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This study was carried out in order to investigate and determine the water requirement and irrigation scheduling in the Vardij district of Tehran province. In order to calculate the reference evapotranspiration, the FAO Penman-Monteith equation was utilized and WUCOLS III method was recruited to vegetation coefficient. The climate data of Chitgar Station (from 2008 to 2017) was used to calculate the reference evapotranspiration and effective rainfall. The results showed that effective rainfall in the studied area was not sufficient to provide the required water for the plant and there is a need for additional irrigation during the growing season. The highest amount (ie 41. 57 mm) of evapotranspiration of Elaeagnus angustifolia L. was observ
The aim of this study was to evaluate the remote sensing algorithm (SEBAL) for estimating actual evapotranspiration in Vardij area in Tehran province. For this purpose Landsat 8 satellite images on June 10th, July 12th, August 13th and September 14th, 2018 and July 15th, 2019 were used. The reference evapotranspiration value (alfalfa plant) was calculated using evapotranspiration obtained from the SEBAL algorithm for the three points where alfalfa was previously cultivated. Using the meteorological station data, reference evapotranspiration was estimated by the experimental methods of FAO Penman- Monteith, Penman -Wright, Hargreaves Samani and Blani Cridel. The values obtained from SEBAL algorithm were compared with the mentioned methods an
In this study, the performance of rainwater harvesting (RWH) was assessed in terms of potential applicability for rainwater saving and non-potable water supply. Rainwater collecting from roofs of buildings was simulated in two cities with cold and semi-arid climate, namely Qazvin and Sanandaj. Rainfall statistics, information on the storage tank size, building roof areas and water demand (non-potable) were obtained. Buildings with roof areas of 100 m2 to 300 m2 were considered for the present study. It can be concluded that for cities located in cold and semi-arid climates, at least 60% of non-potable water can be supplied from roofs with a large area, a minimum 16% and maximum 70% for a low roof area, a minimum 8% and maximum 44%
This study applied a simulation model to evaluate the reliability of rainwater harvesting systems (RWHs) and the potential for rainwater storage was investigated in three different buildings. The results indicated that the tank stores 97.7% of the run‐off from the gym roof. Modelling the volume of the tank connected to the gym roof showed that 100% reliability can not be achieved for a roof with a relatively small area. The reliability for a tank larger than 2600?L was independent of the size of the tank. Maximum reliability of the RWHs was 70% of the total days of the year for a tank volume of 10?000?L, 300?m2 roof area and daily demand of 300?L (60% demand). Minimum reliability was 3% of the total days of the year for a tank volume of
Assessing the performance of rainwater harvesting systems, which is one of the effective ways to cope with the water shortage crisis, leads to better management of these systems. In this paper, the reliability of rainwater harvesting systems and the overflow ratio of storage tanks were investigated for different climatic conditions, different volumes of tanks, and different roof areas. The results indicated that in the cities of Rasht, Sari, Tabriz, and Yazd, using a 10-m3 tank, non-potable water needs of a four-person family can be supplied from a 100-m2 roof area for 67.3, 42.98, 12.07, and 1.35% of the days during a year. Further, if a 1-m3 tank is used in Rasht, 50.67% of the total harvested water will be overflowed, which
Due to water shortage, increasing production by increasing cultivation area is limited in arid and semi-arid regions and approach to optimize the use of rainfall and limited irrigation to be considered, in order to increase water productivity. Development of rainwater harvesting systems and supplemental irrigation can be effective in increasing semi-irrigated cultivation area and decreasing water shortages. Rainwater harvesting is defined as a method for inducing, collecting, storing and conserving local surface runoff for agriculture in arid and semi-arid regions. The supplemental irrigation in condition which rainfall alone cannot have a good performance can be effective to improve the yield. The objective of this study was to investigate
Fertigation is an effective method to increase water and fertilizer use efficiencies. In present study, a field experiment was carried out factorially in a randomized complete block design with four replicates to evaluate the effects of furrow fertigation on water and fertilizer use efficiencies, yield and yield components of corn. Six fertigation treatments combining two fertilizer split levels (3 and 4 splits) and three levels of urea fertilizer (60, 80 and 100% of required fertilizer) were compared with broadcast fertilization. The results showed that application of nitrogen in four splits, provided more grain yield. Besides, by consuming low fertilizer in the fertigation treatments due to broadcast fertilization method, water and fertil
Streets and roofs of buildings in cities will act as an obstacle to the penetration of rainwater into the soil, resulting in increased runoff in the city. One of the practical solutions that can be effective in addition to meet part of the non-potable needs of the residents is to reduce the runoff of the city's surface and its damages, as well as the Performance of rainwater harvesting systems. In this method, a large part of runoff is stored in the tanks. In this paper, by simulating the roofing surfaces system of residential buildings in Matlab, optimization of rainwater storage tanks in Karaj and Ahvaz was investigated. According to optimal tank volume, rainfall statistics and specifications of residential buildings, to analyze the volum
Water resources limitation is the most important problem in sustainable agriculture development in Iran. The optimum use of water in agriculture is an inevitable necessity to conservation of water resources. The use of modern irrigation methods and the application of management strategies such as deficit irrigation will increase the crops yield and water productivity. The purpose of this study was to investigate the effects of different irrigation levels and depth of drip irrigation lateral placement on yield, yield components and some morphological traits of winter wheat in Sanandaj. Field experiment was conducted in 2018 as a split plot based on complete randomized block design. The main plots and sub plots of the present study were irrig
Introduction: Broadcast fertilization method increases fertilizer losses while results in lower nutrient absorption by plant roots. Fertigation is an effective method to increase water and fertilizer efficiency and to reduce the losses of nitrogen. Moreover, it allows farmers to apply the nutrients in splits and few amounts in response to crop needs. In the present study, a field experiment was conducted to investigate the effects of split application of fertilizer in furrow fertigation on nitrogen losses and corn yield. Materials and Methods: Field experiments were carried out factorially in a randomized complete block design with four replicates. Experimental treatments were consisted of three fertilizer splits (two, three, and four split
Water for agriculture is one of the most important factors in arid and semi-arid areas and municipal wastewater treatment wastewater treatment Subject Category: Miscellaneoussee more details is an important resource for this purpose. Therefore, potential of transfer contaminations is a serious problem regarding use of treated wastewater for agriculture. Due to the risk of transfer contaminations through the use of wastewater, the study of transfer microbes in soil in recent decades has been of interest to researchers. In the present study, the transfer of bacteria fecal coliform was investigated in a lysimeter and the HYDRUS-1D model was used to simulate water flow water flow Subject Category: Miscellaneous
Information on water soil content and its distribution is vital for field water management in subsurface irrigation. The objective followed in this study was to simulate the extent of wastewater distribution taking into account root water uptake and evaporation from the soil surface under, subsurface drip irrigation system. In this regard, a field experiment was conducted with lettuce as the crop, to collect the required data. Soil hydraulic properties were obtained through an assessment of in-situ soil water pressure heads as well as water contents. Soil matric potentials, under tensiometery range, were obtained by use of tensiometers and the related water contents by a TDR instrument. For the simulation purposes, the HYDRUS-2D model was m
Although the evidence for anthropogenic climate change is overwhelming, it is still standard practice to preface the statement by saying; most climate scientists believe that increasing concentrations of greenhouse gases have led to changes in climate. According to the fifth IPCC report, increasing concentrations of CO2 and other greenhouse gases has led to fundamental changes due to anthropogenic activities in the global climate over the course of the last century. These changes in the climate will lead to changes in water demands of existing irrigation networks. In the agricultural sector, there are multiple variables which will be affected by climate change. For instance, evapotranspiration is controlled by climatic variables (such as te
Although the evidence for anthropogenic climate change is overwhelming, it is still standard practice to preface the statement by saying; most climate scientists believe that increasing concentrations of greenhouse gases have led to changes in climate. According to the fifth IPCC report, increasing concentrations of CO2 and other greenhouse gases has led to fundamental changes due to anthropogenic activities in the global climate over the course of the last century. These changes in the climate will lead to changes in water demands of existing irrigation networks. In the agricultural sector, there are multiple variables which will be affected by climate change. For instance, evapotranspiration is controlled by climatic variables (such as te
For drying paddy soils, underground drainage system is imperative and the application of theoretical equations in design of underground drainage system is not efficient for all farms, either, therefore, the construction of experimental farms prior to the massive construction projects is inevitable. To determine the underground drainage system parameters in paddy experimental fields of human resources and agricultural development center of Mazandaran Province, Iran, becomes to the main goal of this study. Owing to the excessive rainfall in these regions, the fluctuation of water with its corresponding none-steady state happens. To achieve the goal on the construction of experimental farms, underground water surface level was measured in an a
Assessment of the reliability and quality of historical precipitation data is required in the modeling of hydrology and water resource processes and for climate change studies. The homogeneity of the annual and monthly precipitation data sets throughout Iran was tested using the Bayesian, Cumulative Deviations, and von Neumann tests at a significance level of 0.05. The precipitation records from 41 meteorological stations covering the years between 1966 and 2005 were considered. The annual series of Iranian precipitation were found to be homogeneous by applying the Bayesian and Cumulative Deviations tests, while the von Neumann test detected inhomogeneities at seven stations. Almost all the monthly precipitation data sets are
For drying paddy soils, underground drainage system is imperative and the application of theoretical equations in design of underground drainage system is not efficient for all farms, either, therefore, the construction of experimental farms prior to the massive construction projects is inevitable. To determine the underground drainage system parameters in paddy experimental fields of human resources and agricultural development center of Mazandaran Province, Iran, becomes to the main goal of this study. Owing to the excessive rainfall in these regions, the fluctuation of water with its corresponding none-steady state happens. To achieve the goal on the construction of experimental farms, underground water surface level was measured in an a
Assessment of the reliability and quality of historical precipitation data is required in the modeling of hydrology and water resource processes and for climate change studies. The homogeneity of the annual and monthly precipitation data sets throughout Iran was tested using the Bayesian, Cumulative Deviations, and von Neumann tests at a significance level of 0.05. The precipitation records from 41 meteorological stations covering the years between 1966 and 2005 were considered. The annual series of Iranian precipitation were found to be homogeneous by applying the Bayesian and Cumulative Deviations tests, while the von Neumann test detected inhomogeneities at seven stations. Almost all the monthly precipitation data sets are homogeneous an
This paper evaluates the efficiency of using surface water simulation results to improve the accuracy of groundwater simulation due to improving the accuracy of its input boundary conditions. The three most important data sets of boundary conditions in groundwater flow simulation are groundwater recharge, evapotranspiration rates and their regional distributions that little information is usually available about them. Moreover, the incorrect definition of these values can lead to uncertain groundwater modeling that is not applicable for groundwater resources management. In the most of previous studies done in Iran, percentage of the average regional precipitation and the local pan evaporation data (available from local weather stations) are