scholarly journals Evapotranspiration estimation at the Kis-Balaton wetland

Időjárás ◽  
2021 ◽  
Vol 125 (3) ◽  
pp. 419-430
Author(s):  
Angela Anda ◽  
László Menyhárt ◽  
Brigitta Simon
Keyword(s):  
Water Resource Management ◽  
Reference Evapotranspiration ◽  
Open Water ◽  
Common Reed ◽  
Natural Ecosystem ◽  
Vegetation Composition ◽  
Time Period ◽  
Evapotranspiration Rate ◽  
Evapotranspiration Estimation ◽  
Crop Coefficients

Evapotranspiration rate, ETaand vegetation composition strongly influence the water budget of wetland impacting available water and water resource management. One of the goals of this study was to estimate the areal ETa of the Kis-Balaton wetland, KBW (natural ecosystem) between 1997 and 2012. This time period was free of any human intervention. ETa was accounted for different vegetation classes through the multiplication of the reference evapotranspiration, ET0 by previously determined crop coefficients in each vegetation/open water classes. Besides common reed and cattail, five other groups were separated, including open water as an independent class. The evapotranspiration sums were strongly impacted by annual mean air temperature, Ta. One degree increment in annual average Ta will increase the yearly ETa sums in about 100 mm. The yearly areal ETaof KBW ranged from 737.08 mm to 896.63 mm with an average of 802.07 mm during the 16-year study.

scholarly journals Irrigation scheduling strategies for pepper based on evaporation and reference evapotranspiration

2021 ◽  
Vol 26 (51) ◽  
pp. 69-76
Author(s):  
Borivoj Pejić ◽  
Ivana Bajić ◽  
Ksenija Mačkić ◽  
Dušanka Bugarski ◽  
Slobodan Vlajić ◽  
...  
Keyword(s):  
Reference Evapotranspiration ◽  
Soil Layer ◽  
Open Water ◽  
Irrigation Scheduling ◽  
Climatic Conditions ◽  
Vegetable Crops ◽  
Irrigation Water Use ◽  
Evapotranspiration Rate ◽  
Crop Coefficients ◽  
Novi Sad

The experiment with drip irrigated pepper was conducted at the Rimski Šančevi experimental field of the Institute of Field and Vegetable Crops in Novi Sad in 2019. The irrigation was scheduled on the basis of the water balance method. Two methods were used to compute the daily evapotranspiration of pepper (ETd): reference evapotranspiration (ETo) and evaporation from an open water surface (Eo). Crop coefficients (kc) and corrective coefficients (k) were used to convert ETo and Eo values into ETd. Kc and k were 0.3-0.4, 0.6-0.7, 0.9-1.1, 0.8-0.9 and 0.4, 0.7, 1.0 and 0.8 for initial stage, crop development, mid season, and late season, respectively. ETo was calculated by the Hargreaves equation. Eo values were measured by a Class-A pan located at a meteorological station near the experimental plot. Irrigation started when readily available water (RAW) in the 0.3 m soil layer was completely absorbed by plants. Differences in crop yield (Y) and irrigation water use efficiency (IWUE) obtained using Eo (42.58 t ha-1, 15.20 kg m-3) and ETo (40.78 t ha-1, 14.56 kg m-3) were not statistically different. Evapotranspiration rate was 364.2 mm and 337.3 mm in Eo and ETo variant, respectively. The fact that the differences in Y and IWUE between different calculations of ETd were not statistically significant indicates that both methods can be recommended for irrigation scheduling programs for pepper in the climatic conditions of the Vojvodina region. However, priority should be given to ETo due to the easy accessibility and reliability of data.

scholarly journals Reference evapotranspiration estimation by different methods for the sucroenergy sector of Colombia

2021 ◽  
Vol 25 (9) ◽  
pp. 583-590
Author(s):  
Christian J. Mendoza C. ◽  
Andrés J. Peña Q.
Keyword(s):  
Water Resource Management ◽  
Mean Squared Error ◽  
Reference Evapotranspiration ◽  
Important Variable ◽  
Minimum Requirement ◽  
Class A ◽  
Relative Air Humidity ◽  
Historical Series ◽  
Evapotranspiration Estimation ◽  
Class A Pan

ABSTRACT In the Colombian Sugarcane Research Center CENICAÑA, efficient use of water is always performed based on estimating reference evapotranspiration. In this method, class A pans have been used to estimate the reference evapotranspiration, which provides a more precise estimate of this important variable for water resource management. The objective of this study was to evaluate different reference evapotranspiration methods for the region of influence of the climatological station of the CENICAÑA experimental station. The class A pan method traditionally used in CENICAÑA was compared with and the Penman-Monteith FAO 56 standard method. The historical series used was from January 1, 1994, to December 31, 2014. The climatic variables were the maximum, mean, and minimum temperatures, the mean relative air humidity, solar radiation, and wind speed at 10 m. Willmott’s coefficients, the confidence index (c), and the root mean squared error were used in the performance evaluation. In the comparison with the Penman-Monteith FAO 56 method, all methods presented performance below the minimum requirement of (c) = 0.400. When all methods were compared with the method used in CENICAÑA (Class A pan), only the Penman-Monteith FAO 56 method showed performance classified as good (c = 0.689).

Annual Evapotranspiration and Crop Coefficients of Ligustrum japonica Growing in Three Container Sizes

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 512c-512
Author(s):  
R.C. Beeson
Keyword(s):  
Reference Evapotranspiration ◽  
Actual Evapotranspiration ◽  
Rooted Cuttings ◽  
Supplemental Irrigation ◽  
Mean Size ◽  
Crop Coefficients ◽  
Marketable Size

The objective of this study was to determine crop coefficients (KC) for Ligustrum japonica growing in three container sizes using the Penman equation to calculate reference evapotranspiration (ETR). Rooted cuttings were transplanted into 3-liter containers and upcanned as needed into 10- and 23-L containers. Production was scheduled such that a series of plants in each container size were about 2 months from commercial marketable size every 4 months. Beginning 1 Jan. 1995 until 31 Dec. 1996, three uniform plants of each size were suspended in weighing lysimeters and surrounded by similar size plants filling an area 3.7 by 4.9 m. Plants within each area were overhead irrigated at 2000 h as needed, based on a 30% moisture allowed deficit. Plants were exchanged every 4 months such that the annual mean size was that of a marketable plant. Actual evapotranspiration (ETA) was calculated from half-hour measurements of each plant's weight and adjusted for rainfall. From these and daily calculated ETR, KC were determined for each size of container. KCs ranged from 1.06 to 1.50 when ETA was converted to mm/day based on allocated bed space. Comparisons of volumes of supplemental irrigation to ETA and effects of assumptions required in converting ETA to mm/day will be discussed.

scholarly journals The Water Needs of Grapevines in Central Poland

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 416
Author(s):  
Barbara Jagosz ◽  
Stanisław Rolbiecki ◽  
Roman Rolbiecki ◽  
Ariel Łangowski ◽  
Hicran A. Sadan ◽  
...  
Keyword(s):  
Climate Change ◽  
Temporal Variability ◽  
Time Trend ◽  
Reference Evapotranspiration ◽  
Growing Season ◽  
Water Requirements ◽  
Climate Conditions ◽  
Central Poland ◽  
Crop Coefficients ◽  
Near Future

Climate warming increases the water needs of plants. The aim of this study was to estimate the water needs of grapevines in central Poland. Water needs were calculated using the crop coefficients method. Reference evapotranspiration was assessed by the Blaney–Criddle’s equation, modified for climate conditions in Poland. Crop coefficients were assumed according to the Doorenbos and Pruitt method. Water needs were calculated using the data from four meteorological stations. Rainfall deficit with the probability occurrence of normal years, medium dry years, and very dry years was determined by the Ostromęcki’s method. Water needs of grapevines during the average growing season were estimated at 438 mm. Upward time trend in the water needs both in the period of May–October and June–August was estimated. Temporal variability in the water needs was significant for all of the provinces. These changes were mainly impacted by a significant increasing tendency in mean air temperature and less by precipitation totals that did not show a clear changing tendency. Due to climate change, vineyards will require irrigation in the near future. The use of resource-efficient irrigation requires a precise estimate of the grapevines’ water needs. The study identified the water requirements for grapevines in central Poland.

Improvement of Makkink model for reference evapotranspiration estimation using temperature data in Northwest China

2018 ◽  
Vol 566 ◽  
pp. 264-273 ◽  
Author(s):  
Qingwen Zhang ◽  
Ningbo Cui ◽  
Yu Feng ◽  
Daozhi Gong ◽  
Xiaotao Hu
Keyword(s):  
Reference Evapotranspiration ◽  
Northwest China ◽  
Temperature Data ◽  
Evapotranspiration Estimation

scholarly journals Performance of different methods for reference evapotranspiration estimation in Jaíba, Brazil

2018 ◽  
Vol 22 (2) ◽  
pp. 83-89 ◽  
Author(s):  
Gustavo H. da Silva ◽  
Santos H. B. Dias ◽  
Lucas B. Ferreira ◽  
Jannaylton É. O. Santos ◽  
Fernando F. da Cunha
Keyword(s):  
Wind Speed ◽  
Solar Radiation ◽  
Standard Method ◽  
Reference Evapotranspiration ◽  
Meteorological Data ◽  
Air Humidity ◽  
Method Performance ◽  
Relative Air Humidity ◽  
Evapotranspiration Estimation ◽  
Missing Variables

ABSTRACT FAO Penman-Monteith (FO-PM) is considered the standard method for the estimation of reference evapotranspiration (ET0) but requires various meteorological data, which are often not available. The objective of this work was to evaluate the performance of the FAO-PM method with limited meteorological data and other methods as alternatives to estimate ET0 in Jaíba-MG. The study used daily meteorological data from 2007 to 2016 of the National Institute of Meteorology’s station. Daily ET0 values were randomized, and 70% of these were used to determine the calibration parameters of the ET0 for the equations of each method under study. The remaining data were used to test the calibration against the standard method. Performance evaluation was based on Willmott’s index of agreement, confidence coefficient and root-mean-square error. When one meteorological variable was missing, either solar radiation, relative air humidity or wind speed, or in the simultaneous absence of wind speed and relative air humidity, the FAO-PM method showed the best performances and, therefore, was recommended for Jaíba. The FAO-PM method with two missing variables, one of them being solar radiation, showed intermediate performance. Methods that used only air temperature data are not recommended for the region.

Framework for Standardizing Less Data-Intensive Methods of Reference Evapotranspiration Estimation

2018 ◽  
Vol 32 (13) ◽  
pp. 4159-4175 ◽  
Author(s):  
Laishram Kanta Singh ◽  
Madan K. Jha ◽  
Mohita Pandey
Keyword(s):  
Reference Evapotranspiration ◽  
Data Intensive ◽  
Evapotranspiration Estimation
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