This paper has focused on the application of hydro- geochemical techniques in conceptualizing of groundwater and to estimate recharge/discharge and the renewability of aquifer in Hashtgerd Watershed, Iran. At first, the aquifer boundary was defined based on data of existing wells and basin morphologic ...
This paper has focused on the application of hydro- geochemical techniques in conceptualizing of groundwater and to estimate recharge/discharge and the renewability of aquifer in Hashtgerd Watershed, Iran. At first, the aquifer boundary was defined based on data of existing wells and basin morphologic conditions. Estimation of recharge rate at different depth intervals by using tracer mass balance was done for 291 representative groundwater samples which includes 195 samples from soil and water of unsaturated zone in depths of 30 to 90 m (sampling in each meter), 10 samples were taken from rainfall, five samples from Qanats and 21 samples from wells and 60 samples taken from surface water in the study area. Based on water balance technique applying to a 7 year measured data and evaluation of hydrological and hydro- geological processes in the Watershed, average groundwater depletion was calculated at 0.37 m/year that indicated annual recharge rate of 245 million cubic meter (mcm) and over use of storage capacity of the aquifer. The groundwater studies showed that the natural recharge from direct rainfall is about 2% of total recharge. The annual recharge rate over an area of 752 km2 varies from 2.3 to 15.1 mm/yr. The required time for aquifer recharge from rainfall for the aquifer of 30 m thickness in the southern part of the aquifer is 1200 years while for aquifer of 90 m thickness in the north, recharge time is around 1100 years. On the other hand, in north and south of the aquifer, transitivity rates are 2500 and 300 m2/day, respectively with the groundwater renewability of 2.92 years which shows the importance of renewability of groundwater via concentrated/linear recharge from fractured zones. Studies of direct recharge in other parts of the world have shown that direct recharge rates may vary from zero to around 40% of mean rainfall volume. The results of this study revealed that around 98% of aquifer recharge occurs via concentrated/linear recharge from fractured zones with the average renewability of three years. Then it is recommended to consider the above mentioned geologic features in concentrated recharge of aquifer in saturated zone by watershed management, floodwater spreading and vegetation cover improvement projects.
R Tahmaseb; F . Sharifi; F Kaveh; A Tavassoli
Volume 63, Issue 3 , December 2010, , Pages 359-373
One of the major sectors of water loss is the loss of rain runoff. Kirkby (2001) the Effect of soil surface characteristics in the production of runoff in time and space scales concluded that soil properties such as undulating, soil texture and structure on the amount and spatial pattern of runoff are ...
One of the major sectors of water loss is the loss of rain runoff. Kirkby (2001) the Effect of soil surface characteristics in the production of runoff in time and space scales concluded that soil properties such as undulating, soil texture and structure on the amount and spatial pattern of runoff are effective. In this research that was conducted in the Latian watershed, twenty experimental plot Manufacturer runoff collected at the end they were constructed Bankettes longitudinal dimension equal to the width of runoff plot, poster collection, depth 0.5 meter and width of 0.5 meter was constructed. Depth of rainfall runoff from natural and 12 each with artificial rainfall intensity rainfall simulator with 8 mm to 42 mm per hour was established, was measured. Since the end Bankettes within plots were covered with plastic, all collected runoff was measured on it. The plastic cover was pulled out of water completely penetrating Bankette. After 24 hours on Bankette collected water depth was measured so that how deep the penetration has. After the plastic cover was created to prepare for the next runoff is measured. Part of the rainwater Collected in a barrel with a volume of 220 liter were stored on the first of the spring was covered with a plastic cover to prevent evaporation of collected water for limited irrigation water supply in June to 30 July to 15 of 62 mm were used and in forage maize plots nine branches were planted SC704. The results showed that compared with the yield ratios of 1:1, 2:1 and 3:1 (ratio of surface runoff collected rain Manufacturer of level of corn planted) yield of forage corn, respectively 9.6, 22.6 and 28.8 T.ha respectively. Whereas in the control treatment, there was no water limitation and the rate of 41.5 T.ha of forage maize yield was, The total water used in the three above treatments, respectively 616, 696 and 776 mm was. (In addition to direct rain water collected from runoff) and supplementary irrigation water depths in all three treatments was 62 mm. Thus yield respectively 23, 55 and 69 percent compared to the control (grown with full irrigation) has been. In this research the effect of vegetation and soil in runoff amounts were compared.
B. Motamedvaziri; H. Ahmadi; M. Mahdavi; F. Sharifi; N. Javaheri
Volume 62, Issue 2 , October 2009, , Pages 283-298
Estimation of river sediment load is one of the most important issues in design of hydraulic structures, investigating water quality, conserving fish habitat, estimating erosion and determining watershed management effects. There are two methods for estimating sediment load: empirical and hydrological ...
Estimation of river sediment load is one of the most important issues in design of hydraulic structures, investigating water quality, conserving fish habitat, estimating erosion and determining watershed management effects. There are two methods for estimating sediment load: empirical and hydrological methods. Existence of numerous empirical methods for estimation of river sediment load and a wide range of calibration coefficients shows that a suitable analytical or empirical method does not yet exist to accurately estimate the sediment load. Also, hydrological methods are not able to recognize and separate the specific data measuring conditions and they can not show the temporal variation of sediment loads. In spite of these problems, nowadays, researchers are using Artificial Intelligence methods such as Fuzzy Logic. In this study, the measured suspended sediment load at hydrometric station of Sarcham located on Zanjanroud river is analyzed using USBR and FAO methods (common hydrological methods). Furthermore, suspended sediment load are estimated with a model developed based on Fuzzy Logic rules. In order to estimate suspended load using fuzzy method, one method named Supervised Fuzzy C- mean Clustering Method, is used. Then the results of hydrological and fuzzy methods are compared. The results showed that the temporal variation of sediment loads can be analyzed using a fuzzy method. Also the results obtained using the fuzzy method in comparison with the corresponding values obtained using the usual hydrological methods shows a better correlation with the observed values.