JWSS - Journal of Water and Soil Science

Occurrence of local scour is one of the most significant causes of damage to the pipes. Therefore, safe and economical design of pipes in the flow path requires a good estimate. In this study, based on the important and effective parameters in the scouring phenomenon, in order to develop educational patterns according to the data obtained in the laboratory of Ahvaz Islamic Azad University, models based on artificial neural networks were created with the NeuroSolution5 software. MLP, GFF and RBF were the models used in this study; after comparing, MLP was selected as the basis for our study. Finally, the effect of each parameter on scouring was determined using the  artificial neural networks technique, based on which the  shields parameter with a very high effect (more than 95 percent) was determined as one of the most effective causes of the local scour.

Increase in population, agricultural development, and the reduction of surface water resources have resulted in an untapped harvest of ground water. On the other hand, the lack of attention to the balance between the exploitation and recharge of aquifers has led to a drop in water level in the aquifer. To understand the behavior of the ground water system and the status of resources and uses in the basin, as well as the situation of water exchange in these two parts, it is possible to connect reliable groundwater and surface water models The purpose of this study was to simulate Gorganroud aquifer flow by using using the groundwater model to understand the behavior of the aquifer system in different hydrological conditions and to provide a management solution to improve the  supply and demand conditions. First, the status of the aquifer under study was simulated by using the information available in the area by Modflow; then the groundwater model results were transferred to the Water Evaluation and Planning model (WEAP) by the LINK KITCHEN Software. Then different management scenarios including increased irrigation efficiency in agriculture,  the use of refinery effluents and  the reduction of river flow due to climate changes were considered as two combinations of the above scenarios to alleviate water demand under this scenario; so, projections for a period of 20 years water resources of the basin were studied. The results of modflow calibration showed that there was a good agreement between observation and simulated water table, such that the RMSE for Steady and Transient condition was 0/972 and 0/97, respectively. The results also showed that simultaneously applying multiple water management strategies seems to be better than any of its individual states, thereby reducing water withdrawal on various resources.

In addition to the distribution of elements in the soil solid phase, element species in the solution are also very important due to their importance of providing elements for root uptake. For a deeper study of the chemical cycle of elements in saline soils treated with biochar, the study of speciation is very useful and provides a method to reduce or transform the toxicity caused by toxic elements in saline soils. Therefore, to investigate the effect of biochar on Cd speciation in two saline calcareous soils, 15 mg kg^-1 Cd as cadmium chloride was added to the soil sample (200 g), and the soils were incubated for three weeks at 25±2 °C at 80% field capacity. After the incubation period, salinity levels of 20 and 40 mmol kg^-1 as sodium chloride (equal to 3.65 and 7.30 dS m^-1) were added to the soils. Then, the 1% (w/w) of the sugarcane bagasse and biochars produced at 400 and 600 °C were added to the soils, and then incubated for three months at 25±2 °C at 80% field capacity. At the end of the incubation period, for the speciation of Cd in the soil solution (in a 1 to 2 ratio), the concentration of dissolved cations and anions in the soil samples was measured. The results showed that the interaction between salinity, biochar, and soil on Cd²⁺, CdCl⁺, CdCl₂⁰, and Cd(SO₄)₂^2- was significant. The application of biochar in sandy soil reduced (p <0.05) the concentration of CdCl⁺, CdCl₂⁰, CdSO₄⁰, and CdOH⁺ species compared to the control soil, while it did not affect clay soil. Also, salinity caused by sodium chloride in sandy soil increased the concentration of CdCl⁺ and CdCl₂⁰ species and decreased CdSO₄⁰ and CdOH⁺ species compared to the control soil (p <0.05). The results showed that biochar in saline sandy soil was more effective than clay soil in reducing Cd toxicity.