabrizu.ac.ir. [2]- Assistant Prof, Dept. of Earth Science, University of Tabriz. [3]- M.Sc student, Dept. of Earth Science, University of Tabriz.
