JWSS - Journal of Water and Soil Science

Kahgel is one of the oldest traditional mortars in Iran capabilities and performance of which in the past to conserve earthen buildings show that it can be used as a covering for conservation and preservation of earthen architectural structures. The ancient waterproof covering is very efficient at keeping the building dry during the heavy rain showers, but low durability and the need for renewal the plaster due to erosion of rainfall suggest that Kahgel plaster is weak and unstable. So, it is very essential and necessary to find appropriate scientific methods to enhance durability and lifespan of Kahgel plaster. In this research, the effect of silicates micronized additives (including Microsilica, Feldspar, Zeolite, Bentonite and Kaolin) on the stabilization and improvement of the physical and mechanical properties of Kahgel plaster with experimental study by hydraulic conductivity and water erosion Kahgel plaster indicated that using the micronized silicates additives can significantly improve physical and mechanical properties of earth and earthen materials such as Kahgel. Experimental results showed that application of Kaolin 150 microns at 3 wt% (by weight of Kahgel) reduced hydraulic conductivity of the Kahgel plaster at 65% level and Zeolite 45 microns at 3 wt% (by weight of Kahgel) decreased by 85%. In addition evaluation of water erosion of the samples during rainfall by rainfall simulator showed that use of 3 wt% micronized Microsilica, Feldspar, Zeolite and Kaolin decreased sample’s total dry material loss of the Kahgel plaster at least10/5% and maximum up to 37/7% and increased their durability against erosion from rainfall. In addition, results from studies indicate that by reducing the particle size of the additive, their positive effect on physical and mechanical properties of Kahgel mortar increases. On the other hand, 3 wt% is the optimized percentage of micronized silicate additives to improve Kahgel coating and increased amount of additives seems to have no significant impact on the improvement of physical and mechanical properties.
 

Over the years, since the beginning of the national and infrastructural project of Development and Renovation of Paddy Fields of Iranian Northern provinces, it has been essential to evaluate water distribution and delivery Performance of the project to get its feedback in the pursuit of the desired goals. However, the results of the evaluation of a system can reliable when they are based on quantitative indicators, not on personal opinions and empirical judgment. So, in this study, Total Error (TE) of performance of water delivery system, a statistical indicator, and its component including adequacy, water management capability and equity errors were calculated and compared for two concrete and earthen irrigation canals. This analysis was done based on calculating water demand and measuring the volume of delivered water between outlets during the irrigation season in the paddy fields of Esmaelkola of Joybar city, in 2015. According to the results, although the concrete channel (0.28) had less error than the earthen channel (0.43) and in the concrete channel, as compared to the earthen channel, the share of the components of adequacy and water management capability from the total error was dropped from 47% to less than 10%, but the error in the water delivery of the concrete channel was still high due to the error in the equity of distribution, whose value was 0.25 (90% of the total error). Therefore, in order to reduce the performance error, after channel lining, it would be necessary to make fundamental changes in the intake and flow control structure in addition to the training of irrigators regarding water delivery based on water demand.

Labyrinth weirs are the economic structures to increase the weir output efficiency in limited widths, which can be seen in the plane f trapezoidal and triangular forms. These weirs with a hydraulic load and fixed width pass the more discharge in comparison to other type of weirs. In this study, labyrinth weirs trapezoidal in plane form were investigated. The experiments were performed on 27 laboratory models with 9 different discharge rates and a total of 243 tests. The results showed that, in all of the composite trapezoidal labyrinth weirs, the ratio of discharge coefficient to H_t/p (H_t: Total hydraulic load and p: weir length) weir length was increased at first; after reaching the maximum rate, it started to decrease. According to the suggested general relation, the utmost impact on discharge coefficient resulted from the cycle number and  H_t/p relation. Creating new labyrinth on the wing of the weir led to the increase of the effective length; as a result of it, the discharge rate increased in a specific amount of H_t/p. Also, the discharge through a trapezoidal labyrinth weir with the semicircular planform was better than the square; the square, in turn, was better than the simple trapezoidal weirs.

Trees decline is a complex physiological disease that results from the interactions between several factors, one of which is heavy metal stress that ultimately leads to the death of trees. This experiment, which was conducted during 2016-2017 at the campus facility of the Department of Horticulture at Isfahan University of Technology, was conducted to investigate the effects of inoculation with arbuscular mycorrhizal fungi (AMF) (Rhizophagus intraradices and Funneliformis mosseae inoculated, and the combination of both species) and plant growth promoting rhizobacteria (PGPR), Pseudomonas Flourescens, on the growth responses of Arizona cypress (Cupressus arizonica G) to different concentrations of cadmium (0, 5, 10, 15, 20); this was done as a factorial experiment based on a completely randomized design, with three replications. The interactions between AMF, PGPR, and cadmium on potassium and iron concentration, height, and dry weight of Arizona cypress seedlings were significant. By increasing the concentration of cadmium in most of the treatments, the colonization, phosphorus, potassium and iron concentrations, height and dry weight of the shoot Arizona cypress seedlings were decreased, while the percentage of electrolyte leakage and proline content were increased. The AMF-inoculated plants increased phosphorus, potassium and iron concentrations, Height, shoot dry weight, proline content and reduced electrolyte leakage percentage, as compared to non-mycorrhizal (control) plants. In plants inoculated with both microorganism (mycorrhizal fungi and Pseudomonas), there was a positive effect regarding the concentration of nutrients such as potassium and iron; there was also the improvement of growth characteristics such as height and dry weight of the seedlings, as well as the appearance and freshness of the plant. The results, therefore, showed that inoculation of Arizona cypress seedlings with the combination of mycorrhizal fungi and Pseudomonas fluorescens bacteria could have a positive effect on the growth and survival of this tree under Cadmium stress condition.

One of the crucial problems that exist in the irrigation networks is the fluctuation of the water surface flow in the main channel and changes in the flow rate of the intake structure. One of the effective methods to decrease these fluctuations is increasing the weir crest length at the given width of the channel with the use of the labyrinth weirs can be achieved for this purpose. The labyrinth weir is the same linear weir that is seen as broken in the plan view. In this study, a labyrinth weir with a length of 3.72 m, three different heights of 15, 17, and 20 cm, three different shapes of dentate (rectangular, triangular, and trapezoidal), and a linear weir were used in a recirculating flume with 15 m length and 1 m width. The result showed that for a given length and height of weir, with the increasing of the upstream water head to the weir height ratio (), the discharge coefficient decreases. The results showed that by increasing weir height, the discharge coefficient decreases for a given length of the weir. Linear weir and labyrinth weir without dentate create more water depth at the upstream by 3.3 and 1.2 fold compared with dentate labyrinth weir.

Investigating and understanding river change issues is one of the important factors in sediment hydraulic sciences and river engineering. These studies can be done with the help of physical, mathematical models, or both, but due to financial and time constraints, mathematical models are more general and often used. In this study, the GSTARS model was used to investigate erosion and sedimentation and select the most appropriate function in 12.5 km in length from the Talar river in Mazandaran Province. Simulation using the 55 sections taken in 2006, the daily flow data of the hydrometric station of the Shirgah, located at the beginning of the rich and characteristics of the river sediment, was done. The calibration and validation of the model with cross sections taken in 2012 showed that Yang's sediment transport equation has the highest correlation with reality and can be used to predict river change. The amount of sediment depleted from the case study using the Yang equation is estimated at 8590 tons per year. Also, the study of longitudinal profiles of the river with different sediment transfer functions showed that the study reach at the end range has an erosion trend and is not capable of sand and gravel mining.

A compound sharp-crested weir is often used to measure a wide range of flows with appropriate accuracy in open channels. In this study, experiments were performed to investigate the hydraulic flow through a compound weir of circular-rectangular with changes in hydraulic and geometric parameters in free and submerged flow conditions. The characteristics of the weirs include rectangular spans width of 39 cm, a circular radius of 5, 7.5, and 12.5 cm, and heights of 10 and 15 cm. The results showed that by increasing the radius and height of the Weir, upstream water depth increases around 28.4%. At a constant h/p, the discharge coefficient increases with the increasing radius of the circular arc. Also, in the submerged conditions, the discharge coefficient is less (around 40%) than in the free flow condition, which is due to the resistance of the depth of the created stream against the passage of the flow.

The agricultural sector as one of the most important sectors of water consumption has great importance for the sustainability of the country's water resources systems. The objective of this study was to estimate the river water abstraction (RWA) for agricultural consumption in the study area of Nobaran in the Namak Lake basin. The RWA was estimated using variables related to morphological, hydrological, and land use factors, as well as a combination of their variables collected through field sampling. Data mining methods such as adaptive-network-based fuzzy inference systems (ANFIS), group method of data handling (GMDH), radial basis function (RBF), and regression trees (Rtree) were also used to estimate the RWA variables. In the current study, the GMDH₂₄ model with a combined scenario including the variables of river width, river depth, minimum flow, maximum flow, average flow, crop, and the garden cultivated area was adopted as the best model to estimate the RWA variable. The RMSE value for the combined scenario of the GMDH₂₄ model was found to be 0.046 for estimating RWA in the Nobaran study area. The results showed that the performance of the GMDH₂₄ model for estimating RWA for maximum values is very acceptable and promising. Therefore, modeling and identifying various variables that affect the optimal RWA rate for agricultural purposes fulfills the objectives of integrated water resources management (IWRM).