IRANIAN JOURNAL OF IRRIGATION AND DRAINAGE
Year:2023 | Volume:16 | Issue:5|Papers Count:15

The main objectives of this study was the evaluation of CRU TS4. 05 and ERA5 datasets accuracy to monthly precipitation (P), temperature (T) and Potential Evapotranspiration (PET) variables in different climates across Iran. To achieve the research aim, daily measured data from 100 synoptic meteorological stations and monthly P, T and PET products of CRU TS4. 05 and ERA5 datasets are used at a spatial resolution of 0. 5°, ×0. 5°,and 0. 25°, ×0. 25°,from 1987 to 2019. The mean absolute error values for P, T and PET variables in Hyper-arid (HA), Arid (AR), Semi-arid (SA), Sub-humid (SH) and Humid (HU) climates of CRU TS4. 05 datasets are equal to 6, 9, 13, 28 and 81 mm month-1, 1. 7, 1. 5, 1. 8, 2. 7, 2. 5 oC and 171, 84, 38, 44 and 47 mm month-1, and of ERA5 datasets are equal to 5, 9, 18, 28 and 40 mm month-1, 1. 1, 1. 6, 1. 9, 3. 0 and 1. 0 oC and 227, 91, 46, 46, 44 and 48 mm month-1, respectively. Results of this study have declared that more accuracy of two datasets (CRU TS4. 05 and ERA5) to T, PET and P, respectively. Although, the main results show that accuracy of ERA5 datasets are more than CRU TS4. 05 datasets, but it is recommended to use ERA5 P products in SH and HU climates, and CRU TS4. 05 PET products in HA and AR climates.

Potato is the fifth largest food source in the world, which is widely cultivated in Iran. Due to the sensitivity of this crop to the amount of irrigation water, it is necessary to investigate the effect of different amounts of irrigation on it. For this purpose, SWAP model was used as a powerful tool for potato simulation. At first, to evaluate this model, biennial data (1998-1999) collected from a research station in ChaharTakhteh, Shahrekord were used. These data include five levels of water stress (E0, E1, E2, E3 and E4, respectively, indicating 100, 85, 70, 50 and 30% water supply) and three stress application times (T1, T2, and T3 indicating 50, 100, and 150 days after sowing, respectively). NRMSE values for yield and water use efficiency showed that SWAP model in both calibration and validation were excellent (NRMSE < 0. 1). The error of this model for simulating yield in the calibration and validation stages was equal to 1. 42 ton. ha-1 (4. 6 percent) and 2. 36 ton. ha-1 (7. 2 percent), respectively. The error value of this model for water consumption efficiency in the mentioned two stages was 0. 04 kg. m-3 (4. 9%) and 0. 33 kg. m-3 (7. 7%), respectively. The efficiency of the SWAP for potato simulation during calibration and validation was acceptable. Potato irrigation planning using SWAP showed that to achieve maximum yield, the irrigation water depth in the first growing period is equal to 750 mm and irrigation depths are 900 mm in subsequent periods.

An experiment was conducted in a commercial greenhouse to determine cucumber (Negin cultivar) evapotranspiration and crop coefficient in two seasons of winter and spring cultivation in Hamedan province,Irrigation was done to meet 100% of the water requirement based on reaching the suction tensiometer to the field capacity (40 to 50 cm),The soil water balance was used to estimate plant evapotranspiration in the greenhouse,Stanghellini and FAO Penman-Monteith evapotranspiration methods were 214,2 and 181,5 mm in winter and 222,3 and 227,6 mm in spring,respectively,The evapotranspiration ratio by the FAO Penman-Monteith method inside and outside the greenhouse in winter and spring cultivation was 0,8 and 0,81,respectively,The actual evapotranspiration from soil water balance in winter and spring cultivation were 148,2 and 210,4 mm,respectively,The results showed that the average crop coefficient in the initial,middle,and final stages of the growing season in winter planting was 0,69,1,43,and 1,05,and in spring planting were 0,63,1,15,and 0,9,respectively,The results of this study showed the necessary scientific basis for optimizing irrigation and saving water consumption,creating appropriate irrigation planning,and improving the crop water use efficiency in the greenhouse,Also,by reducing excessive water consumption,it can reduce energy consumption and provide a maximum increase in product production efficiency and economic efficiency,The investigation of evapotranspiration,crop canopy growth,and humidity changes during the growing season also showed that it is necessary to prevent the development of plant diseases,to use a higher ventilation level or forced ventilation in greenhouses,

Importance of rice as a staple crop for feeding of human being is obvious. Besides, water is major input for rice production. Water crisis is one the serious interest for present and future conditions of IRAN. Then, this research conducted for investigation of mid-summer drainage effects on yield, Water consumption and water productivity of Hashemi and Fajr rice cultivars. For obtaining this purpose, a field experiment was carried out in 2014 at the end of tillering stage as a factorial in basis of randomized complete block design in 3 replications with 5 mid-summer drainage treatments i. e. 0, 3, 5, 7 and 9 in Babolsar. Results showed that the effects of midsummer drainage and variety on water consumption, Grain yield and water productivity were significant (p<0. 01), and mid-summer drainage with 5 days’,duration on both cultivars had the highest water productivity, 0. 92 and 1. 30 Kg/m3 respectively. Also maximum yield and minimum water consumption resulted for 5 days’,mid-summer drainage treatment. Thus, 5 days’,duration for mid-summer drainage of Paddyfield was recommended for this region.

Evapotranspiration is one of the main components of any region's water balance. Its accurate estimation is very necessary for hydrological studies, designing irrigation and drainage systems, and planning irrigation systems. In this research, the M5 tree model, M5 Rules, K Star, Rep Tree, artificial neural network model, and ANN-PSO neural network hybrid model in the estimation of reference evapotranspiration in two different climatic regions in Markazi Province based on the FAO Penman-Monteith model were evaluated. The data used included minimum and maximum temperature, average relative humidity, and wind speed at a height of two meters and sunny hours from the synoptic stations of Delijan and Tafresh between 2004-2021. To evaluate the models, the Root Mean Square of Error (RMSE), Mean Absolute Error (MAE) and Correlation Coefficient (R) indices were used. The analysis of the results showed that for both stations, ANN-PSO neural network hybrid model had the best performance with RMSE=0. 3115, MAE=0. 2441 and R=0. 9989 for the Delijan station and RMSE=0. 2915, MAE=0. 2355 and R=0. 9989 for Tafresh station and tree model M5 with RMSE=0. 2793, MAE=0. 2398 and R=0. 9967 for Delijan station and RMSE=0. 2803, MAE=0. 2306 and R=0. 9969 for Tafresh station. Also, the Rep Tree model had the weakest performance among the models examined in this research. Considering that the tree model provides simple, linear and more comprehensible relationships for estimating reference evapotranspiration in addition to optimal accuracy, this model is recommended for estimating evapotranspiration in this region.

Local scour downstream of the hydraulic structures is of great importance. In wide channels, a set of multi gates instead of a single gate may be responsible for transferring water and adjusting upstream water level due to difficulty in gate maneuvering, economic considerations, and ease of movement. Operating parallel sluice gates can create different scenarios owing to clogging or failure in some gates. This study was aimed to assess the effect of different cases of parallel sluice gates operational management, gate opening to channel width ratio, and length of the separator walls on local scour development downstream of parallel sluice gates in different operations. Five operational scenarios were investigated on three parallel sluice gates. The results of the present study showed that the dimensions of the scour hole are a function of the symmetrical and asymmetrical operation of the gates. By reducing the gate opening to channel width ratio, the dimensions of the scour hole increased compared to the classical hydraulic jump mode. Maximum scour depth in the symmetric operational management scenario (B) and the asymmetric scenario (A), increased by 120% and 43%, respectively, compared to the ABC scenario. Increasing the length of the separating walls can be a suitable option to control the dimensions of the scour hole in different operations. Owing to a 20% increase in the length of the separator walls, the maximum scour depth decreased by 68% in the maximum Froude number (8. 6) and 122% in the minimum Froude number (4. 5) in scenario B. These percentages for scenario A are equal to 17 and 58, respectively. In addition, relations were presented to estimate the dimensions of scour hole in the symmetrical and asymmetrical operation of the parallel gates.

The purpose of this study was to determine the yield potential of winter wheat (Triticum aestivum) in Isfahan province and the appropriate cultivation date in different regions of the province using the CSM-CERES-Wheat plant model. For this purpose, 63 main areas of wheat cultivation were selected and their soil information was entered into the model. The model was run using meteorological data for 63 soil profiles, 18 different planting dates and 15 common wheat cultivars in the province with agronomic management without water and nitrogen stress. Average biomass production potential in the study area was 26392. 47±,780. 99 kg ha-1, grain yield 11914. 17±, 442. 62 kg ha-1, water productivity (WP) 1. 73±, 0. 11 kg m-3 and irrigation water efficiency (WPi) was 2. 49±, 0. 30 kg m-3. WP of the eastern regions of Zayandehrud basin (Varzaneh, Kabutarabad and lenjanat) was 12. 82% higher than the western regions (Fereydunshahr, Fereydan and Chadegan) and WPi for the western regions was 16. 30% higher than the eastern regions. In western and northwestern regions of the province, the production portion of green water is 38. 31% and in eastern regions of the province is 18. 86%. therefore, it is recommended to use the capacity of green water under any conditions in the western and northwest regions in addition to planting on suitable dates. Planting dates varied for different regions depending on whether the goal was to maximize the yield or water productivity index. Suitable planting date was obtained as following: for Fereydan, Fereydunshahr and Chadegan regions 26 September to 15 October, Khansar and Tiran 26 September to 25 October, Golpayegan 5 October to 5 November, Lenjanat, Najafabad, Kabutarabad and Varzaneh 15 October to 25 November.

In this research, 11 extreme climatic indicators out of 27 indices defined by the ETCCDI task team have been studied. The capability of the CMIP6 model in the simulation of selected historical climatic extreme indices has been evaluated. The observation and future periods are considered to be 1989-2014 and the three 25-year periods of 2026-2050, 2051-2075, and 2076-2100, respectively. Three Earth System Models (ESM) including ACCESSCM2, MIROC6, and MRI-ESM2-0 were evaluated for this study. CMHyd and Rclimdex software are used for downscaling and estimating the daily mean and extremes of precipitation and temperature under three SSP scenarios of SSP1-2. 6, SSP2-4. 5, and SSP5-8. 5. The results showed that among the three ESM models, the ACCESS-CM2 model has a better capability when compared to other models in simulating historical extremes of precipitation and temperature, so, it was selected as the appropriate model for future projection. The results showed that, in all SSP scenarios and over three near, mid, and far futures periods, the cold night index (TN10p) has decreasing trend and the warm nights (TN90p) percentage has a significant increasing trend at 95% confidence level. The number of summer days (SU25) has an increasing trend in all SSP scenarios in the near future at a 90% confidence level. It has also increasing trend in mid future under SSP2-4. 5 and SSP5-8. 5 and far future in SSP1-2. 6. Awareness of the future perspective of extreme rainfall indices due to their impact on soil erosion can be used in soil management planning and also Information on rainfall and temperature extreme events can be used in water resources management planning.

Evaluation as one of the basic steps of integrated management of water resources is one of the most important stages of its planning and implementation. In this regard, the water accounting system as a tool for organizing and combining data collected from different sources in order to compile an information system and provide the possibility of integrated assessment of water resource systems through the link between physical data and Economic is introduced. The area in question is the study area of the middle Karun basin. The economicenvironmental accounting framework for water, after compiling water accounts related to the region, corresponding to the agricultural year 2012-2013, The status of water resources was analyzed by extracting indicators. Then, in order to simulate and observe the effects of different scenarios of the cultivation pattern, the studied water system, including all harvests and inputs to Karun, was modeled with the help of WEAP simulator in the period of 1335-93. With the help of water accounting tables and the calculation of indicators such as value-added productivity, economic efficiency of water in the region, etc., the results showed that the agricultural sector, with the amount of 7461 million cubic meters, has allocated the largest amount of water consumption, so that among the products Agriculture of sugarcane and corn plants have the highest and lowest amount of water consumption with 6545 and 10 million cubic meters, respectively. Drinking and service sector with 232 million cubic meters and industry and mining with 85 million cubic meters in terms of water consumption, respectively They are in second and third place. Based on the results obtained from the model of changing the cultivation pattern (50% reduction of sugarcane plant and replacing it with sugar beet plant) and 10% and 20% reduction of environmental nodes will improve the water resources system of the region.

Ponds are large storage pools that arises from the excavation of an area, embankment and its consolidation by creating walls and fences. Ponds have multiple uses, in addition to storing agricultural water, they are also used for bird hunting and fishing, etc. Therefore, due to the importance of ponds, the overall purpose of this research was investigating the legal (property rights) and the operating system of ponds of Guilan province from the perspective of exploiting farmers. This is an applied, descriptive-survey and mixed quantitative-qualitative of concurrent-triangulation mixed methods design. The statistical population of the study is the villagers exploiting the ponds of Soomehsara, Fooman and Shaft cities located in the west of Gilan province, which were selected completely randomly. Research data collection was done through library and field study. The researcher-made questionnaire was the main tool for collecting information required for this research, the validity of which was performed by ten university professors and experts, the reliability was confirmed with a value of 0. 83. The result showed that in the opinion of farmers exploiting the ponds, ineffective in developing the area under rice cultivation, increasing the annual income from other occupations (non-rice cultivation), and developing sub-jobs. In supplying rice water, participation in water distribution, job creation and annual income of rice cultivation, farmers' satisfaction with the main and secondary jobs, improving the economic and social situation of farmers have an effect and the relationship between this variables are significant. It was also found that the relationship between the attitudes of exploitative farmers and the variables related to the the legal system and operation governing ponds (how to distribute water, satisfaction with how to distribute other by-products of ponds, satisfaction The protection of the ponds and the government's policies for the survival of the ponds) are significant and positive.

In this study the possibility of using fuzzy inference system efficiency, creating a bridge between meteorological, plant parameters, and Daily Yield, and comparing the accuracy of Daily Yield using these systems were investigated. After analyzing the different models and different combinations of daily meteorological data, seven models for estimating daily Yield were presented. For these models, the calculated Yield from AQUACROP model was considered as a base and the efficiency of other models was evluated using statistical methods such as root mean squared error, error of the mean deviation, coefficient of determination, Jacovides (t) and Sabbagh et al. (R2/t) criteria. An experiment was carried out during the 2014-2015 growing season in the Agricultural Research and Education Center of Khorasane Razavi province using a randomized complete block design with a split plot arrangement and four replications. This experiment was including of three irrigation levels treatments as the main plot and three method of planting treatments (transplanting 20-days, transplanting 30-days and direct seeded) as subplots. From the available data, 75 percent was used for training the model and the rest of 25 percent was utilized for the testing purposes. The results derived from the fuzzy models with different input parameters as compared with AQUACROP model showed that fuzzy systems were very well able to estimate the daily Yield. Fuzzy model so that the highest correlation with the 9 input variables (r=0. 98) had in mind and evaluate other parameters, the model with 2 parameters, match very well with the AQUACROP model had stage training. In the test phase, training phase was very similar results and the model with the second phase of harvest index and canopy cover will get the best match. According to the results of this study it can be concluded that fuzzy model approach is an appropriate method to estimate the daily yield.

Drought events in dry and semi dry climates are of great importance due to the extensive and costly effects they have on various economic and environmental sectors. In recent years, the effects of this natural phenomenon have been very evident, especially on rainfed crops. In this study, the effects of drought on two strategic rainfed crops of Iran (wheat and barley) were evaluated. Since the agricultural sector is vulnerable to climate change, it is very important to identify the most appropriate tools to monitor the impact of climate on the productivity of agricultural products. Therefore, evaluating the effects of drought indicators is the most effective tool. Various drought indicators have been used to evaluate the impact of drought on rainfed wheat and barley yields across diferent climates of Iran, which include,Standard Precipitation Index (SPI), Standard Precipitation Evaporation and Transpiration Index (SPEI), Standard Soil Moisture Index of the upper two layers (SSI1 and SSI2), Standard Multivariate Drought Index including,MSDI1 was based on precipitation and reference evapotranspiration (P&ETref), MSDI2 was based on precipitation and soil moisture in the first soil layer (P&SM1), and MSDI3 was based on precipitation and soil moisture in the second soil layer (P&SM2). Two sets of crop performance data at different spatial scales and time periods were used in the analysis. The results showed that the drought indices calculated in different time scales of SPI and SPEI had the highest correlation with rainfed wheat and barley yields in semi dry (0. 7 and 0. 77), dry (0. 68 and 0. 64), very dry (0. 63 and 0. 61) and humid (0. 64 and 0. 52) climates, respectively. Also, the results showed that different patterns of response of crops to drought occur depending on the climate type, the period of the year and the time scale of the drought. The different responses across the country were related to the season and the values of different climate variables.

Drought and salinity stresses are among the main challenges in the agricultural sector, especially in arid and semi-arid regions. Safflower is one of the oilseed and industrial plant that its cultivation can provide part of the country's need for oilseed crops. In this study, in order to investigate the interaction effect of salinity and drought stresses on safflower (cv Goldasht), a factorial experiment was conducted in 2020 as a completely randomized design with three replications in the greenhouse of Pistachio Research Station of Ardakan city located in Yazd province. The irrigation treatments were applied as 5 (I1), 10 (I2) and 15 (I3) days of irrigation interval and salinity levels of irrigation water were included 0. 7 (S1), 4 (S2), 7 (S3) and 10 (S4) dS/m. At the end of the growth period, safflower traits such as grain yield, 1000-seed weight, shoot dry weight, harvest index, water productivity, leaf area, evapotranspiration, electrolyte leakage and SPAD index were measured. Results showed that the main effect of the salinity levels of the irrigation water and irrigation intervals were significant on all traits. Also, the interaction effects of salinity and irrigation interval were significant on all traits except leaf area and electrolyte leakage at one percent level. By increasing irrigation water salinity and lengthening of irrigation interval, all traits decreased except electrolyte leakage percentage. In the highest salinity level (S4) compared to the control treatment (S1), the average of evapotranspiration during the stress period and grain yield decreased by 32 and 84. 7 percent, respectively. Increasing irrigation interval up to 15 days reduced evapotranspiration during the stress period and grain yield by 38 and 86. 4 percent compared to 5 days irrigation interval, respectively. The coefficient of readily available water for safflower grain yield was obtained 0. 45. The salinity threshold of the soil solution for reducing safflower grain yield was obtained about 3. 4 dS/m and the slope for decreasing grain yield was 5. 8% per unit increase in salinity.

Nowadays, production of economic production is one of the most important of policymaker’, s attentions. Address to this. It is necessary to merge the farmer’, s aims along policy makers as well as their necessities. Therefore, the current study attempted to investigate on optimum cropping pattern of agricultural crops in Kurdistan province respect to each county emphasizing on minimize virtual water. To follow research aim the necessary data were collected for the agricultural year 2019-20 using goal programming. The results showed that, the current cropping pattern does not has no comparative advantage and it has to experience significant change. In other words, the current cropping pattern willing must to change from mixed form to specialized one according to comparative advantage according to resource possibilities of each district. The range of change showed that, there are significant decrease and increase in some crops compare to current situation. The results showed that, irrigated wheat did not get permission to enter optimum model. In addition, the most of current crop due to low return as well as disadvantage of study area omitted in recommended pattern.

Water scarcity is a major limiting factor for agriculture in all arid and semi-arid regions of the world. Identification of various genotypes to produce drought-tolerant cultivars requires an assessment of their sugar yield under deficit irrigation conditions. Implementation of irrigation system and an appropriate level of water stress are therefore absolutely necessary in assessing genotypes for drought tolerance. For this purpose, four genotypes under eight irrigation treatments in a split plot design based on a Randomized Complete Block with four replications during the years 1387 and 1388 the Research and Education Center for Agriculture and Natural Resources Hamadan were evaluated. Eight irrigation treatments consisted of three treatments of furrow irrigation after 80, 130 and 180 mm, two treatments of tape irrigation, including irrigation after 30 mm with 100%and irrigation after 30 mm with 50% supply of water requirement of sugar beet and three tape irrigation treatments including 80, 130 and 180 mm cumulative evaporation from the evaporation pan in main plots and four genotypes in sub plots. The results showed that the interaction between genotypes and irrigation for the drought susceptibility index (DSI) was significant at 5% probability level. Reduced sugar yield of sugar beet genotypes caused by reduction of the amount of water (30mm tape irrigation with 50% of supply of water requirement) was more severe than the different irrigation intervals. Furrow irrigation is not an efficient and effective method of evaluating drought tolerance of sugar beet genotypes. Therefore, in order to evaluate drought tolerance of genotypes in breeding programs and produce drought-tolerant genotypes, tape irrigation method after 30 mm cumulative evaporation with supplying 50% of the plant water requirement, is introduced and recommended as an appropriate method and drought stress level.