Crop coefficient (Kc) is an important factor contributing to estimation of evapotranspiration, and is also used to determine the irrigation schedule. This study investigated and determined the monthly Kc of winter wheat (Triticum aestivum... more
Crop coefficient (Kc) is an important factor contributing to estimation of evapotranspiration, and is also used to determine the irrigation schedule. This study investigated and determined the monthly Kc of winter wheat (Triticum aestivum L.) using five vegetation indices (VIs): Normalized Difference Vegetation Index (NDVI), Difference Vegetation Index (DVI), Soil Adjusted Vegetation Index (SAVI), Infrared Percentage Vegetation Index (IPVI), and Ratio Vegetation Index (RVI) of four basins in Golestan province, Iran. 14 Landsat-8 images according to crop growth stage were used to estimate monthly Kc of wheat. VIs were calculated based on infrared and near infrared bands of Landsat 8 images using Geographical Information System (GIS) software. The best VIs were chosen after establishing a regression relationship among these VIs with FAO Kc and Kc that was modified for the study area by the previous research based on R² and Root Mean Square Error (RMSE). The result showed that local modified SAVI with R²= 0.767 and RMSE= 0.174 was the best index to produce monthly wheat Kc maps.
Determination of temporal and spatial distribution of water use (WU) within agricultural land is critical for irrigation management and could be achieved by remotely sensed data. The aim of this study was to estimate WU of dwarf green... more
Determination of temporal and spatial distribution of water use (WU) within agricultural land is critical for irrigation management and could be achieved by remotely sensed data. The aim of this study was to estimate WU of dwarf green beans under excessive and limited ...
In present study spatial crop coefficient (Kc) estimated from Surface Energy Balance Algorithms for Land (SEBAL) model was compared with simulated spatial Kc based on Normalized Difference Vegetation Index (NDVI) and Leaf Area Index... more
In present study spatial crop coefficient (Kc) estimated from Surface Energy Balance Algorithms for Land (SEBAL) model was compared with simulated spatial Kc based on Normalized Difference Vegetation Index (NDVI) and Leaf Area Index (LAI). For selection and comparison of optimal model statistical tests were applied. Statistical tests have revealed that LAI based spatial Kc (LAI-Kc) model has best performances (R2=0.976) in context of spatial Kc compared to NDVI-Kc model with respect to SEBAL-Kc. Further, results show that LAI based simulated spatial Kc has good coefficient of determination (R2, second order polynomial) of 0.976 (at 95%), Multiple R=0.94, and Standard error= 0.11) with SEBAL-Kc rather than NDVI-Kc. The procedure for spatial LAI-Kc presented in this paper should be useful in other regions of the globe to understand crop water requirement studies based on evapotranspiration.
A study was carried out to determine the crop water requirement of some selected crops for the area around Kampe (Omi) Dam Irrigation Project. These crops include rice, maize, tomato, vegetable amaranth, pepper, onion and cabbage. Crop... more
A study was carried out to determine the crop water requirement of some selected crops for the area around Kampe (Omi) Dam Irrigation Project. These crops include rice, maize, tomato, vegetable amaranth, pepper, onion and cabbage. Crop water requirement for each of the crops was determined by using 25-year climatic data in CROPWAT. Reference crop evapo-transpiration (ETo) was determined using
To characterize the interactions between variable water supply and crop load on vegetative growth and water relations of an olive orchard (cv. Morisca) planted in 1998 at 417treesha−1, two different experiments were conducted over a... more
To characterize the interactions between variable water supply and crop load on vegetative growth and water relations of an olive orchard (cv. Morisca) planted in 1998 at 417treesha−1, two different experiments were conducted over a six-year period (2002–2007) in Badajoz, Southwest of Spain. Experiment 1, assessed the responses during the early years of the orchard (2002–2004) using four irrigation treatments
... remote sensing data Jaime Garatuza-Payan, Antonio Tamayo Dept. of Water and Environmental Sci. Instituto Tecnologico de Sonora Cd. Obregon, Son., Mexico garatuza@itson.mx Christopher Watts, Julio C. Rodríguez IMADES Hermosillo, Son.,... more
... remote sensing data Jaime Garatuza-Payan, Antonio Tamayo Dept. of Water and Environmental Sci. Instituto Tecnologico de Sonora Cd. Obregon, Son., Mexico garatuza@itson.mx Christopher Watts, Julio C. Rodríguez IMADES Hermosillo, Son., Mexico ...
Water for food production represents by far the largest share among all uses and its demand keeps growing with increasing population. The lack of water can affect disfavour the economic and social stability of entire regions. New... more
Water for food production represents by far the largest share among all uses and its demand keeps growing with increasing population. The lack of water can affect disfavour the economic and social stability of entire regions. New technologies (Earth Observation, Geographic Information Systems) provide the possibility of time and spatial observation for the decision support and management. PLEIADeS (Participatory multi-Level EO-assisted tools for Irrigation water management and Agricultural Decision -Support) addresses the efficient and sustainable use of water for food production in water - scarce environments with the use of satellite data and GIS. To the present study is described the process that applied for the computation of crop coefficient Kc that constitutes the basic parameter for the computation of evapotraspiration and accordingly the water needs of crops. Monitoring of Kc with ground based measurements is a time-consuming process and almost unfeasible to apply in large s...
Accurate estimation of ET from field crops/orchards is the basis for better irrigation water management. In areas like Mesilla Valley, NM, where water is scarce, it is even more important to precisely determine the crop ET. An OPEC energy... more
Accurate estimation of ET from field crops/orchards is the basis for better irrigation water management. In areas like Mesilla Valley, NM, where water is scarce, it is even more important to precisely determine the crop ET. An OPEC energy balance system was run for 117 days (June 22 October 14, 2001) in a matured pecan farm at Mesilla Valley, NM.
SEBAL (Surface Energy Balance Algorithm for Land) is a remote sensing model comprised of twenty-five submodels for calculating crop water requirements or evapotranspiration (ET) for large areas. SEBAL was developed in the Netherlands by... more
SEBAL (Surface Energy Balance Algorithm for Land) is a remote sensing model comprised of twenty-five submodels for calculating crop water requirements or evapotranspiration (ET) for large areas. SEBAL was developed in the Netherlands by Bastiaanssen and has been modified during Idaho studies for application to irrigated agriculture, rangeland, mountainous terrain and clear, cold lakes under semiarid conditions. SEBAL has been applied in many developing countries and has now been applied in southern Idaho to predict monthly and seasonal ET for water rights accounting and for operation of ground water models. Results from SEBAL have been compared and validated using precision weighing lysimeter measurements from the United States Department of Agricultural Research Center at Kimberly, Idaho. ET maps via SEBAL provide the means to quantify, in terms of both the amount and spatial distribution, the ET on a field-by-field basis. ET from satellite images may ultimately replace current pro...
Eight-year-old Murcott orange trees (Citrus sinensis (L.) Murcott) grown in greenhouse lysimeters filled with sandy soil were used to investigate seasonal variations in daily and hourly evapotranspiration. The study was conducted in Japan... more
Eight-year-old Murcott orange trees (Citrus sinensis (L.) Murcott) grown in greenhouse lysimeters filled with sandy soil were used to investigate seasonal variations in daily and hourly evapotranspiration. The study was conducted in Japan during the summer of 2000 ...
Accurate estimations of plant evapotranspiration and its spatial distribution are fundamental for the evaluation of vegetation water stress. Satellite remote sensing techniques represent precious tools for the evapotranspiration... more
Accurate estimations of plant evapotranspiration and its spatial distribution are fundamental for the evaluation of vegetation water stress. Satellite remote sensing techniques represent precious tools for the evapotranspiration estimations at large scale. Many studies are based on the use of thermal signals as inputs for energy balance equations that are solved to estimate evapotranspiration (e.g., Bastiaanssen et al., 1998; Ayenew,
