JWSS - Journal of Water and Soil Science

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The relation between high molecular weight glutenin subunit alleles and flour quality traits have been studied for 117 recombinant inbred lines (RILs) derived by single seed descend to F₇ from a cross of Anza, a low quality cultivar, and Inia, a high quality cultivar, containing different alleles at 3 GLU-1 seed storage protein loci. RILs were classified by SDS-PAGE for the 8 possible combinations of the alleles. The allelic variation at the GLU-D1 locus accounted for most of the variation observed in SDS-sedimentation, mixing time and tolerance, and protein content. The GLU-D1 allele encoding the subunits 5+10 was superior to its allelic counterpart, encoding 2+ 12. All three loci had significant single locus additive effects for SDS-sedimentation volume and mixing tolerance. The additive effects of GLU-D1 locus on mixing time and protein content were also significant. The epistatic additive effects were mostly negative and with the exception of α_AB and α_AD for SDS-sedimentation volume were not significant.

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One of the most vital problems in the storage and utilization of surface waters for drinking, flood control, hydropower, and agricultural purposes is that of sedimentation in reservoirs and subsequent decline of dam lifetime. The useful lifetime of a dam is defined as the time necessary for approximately 80% of the volume of its initial capacity to be filled by sediments washed in by water. It is a function of the volume of the incoming sediments, specific weight of sediments, and reservoir trap efficiency. Trap efficiency depends on sediment characteristics, life, shape, and rule curves of the reservoir as well as on the capacity-inflow ratio. It is the purpose of the present study to calculate sediment trap efficiency of small dams and also to determine the relationship(s) among the effective parameters in the Chaharmahal and Bakhtiary region. For our purposes, 14 small earth dams (with heights of less than 15 m and capacities of about 1 MCM) were selected around Shahrekord and Borougen. Since no data were available on the erosion and sedimentation for these dams, the MPSIAC empirical model was used to estimate the incoming sediment to the dams' reservoirs. The model considers nine factors effective on erosion and sediment production in each watershed. These factors were analyzed for the watershed of each dam under study and the annual sediment yield was calculated. The amount of sediments retained in the reservoirs as a result of the working life of the dams was estimated by reservoir surveying. The trap efficiency was calculated for all the reservoirs under study. The results obtained revealed that the trap efficiencies for these small dams ranged from 10.4 to 68.9%. New curves were developed and suggested for the trap efficiency of small dams based on these results.

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Water requirements of paddy fields in the Gilan Province are provided for by a large irrigation network including Sepidrud reservoir dam, Tarik diversion dam, Fumanat network, Sangar diversion dam, and Sangar right and left canals. Because of the deposition of sediments in the Sepidrud reservoir, its capacity has been reduced profoundly. To overcome this problem, sediments are flushed in the second half of each year. The sediments coming from erodible surfaces of the Sepidrud watershed area out flowing from the dam in the spring, and the deposited sediments in the Sepidrud river in the second half of each year are a great hazard for the irrigation network. The objective of this research is to study the effect of the sediments on Sepidrud network. In this research, sediment data from the hydrometric station near Sepidrud dam were analyzed. Sediment samples were collected by a hand sampler (type DH-48) from Tarik and Sangar diversion dams, upper and lower ends of Sangar desilting basin, BP₄ and SP₃ canals, and field ditches and drains. Water discharge was measured by a current meter. Deposited materials in irrigation structures were sampled for grading. The results from this study indicate that the Sepidrud river and Tarik diversion dam deposit sediments at low discharges, but at high river discharges these sediments were found to he erodible. Average efficiencies of left and right desilting basins of Sangar diversion dam were 15.3% and 11.2%, respectively. The area located in Fumanat section, which receives water from Tarik diversion dam, requires desilting structures. The irrigation structures of the network are in danger of sediments. The main and the secondary canals, compared with 3rd and 4th order canals, have less settled sediments in them.

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Gypsiferous soils, as the most characteristic soil in arid and semi-arid regions, are widespread in Isfahan Province. The north-west region of Isfahan is a closed basin and is surrounded by geologic formations. This area is a part of Zayandehrood watershed. The origin of gypsum in this area was investigated in this study. Considering the geologic distribution of gypsum, twenty-two locations, suspected to have been affected by gypsum, were selected for sampling. Natural and artificial excavations were used to discover their relationships. To distinguish the differences between fresh and weathered shales, some fresh samples were taken from the depth of Shemshak formations (a lead mine).

Field observations showed that in Shemshak and Nayband formations, gypsic crystals were present within the layers of weathered shales, and pyrite was observed only in the mine shales. In weathered red conglomerates (Lower Cretaceous), considerable amounts of gypsum had accumulated. In the hydrothermal veins of Shemshak and Nayband formations, gypsic crystals were found in matrix or between rock layers. In some parts, the Qom formation (Evaporate sediments) contained plenty of gypsum.

From field observations and analytical data, such as mineralogy of untreated and floated rock powders, determination of residual sulfides in shales, and the examination of thin and polished sections of rocks, we conclude that the origin and main resources of gypsum in our study area are as follows:

1. Gypsum being released from Cretaceous limes particularly from red conglomerates

2. Oxidation of pyrite and any sulfidic minerals existing in shales

3. Gypsum being released from evaporates (Qom formation and Oligomiocenic Marls)

4. Gypsum formed through hydrothermal reactions during late Tertiary.

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The application of “Modified Einstein Procedure” is recommended by the Specialized Committee on Sediment, Iranian Ministry of Energy. However, this method has not been applied to any river in the country. It is the purpose of this study to investigate the total sediment load of the Karun and Karkheh rivers at Ahwas and Hamidieh stations.

The graphical calculations of the method are very complicated and time consuming. Therefore, a mathematical model has been developed in this study to improve the accuracy, simplicity and speed of computations. The required data were obtained from the above stations for seven years (1988-95), and applying these data, the total sediment load was calculated using the model. The bed load for the above stations was also computed and the ratio of bed load to total sediment load was calculated. In addition, measured data from East Fork river (in USA) were applied to examine the accuracy of the method in estimating the bed load. Comparison of the measured and computed results shows that the “Modified Einstein Procedure” estimates the amount of bed load with a high accuracy. The relationship between the bed load and suspended load and also between the total load and the stream discharge have also been established.

Finally, it is concluded that the “Modified Einstein Procedure” with minor modifications can be successfully applied for the above-mentioned rivers of Karun and Karkheh.

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Many sediment transport equations have been developed for estimation of the river sediment materials during the past four decades. There are significant differences in the results from these equations when applied to compute sediment transport for a specific river. Therefore, application of an equation for estimation of a river sediment load is not an easy task. In this study, 12 important sediment transport equations including Meyer-Peter and Muller, Einstein, Bagnold, Engelund and Hansen. Toffaleti, Ackers and White, Yang, Van Rijn, Wiuff, Samaga et al, Beg and Fazel were tested against the measured field data of four major Khuzestan rivers, namely, the Karoon, the Dez, the Karkheh, and the Maroon. For accurate results and rapid computation, a computer program was developed for this purpose. Over 490 measured data from the gauging stations of these rivers are selected. Using these data, the hydraulic parameters and the bed material of the gauging stations are determined.

The results of the computer program are analyzed and compared with the measured data. The results from this study show that those equations which are based on the energy exchange of the flow, are generally in good agreement with the measured data for Khuzestan Rivers. From these equations, the Engelund and Hansen’s equation generally predicts satisfactory results for the all gauging stations except for the Maroon River gauging station. And finally if the sediment load computed by the Beg’s method is multiplied by a factor of 0.1, the results approximately match those obtained from the Engelund and Hansen’s method.

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Soil erodibility in arid regions, particularly in less developed soils, greatly depends on parent material. The objectives of this study included comparison of the potential of runoff and sediment production in soils with different parent materials and identification of the highly sensitive parent materials in Golabad watershed, 60 km northeast of Isfahan, with about 160 mm of annual precipitation and various geological formations, as one of the highly erodible watersheds in Iran. Soils formed on twelve different parent materials were selected. Rainfall simulator was run for 80 minutes on three replicates of each soil. To have an idea about the rate of runoff and sediment generation with time, runoff loaded with sediment was collected every 10 minutes using plastic containers. After measuring the volume of each runoff sample, it was dried and the amount of sediment was measured. The mechanical parameters of the applied rain were: intensity about 40 mm/hr, rain drop average diameter: 6.56 mm plot size: 1 m² and kinetic energy of 13.7-17.2 J/m².mm. Based on the rainfall simulation experiments, soils formed on green andesite and slightly dissected alluvium derived from both sedimentary and igneous rocks created the highest amount of runoff. They also created runoff much more rapidly as compared to other soils. In contrast, soils developed on granodiorite and moderately undulating alluvium produced the least volume of runoff. Furthermore, maximum quantity of sediment was produced from the soils occurring on green andesite and shale. The least sediment yield was observed in soils developed on granodirite and moderately undulating alluvium. Soils formed on shale created the highest sediment concentration and no significant differences were observed among other soils. Based on the results obtained, soils were ranked according to sensitivity to erosion. It is concluded that soil parent materials have a high influence on the production of runoff and sediment yield in Golabad watershed.

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Of the applications of remote sensing and satellite images in natural resources is distinguishing and detection of changes in land surface. The image classification using Maximum Likelihood (MLC) is one the prevalent method which is used in a study of the application of TM and ETM+ satellite images to detect sediment deposition on an implemented floodwater spreading scheme. In order to implement the research, field sampling and checking were done using transect networking method by selection of 30 sample points in floodwater spreading area as well as another 30 control points in the study area. The results of the study are shown that detection of sediment deposition using MLC method by application of LANDSAT TM and ETM+ can lead to increase the precision of change detection up to 82 percent. Furthermore, the results also show that the trend and changes due to sediment deposition on water spreading area can be precisely detected. Considering the present and potential applicability of the applied method in distinguishing changes due to sediment deposition on land surface which is absorbed on 450 hectares of water spreading area in this research study, it can be pointed out that the use of this method in larger area could be tend to increase the precision of change detection and to decrease the required time.

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This research is aimed to predict erosion and sedimentation of Tang-e-Kenesht basin in Kermanshah province using MPSIAC and EPM models in GIS software. This basin has about 14348 hectare area. This region has various vegetation, geology and soil texture and land use types. The basin has divided into 9 sub-basins and its maximum and minimum elevations are 3300 and 1400 m, respectively. Needed data were collected in part through published reports, while the remainings were derived by field survey. Necessary maps in MPSIAC and EPM models were prepared in Autocad-2000 medium and were transported to Arc-Info, after some revisions to them. After constructing topologies for all polygons, we entered all layers weights in Arc-View software. Combinations of all layers were managed thereafter. Nine layers for MPSIAC model and three layers for EPM model were combined to result the final layer of erosion and sedimentation. Basin erosion was calculated as 1002.7 and 1739.2 m³/Km² by MPSIAC and EPM models, respectively. The result for basin sediment was 521.7 and 307.8 m³/Km², respectively. Thereafter, medium and high erosion classes were found for the two models under study, respectively. Due to not fully compatible tables for EPM model and its subjective nature, one can conclude that MPSIAC model may have better performance.

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One of the simple methods for erosion control, flood mitigation and flood damage reduction in the streams is building the checkdams. The present study was carried out to evaluate the performance of checkdams, location across the streams in the retention of the fine sediments in Droudzan watershed in Southern Iran. For this purpose, a number of streams with many stabilized check dams which were more than 27 years old were selected. For each stream, three check dams (one at the far beginning (upstream), the second one at the middle and the third one at the far downstream) were selected. In each stream, a number of samples were taken from retained sediment behind the selected check dams and also original soil was taken from both sides of the same check dams. Laboratory analysis on the size of particles and also texture of soil and sediment samples showed that in general, soils taken from both sides of the check dams were finer than sediment behind the same check dams. Comparison of particle sizes showed in all streams except Joobkhaleh (with extensive tree coverage) the performance of the third check dams (far downstream) in fine sediment retention is much better than the second one (at the middle) and the second one is more effective than the first one (upstream). Comparison of sands, silt, and clay percentage of soil and sediment also showed that in all streams except Joobkhaleh the clay and silt percentage behind the third check dam is more than the second check dam and that of the second check dam is more than the third one (upstream). In the same way, results showed that the sand retained behind the first check dam, was more than the sand behind the second and first checkdams, respectively. Therefore, if the retention of the fine sediments is the main purpose of the check dam construction, it is recommended that they be built in the far downstream rather than in the upstream of waterways.

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Sedimentation and consolidation of cohesive sediments near the dam body can cause many problems such as clogging the bottom outlets and entering the sediments into the hydropower intakes. Flushing of these sediments through the bottom outlet will be successful only if the hydraulic conditions are designed according to the physical and mechanical properties of consolidated sediments. During the past decades many researches have been conducted on the distribution of non cohesive sediments in the reservoir, yet little information is available for cohesive sediments. Therefore the main purpose of this study is to conduct a physical model study to investigate the process of sedimentation and consolidation of cohesive sediments in the dam reservoir. The experimental tests were conducted in a settling column test with a height of 3.8 m and diameter of 0.3m. The sediment samples were collected from the Dez dam reservoir since it is predicted that in less than 5 years the sediment will reach to such an elevation that can enter into the hydropower intakes. The obtained results show that there is a an algorithmic relationship between the time and changing of the sediment concentration during the sedimentation and self-weight consolidation processes. This process can be divided into four separate phases. It is also of note that in this paper the effective stress-void ratio and coefficient of permeability – void ratio relationship were obtained as a power relationship, which are in agreement with the results obtained by other investigators. These relationships can be used as primary data in the mathematical model of sedimentation and consolidation.

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  In order to quantitatively evaluate the sediment yield in ungauged basins, it is necessary to use empirical models. The EPM model, as a model which is using in Iran, has sometimes been evaluated. Most evaluations have often been conducted by using river's sediment information and direct measurements of dam reservoir sedimentation have been less used, while the sediment measurement method on reservoir is more carefully. 9 small watersheds from Semnan province (Iran) were selected in this research. There is a small earth dam which have been built on the outlet of each watershed in the past years that them age is 10 years. These dams have not been weirs since they have been building to now. Therefore total of sediment yield volumes of each watershed are entrapped in the dam reservoirs. The volume of sediments deposited in reservoir were calculated by surveying. Sediment's apparent specific weights were measured in each reservoir and the volume of sediments transformed into sediments weight. By EPM model the volume and weight of sediment yield were estimated. Values of sediment yield measured in reservoirs were compared with estimated values by t-test. The results showed that at level 5%, there was not any significant difference between sediment yield values estimated in reservoirs by EPM model in comparison with values of volume and weight which were measured. But determination of performance and relative root mean square error showed that EPM model has low efficiency for estimation of sediment yield in the case study of watersheds.

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  This research was carried out to study the impacts of geomorphologic characteristics of claypan on land use and land degradation. Databank of the study area was constructed and digital terrain model of claypan was prepared. By using GIS techniques spatial distributions of the subsurface drainage network, sediment transportation index and wetness index were calculated. The results indicate that the depth to the claypan is between 0 (where the pan is exposed at the surface) to 605 cm. There are several depressions in the claypan which are filled by new sediments. Each depression has a catchment which is charged by the drainage water of its attributed lands. While a depression drains naturally or synthetically, the attributed soils over the depression are in non saline or moderate salinity condition otherwise, a marshland, a waterlogging area or a salt crust zone develops over there. The results also indicated that soil surface salinity is a function of depth to claypan and drainage condition of area. The trends of salinity extension are different for closed and open catchments and the depth to the claypan could be estimated using electrical conductivity. The results also show that analysis of microtopography of soil surface and soil stratification should be considered for designing irrigation and drainage networks.

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‏ In this research the effects of two common cooking processes of foods, namely, autoclave and extrusion cooking on the molecular and physicochemical properties of wheat starch were investigated. The results showed that the solubility of the autoclaved samples increased with increasing the temperature while their relative viscosity decreased. These findings indicated that the molecular degradation of starch could occur during autoclave cooking. Moreover, constant sedimentation coefficient (s-value) of amylose and decreasing the s-value of amylopectin with increasing the temperature further confirmed degradation of amylopectin in particular. The results of the extruded samples showed that reduction in water content may increase the shear and pressure produced during extrusion cooking, which in turn could cause several changes in starch properties including degradation of starch granules, formation of amylose-lipid complex and degradation of amylopectin (as determined by reduction of the s-values). Also, reduction in water content could increase the puffiness of the final products and reduce the cold-water and final viscosities of the extruded samples. These observations may indicate the importance of the molecular studies of starch for better interpretation of physical changes of the final products.

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Soil erosion is an important economical, social and environmental problem requiring intensive watershed management for its control. In recent years, modeling has become a useful approach for assessing the impact of various erosion-reduction approaches. ِDue to limited hydrologic data in mountainous watersheds, watershed modeling is, however, subject to large uncertainties. In this study, SWAT2000 was applied to simulate runoff and sediment discharge in Beheshtabad watershed, a sub-basin of Northern Karun catchment in central Iran, with an area of 3860 km2. Model calibration and uncertainty analysis were performed with SUFI-2. Four indices were used to assess the goodness of calibration, viz., P-factor, d-factor, R2 and Nash-Sutcliffe (NS). Runoff data (1996-2004) of six hydrometery stations were used for calibration and validation of this watershed. The results of monthly calibration p-factor, d-factor, R2 and NS values for runoff at the watershed outlet were 0.61, 0.48, 0.85 and 0.75, respectively, and for the validation, these statistics were 0.53, 0.38, 0.85 and 0.57, respectively. The values for calibration of sediment concentration at the watershed outlet were 0.55, 0.41, 0.55 and 0.52, respectively, and for the validation, these statistics were 0.69, 0.29, 0.60 and 0.27, respectively. In general, SWAT simulated runoff much better than sediment. Weak simulation of runoff at some months of the year might be due to under-prediction of snowmelt in this mountainous watershed, model’s assumptions in frozen and saturated soil layers, and lack of sufficient data. Improper simulation of sediment load could be attributed to weak simulation of runoff, insufficient data and periodicity of sediment data.

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After construction of a dam across a river, sediments settle behind the dam. It is important for dam designers to estimate the rate and distribution of sediments in the reservoir. In this study, the accuracy of area-increment and area-reduction empirical methods to predict the sediment distribution of Dez, Dorudzan and Shahid Abbaspour reservoirs is evaluated. The last measurement of sediment in these reservoirs was in 2003 (Dez), 2005 (Dorudzan) and 2005 (Shahid Abbaspour). The comparison between actual sediment distribution and predicted sediment distribution by using area-increment and area-reduction methods showed the maximum error at the depth of sediment behind the dam. At higher elevations, the error decreased and reached zero when the elevation was maximum. For Dorudzan reservoir, which has the least sediment volume (31 Mm3), the area-reduction method is less accurate, as compared to the area-increment method (81% vs. 37.5%). For Dez and Shahid Abbaspour reservoirs, where their sediment volume is high (608 and 737 Mm3, respectively), the error of the two methods is relatively equal (in Dez, 29% for both methods, and in Shahid Abbaspour, 22% for area-reduction and 25% for area-increment methods). After long-time sedimentation, the shape factor decreased and reservoir type of all three reservoirs changed to 2.

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The use of suitable empirical models for estimation of soil erosion and sediment yield is essential because of nonexistence or shortage of associated data in many watersheds. In the present study, the applicability of the USLE and its different versions Viz. MUSLE-S, AOF, MUSLT, MUSLE-E, USLE-M and AUSLE in estimation of storm-wise sediment yield from standard plots installed in dry farming, ploughed and rangeland treatments was evaluated. To conduct the study, the entire input data were collected from plots installed in three replicates in each treatment in Khosbijan Natural Resources Research Station in Arak Township. The models’ estimates were then compared with the observed sediment data for 12 storm events. Contrary to high correlation among different models’ estimates, the models used in estimation of measured sediment data were found inapplicable. However, significant relationship (r=94.4%) and non-significant relationship with correlation coefficients less than 50% were found between MUSLE-E, and MUSLE-S and MUSLE-E estimates and measured data in rangeland, dry farming and ploughed treatments, respectively.

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Erosion plots are basically used for studying erosion processes and many related problems. However, the possibility to extend the results of experimental plots to surrounding watersheds is rarely taken into account. In the present study, an attempt was made to study on the accuracy of soil erosion plots in estimation of runoff and sediment yield from small watersheds. Towards this attempt, 12 experimental plots with length of 2, 5, 10, 15, 20 and 25 meter were installed on two north and south facing slopes in Sanganeh watershed, northeastern Razavi Khorasan Province with an area of ca. 1 ha. The performance of the plots in estimation of runoff and sediment was controlled by data collected at the main outlet associated with 12 storm events occurred during November 2006 to June 2007. The results showed that the accuracy of plot estimates on sediment and runoff improved while the plot length increased. The optimal length for estimation of sediment and runoff parameters was found to be equal to average slope length and more than 20m.

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Reservoir sedimentation is an unavoidable problem which has unsuitable effects on reservoirs such as decreasing of reservoir useful volume, decreasing of dam stability, unsuitable operation of operational gates and penstocks and decreasing of flood control volume. The minimization of reservoir sedimentation is a nonlinear and constrained optimization problem. Constrains imposed include reservoir storage level and releases in each time, and reservoir storage level in the end of operational period. In this study, after calibration of GSTARS3 software, one of the newest mathematical model for simulation of river and reservoir sedimentation developed by USBR, for region of Voshmgir dam, results of running of software were converted as a part of data file to an optimization model by a mediator computer program. After running the optimization model, results were converted to GSTARS3 by another mediator computer program. Then, GSTARS3 was run again with new data file, obtained from running the optimization model. Results of running of GSTARS3 were converted to the optimization model again. The continuation of this process (loop) finished when the desired accuracy was obtained. In other words, the optimum condition was obtained when the running of this loop finished. The constrained optimization problem changed to unconstrained problem using penalty function method. The Powell method, a method of direct search methods, was used to solve this unconstrained optimization problem. Capabilities of the model were demonstrated through its application to the Voshmgir dam in Gorgan for a 12 month period to obtain the optimal operation policy for minimization of reservoir sedimentation.

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Rainfall erosivity force as on important factor in soil erosion and sediment yield has been introduced in different indexes. The objective of this study was to determine suitable rainfall erosivity indices for two climates of semi-arid in Maravetape and very humid in Sangdeh, both in Khazar watershed, by correlation between rainfall erosivity indices and sediment outflow from erosion plots. For this purpose, the rainfall intensities in different time steps and the amount of rainfalls of 12 events in Maravetape and 11 events in Sangdeh have been used. Twonty five rainfall erosivity indexes were calculated based on rainfall intensity. The amount of soil loss measured after each rainfall event in 1.8×22.1 m2 erosion plots. The results of the study revealed that in very humid climate of Sangdeh and in semi-arid climate of Maravetape had high correlation of 0.803 and 0.727 (at the level of 99 percent) with sediment yield and they were applied indices in these climates of Khazar watershed. In general, the groups of 10 and 30 minutes are better than other erosivity indices in the study areas.