Journal articles on the topic 'Evapotranspiration'
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Nakamichi, Takeshi, and Toshitsugu Moroizumi. "Applicability of three complementary relationship models for estimating actual evapotranspiration in urban area." Journal of Hydrology and Hydromechanics 63, no. 2 (June 1, 2015): 117–23. http://dx.doi.org/10.1515/johh-2015-0011.
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Abstract The characteristics of evapotranspiration estimated by the complementary relationship actual evapotranspiration (CRAE), the advection-aridity (AA), and the modified advection-aridity (MAA) models were investigated in six pairs of rural and urban areas of Japan in order to evaluate the applicability of the three models the urban area. The main results are as follows: 1) The MAA model could apply to estimating the actual evapotranspiration in the urban area. 2) The actual evapotranspirations estimated by the three models were much less in the urban area than in the rural. 3) The difference among the estimated values of evapotranspiration in the urban areas was significant, depending on each model, while the difference among the values in the rural areas was relatively small. 4) All three models underestimated the actual evapotranspiration in the urban areas from humid surfaces where water and green spaces exist. 5) Each model could take the effect of urbanization into account.
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Karishma, C. G., Balaji Kannan, K. Nagarajan, S. Panneerselvam, and S. Pazhanivelan. "Spatial and temporal estimation of actual evapotranspiration of lower Bhavani basin, Tamil Nadu using Surface Energy Balance Algorithm for Land Model." Journal of Applied and Natural Science 14, no. 2 (June 18, 2022): 566–74. http://dx.doi.org/10.31018/jans.v14i2.3412.
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Estimating evapotranspiration's spatiotemporal variance is critical for regional water resource management and allocation, including irrigation scheduling, drought monitoring, and forecasting. The Surface Energy Balance Algorithm for Land (SEBAL) method can be used to estimate spatio-temporal variations in evapotranspiration (ET) using remote sensing-based variables like Land Surface Temperature (LST), Normalized Difference Vegetation Index (NDVI), surface albedo, transmittance, and surface emissivity. The main aim of the study was to evaluate the actual evapotranspiration for the lower Bhavani basin, Tamil Nadu based on remote sensing methods using Landsat 8 data for the years 2018 to 2020. The actual evapotranspiration was estimated using SEBAL model and its spatial variation was compared over different land covers. The estimated values of daily actual evapotranspiration in the lower Bhavani basin ranged from 0 to 4.72 mm day-1. Thus it is evident that SEBAL model can be used to predict ET with limited ground base hydrological data. The spatially estimated ET values will help in managing the crop water requirement at each stage of crop and irrigation scheduling, which will ensure the efficient use of available water resources.
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Fadipe, O. B., G. C. Ufoegune, O. A. Ogidan, A. A. Ekaun, and D. A. Adenuga. "Evaluation and Mapping of Evapotranspiration in Forest-Savanna Transition Zone of Ogun State, South-Western Nigeria." Journal of Applied Sciences and Environmental Management 27, no. 8 (September 3, 2023): 1771–77. http://dx.doi.org/10.4314/jasem.v27i8.22.
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Evapotranspiration's impact on crop production, determined by water consumption in plants, varies across locations due to surface and climate differences. Traditional ground-based methods for measurement fall short in capturing these variations. In order to address this, the study evaluated and mapped the evapotranspiration in the forest-savanna transition zone of Ogun State, South-western Nigeria using a geo-informatics approach. Over six years, 12 Landsat images were collected, representing dry and wet seasons. These images were used to estimate the Normalized Difference Vegetative Index (NDVI), indicating vegetation density, and compute evapotranspiration values across the area. During the dry season, NDVI ranged from -0.326 to 0.376, and during the wet season, it ranged from -0.435 to 0.780, showing higher vegetation cover in the wet season. Evapotranspiration values varied across different regions. In Abeokuta South, Abeokuta North, and Odeda Local Government Areas, values ranged from 2.83 to 6.37 mm/day, 0.12 to 2.64 mm/day, and 3.12 to 5.44 mm/day, respectively, influenced by varying vegetation characteristics. The geo-informatics approach offered a realistic representation and spatial understanding of evapotranspiration, proving cost-effective and accessible. In conclusion, the study recommends the geo-informatics approach for evapotranspiration measurement due to its ability to consider spatial characteristics. This understanding is essential for effective water resource management and crop planning in the Forest-Savanna transition zone of Nigeria.
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Wang, Manqi. "Evaluating long-term potential evapotranspiration and soil moisture dynamics at Shanghai City China." E3S Web of Conferences 228 (2021): 02004. http://dx.doi.org/10.1051/e3sconf/202122802004.
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As the finical hub of China, the Shanghai metropolitan area is one of the most important regions on earth, which requires significant efforts in water, energy and resources management and supply. Ongoing dynamic changes in climate have posed large uncertainties in our ability to better quantify, estimate and predict future hydrological and ecological responses, including soil moisture dynamics and potential evapotranspirative demands. Given these significant implications, in this study, we focused on better understanding long-term dynamic trends in soil moisture and potential evapotranspiration at Shanghai with the Hargreaves equation and 1-Dimensional flow transport with Richard’s equation. We further tested how perturbations in temperature and precipitation patterns influence soil moisture and potential evapotranspiration responses. Our results suggested significant correlation between temperature and potential evapotranspiration as well as precipitation inputs and soil moisture. We believe these results can provide useful insights to help us better understand the hydrological responses at Shanghai to climate change.
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Marganingrum, Dyah, and Heru Santoso. "Evapotranspiration of Indonesia Tropical Area." Jurnal Presipitasi : Media Komunikasi dan Pengembangan Teknik Lingkungan 16, no. 3 (September 20, 2019): 106–16. http://dx.doi.org/10.14710/presipitasi.v16i3.106-116.
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Indonesia is an archipelago country with a tropical climate. The region of Indonesia is quite large and located between two continents (Asia and Australia) and between two oceans (Indian and Pacific), making the territory of Indonesia has a unique climate pattern. One of the climate variables that quite important to be studied in this chapter is evapotranspiration. The Thornthwaite method was used to estimate potential evapotranspiration based on average air temperature. The relationships between evapotranspiration, precipitation, and elevation were then examined. Besides, temperature variations that affect climate patterns between monsoonal and equatorial regions were compared, between the mainland and small islands, and between mountain and coastal area. The impact of global warming was also examined on the climate and potential evapotranspiration of the Indonesian region. Data analysis showed that evapotranspiration correlates weakly with precipitation, and the contrary, the evapotranspiration correlates strongly with elevation, with correlation indices of 0.02 and 0.89, respectively. The study confirmed that air temperature is the primary controlling variable of the evapotranspiration in this very heterogeneous landscape. Under a global temperature increase of 1.5 °C above the pre-industrialized year (1765), the evapotranspiration is expected to increase in a range from 4.8 to 11.1%. In general, the excess of water to restore soil moisture in the future tends to decrease, i.e., drier.
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Hattendorf, M. J., and J. R. Davenport. "Cranberry Evapotranspiration." HortScience 31, no. 3 (June 1996): 334–37. http://dx.doi.org/10.21273/hortsci.31.3.334.
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Cranberry (Vaccinium macrocarpon Ait.) evapotranspiration (ET) has not been documented. Micrometeorological techniques based on canopy temperature minus air temperature were used to estimate ET on `Stevens' and `Crowley' cranberry at Long Beach (lat. ≈46°20′N, long. 124°W) and Grayland (lat. ≈46°47′N, long. 124°W), Wash., in 1991 and 1992, respectively. Cranberry ET was 55% of Priestley–Taylor reference ET and ranged from <0.5 to >4 mm·d–1. The Priestley–Taylor reference ET was a very good predictor of cranberry ET (r2 = 0.795). Running 7-day cumulative ET ranged from 7 to 17 mm·week–1.
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Anderson, Ray, and Andrew French. "Crop Evapotranspiration." Agronomy 9, no. 10 (October 5, 2019): 614. http://dx.doi.org/10.3390/agronomy9100614.
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Evapotranspiration (ET) is one of the largest components of the water cycle, and accurately measuring and modeling ET is critical for improving and optimizing agricultural water management. However, parameterizing ET in croplands can be challenging due to the wide variety of irrigation strategies and techniques, crop varieties, and management approaches that employ traditional tabular ET and make crop coefficient approaches obsolete. This special issue of Agronomy highlights nine approaches to improve the measurement and modeling of ET across a range of spatial and temporal resolutions and differing environments that address some of the challenges encountered.
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Huang, Bingru, and Jack D. Fry. "Turfgrass Evapotranspiration." Journal of Crop Production 2, no. 2 (September 10, 2000): 317–33. http://dx.doi.org/10.1300/j144v02n02_14.
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Zhang, Baozhong, He Chen, Di Xu, and Fusheng Li. "Methods to estimate daily evapotranspiration from hourly evapotranspiration." Biosystems Engineering 153 (January 2017): 129–39. http://dx.doi.org/10.1016/j.biosystemseng.2016.11.008.
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Malek, Esmaiel. "Night-time evapotranspiration vs. daytime and 24h evapotranspiration." Journal of Hydrology 138, no. 1-2 (September 1992): 119–29. http://dx.doi.org/10.1016/0022-1694(92)90159-s.
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Chiew, Francis H. S., and Christopher P. Leahy. "Comparison of evapotranspiration variables in Evapotranspiration Maps for Australia with commonly used evapotranspiration variables." Australasian Journal of Water Resources 7, no. 1 (January 2003): 1–11. http://dx.doi.org/10.1080/13241583.2003.11465223.
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Mohawesh, O. E. "Evaluation of evapotranspiration models for estimating daily reference evapotranspiration in arid and semiarid environments." Plant, Soil and Environment 57, No. 4 (April 21, 2011): 145–52. http://dx.doi.org/10.17221/240/2010-pse.
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Daily outputs from eight evapotranspiration models were tested against reference evapotranspiration (ETo) data computed by FAO56PM to assess the accuracy of each model in estimating ETo. Models were compared at eight stations across Jordan. Results show that Hargreaves modified models were the best in light of mean biased error (MBE), root mean square error (RMSE) and mean absolute error (MAE). The MBE, RMSE, and MAE values ranged from –1.47 to 0.81, 3.87 to 1.14 and 0.87 to 3.15 mm/day for HarM1, and from –1.45 to 0.89, 1.08 to 3.91, and 0.85 to 3.16 mm/day for HarM2, respectively, which would make it the best models in light of the MBE, RMSE and MAE ranging from –6.18 to 2.79, 6.90 to 1.08 and 4.74 to 0.85 mm/day for all models and stations. Comparisons were also made using three composite regions: countrywide, semiarid, and arid regions. In conclusion, local calibration is needed for the whole models or the linear regression can be used to calculate the ETo.
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Prashar, Chit R. K., Govind C. Sharma, and Mohamadou Gandah. "Evapotranspiration of Onion in Sahelian Niger." Experimental Agriculture 30, no. 4 (October 1994): 473–76. http://dx.doi.org/10.1017/s001447970002473x.
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SUMMARYIrrigation responses of three locally adapted onion cultivars were studied in drainage type lysimeters and under field conditions on a deep sandy loam soil, free of salinity problems, at Maradi in Niger. Evapotranspiration (Et) was established by the water balance method, and used to establish the rate of water use. The peak rate of water use was 7.5 mm per day during the bulb formation stage. Irrigating onions when the available soil moisture to a depth of 20 cm had been depleted by 40% increased the yield more than irrigation at 60 or 80% depletion. The mean yield from plots receiving frequent irrigation was 33 t ha−1.Evapotranspiratión de la cebolla en el sahel nigeriano
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THORAT, P. G. "A study of agrometeorological parameters for the Kharif maize at Anand (Gujarat)." MAUSAM 53, no. 2 (January 18, 2022): 127–32. http://dx.doi.org/10.54302/mausam.v53i2.1628.
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A study was conducted on the behaviour of evaporation, evapotranspiration and potential evapotranspiration in different phenological phases, during the years 1989, 1990 and 1991 for Kharif Maize crop at Anand (Gujarat). It has been noticed that evapotranspiration and potential evapotranspiration attained maximum values in grain phase. In harvesting phase relative evapotranspiration and crop coefficient had lowest values. The seasonal crop coefficient was obtained 0.84. An attempt has been made in this paper to develop the regression models to estimate potential evapotranspiration and relative evapotranspiration.
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Chiew, FHS, and TA Mcmahon. "An Australian comparison of Penman's potential evapotranspiration estimates and class A evaporation pan data." Soil Research 30, no. 1 (1992): 101. http://dx.doi.org/10.1071/sr9920101.
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Estimates of potential evapotranspiration are required to serve as an aid for estimating actual evapotranspiration. Penman's combination equation is generally accepted as an appropriate method for estimating potential evapotranspiration. However, as all the climatic data required to calculate Penman's potential evapotranspiration are seldom available, potential evapotranspiration is more commonly approximated as a factor times standard evaporation pan reading. In this paper, linear regression equations relating Penman's potential evapotranspiration for land surfaces to Class A evaporation pan data over several time periods are developed for various climatic regions throughout Australia. The analyses indicate that the correlations between daily estimates of Penman's potential evapotranspiration and pan data are poor, and therefore, pan data should be treated with caution if used to approximate daily potential evapotranspiration. The correlations improve over longer time periods, and the equations developed for three-day and weekly totals may be used as a last resort to approximate potential evapotranspiration in areas where climatic data required to calculate potential evapotranspiration are not available.
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RAJEGOWDA, M. B. "ESTIMATION OF EVAPOTRANSPIRATION." MAUSAM 45, no. 3 (January 1, 2022): 278. http://dx.doi.org/10.54302/mausam.v45i3.2497.
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Salahou, Mohamed Khaled, Raphinos Tackmore Murava, and Xiu Ju Zhang. "Reference Evapotranspiration Models." Applied Mechanics and Materials 256-259 (December 2012): 2444–53. http://dx.doi.org/10.4028/www.scientific.net/amm.256-259.2444.
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This paper will examine the concept of evapotranspiration (ET) in more detail and provide more details into the concept of reference evapotranspiration (ETo) and of the measurement and estimation of ETo. Studies of ET models usually involve the comparison of a single model in different climates, different model types in the same location, or model output to either lysimeteric measurements or a local evaporation pan. This paper will examine the performance of ET models versus ET measured using lysimetery or pan evaporation and the performance of ET models when compared to a standard ETo model. A review of the performance of pan evaporation to the standard ETo model will also be performed.
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Rock, Steve, Bill Myers, and Linda Fiedler. "Evapotranspiration (ET) Covers." International Journal of Phytoremediation 14, sup1 (January 2012): 1–25. http://dx.doi.org/10.1080/15226514.2011.609195.
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Duce, P., R. L. Snyder, and D. Spano. "FORECASTING REFERENCE EVAPOTRANSPIRATION." Acta Horticulturae, no. 537 (October 2000): 135–41. http://dx.doi.org/10.17660/actahortic.2000.537.13.
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., M. D. Mata. "EVALUATION OF EVAPOTRANSPIRATION." International Journal of Research in Engineering and Technology 03, no. 21 (June 25, 2014): 43–47. http://dx.doi.org/10.15623/ijret.2014.0321011.
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Rodrigues Maia, Felipe. "EVAPOTRANSPIRATION TANK (TVAP)." Journal of Interdisciplinary Debates 4, no. 02 (June 24, 2023): 114–42. http://dx.doi.org/10.51249/jid.v4i02.1388.
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The following work presents a proposal for rural, sustainable, economic development and aims to demonstrate the advantages of implementing an economically viable system to promote the treatment of domestic sewage in rural areas. This is an exploratory research, carried out from a literature review. The selected method consists of an evapotranspiration tank, which stands out from the others for its simplified feature for segregating black and gray water and for providing sewage treatment. Although it is still considered a rudimentary sewage collection system, the importance of developing proposals for these systems is highlighted, since rural effluents in most cases do not have a correct destination or reuse, generating a large environmental liability. Through reuse processes and the use of low-cost technologies, it is possible to make the effluents innovative products and even use them in the community itself, in order to enhance the organic cultivation of vegetables or forage plants to feed the ruminants of the property and with low production cost, as it is a simple and cheap solution for those farmers who do not have many resources on their property or around their water sources, something that, by the way, is very rare to find, especially in the northeastern semi-arid region. . With the lack of sanitation in rural areas, it is inevitable to obtain by-products and this work proved to be economically viable, with ease of implementation and maintenance accessible to the low-income population, in addition to being an ecologically correct alternative.
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Košková, R., and S. Němečková. "Assessment of evapotranspiration simulations in the Malše basin." Soil and Water Research 4, Special Issue 2 (March 19, 2010): S111—S122. http://dx.doi.org/10.17221/479-swr.
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The application of the distributed hydrological model brings the benefits of assessment of the spatially distributed quantities which are hard to measure in the field over a larger area, e.g. evapotranspiration. The Malše River basin has been chosen for the evaluation of evapotranspiration simulation by the distributed hydrological model, SWIM (Soil and Water Integrated Model). The primary interest in this analysis was to assess the ability of the hydrological model to simulate the actual evapotranspiration on larger scales and to evaluate its dependence on the landscape characteristics such as the vegetation cover, soil type, and average precipitation amount during the simulation. Annual actual evapotranspiration in each hydrotope was evaluated in the simulation period of 1985–1998. Because of the lack of the data observed (evapotranspiration), the model was calibrated on the discharge time series. The credibility was quantified using Nash Sutcliffe efficiency which was more than 0.7. The main trends of the simulated actual evapotranspiration were evaluated and assessed as satisfactory. The differences in the soil types did not seem significant for the evapotranspiration variation, the monthly average values among soil types differing by ± 10% except histosol. On the other hand the differences in the land-use categories strongly influenced the amount of evapotranspiration (–30; +50%). It appears that the model SWIM overestimates the actual evapotranspiration in the spring and, on the other hand, underestimates that in the autumn according to the comparison with the only data available in the entire Climate Atlas of the Czech Republic.
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Pejić, Borivoj, Ksenija Mačkić, Ivana Bajić, Vladimir Sikora, Dejan Simić, Milena Jančić-Tovjanin, and Boško Gajić. "Calculation of maize evapotranspiration using evaporation and reference evapotranspiration methods." Zemljiste i biljka 69, no. 2 (2020): 15–25. http://dx.doi.org/10.5937/zembilj2002015p.
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Analysis of irrigation scheduling of maize was done by using evaporation from the free water surface (Eo) and correction coefficients (k) and reference evapotranspiration (ETo) and crop coefficients (kc). The field experiment was carried out in 2018 on the Experimental field of the Institute of field and vegetable crops in the Department of alternative crops in Bački Petrovac. Maize hybrid NS 6030 was used for the trials. The plants were irrigated by a drip system with a lateral in each row with drippers spaced every 0.33 m. The drippers had an average flow rate of 2.0 l h-1 under the pressure of 70 kPa. The differences in yield of maize in the irrigation conditions were not statistically significant compared to the variant without irrigation because the year was favorable for maize production. As well there was no difference among variants used for the calculation of maize evapotranspiration. Maize evapotranspiration in the growing season (ETm) were 502 mm and 429 mm by using ETo and kc and Eo and k. Monthly values of ETm during the growing season were consistent regardless of the calculation methods, except in July. Values of ETm in July of 151 mm and 107 mm calculated by using ETo and kc and Eo and k methods as well the daily values which are correlated with the monthly have to be checked in irrigation scheduling of maize in the following investigation period. If statistical significance in maize yield between different methods of calculation is determined, the procedure with a higher yield has to be accepted in the calculation of ETm in the climatic conditions of the Vojvodina region. Otherwise, if the differences in maize yield are not statistical significance a method of calculation by using Eo and k will be recommended, because the value of the lower daily water used on maize evapotranspiration may be considered more realistic.
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Shoemaker, W. Barclay, and David M. Sumner. "Alternate corrections for estimating actual wetland evapotranspiration from potential evapotranspiration." Wetlands 26, no. 2 (June 2006): 528–43. http://dx.doi.org/10.1672/0277-5212(2006)26[528:acfeaw]2.0.co;2.
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Faisol, Arif, Indarto Indarto, Elida Novita, and Budiyono Budiyono. "An Evaluation of MODIS Global Evapotranspiration Product as Satellite-Based Evapotranspiration Data for Supporting Precision Agriculture in West Papua - Indonesia." JOURNAL OF TROPICAL SOILS 26, no. 1 (January 5, 2021): 43. http://dx.doi.org/10.5400/jts.2021.v26i1.43-49.
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Precision Agriculture has been a significant issue since the middle of the 1980s. Evapotranspiration is one of the main parameters in precision agriculture to analyze real water needs in the agriculture area and managing water resources. Traditionally evapotranspiration estimates by directly measured methods, i.e., lysimeter, pan-evaporation, eddy covariance, Bowen ratio, soil water, and climate data analysis. These methods are expensive techniques with low spatial representativeness. The utilization of remote sensing technology is expected to be an alternative solution for providing evapotranspiration data with a cost-effective and high spatial representative. This research aims to evaluate the MODIS global evapotranspiration as satellite-based evapotranspiration in estimating evapotranspiration in West Papua. Four (4) statistical parameters, i.e., mean error (ME), root means square error (RMSE), relative bias (RB), and mean bias factor (MBF), are using for evaluation. The research showed that MODIS global evapotranspiration was overestimated in estimating evapotranspiration in West Papua. However, MODIS global evapotranspiration has an acceptable accuracy in estimating evapotranspiration in West Papua indicated by ME = 0.66 mm/day, RMSE = 0.94 mm/day, RB = 0.27, and MBF = 0.81. Therefore, MODIS global evapotranspiration can be used as an alternative solution for providing evapotranspiration data in West Papua with a cost-effective.
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ABHIJIT SARMA and KRISHNA BHARADWAJ. "Determination of crop-coefficients and estimation of evapotranspiration of rapeseed using lysimeter and different reference evapotranspiration models." Journal of Agrometeorology 22, no. 2 (November 6, 2021): 172–78. http://dx.doi.org/10.54386/jam.v22i2.158.
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Accurate estimation of evapotranspiration of rapeseed is essentially required for irrigation scheduling and water management. The present study was undertaken during 2015-16 and 2017-18 in ICR Farm, Assam Agricultural University, Jorhat to determine the crop coefficients (Kc) and estimate evapotranspiration of rapeseed using lysimeter and eight reference evapotranspiration models viz. Penman-Monteith, Advection-Aridity (Bruitsaert-Strickler), Granger-Gray, Makkink, Blaney-Criddle, Turc (1961), Hargreaves-Somani and Priestly-Tailor models. During 2015-16, the crop coefficients were developed by these models. Actual evapotranspiration was determined by three weighing type lysimeters. During 2017-18, evapotranspiration was estimated by multiplying reference evapotranspiration with Kc derived by different models and compared with actual evapotranspiration estimated by lysimeter during similar growing periods. All the models except Turc (1961) showed less than 10% deviation between actual and estimated ET. The estimated evapotranspiration using Penman-Monteith and Priestly-Tailor reference evapotranspiration recorded the lowest MAE and RMSE. The study revealed that estimated evapotranspiration using Penman-Monteith reference evapotranspiration gave the best estimate of evapotranspiration of rapeseed followed by Priestly-Tailor. The crop coefficients for initial, mid and end stages were 0.83, 1.20 and 0.65, respectively for Penman-Monteith and 0.70, 1.05 and 0.55, respectively for Priestly-Tailor.These results can be used for efficient management of irrigation water for rapeseed.
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Agegn Asres, Ligalem, and Melaku Adugnaw Walle. "Challenge of Rainfall Uncertainty in the Study of Deficit Irrigation." Environmental Research, Engineering and Management 80, no. 2 (July 5, 2024): 109–17. http://dx.doi.org/10.5755/j01.erem.80.2.34118.
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One of the alternative methods for managing irrigation water is deficit irrigation, particularly alternate furrow irrigation (AFI). This deficit in irrigation is affected by uncontrolled rainfall. In line with this, rainfall uncertainty causes a variation between the measured actual crop evapotranspiration and the theoretical crop evapotranspiration. Let us imagine that rain falls during the deficit irrigation research, and the soil moisture under the deficit experiment is then raised to the soil field capacity. It is incorrect to report the result as a deficit. Thus, there is a research gap on the effect of rainfall uncertainty on the quantity of theoretical and actual crop evapotranspiration under deficit irrigation. This study was carried out at the Arba Minch University demonstration site on onion crops. Using CROPWAT 8.0 software, the reference evapotranspiration (ETo) was calculated using the Penman-Monteith formula. The crop coefficient and ETo were used to calculate the theoretical crop evapotranspiration. In contrast, actual crop evapotranspiration was calculated using soil moisture measurements before and after each irrigation event after applying theoretical crop evapotranspiration. As a result, there is a significant difference between the calculated theoretical crop evapotranspiration and actual crop evapotranspiration from a deficit study. Thus, the calculated seasonal theoretical crop evapotranspiration was 201.72 mm. On the other hand, the actual crop evapotranspiration was 275.82 mm. This revealed that the actual crop evapotranspiration was greater than the calculated theoretical crop evapotranspiration by 36.7%. Uncontrolled rainfall was identified as the output’s cause. This has an evident effect on the deficit in experimental research. Hence, conducting the deficit experiment in a greenhouse is more reasonable. In addition, it is possible to assess actual crop evapotranspiration based on daily soil moisture measurements and report the deficit level based on the measured amount.
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Wang, Yuxuan, Yinhuan Ao, and Zhaoguo Li. "Evapotranspiration Characteristics of Different Oases and Effects of Human Activities on Evapotranspiration in Heihe River Basin." Remote Sensing 14, no. 24 (December 11, 2022): 6283. http://dx.doi.org/10.3390/rs14246283.
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Evapotranspiration plays a decisive role in the whole oasis ecosystem and is an important factor to maintain the ecological stability of oases. To quantitatively analyze the evapotranspiration differences of oases at different scales and the expansion of urbanization, it is necessary to compare and discuss them at different time scales. In this study, the spatial and temporal characteristics of evapotranspiration of Zhangye Oasis, Jinta Oasis, and Ejina Oasis in the Heihe River basin were analyzed by using the remote sensing dataset of daily surface evapotranspiration of 100 m resolution from 2010 to 2016. The difference in evapotranspiration intensity in different oases was analyzed, and the influences of irrigation and urbanization expansion on evapotranspiration were discussed. The conclusion is as follows: Zhangye Oasis is the largest oasis in the area and, compared with other oases, due to the largest proportion of wetland and farmland in the underlying surface, the intensity of evapotranspiration is also the largest, reaching 650 mm/year on average. There is no obvious annual change; the range of evapotranspiration changes fluctuates between positive and negative 60 mm/year. Jinta Oasis began to decline after 2012; the evapotranspiration value dropped from 620 mm/tear to 560 mm/year, while Ejina Oasis showed a slight increase after 2014. In the irrigation stage, the evapotranspiration intensity increased significantly. Especially in the peak season of crop growth, the evapotranspiration after irrigation increased by 4 mm/day compared with that before irrigation. The evapotranspiration in urban and oasis areas is different in summer: compare that of 2010 with 2016—the evapotranspiration intensity of the expanding towns in the northeast direction decreased by about 50 mm/month, the northwest expanding towns decreased by about 110 mm/month. There was no obvious annual change in evapotranspiration in the urban area. With the expansion of urbanization, the evapotranspiration intensity in oases decreased. The results of this study provide some reference for the study of oasis irrigation activities and urbanization expansion.
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Yang, Liangyan, and Hui Kong. "Analysis of the Changes and Influencing Factors of Evapotranspiration in Fuping County based on Meteorological Data." Journal of Innovation and Development 3, no. 2 (May 31, 2023): 61–63. http://dx.doi.org/10.54097/jid.v3i2.9150.
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Using meteorological station data, this paper analyzes the annual evapotranspiration and influencing factors in Fuping County from 1998 to 2017, and explores the dominant meteorological factors that affect the changes in evapotranspiration. The results show that from 1998 to 2017, the annual evapotranspiration in Fuping County showed a significant upward trend, with a growth rate of 9.9mm/a; The correlation between evapotranspiration and meteorological factors on a daily scale shows temperature>pressure>relative humidity>wind speed. There is a positive correlation between NDVI and evapotranspiration, with a correlation coefficient of 0.6693, indicating that surface evapotranspiration in the region is significantly influenced by underlying surface characteristics. Overall, temperature and vegetation are the main factors affecting evapotranspiration changes in Fuping County.
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Laounia, Nehal, Hamimed Abderrahmane, Khaldi Abdelkader, Souidi Zahira, and Zaagane Mansour. "Evapotranspiration and Surface Energy Fluxes Estimation Using the Landsat-7 Enhanced Thematic Mapper Plus Image over a Semiarid Agrosystem in the North-West of Algeria." Revista Brasileira de Meteorologia 32, no. 4 (December 2017): 691–702. http://dx.doi.org/10.1590/0102-7786324016.
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Abstract Monitoring evapotranspiration and surface energy fluxes over a range of spatial and temporal scales is crucial for many agroenvironmental applications. Different remote sensing based energy balance models have been developed, to estimate evapotranspiration at both field and regional scales. In this contribution, METRIC (Mapping EvapoTranspiration at high Resolution with Internalized Calibration), has been applied for the estimation of actual evapotranspiration in the Ghriss plain in Mascara (western Algeria), a semiarid region with heterogeneous surface conditions. Four images acquired during 2001 and 2002 by the Landsat-7 satellite were used. The METRIC model followed an energy balance approach, where evapotranspiration is estimated as the residual term when net radiation, sensible and soil heat fluxes are known. Different moisture indicators derived from the evapotranspiration were then calculated: reference evapotranspiration fraction, Priestley-Taylor parameter and surface resistance to evaporation. The evaluation of evapotranspiration and surface energy fluxes are accurate enough for the spatial variations of evapotranspiration rather satisfactory than sophisticated models without having to introduce an important number of parameters in input with difficult accessibility in routine. In conclusion, the results suggest that METRIC can be considered as an operational approach to predict actual evapotranspiration from agricultural areas having limited amount of ground information.
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Guo, Wenzhe, Jundong Xu, Xuetong Liu, Hongkai Dang, Shibo Fang, and Yueying Li. "A Pathway Analysis of Evapotranspiration Variation Characteristics and Influencing Factors of Summer Maize in the Haihe Plain." Water 16, no. 13 (June 26, 2024): 1819. http://dx.doi.org/10.3390/w16131819.
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The Haihe Plain in China is situated in the world’s largest groundwater funnel area, with per capita water resources far below the internationally recognized “extremely water-scarce” standard. To address the issue of water shortage in summer maize-planting areas of the Haihe Plain, we conducted research on the variation of summer maize evapotranspiration using a medium-sized lysimeter. This study aims to provide technical support for water-saving irrigation in summer maize fields. Through path analysis, direct and indirect influencing factors affecting the evapotranspiration of summer maize fields were determined. The results showed that the cumulative evapotranspiration of bare ground and farmland during the entire growth period of summer maize was 173.57 mm and 382.97 mm, respectively, with evapotranspiration intensities of 1.52 mm/d and 3.36 mm/d, respectively. Evapotranspiration during the maturity stage of summer maize was the least, accounting for only 1.82% of total evapotranspiration during the entire growth period. The period from the jointing to milk-ripening stage is when evapotranspiration in maize fields is at its highest. During this period, evapotranspiration in maize fields amounted to 265.58 mm, accounting for 69.35% of total evapotranspiration. The evapotranspiration intensity was 3.59 mm/day, which is 1.34 times higher than that of bare soil. The evapotranspiration intensities during each growth stage were ranked as jointing stage > tasseling-silking stage > seedling stage > milk maturity stage > maturity stage. The daily evapotranspiration of summer maize fields showed a “unimodal” curve with low values in the morning and evening, and high values at noon. Path analysis indicated that daily radiation and maximum daily temperature had the greatest impact on the evapotranspiration of maize fields, with the direct effect of maximum daily temperature being restrictive and the indirect effect being promotive, resulting in an overall promotive effect.
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Ling, Minhua, Yuanqing Yang, Chenyang Xu, Lili Yu, Qinyuan Xia, and Xiaomin Guo. "Temporal and Spatial Variation Characteristics of Actual Evapotranspiration in the Yiluo River Basin Based on the Priestley–Taylor Jet Propulsion Laboratory Model." Applied Sciences 12, no. 19 (September 28, 2022): 9784. http://dx.doi.org/10.3390/app12199784.
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Evapotranspiration is an important part of the hydrological cycle, affecting the terrestrial hydrological process and the relationship between water resource transformation. Analyzing and mastering the temporal and spatial variations in evapotranspiration are of great significance for the rational development, utilization, and protection of water resources in the basin. Based on MODIS remote sensing data and combined with meteorological and hydrological data, the PT-JPL model was used to estimate the actual evapotranspiration of the Yiluo River Basin, and the applicability of the PT-JPL model for estimating actual evapotranspiration in the basin was analyzed. The spatial and temporal characteristics of actual evapotranspiration in the Yiluo River Basin were analyzed, and the correlation between actual evapotranspiration in the basin and influencing factors such as precipitation, temperature, and vegetation was explored. The main conclusions are as follows: the PT-JPL model has good applicability in the Yiluo River Basin; the total actual evapotranspiration in the basin showed a decreasing trend, which was consistent with the trend of precipitation, indicating that the actual evapotranspiration may be limited by water conditions in the study area. The evapotranspiration of the basin was higher in the upstream and lower in the downstream, which may be related to the better vegetation coverage in the upper basin than in the downstream. As an important indicator of vegetation change, NDVI showed a good correlation with evapotranspiration, which also verified this. In addition, the correlation between evapotranspiration and temperature was also good.
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Daud, Arifin, Citra Indriyati, and Sarah Yuli Hasanah. "Analisis Evapotranspirasi Menggunakan Metode Penman-Monteith pada Vertical Garden." Cantilever: Jurnal Penelitian dan Kajian Bidang Teknik Sipil 10, no. 1 (May 31, 2021): 19–26. http://dx.doi.org/10.35139/cantilever.v10i1.65.
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The development of environmentally friendly infrastructure is very important to reduce the environmental damage that has occurred. Environmentally friendly infrastructure can be supported by vertical garden. Plants in vertical garden undergo evaporation process called evapotranspiration process. The evapotranspiration process can be used to find out the needs of water in plants. The method used to obtain the evapotranspiration value is the Penman-Monteith method. The plants used are Plectranthus scutellarioides, Begonia, Coleus, Euodia ridleyi dwarf, Euodia ridleyi, and Chlorophytum comosum. The reference evapotranspiration value in The Hydraulic Laboratory of Sriwijaya University is 4.9826 mm/day and the smallest is 2.1262 mm/day. The reference evapotranspiration value is influenced by temperature, wind speed, and humidity conditions. Based on these three influences, temperature has a greater influence on the reference evapotranspiration. The largest evapotranspiration value of the six types of plants used is the Plectranthus scutellarioides, which is 3.3347 mm/day, the evapotranspiration value of the smallest plant is Euodia ridleyi dwarf, which is 2.6616 mm/day. The location and arrangement of plants and environmental conditions such as temperature, humidity, wind speed affect the amount of evapotranspiration value.
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ABDEL-LAH, Ahmed Khalaf, Kunio WATANABE, and Ushio KUROKAWA. "Seasonal Change of Evapotranspiration and Influence of Plant Density on Evapotranspiration." Journal of the Japan Society of Engineering Geology 37, no. 6 (1997): 446–51. http://dx.doi.org/10.5110/jjseg.37.446.
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Omondi, J. O., N. W. Mungai, J. P. Ouma, and F. P. Baijukya. "Shoot water content and reference evapotranspiration for determination of crop evapotranspiration." African Crop Science Journal 25, no. 4 (November 27, 2017): 387. http://dx.doi.org/10.4314/acsj.v25i4.1.
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Allen, Richard G., Albert J. Clemmens, Charles M. Burt, Ken Solomon, and Tim O’Halloran. "Prediction Accuracy for Projectwide Evapotranspiration Using Crop Coefficients and Reference Evapotranspiration." Journal of Irrigation and Drainage Engineering 131, no. 1 (February 2005): 24–36. http://dx.doi.org/10.1061/(asce)0733-9437(2005)131:1(24).
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Weiss, Oliver, Bernhard Scharf, and Ulrike Pitha. "Evapotranspiration of Technical Substrates – Methodology for Calculating Evapotranspiration of Technical Substrates." Journal of Ecological Engineering 20, no. 9 (October 1, 2019): 28–37. http://dx.doi.org/10.12911/22998993/112340.
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Hiestand, Mikael P., Heather J. Tollerud, Chris Funk, Gabriel B. Senay, Kate C. Fickas, and MacKenzie O. Friedrichs. "SSEBop Evapotranspiration Estimates Using Synthetically Derived Landsat Data from the Continuous Change Detection and Classification Algorithm." Remote Sensing 16, no. 7 (April 6, 2024): 1297. http://dx.doi.org/10.3390/rs16071297.
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The operational Simplified Surface Energy Balance (SSEBop) model has been utilized to generate gridded evapotranspiration data from Landsat images. These estimates are primarily driven by two sources of information: reference evapotranspiration and Landsat land surface temperature (LST) values. Hence, SSEBop is limited by the availability of Landsat data. Here, in this proof-of-concept paper, we utilize the Continuous Change Detection and Classification (CCDC) algorithm to generate synthetic Landsat data, which are then used as input for SSEBop to generate evapotranspiration estimates for six target areas in the continental United States, representing forests, shrublands, and irrigated agriculture. These synthetic land cover data are then used to generate the LST data required for SSEBop evapotranspiration estimates. The synthetic LST, evaporative fractions, and evapotranspiration data from CCDC closely mirror the phenological cycles in the observed Landsat data. Across the six sites, the median correlation in seasonal LST was 0.79, and the median correlation in seasonal evapotranspiration was 0.8. The median root mean squared error (RMSE) values were 2.82 °C for LST and 0.50 mm/day for actual evapotranspiration. CCDC predictions typically underestimate the average evapotranspiration by less than 1 mm/day. The average performance of the CCDC evaporative fractions, and corresponding evapotranspiration estimates, were much better than the initial LST estimates and, therefore, promising. Future work could include bias correction to improve CCDC’s ability to accurately reproduce synthetic Landsat data during the summer, allowing for more accurate evapotranspiration estimates, and determining the ability of SSEBop to predict regional evapotranspiration at seasonal timescales based on projected land cover change from CCDC.
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Prévost, Marcel, Jean Stein, and André P. Plamondon. "Water balance and irrigation planning in a forest tree nursery." Canadian Journal of Forest Research 19, no. 5 (May 1, 1989): 575–79. http://dx.doi.org/10.1139/x89-090.
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A soil water budget was established to estimate the water loss from the 0- to 60-cm layer as a result of evapotranspiration in a forest tree nursery. Estimated evapotranspiration totaled 69% of potential evapotranspiration (as estimated by the Penman equation) for 36 selected periods from May 15 to July 30, 1975. The root zone (0- to 15-cm layer) supplied 58% of the total evapotranspired water from the soil profile. Evapotranspiration from this layer was found to be a good predictor of total water loss. Evapotranspiration from the root zone, expressed as a percentage of potential evapotranspiration, was related to soil water tension at 3 cm depth. This relationship, combined with a knowledge of soil hydrodynamic properties, can be used to estimate evapotranspiration from the 0- to 60-cm soil profile, which in turn can be used to predict irrigation needs. For practical purposes, a relationship using net radiation instead of potential evapotranspiration can also be used. Depending on the available information, either of these two relationships may be used for irrigation planning.
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Seiler, Christian, and Arnold F. Moene. "Estimating Actual Evapotranspiration from Satellite and Meteorological Data in Central Bolivia." Earth Interactions 15, no. 12 (May 1, 2011): 1–24. http://dx.doi.org/10.1175/2010ei332.1.
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Abstract Spatial estimates of actual evapotranspiration are useful for calculating the water balance of river basins, quantifying hydrological services provided by ecosystems, and assessing the hydrological impacts of land-use practices. To provide this information, the authors estimate actual evapotranspiration in central Bolivia with a remote sensing algorithm [Surface Energy Balance Algorithms for Land (SEBAL)]. SEBAL was adapted for the effects of topography (particularly for elevation, slope, and aspect) and atmospheric properties on incoming solar radiation. Instantaneous fluxes are converted to daily and annual fluxes using reference evapotranspiration. The required input data consist of meteorological data and satellite data. Results show more evapotranspiration for humid regions and less evapotranspiration for dry regions and deforested land. Actual evapotranspiration estimates are compared with annual precipitation measurements from 27 meteorological observations. In case annual actual evapotranspiration is estimated correctly, it must be lower than the precipitation measurements. This is the case for 23 stations. The remaining four stations are all located at higher altitudes (>2700 m). Unfortunately, no actual evapotranspiration measurements are available for additional validation purposes.
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Xie, Jingkai, Li Liu, Yitong Wang, Yue-Ping Xu, and Hao Chen. "Changes in actual evapotranspiration and its dominant drivers across the Three-River Source Region of China during 1982–2014." Hydrology Research 53, no. 2 (February 1, 2022): 297–313. http://dx.doi.org/10.2166/nh.2022.076.
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Abstract Evapotranspiration is an essential element of the hydrological process. This study derived the long-term series of evapotranspiration from 1982 to 2014 over the three basins, namely source regions of the Yangtze River (SRYR), the Huang River (SRHR) and the Lancang River (SRLR) in the Three-River Source Region of China by integrating multiple sources of evapotranspiration estimates based on the Bayesian model averaging approach, which made full use of the strengths of land surface models and satellite-based products to constrain uncertainties. Then, we analyzed the influences of climate change on evapotranspiration based on the partial least squares regression model. Results indicate that (1) the agreement between various evapotranspiration products and water balance-derived evapotranspiration estimates varies from region to region in the Three-River Source Region of China; (2) annual evapotranspiration increases in the SRYR (3.3±0.8 mm/yr) and the SRHR (0.8±0.4 mm/yr), whereas no significant trends are observed in the SRLR during 1982–2014; (3) annual evapotranspiration is found most sensitive to precipitation and temperature in the SRYR and the SRHR, while it is dominated by relative humidity and temperature in the SRLR during 1982–2014. Our results have important implications for understanding evapotranspiration variability and future water security in the context of global climate change.
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Raddatz, R. L., and C. F. Shaykewich. "Impact of warm summers on the actual evapotranspiration from spring wheat grown on the eastern Canadian prairies." Canadian Journal of Soil Science 78, no. 1 (February 1, 1998): 171–79. http://dx.doi.org/10.4141/s97-068.
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How do warm summers (June–July–August) influence the actual evapotranspiration totals from cropped land sown to spring wheat on the eastern Canadian Prairies? The eastern Prairies is a semi-arid region where over 60% of the land is cultivated. Over a third of the cropped land is usually sown to spring wheat. A comparison of mean summer temperatures and modelled evapotranspiration, for the years 1988 to 1996, demonstrated that with the current environmental conditions and farming practices, warm summers have lower actual evapotranspiration totals from spring wheat than cool summers. The average daily actual evapotranspiration rate is generally higher in years with higher mean summer temperatures; however, the crop growth-period is shorter. The net effect is lower total actual evapotranspiration from spring wheat. This suggests that climate warming on the eastern Canadian Prairies, if the current trend continues and all other factors remain equal, will reduce, on average, the total actual evapotranspiration from spring wheat. A reduction in the growth-period actual evapotranspiration from lands sown to spring wheat will likely decrease the total actual evapotranspiration for the entire warm season as growth-period evapotranspiration currently makes up about three-quarters of the seasonal total. However, the magnitude and timing of the reduction is far from certain. The consequence for agriculture may be a reduction in the average spring wheat yield because yield is positively correlated with the actual evapotranspiration total from the crop. Key words: Modelling, crop growth-period, yield, climate warming
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Hofreiter, Milan, and Vladimír Jirka. "Uncertainty Analysis of Evapotranspiration Estimates in Ecosystems." Asian Journal of Science and Applied Technology 2, no. 1 (May 5, 2013): 30–38. http://dx.doi.org/10.51983/ajsat-2013.2.1.742.
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Many hydrologic models and agricultural management applications require evapotranspiration estimates. The intensity of evapotranspiration is mainly determined by mathematical models rather than by direct measurement. In addition to its own estimate of evapotranspiration it is necessary to determine the uncertainty of this estimate. This uncertainty is not usually mentioned. In this paper these formulas are derived for the uncertainty estimate of evapotranspiration under simplifying assumptions. These assumptions enabled one to derive an expression of evapotranspiration estimation uncertainty suitable for practical applications. The paper focuses on both the absolute and the relative uncertainty of evapotranspiration estimation. The derived formulas can be used for determining the uncertainty in evapotranspiration estimation, but as well as for the accuracy estimate which is necessary for the measuring of input variables. The derived relationship shows that the net radiation should be more accurately measured than the other energy fluxes that have an influence on evapotranspiration. It follows that the relative uncertainty of evapotranspiration is primarily influenced by the relative uncertainty of net radiation. The uncertainty in the measurement of net radiation was derived from data obtained by using a radiometer which was equipped with a pair of pyranometers and with a pair of pyrgeometers. Planck’s Law was used for spectral analysis. The possible presence of systematic errors in the measuring of net radiation was evaluated for its potential impact on the errors of the evapotranspiration estimate. This paper is accompanied by measurement records and graphs documenting the achieved results.
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Hofreiter, Milan, and Vladimír Jirka. "Uncertainty Analysis of Evapotranspiration Estimates in Ecosystems." Asian Review of Mechanical Engineering 1, no. 1 (May 5, 2012): 47–53. http://dx.doi.org/10.51983/arme-2012.1.1.2512.
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Many hydrologic models and agricultural management applications require evapotranspiration estimates. The intensity of evapotranspiration is mainly determined by mathematical models rather than by direct measurement. In addition to its own estimate of evapotranspiration, it is necessary to determine the uncertainty of this estimate. This uncertainty is not usually mentioned. In this paper these formulas are derived for the uncertainty estimate of evapotranspiration under simplifying assumptions. These assumptions enabled one to derive an expression of evapotranspiration estimation uncertainty suitable for practical applications. The paper focuses on both the absolute and the relative uncertainty of evapotranspiration estimation. The derived formulas can be used for determining the uncertainty in evapotranspiration estimation, but as well as for the accuracy estimate which is necessary for the measuring of input variables. The derived relationship shows that the net radiation should be more accurately measured than the other energy fluxes that have an influence on evapotranspiration. It follows that the relative uncertainty of evapotranspiration is primarily influenced by the relative uncertainty of net radiation. The uncertainty in the measurement of net radiation was derived from data obtained by using a radiometer which was equipped with a pair of pyranometers and with a pair of pyrgeometers. Planck’s Law was used for spectral analysis. The possible presence of systematic errors in the measuring of net radiation was evaluated for its potential impact on the errors of the evapotranspiration estimate. This paper is accompanied by measurement records and graphs documenting the achieved results.
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Sello, Lehlohonolo, Akhona Maqhubela, and Gaathier Mahed. "Remote sensing-based evapotranspiration determination: A review of single-source energy balance models." South African Journal of Geomatics 11, no. 2 (September 1, 2022): 262–73. http://dx.doi.org/10.4314/sajg.v11i2.7.
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Remote Sensing evapotranspiration models are critical in order to understand the cycling of water in the environment. Initially, an outline of the concepts related to evapotranspiration, as well as the shortcomings of land-based methods, is presented. The aim of the study was based on reviewing remote sensing evapotranspiration models which provide an alternative data source. These models have proved to be a cheaper alternative to mapping and estimating spatiotemporal evapotranspiration measurements across local and regional scales. This paper reviews the single-source energy balance model, which differs from the two-source model, for estimating spatiotemporal measurements of evapotranspiration. The single-source energy balance model is underpinned by mathematical equations which differentiate the various single-source evapotranspiration models (Surface Energy Balance Systems, Simplified Surface Energy Systems, Surface Energy Balance Algorithm, and Mapping Evapotranspiration at high Resolution and with Internalised Calibration). The soil surface and forest canopy components were observed to be the major difference between the single and dual-source models. Further advice was discussed on the implementation of the OpenET tool, which provides an open and accessible satellite-based estimation of evapotranspiration for improved water management.
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Wang, Shiyan, Chang Liu, Yiqian Tan, Jie Wang, Fei Du, Zhen Han, Zhi Jiang, and Liang Wang. "Remote sensing inversion characteristic and driving factor analysis of wetland evapotranspiration in the Sanmenxia Reservoir area, China." Journal of Water and Climate Change 13, no. 3 (October 7, 2021): 1599–611. http://dx.doi.org/10.2166/wcc.2021.247.
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Abstract Evapotranspiration in the hydrologic cycle realizes the energy and water transport in the atmosphere. Evapotranspiration differences concerning land-use types provide data for studying the evapotranspiration of river basins. To investigate the evapotranspiration in the reservoir under artificial regulation, we selected the river basin in the Sanmenxia Reservoir as the study area. Data sources are two-period Landsat8 OIL_TIRS remote sensing images during the growing season of wetland plants. Based on meteorological data in this river basin, we investigated the evapotranspiration differences of different land-use types using the Surface Energy Balance Algorithm for Land model. The FAO Penman–Monteith formula verified the remote sensing inversion results. Analysis shows that significant differences were manifested between wetland and non-wetland landscapes in evapotranspiration among different land-use types. Non-wetland landscapes accounted for about 97.23% of the river basin's total area, but their daily average evapotranspiration was only 7.26 mm/d. Those of wetland landscapes were 2.77% and 12.17 mm/d. In this river basin, the differences between the wetland and non-wetland landscapes in evapotranspiration are mainly associated with plant diversity, vegetation coverage and surface temperature (beyond other driving factors like meteorological and hydrological solar radiation factors).
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Faski, Gita Ivana Suci Lestari, and Ignasius Loyola Setyawan Purnama. "The Impact of Global Climate Change to Climate Condition of Bengkulu Watershed, Indonesia." E3S Web of Conferences 325 (2021): 08010. http://dx.doi.org/10.1051/e3sconf/202132508010.
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Global climate change that occurred in this century can affect the pattern of rain and increase in temperature on earth. This study aims to determine and analyze the increase in rainfall, air temperature, potential evapotranspiration and actual evapotranspiration in the Bengkulu watershed. For this reason, the regional rainfall is calculated using the Thiessen Polygon, the mean air temperature of the watershed based on the median elevation, potential evapotranspiration using the Thornthwaite Method and actual evapotranspiration using the basis of the difference in rainfall to potential evapotranspiration. The results showed that every year there was an increase in rainfall, air temperature, potential evapotranspiration and actual evapotranspiration in the Bengkulu Watershed. In the 2009-2013 period, the average annual rainfall of 3,581 mm increased to 3,641 mm in the 2014-2018 period. For air temperature, the average monthly air temperature in the Bengkulu Watershed for the 2009-2013 period was 25.8°C, while the air temperature in the 2014-2018 period was 26.1°C. This means that in a period of 5 years there is an increase in temperature of 0.3°C. Furthermore, due to the increase in air temperature, there was an increase in the average monthly potential evapotranspiration from the 2009-2013 period to the 2014-2018 period, namely from 1,493 mm to 1,537 mm, while for actual evapotranspiration there was an increase from 1,486 mm to 1,518 mm.
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Yu, Hongbo, Congming Cao, Qiaofeng Zhang, and Yuhai Bao. "Construction of an evapotranspiration model and analysis of spatiotemporal variation in Xilin River Basin, China." PLOS ONE 16, no. 9 (September 10, 2021): e0256981. http://dx.doi.org/10.1371/journal.pone.0256981.
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Surface evapotranspiration is a water exchange process between the atmosphere, biosphere, and hydrosphere. Accurate evapotranspiration estimations in arid and semi-arid regions are important for monitoring droughts and protecting the ecological environment. The main objective of this study is to build an evapotranspiration estimation model suitable for an effective scientific and objective evaluation of water consumption in the arid and semi-arid regions of the Xilin River Basin based on comprehensive parameters, including meteorological parameters, vegetation coverage, and soil water content. In this study, the community evapotranspiration model was initially constructed using field data, which was then expanded for applicability to the Xilin River Basin based on Geographic Information System technology and spatial heterogeneity characteristics of remote sensing data; both models were significant at the 0.05 level. The monthly evapotranspiration values in July during 2000–2017 and those from April to September (growing season) during the dry, normal, and wet years were calculated using the model at the basin scale. The evapotranspiration showed a generally increasing trend, which was consistent with the fluctuation trend in precipitation in July during 2000–2017. The trend curve for evapotranspiration was gentle during the growing season in dry years, but steep during wet years. The evapotranspiration was the lowest in April, with negligible spatial variations throughout the Xilin River Basin. During May–July, the evapotranspiration was higher than that in other months, in the following order: upper reaches > middle reaches > lower reaches; this was consistent with the vegetation coverage. The evapotranspiration declined and spatial variations were not evident during August–September. The results of this study provide a reference for evapotranspiration model construction and a scientific basis for evaluating regional water resources and protecting the ecological environment.
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Jin, Lei, Shaodan Chen, Haibo Yang, and Chengcai Zhang. "Evaluation and Drivers of Four Evapotranspiration Products in the Yellow River Basin." Remote Sensing 16, no. 11 (May 21, 2024): 1829. http://dx.doi.org/10.3390/rs16111829.
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Evapotranspiration is a key driver of water and energy exchanges between terrestrial surfaces and the atmosphere, significantly influencing ecosystem balances. This study focuses on the Yellow River Basin (YRB), where evapotranspiration impacts both ecological dynamics and human activities. By analyzing actual evapotranspiration data from 1982 to 2017, this research provides insights into its spatial and temporal patterns within the YRB. Furthermore, a comprehensive assessment and comparative analysis were performed on four distinct evapotranspiration product datasets: GLDAS-Noah, ERA5-Land, GLEAM v3.8a, and MOD16A2. Employing the Geodetector model, the research identified seven key influencing factors—the digital elevation model (DEM), slope, aspect, precipitation, temperature, soil moisture, and normalized difference vegetation index (NDVI)—and analyzed their impact on evapotranspiration variations, yielding the following insights: (1) Based on the monthly-scale actual evapotranspiration dataset from 1982 to 2017, the annual average evapotranspiration in the YRB fluctuated between 375 and 473 mm, with an average value of 425 mm. A declining trend in the region’s overall evapotranspiration was discerned using the Theil–Sen median slope estimator and Mann–Kendall trend test. (2) The datasets from GLDAS-Noah, ERA5-Land, and GLEAM exhibited the highest correlation with the observed datasets, all exceeding a correlation coefficient of 0.96. In contrast, the MOD16A2 dataset showed the least favorable performance. The ERA5-Land dataset was particularly noteworthy for its close alignment with observational benchmarks, as evidenced by the lowest recorded root mean square error (RMSE) of 5.09 mm, indicative of its outstanding precision. (3) Employing the Geodetector model, a thorough analysis was conducted of the interactions between evapotranspiration and seven critical determinants. The findings revealed that precipitation and the NDVI were the most significant factors influencing evapotranspiration, with q-values of 0.59 and 0.42 in 2010, and 0.71 and 0.59 in 2015, respectively. These results underscore their pivotal role as the main drivers of evapotranspiration variability within the YRB. Conversely, the q-values for slope in 2010 and 2015 were only 0.01 and nearly zero, respectively, indicating their minimal impact on the dynamics of evapotranspiration in the YRB.
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Khan, Saifullah, and Mahmood Ul Hasan. "Evapotranspiration Distribution and Variation of Pakistan (1931-2015)." Annals of Valahia University of Targoviste, Geographical Series 17, no. 2 (October 1, 2017): 184–97. http://dx.doi.org/10.1515/avutgs-2017-0017.
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AbstractEvapotranspiration is the main element of aridity and desertification and to balance the natural hydrological processes. Pakistan has a high degree of evapotranspiration, as it is in subtropical belt, with long sunshine duration and low cloudiness in summers. June is the warmest month, when the evapotranspiration exceeds 7mm (0.28inches), whereas, January is the coldest month, when evapotranspiration of the country falls to 1mm (0.04inches). The maximum evapotranspiration has been recorded at the southern latitudes of the country (Hyderabad and Jacobabad), while it decreases towards northwest (mountainous region) and Gilgit-Baltistan (Astore and Skardu). This variation in evapotranspiration is due to fluctuation in temperature, precipitation, sunshine duration, wind speed, relative humidity, physical relief and latitudinal as well as altitudinal extend of the country. The average evapotranspiration of Pakistan is 4.5mm with an increase of 1.0mm during 1931-2015. In winter and summer season, the lower Indus basin, has recorded high evapotranspiration as compared to the northern mountainous region. The average evapotranspiration of Pakistan during winter season is 2.7mm, while in summer it is 6.3mm. This variation is due to the variation in the length of day and night, humidity, precipitation, surface pressure, wind speed, and topography of the land. During cold season the average evapotranspiration of the country is 13.7mm, pre-monsoon season 17.1mm, monsoon season 15.8mm and post monsoon season 8mm. Obviously, the highest evapotranspiration of Pakistan has recorded during pre-monsoon season with extreme temperature, scarce precipitation, long sunshine duration, lowest relative humidity, low pressure, and calm winds and chilly condition. Furthermore, during cold (0.1mm), pre-monsoon (3.5mm), and monsoon season (2.2mm) the evapotranspiration shows an increase, where as it reveals a negative deviation of -5.6mm in post monsoon season due to increase in the precipitation from reversible monsoon lows at the southern latitudes of the country. Generally, the evapotranspiration of Pakistan increases from northwest to southeast and a main agent of delimitation of the arid region of the country. The main factors that cause variation in the evapotranspiration of the country from south towards north are temperature, precipitation, sunshine duration, relative humidity, surface pressure, wind speed, fogs, cloudiness, topography, latitudinal and altitudinal extend of the country that required further research.