Aufbereitung meteorologischer Daten zur Unterstützung einer globalen agrarmeteorologischen Beratung

2021 ◽  
Author(s):  
Joachim Namyslo
Keyword(s):  
Air Temperature ◽  
Cascade Model ◽  
Earth System ◽  
Crop Water ◽  
Water Requirements ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Applied Meteorology ◽  
Hermite Spline ◽  
Agricultural Meteorology

<p>Im Rahmen einer agrarmeteorologischen Beratung ist die Berechnung der Verdunstung für spezifische Agrarkulturen mit geeigneten Modellen möglichst auf einer stündlichen Zeitskala erforderlich. Im DWD ist hierzu das Modell AMBAV (Agrarmeteorologisches Modell zur Berechnung der aktuellen Verdunstung) entwickelt worden und wird für die nationale agrarmeteorologische Beratung operationell mit Vorhersagedaten und für Wirkanalysen auch mit Klimadaten verwendet. Insbesondere hinsichtlich globaler Anwendungen liegen gemessene oder mit Klimamodellen berechnete meteorologische Datenzeitreihen häufig nur für eine tägliche Zeitskala, oder als Modelldaten für ausgewählte Elemente bestenfalls in einer 6-stündigen Zeitskala, vor. Dies sind Tagesmittel oder Tagessummen (z.B. Wind bzw. Globalstrahlung und Niederschlag) sowie gegebenenfalls tägliche Extremwerte (Minimum und Maximum der Lufttemperatur, stärkste Tagesböe).</p> <p>Zur Bereitstellung stündlicher Daten aus Tagesdaten wurde daher ein Präprozessor entwickelt, der gemessene Stationsdaten (Modus „Station“) oder modellierte Daten globaler Modelle (Modus „Gitter“) verwendet. Dabei wurde vorausgesetzt, dass im Vorfeld einer Erarbeitung von zeitlichen Disaggregierungsverfahren keine umfangreichen Klimaanalysen durchgeführt werden müssen sondern weitestgehend auf Erfahrung zurückgegriffen werden kann. Vorhandene Programme (z.B. MELODIST) konnten jedoch wegen teilweise anderer Zielstellung oder Datenanforderungen nicht ohne weiteres verwendet werden. So wurde z.B. für die Tagessumme der Globalstrahlung auf das Angström-Verfahren (FAO, 1998), für den Niederschlag auf das Kaskadenverfahren nach Olsson (1998), für die Lufttemperatur auf den „sin-exp-Ansatz“ nach Parton und Logan (1981) und für den Wind auf die „normierte Böen­geschwindigkeit“ (Verkaik, 2000) zurückgegriffen. Für erforderliche Interpolationen werden das Newton-Verfahren und das „cubic hermite spline“ verwendet.</p> <p>Die vorgestellten Verfahren werden mit Stationsdaten des ZAMF und beispielhaft mit Modelldaten des GFCS für Madagaskar angewendet.</p> <p><strong>Literatur</strong></p> <p>FAO (Food and Agriculture Organization), 1998: Crop evaporation – Guidelines for computing crop water requirements. Irrigation and Drainage Paper 56, 300 p.</p> <p>Olsson, J., 1998: Evaluation of a scaling cascade model for temporal rainfall disaggregation. Hydrology and Earth System Sciences, 2, p.19-30.</p> <p>Parton, W.J. and J.A. Logan, 1981: A model for diurnal variation in soil and air temperature. Agricultural Meteorology, 23, p.205-216.</p> <p>Verkaik, J.W., 2000: Evaluation of two gustiness models for exposure correction calculations. Journal of Applied Meteorology, 39, p.1613-1626.</p>

scholarly journals Estimation of the Evapotranspiration and Crop Coefficients of Bell Pepper Using a Removable Weighing Lysimeter: A Case Study in the Southeast of Spain

2021 ◽  
Vol 13 (2) ◽  
pp. 747
Author(s):  
Laura Ávila-Dávila ◽  
José Miguel Molina-Martínez ◽  
Carlos Bautista-Capetillo ◽  
Manuel Soler-Méndez ◽  
Cruz Octavio Robles Rovelo ◽  
...  
Keyword(s):  
Research Work ◽  
Bell Pepper ◽  
Crop Water ◽  
Water Requirements ◽  
Crop Water Requirements ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Precise Knowledge ◽  
Crop Coefficients ◽  
Weighing Lysimeter

Water use efficiency is essential in semiarid regions of Spain, and it can be achieved through a precise knowledge of the real crop water requirements (CWR). The Food and Agriculture Organization of the United Nations (FAO) offers standardized crop coefficients to establish the CWR. However, these coefficients can change due to different conditions, such as climatic variations and cultivation practices. In this work, the evapotranspiration (ETClys) and crop coefficients (KClys) of bell pepper were obtained with a compact removable weighing lysimeter between February and August for two crop seasons (2019 and 2020). ETClys was determined from the water balance, and the KClys values were determined as the ratio of the crop evapotranspiration, measured on the removable weighing lysimeter, and the reference evapotranspiration. The KClys average values for the bell pepper in the initial, middle, and final stages were 0.57, 1.06, and 0.80, respectively. KC regression models were obtained as a function of the fraction thermal units, achieving a maximum correlation of 0.67 (R2). In general, the KC values obtained in this research work were lower in the initial and in the final stages and larger in the middle stage in comparison with the FAO-56 values and other research works values in semiarid conditions. The bell pepper yield increased by 7.72% in 2019 and by 3.49% in 2020 compared to the yield reported by the Ministry of the Environment and Rural and Marine Areas of the Spanish Government in 2019 and with a minimum water loss through drainage. The results in this work can help farmers to determine the crop water requirements and to improve the system efficiency in semiarid locations with similar conditions to those in the study.

scholarly journals Comment on "Technical Note: On the Matt–Shuttleworth approach to estimate crop water requirements" by Lhomme et al. (2014)

2014 ◽  
Vol 11 (5) ◽  
pp. 5367-5375
Author(s):  
W. J. Shuttleworth
Keyword(s):  
United Nations ◽  
Technical Note ◽  
Crop Water ◽  
Water Requirements ◽  
Crop Water Requirements ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
The United Nations ◽  
United Nations Food ◽  
Simple Equations

Abstract. It is clear from Lhomme et al. (2014) that aspects of the explanation of the Matt–Shuttleworth approach can generate confusion. Presumably this is because the description in Shuttleworth (2006) was not sufficiently explicit and simple. This paper explains the logic behind the Matt–Shuttleworth approach clearly, simply and concisely. It shows how the Matt–Shuttleworth can be implemented using a few simple equations and provides access to ancillary calculation resources that can be used for such implementation. If the crop water requirement community decided that it is preferable to use the Penman–Monteith equation to estimate crop water requirements directly for all crops, the United Nations Food and Agriculture Organization could now update Irrigation and Drainage Paper 56 using the Matt–Shuttleworth approach by deriving tabulated values of surface resistance from Table 12 of Allen et al. (1998), with the estimation of crop evaporation then being directly made in a one-step calculation using an equation similar to that already recommended by the United Nations Food and Agriculture Organization for calculating reference crop evaporation.

scholarly journals Irrigation Schedules and Crop Water Requirements for Some Main Crops in Saudi Arabia

2021 ◽  
Author(s):  
Waseem Khan ◽  
Mogtaba Y. ◽  
Jamshaid Rahman ◽  
Murtada Elbashir ◽  
Ziyad AlHussain ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
High Temperature ◽  
Rice Crop ◽  
Effective Rainfall ◽  
Crop Water ◽  
High Demand ◽  
Water Requirements ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Standard Software

Abstract The Food and Agriculture Organization (FAO) CROPWAT 8.0 standard software and the CLIMWAT 2.0 tool affixed to it have been utilized in this study for Qassim Region of Saudi Arabia to find CWRs and irrigation plans for numerous extremely valuable crops of KSA. We were used CROPWAT P. M. method for find out the ETo and (USAD) S. C. method utilized to determine roughly effective rainfall. The analysis demonstrated that ETo change over from 2.84 mm/day in January to reach maximum 9.61 mm/day in July due to high temperature in summer with annual mean was 6.33 mm/day, effective rainfall changes from 0 mm to 53.4 mm. The total IWRs were 308.3 mm/dec, 335.9 mm/dec, 343.6 mm/dec, 853 mm/dec and 1479.6 mm/dec for Barley, Wheat, Maize, Rice and Citrus, respectively. Due to low demand in winter and high demand in summer, the total net irrigation and total gross irrigations are 210.6 mm and 147.4 mm, 176.6 mm and 123.6 mm, 204.5 mm and 143.2 mm, 163.9 mm and 114.7mm for Wheat, Barley, Citrus, and Maize respectively except rice crop. These results showed that Wheat, Barley, Citrus, Maize and Rice crops have 4, 4, 12, 4 and 12 irrigation schedules respectively in a year.

scholarly journals Comment on "Technical Note: On the Matt–Shuttleworth approach to estimate crop water requirements" by Lhomme et al. (2014)

2014 ◽  
Vol 18 (11) ◽  
pp. 4403-4406 ◽  
Author(s):  
W. J. Shuttleworth
Keyword(s):  
United Nations ◽  
Technical Note ◽  
Crop Water ◽  
Water Requirements ◽  
Crop Water Requirements ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
The United Nations ◽  
United Nations Food ◽  
Simple Equations

Abstract. It is clear from Lhomme et al. (2014) that aspects of the explanation of the Matt–Shuttleworth approach can generate confusion. Presumably this is because the description in Shuttleworth (2006) was not sufficiently explicit and simple. This paper explains the logic behind the Matt–Shuttleworth approach clearly, simply and concisely. It shows how the Matt–Shuttleworth can be implemented using a few simple equations and provides access to ancillary calculation resources that can be used for such implementation. If the crop water requirement community decided that it is preferable to use the Penman–Monteith equation to estimate crop water requirements directly for all crops, the United Nations Food and Agriculture Organization could now update Irrigation and Drainage Paper 56 using the Matt–Shuttleworth approach by deriving tabulated values of surface resistance from Table 12 of Allen et al. (1998), with the estimation of crop evaporation then being directly made in a one-step calculation using an equation similar to that already recommended by the United Nations Food and Agriculture Organization for calculating reference crop evaporation.

Empirical Equations to Estimate Evapotranspiration in Mosul City

2020 ◽  
Vol 27 (4) ◽  
pp. 98-102
Author(s):  
Haqqi Yasin ◽  
Luma Abdullah
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Air Temperature ◽  
Reference Evapotranspiration ◽  
Sunshine Duration ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Daily Data ◽  
Daily Sunshine ◽  
Measured Wind Speed

Average daily data of solar radiation, relative humidity, wind speed and air temperature from 1980 to 2008 are used to estimate the daily reference evapotranspiration in the Mosul City, North of Iraq. ETo calculator software with the Penman Monteith method standardized by the Food and Agriculture Organization is used for calculations. Further, a nonlinear regression approach using SPSS Statistics is utilized to drive the daily reference evapotranspiration relationships in which ETo is function to one or more of the average daily air temperature, actual daily sunshine duration, measured wind speed at 2m height and relative humidity

scholarly journals Tree Cover Estimation in Global Drylands from Space Using Deep Learning

2020 ◽  
Vol 12 (3) ◽  
pp. 343 ◽  
Author(s):  
Emilio Guirado ◽  
Domingo Alcaraz-Segura ◽  
Javier Cabello ◽  
Sergio Puertas-Ruíz ◽  
Francisco Herrera ◽  
...  
Keyword(s):  
Forest Cover ◽  
Global Scale ◽  
Classification Model ◽  
Tree Cover ◽  
System Modelling ◽  
Earth System ◽  
Visual Interpretation ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
The Cost

Accurate tree cover mapping is of paramount importance in many fields, from biodiversity conservation to carbon stock estimation, ecohydrology, erosion control, or Earth system modelling. Despite this importance, there is still uncertainty about global forest cover, particularly in drylands. Recently, the Food and Agriculture Organization of the United Nations (FAO) conducted a costly global assessment of dryland forest cover through the visual interpretation of orthoimages using the Collect Earth software, involving hundreds of operators from around the world. Our study proposes a new automatic method for estimating tree cover using artificial intelligence and free orthoimages. Our results show that our tree cover classification model, based on convolutional neural networks (CNN), is 23% more accurate than the manual visual interpretation used by FAO, reaching up to 79% overall accuracy. The smallest differences between the two methods occurred in the driest regions, but disagreement increased with the percentage of tree cover. The application of CNNs could be used to improve and reduce the cost of tree cover maps from the local to the global scale, with broad implications for research and management.

scholarly journals Mathematical Models and Comparative Analysis for Rice and Soya Bean Irrigation Crop Water Needs: A Case Study of Bida Basin Niger State, Nigeria

2021 ◽  
pp. 354-359
Author(s):  
A. Abdulrahim ◽  
M. D Shehu ◽  
E Yisa ◽  
Z. A. Ishaq
Keyword(s):  
Mathematical Models ◽  
Secondary Data ◽  
Computational Method ◽  
Maximum Temperature ◽  
Climatic Data ◽  
Crop Water ◽  
Integral Calculus ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
New Finding

In this manuscript, mathematical models for cropping water need (C.W.N) and the size of land for irrigation (S.L.I) were formulated. The solutions of the models for Crop water need for Soya beans and Rice, and the size of land for irrigation (S.L.I) of the two crops was obtained. We fill the gap by considering the size of the irrigation land which is not considered by the Food and Agriculture Organization (F.A.O). The computational Method of solutions is carried out to get effective results. The climatic data of the study area (Bida Basin) under which our research is based includes: Rainfall, Humidity, Sunshine hours, minimum and maximum temperature, evapotranspiration were secondary data collected from Nigeria Metrological Society (NIMET). We compared the results of CROPWAT 8.0 software developed by the Food and Agriculture Organization (F.A. O) and our computational method so that we can arrive at a new finding and better results. The results for the computational method with the size of Land for irrigation shows that there is an increase in crop water need for the crops than the results of CROPWAT 8.0 software developed by the Food and Agriculture Organization (F.A. O) in which the size for the land is not considered. We therefore, recommended that the integral calculus can be used to estimate the irregular shape of the size of the land if the land shape is not in rectangular form before solutions are given for accuracy and effective results.

scholarly journals CALIBRATION OF THE HARGREAVES-SAMANI EQUATION FOR SPECIFIC PERIODS OF THE YEAR IN THE MUNICIPALITY OF JAÍBA-MG, BRAZIL

2017 ◽  
Vol 25 (5) ◽  
pp. 445-453
Author(s):  
Anunciene Barbosa Duarte ◽  
Lucas Borges Ferreira ◽  
Edson Fagne Dos Santos
Keyword(s):  
Reference Evapotranspiration ◽  
Meteorological Data ◽  
Climatic Conditions ◽  
Crop Water ◽  
Climatic Effects ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Crop Water Demand ◽  
Limited Application ◽  
Monteith Equation

Reference evapotranspiration (ET0) explains the climatic effects on crop water demand. The Food and Agriculture Organization (FAO) recommends the Penman Monteith equation as a standard method for estimating ET0. However, because this equation requires a large amount of meteorological data, it has limited application. An alternative is the Hargreaves-Samani (HS) equation, which only requires air temperature data, and can be calibrated to specifc locations and periods. The present study aimed to calibrate the empirical parameters (coeffcients and exponent) of the HS equation for specifc periods of the year, as well as evaluate the behavior and calibration of this equation throughout the year in the municipality of Jaíba-MG, Brazil. The daily meteorological data from 1996 to 2011 were gathered from a weather station located in the municipality of Jaíba-MG. A general calibration was performed per semester, per season, per month, and during periods with similar climatic conditions. The calibration of the HS equation, in all of the forms studied, promoted better ET0estimations. The calibrations for specifc periods of the year only promoted slight increases in performance in relation to the general calibration, therefore they, in general, presented equal performance to each other.

scholarly journals Technical Note: On the Matt–Shuttleworth approach to estimate crop water requirements

2014 ◽  
Vol 18 (11) ◽  
pp. 4341-4348 ◽  
Author(s):  
J. P. Lhomme ◽  
N. Boudhina ◽  
M. M. Masmoudi
Keyword(s):  
Surface Resistance ◽  
Crop Coefficient ◽  
Technical Note ◽  
Crop Water ◽  
Weather Variables ◽  
Water Requirements ◽  
Crop Water Requirements ◽  
Food And Agriculture ◽  
True Value ◽  
United Nations Food

Abstract. The Matt–Shuttleworth method provides a way to make a one-step estimate of crop water requirements with the Penman–Monteith equation by translating the crop coefficients, commonly available in United Nations Food and Agriculture Organization (FAO) publications, into equivalent surface resistances. The methodology is based upon the theoretical relationship linking crop surface resistance to a crop coefficient and involves the simplifying assumption that the reference crop evapotranspiration (ET0) is equal to the Priestley–Taylor estimate with a fixed coefficient of 1.26. This assumption, used to eliminate the dependence of surface resistance on certain weather variables, is questionable; numerical simulations show that it can lead to substantial differences between the true value of surface resistance and its estimate. Consequently, the basic relationship between surface resistance and crop coefficient, without any assumption, appears to be more appropriate for inferring crop surface resistance, despite the interference of weather variables.

scholarly journals Desempenho de Método de Estimativa da Temperatura Média Diária: Um Estudo em Áreas com Forte Pressão Antrópica (Performance of Method for Estimation of the Mean Daily Air Temperature: A Study in Areas with Strong Anthropogenic Pressure)

2013 ◽  
Vol 6 (4) ◽  
pp. 857 ◽  
Author(s):  
Leonardo Fagner Ponciano Barbieri ◽  
Magaly De Fatima Correia ◽  
Célia Campos Braga ◽  
Weber Andrade Gonçalves ◽  
Magna Soelma Beserra de Moura
Keyword(s):  
Air Temperature ◽  
Meteorological Data ◽  
Lower Troposphere ◽  
Alternative Methods ◽  
Agricultural Expansion ◽  
Anthropogenic Pressure ◽  
Anthropogenic Pressures ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
The Mean

Este trabalho teve como objetivo avaliar o desempenho de métodos alternativos utilizados na estimativa da temperatura do ar média diária na região do Polo de irrigação Petrolina-Juazeiro. Os principais dados meteorológicos utilizados nas avaliações são oriundos de observações feitas nas estações climatológicas de Bebedouro – PE e Mandacaru – BA, pertencentes à Embrapa Semiárido. As análises estatísticas foram realizadas empregando regressão linear e seus respectivos coeficientes de determinação (R2). Os resultados obtidos com a aplicação do método recomendado pela FAO (Food and Agriculture Organization) mostram que a evolução temporal da temperatura é extremamente sensível às mudanças no uso e cobertura da terra. O aumento no teor de umidade na baixa troposfera, decorrente da expansão agrícola em área de caatinga, contribui para a absorção da energia calorífica e elevação da temperatura noturna (temperatura mínima). A B S T R A C T The development of this work aimed to evaluate the performance of alternative methods used to estimate the daily mean air temperature in the Petrolina-Juazeiro irrigation area. The main meteorological data used in the evaluations are observations made at the climatologic stations of Bebedouro – PE and Mandacaru – BA, which belong to Embrapa Semiarid. The statistical analyses were performed using linear regression and their respective coefficients of determination (R2). The results obtained by applying the method recommended by FAO (Food and Agriculture Organization) show that the temperature temporal evolution is extremely sensitive to changes in land use and coverage. The increase in the moisture content in the lower troposphere, due to agricultural expansion in the caatinga area, contributes toward absorption of heat energy and nighttime temperature (minimum temperature) rise. Key-Words: agricultural expansion, climate changes, anthropogenic pressures, semiarid, daily mean air temperature.

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