جستجوی مقالات مرتبط با کلیدواژه « water volume » در نشریات گروه « آب و خاک »

The decline in water level of Lake Urmia is one of the regional environmental crises. One of the measures to rehabilitate Lake Urmia is the inter-basin water transfer from the Zab Basin to Lake Urmia through the Kani-Sib tunnel. The aim of the present study is the hydraulic and hydrological investigation of the water transfer project from Kani-Sib Dam to Lake Urmia. To achieve this goal, the water transfer from the Zab basin to Lake Urmia was simulated in the form of three scenarios (empty reservoir, half-full reservoir and full reservoir) for 10-years period and evaluated hydrologically and hydraulically. Solving the water balance equation with the intervention of the hydraulic relations of the tunnel water transfer flow and dam peak overflow was investigated in the MATLAB software environment on a daily basis. The results of the present study revealed that the outlet of the tunnel will be less than the amount determined in the Urmia lake reclamation headquarters program (600 MCM). It should be noted that the transferable volume of water (with 100% efficiency) in the dry hydrological period (similar to 77-78 year) will be around 190 MCM. In addition, in the case of high water (similar to 82-83 year), the tunnel outlet will be around 767 MCM.

By evaluating irrigation systems, their performance can be improved. The purpose of this study was to evaluate the center pivot irrigation system in some fields of Semnan province. Also, the amount of water consumption in the field was compared with the water requirement and the national water document. For this purpose, center pivot irrigation systems were studied in three fields. Average potential and actual application efficiency (PELQ and AELQ), distribution uniformity (DU), uniformity coefficient (CU) and evaporation and wind losses were 69.1, 67.2, 76.7, 82.1 and 7.6% respectively. The average of the above parameters was good. The operation of center pivot systems was easier than other sprinkler systems due to the mechanization of center pivot systems. Technical problems in one system reduced uniformity and efficiency. The volume of water consumption in field 3 was less than the irrigation requirement thus deficit irrigation was done. Irrigation water productivity in alfalfa and wheat fields was 0.92 and 0.79 kg/m3, respectively. Considering appropriate irrigation frequency and time, night irrigation to reduce evaporation and wind losses and paying more attention to educating farmers on proper operation of system were the important factors in increasing irrigation efficiency and water productivity.

One of the important indicators in determining water use efficiency for agricultural productions is the index of water consumption efficiency. This study was conducted to determine the water use efficiency of pistachio in Sirjan city located in the southwest of Kerman province in 2015. To compare bubbler and subsurface drip irrigation methods, 27 pistachio orchards with an area of ​​1373 hectares were selected to determine water use efficiency, of which four orchards were equipped with the bubbler system and the rest were equipped with subsurface system. Bubbler discharge, irrigation time, area of ​​each irrigation plot and crop yield were studied. By measuring the volume of irrigation water after irrigating the field and the amount of water wasted along the route, the average gross volume of applied irrigation water was calculated. After harvesting, the average yield of pistachio per hectare was calculated. The results of this study showed that the subsurface drip irrigation method compared to bubbler irrigation method, not only significantly increases water use efficiency but also increases crop yield by 34%. Therefore, according to the results and also the current water shortage conditions in Sirjan city, the use of subsurface drip irrigation method is more appropriate than bubbler irrigation to irrigate pistachio orchards.