a. haghizadeh

In this research, soft computational models including multiple adaptive spline regression model (MARS) and data group classification model (GMDH) were used to estimate the geometric dimensions of stable alluvial channels including channel surface width (w), flow depth (h), and longitudinal slope (S) and the results of the developed models were compared with the multilayer neural network (MLP) model. To develop the models, the flow rate parameters (Q), the average particle size in the floor and body (d50) as well as the shear stress (t) as input and the parameters of water surface width (w), flow depth (h), and longitudinal slope (S) were used as output parameters. Soft computing models were developed in two scenarios based on raw parameters and dimensionless form independent and dependent parameters. The results showed that the statistical characteristics in estimating w, the best performance is related to the MARS model, whose statistical indicators of accuracy in the training stage are R2 = 0.902, RMSE=1.666 and in the test phase is R2 = 0.844, RMSE=2.317. In estimating the channel depth, the performance of both GMDH and MARS models is approximately equal, both of which were developed based on the dimensionless form of flow rate as the input variable. The statistical indicators of both models in the training stage are R2 » 0.90, RMSE » 8.15 and in the test phase is R2 » 0.90, RMSE = 7.40. The best performance of the developed models in estimating the longitudinal slope of the channel was related to both MARS and GMDH models, although, in part, the accuracy of the GMDH model with statistical indicators R2 = 0.942, RMSE = 0.0011 in the training phase and R2 = 0.925, RMSE = 0.0014 in the experimental stage is more than the MARS model.

This study aimed to assess the water quality of Ardak River and analyze its suitability for drinking and agricultural purposes.

In this research, water samples were collected during dry and wet seasons in 2018 from previously selected 5 sampling stations. Then, the water quality index (WQI) and irrigation-related indices were calculated.

The calculated WQI values are between 156.77 and 379.59 in the study area, which shows the water quality of Ardak River is in the “poor” to “unsuitable for drinking” range both periods. The effects of water quality parameters on the WQI were evaluated, and the obtained outcomes indicate that the highest mean effective weight value belongs to the fecal coliform and phosphate parameters compared to the other parameters. Furthermore, various indices such as sodium adsorption ratio (SAR), residual sodium carbonate (RSC), magnesium hazard (MH), Kelly’s index (KI), and Permeability index (PI) were used to assess river water quality for irrigation purposes. The results indicate that the river water quality is generally moderately suitable to safe with exceptions at a few sampling stations in the dry season, which are unsuitable for irrigation purposes.

Due to the negative effects of anthropogenic pollutants such as animal husbandry, intensive agricultural activities, and rural wastewater discharging, the water quality of the Ardak River is deteriorating. Therefore, necessary protection steps should be taken in the Ardak Watershed.

Groundwater is one of the most dispersed and most important sources of the earth's crust. The groundwater flow in the karstic rocks is completely different from the movement of this fluid in nonkarstic zones, This flow shows the specific hydrological characteristics of the karstic zones. For the full development of underground water reservoirs, it has to be highly assessed in terms of quantitatively and qualitatively to avoid unnecessary information and assumptions from groundwater, resulting in false usage and reduction. Since karst water resources, large reserves of underground water in different regions of the country, Especially in the study area, it is necessary to be more dynamic and active in the management and preservation of water resources. The purpose of this study was to Assesment of hydraulic parameters of Karstic aquifers in Khorramabad city. In this study, seven regional aquifer Karstic were studied. All of the studied mirages are inundated and exited from carbonate formations. As the aquifers of Robat, Motahari, Golestan, Gerdab Sangi, Changhai (Niloofar), Nawekash, and Dureh Karst Formation has been developed; and kyo aquifer, despite the fact that it has the most drainage, is located in less developed formations. By comparing dynamic storage and annual discharge volumes, Because the dynamic storage volume of the Mirage Kyo, Gerdab sangi, Robat and Dureh is less than the annual evacuation volume, if the wells are dug in the limestone formation of the aquifer and then exploited, the springs will not be able to drain at the peak of consumption. Therefore, it is suggested that this should be avoided as much as possible. Given that the duration of the dynamic storage of the Mirage Kyo is low, the Gerdab sangi is small and the type of mirage is also non-permanent. It is suggested that these mirages should not be used for development projects when the aquifer Recharge is cut off.