evapotranspiration estimation Articles
-
Analysis of potential evapotranspiration using 11 modified temperature–based models
The evapotranspiration was estimated using 11 temperature–based models and was compared with the FAO Penman–Monteith model. The results showed that the modified Hargreaves–Samani models estimate the evapotranspiration better than the other models in the most provinces of Iran. However, the values of R² were less than 0.98 for 15 provinces of Iran. Therefore, the models were calibrated and ...
-
Estimating evapotranspiration using the complementary relationship and the Budyko framework
Several models have been developed to estimate evapotranspiration. Among those, the complementary relationship has been the subject of many recent studies because it relies on meteorological data only. Recently, the modified Granger and Gray (GG) model showed its applicability across 34 diverse global sites. While the modified GG model showed better performances compared to the recently ...
-
Measurement and modelling of the water requirement of some greenhouse crops with artificial neural networks and genetic algorithm
Crop evapotranspiration is the most important parameter for management of irrigation systems in greenhouses. This study was conducted to determine the evapotranspiration of cucumber, tomato and peppers, using micro–lysimeter during seven months in a greenhouse located in central region of Iran. Reference evapotranspiration estimated using drainage lysimeters and the water balance of soil ...
-
Modelling seasonal evapotranspiration of arid lands in China
The measurement of actual evapotranspiration, a key term in the water balance equation, has become a very important issue. Many good methods exist for estimating actual evapotranspiration; however, most of these require complicated inputs. Here, a simple but robust model for estimation of actual evapotranspiration in arid areas of western China is proposed. This model is a visual system with a ...
-
Calibration of the Hargreaves–Samani method for the calculation of reference evapotranspiration in different Köppen climate classes
The Penman–Monteith equation (FAO-56) is accepted as the standard model for estimating reference evapotranspiration (ETo). However, the major obstacle to using FAO-56 widely is that it requires numerous climatic data. The Hargreaves–Samani (HS) method is frequently used for the calculation of ETo since it is based on measurements of daily minimum and maximum air temperature alone. Those are ...
-
Assessing the sensitivity of SWAT physical parameters to potential evapotranspiration estimation methods over a coastal plain watershed in the southeastern United States
One of the key inputs of a hydrologic budget is the potential evapotranspiration (PET), which represents the hypothetical upper limit to evapotranspirative water losses. However, different mathematical formulas proposed for defining PET often produce inconsistent results and challenge hydrological estimation. The objective of this study is to investigate the effects of the Priestley–Taylor ...
-
Actual daily evapotranspiration and crop coefficients for an alpine meadow in the Qilian Mountains, northwest China
Actual daily evapotranspiration (ETa) was measured in two weighing micro-lysimeters, from 1 July 2009 to 30 June 2011 on an alpine meadow in the Qilian Mountains, northwest China. The findings showed that the mean daily ETa in the unfrozen and frozen periods was 2.0 mm and 0.2 mm, respectively. The dominant factor affecting ETa in the unfrozen period was net radiation (RN), whereas those in ...
-
Prediction of daily crop reference evapotranspiration (ET0) values through a least-squares support vector machine model
Real-time prediction of daily reference crop evapotranspiration (ET0) is the basis for estimating crop evapotranspiration and for computing crop irrigation requirements. In recent years, least-squares support vector machines (LSSVMs) have been applied for forecasting in many fields of engineering. In this paper, LSSVMs are applied to forecast ET0 using public weather forecasting data (minimum and ...
-
Evaluation of the FAO Penman–Montheith, Priestley–Taylor and Hargreaves models for estimating reference evapotranspiration in southern Malawi
This study evaluated the performance of the Food and Agriculture Organization (FAO) Penman–Monteith (PM) reference evapotranspiration (ET0) method for various limited data scenarios in southern Malawi. The study further evaluated the full data PM method against the radiation-based Priestley–Taylor (PT) and the temperature-based Hargreaves (HAG) methods, which are less ...
-
Integrating genetic algorithm and support vector machine for modeling daily reference evapotranspiration in a semi-arid mountain area
Accurate estimation of evapotranspiration is vitally important for management of water resources and environmental protection. This study investigated the accuracy of integrating genetic algorithm and support vector machine (GA-SVM) models using climatic variables for simulating daily reference evapotranspiration (ET0). The developed GA-SVM models were tested using the ET0 calculated by ...
-
Estimation of maize evapotranspiration using extreme learning machine and generalized regression neural network on the China Loess Plateau
Accurately estimating crop evapotranspiration (ET) is essential for agricultural water management in arid and semiarid croplands. This study developed extreme learning machine (ELM) and generalized regression neural network (GRNN) models for maize ET estimation on the China Loess Plateau. Maize ET, meteorological variables, leaf area index (LAI), and plant height (hc) were continuously ...
-
White wheat grain quality changes with genotype, nitrogen fertilization, and water stress
The production of hard white winter (HWW) wheats (Triticum aestivum L.) with acceptable protein content and quality over different environments requires the correct combination of genotypes and management practices. The objectives of this study were to evaluate moisture deficit and N management on grain protein and quality of seven HWW and two soft white winter (SWW) genotypes, and to identify ...
-
Remote sensing estimation of actual evapotranspiration and crop coefficients for a multiple land use arid landscape of southern Iran with limited available data
The Gareh Bygone Plain is an arid area, south of Zagros Mountains, in Southern Iran, where a floodwater spreading project has been implemented for artificial recharge of groundwater. Knowledge/mapping of actual evapotranspiration for the mainland uses (natural pasture, irrigated crops and tree plantations) is of major importance for water management in this remote area. The Surface Energy ...
-
Intake and digestibility of ‘Coastal’ bermudagrass hay from treated swine waste using subsurface drip irrigation
Waste handling systems for confined swine production in the upper South (approximately 32–37° N and 79–93° W) depend mainly on anaerobic lagoons and application of the waste effluent to cropland. The main objective of this study was to evaluate the quality of ‘Coastal’ bermudagrass [Cynodon dactylon (L.) Pers.] hay receiving effluent generated from a raw swine waste treatment system designed to ...
-
Evaluation of different data management scenarios for estimating daily reference evapotranspiration
Temperature and solar radiation-based modeling procedures are reported in this study for estimating daily reference evapotranspiration (ET0) by using gene expression programming (GEP) and adaptive neuro-fuzzy inference system (ANFIS). A comparison is also made among these techniques and the corresponding traditional temperature/radiation-based ET0 estimation equations. Two data management ...
-
Modifying Hargreaves–Samani equation with meteorological variables for estimation of reference evapotranspiration in Turkey
The Food and Agriculture Organization advocates the Penman–Monteith (FAO-56 PM) equation as the standard model for estimation of the reference evapotranspiration (ET0) because it is considered to have better accuracy. However, in regions where meteorological variables such as solar radiation, wind speed, and relative humidity are not gauged, the Hargreaves–Samani (HS) equation is resorted to ...
-
Comparison of three data-driven techniques in modelling the evapotranspiration process
Evapotranspiration is one of the main components of the hydrological cycle as it accounts for more than two-thirds of the precipitation losses at the global scale. Reliable estimates of actual evapotranspiration are crucial for effective watershed modelling and water resource management, yet direct measurements of the evapotranspiration losses are difficult and expensive. This research explores ...
-
Potential evapotranspiration change and its attribution in the Qinling Mountains and surrounding area, China, during 1960–2012
Based on the observational data of 47 meteorological stations in the northern and southern regions of the Qinling Mountains (NSQ) during 1960–2012, this paper estimated the potential evapotranspiration (ET0) by using the Penman–Monteith method. Further, a quantitative study was conducted of the ET0 spatial distribution pattern, temporal variation rules, influencing factors and attributions. ...
-
Satellite-based estimation of actual evapotranspiration in the Buyuk Menderes Basin, Turkey
Evapotranspiration (ET) is one of the most important components of the hydrological cycle, but it is often the most difficult variable to determine at basin scale. Traditionally, ET is estimated using point-based measurements collected at meteorological stations, but the non-spatial nature of these measurements often leads to significant errors when utilized at watershed scale. In this study, ...
-
Late Spring Almond Irrigation
Late spring (late April to early June) is an important time in almond orchard development. During this time, the almond embryo is developing into a mature kernel. At this point in the season, proper irrigation management can be a major contributor to the difference between a marginal and major improvement in crop yield and quality. Development is complete when the kernel fills the shell ...
Need help finding the right suppliers? Try XPRT Sourcing. Let the XPRTs do the work for you