JWSS - Journal of Water and Soil Science

Due to the increasing number of small crops, the system of irrigation without a pump can be an economical way. Therefore, in this research, the effects of the type of droplet and the height of water supply system utilization on the characteristics of water distribution (discharge, dispersion uniformity coefficient (CU) and coefficients of variation of discharge) were investigated. In this research, the pressure functions of 1, 2, 3 and 4 meters and three irrigation repeats were investigated; also, the discharge characteristics of jet pots of 2 and 8 nozzles, easy dripper and netafim were addressed. The results indicated that at 1 m pressure, drippers of pots of 2 and 8 nozzles with the uniformity coefficients of distribution were equal to 89.39 and 99.30%, and the discharge rate was 3.60 and 3.62 liters per hour at a pressure of 2 m. An easy-drain drip with a discharge rate of 3.85 L / h and a uniform distribution of 99.44%, at a height of 3 and 4 m, the droplets of the netafim with an outlet discharge were 3.87 and 3.97 liters per hour and the uniformity coefficients of 99.32 and 99.47 percent had the best broadcast conditions. According to these significant differences (P <0.05), it can be concluded that at pressures less than 2 m of jar droplets and at more than 3 m, netafim and Easy Dipper types could  have better leakage due to pressure regulators. In general, each of the four types of emitters produced a uniform dispersion and the optimum discharge at different pressures.

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.