Hossein Saadati
Abstract
In this study, rainfall, percolation and hydrogeological processes relationship were evaluated using geochemical tracers to determinate paleoclimate in the Ardabil Plain. The occurrence of dry and wet periods was also determined with the help of tracer used in six profiles. The Dry and ...
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In this study, rainfall, percolation and hydrogeological processes relationship were evaluated using geochemical tracers to determinate paleoclimate in the Ardabil Plain. The occurrence of dry and wet periods was also determined with the help of tracer used in six profiles. The Dry and wet periods were then evaluated by the Edmund-Allison equations based on interpretation of soil water chloride concentrations and long–term precipitation measured in different periods. Applying the chloride mass balance technique to soil water chloride profiles improved the boundary conditions associated with wetter and drier climate in last times. The estimated ages through sediment cores chemistry varied from 737 years in Imijah core to 4511 years in Gharahlar core with two recorded dry and wet periods. Precipitation of recently drier climate was estimated around 202 mm in 116 last years and second drier climate was estimated around 83 mm in 473 last years. Precipitation of recently wetter climate was also estimated around 451 mm in 210 last years and second wetter climate was estimated around 703 mm in 735 last years. The second wetter had the highest amount of precipitation in 3600 years period. The Ardabil plain had a moderate drier climate since 1100 to 2900 years ago. In addition, the results showed that the wetter climate happened during last 2900 to 3550 years. According to this results, the present climate moves towards drier climate. A comparative analysis of data from six profile sites indicated that there were short term oscillations of wetter and drier climate.
Hossein Saadati; Shaban Ali Gholami; Foroud Sharifi
Volume 1, Issue 2 , July 2009, , Pages 87-98
Abstract
Lack of hydrometric data is the main issue for research and executive plans. In the present study in order to solve this issue, the capability of SWAT model has been studied in terms of daily discharge simulation in un-gauged watersheds. This model can simulate six hydrological and biological processes ...
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Lack of hydrometric data is the main issue for research and executive plans. In the present study in order to solve this issue, the capability of SWAT model has been studied in terms of daily discharge simulation in un-gauged watersheds. This model can simulate six hydrological and biological processes such as daily discharge, daily sediment, yearly and monthly water balance, water quality, agricultural products and estimation of vegetative cover for different animal grazing management systems. Simulation has been done for both gauged and un-gauged basins in Kasilian catchment for two time periods as calibration and validation of model. Calibration has been done using data derived from 4 years recording data (1987-1981) while validation has been done using 6 years data (1981-1986). Results show that, ABF, CN2 and REVAPC parameters are most sensitive and also Z and T-Laps parameters are low sensitive among other parameters. The model simulated runoff reasonable with r2=0.69, PBIAS=-2.5, and NS=0.72, whereas, the validation of model for the same data showed that r2=0.57, PBIAS=4.3, and NS=-0.54, which indicates that the performance this model is not quite valid for low stream flows because of sensitivity of hydrological parameters. The new version of SWAT model, modified during 2000 to 2005, has a capability in using GIS, thus it can be used in the same study area.
