Articles
Using remote sensing models to determine evapotranspiration of a pomegranate orchard in a Mediterranean-type climate
Article number
1395_7
Pages
45 – 52
Language
English
Abstract
Information about the atmospheric evaporative demand of pomegranate (Punica granatum L.) trees is crucial to guide irrigation practices.
Based on a normalized difference vegetation index (NDVI), the study aimed to analyse the evapotranspiration of a 13-year-old pomegranate orchard under irrigation in Wellington, Western Cape province of South Africa, using different remote sensing approaches.
The reference evapotranspiration(ETo) calculated by using the FAO56 Penman-Monteith equation at selected growing stages from flowering to harvest ranged from 2.8 mm d‑1 in September 2022 to 3.7 mm d‑1 in March 2023. In contrast, ETo estimated using remote sensing-based eeflux ranged from 3.2 to 5.5 mm d‑1, respectively.
The NDVI was calculated based on Landsat 8 satellite data downloaded from USGS website and analysed using QGIS. The output from Landsat data indicated that the highest NDVI value of 0.6 was obtained during December and the lowest value of 0.3 in March, and NDVI estimated by eeflux indicated 0.7 and 0.6 respectively, during the growing season.
There was a moderate correlation relationship between estimates of both methods for ETo (r=0.67) and NDVI (r=0.54).
Based on a normalized difference vegetation index (NDVI), the study aimed to analyse the evapotranspiration of a 13-year-old pomegranate orchard under irrigation in Wellington, Western Cape province of South Africa, using different remote sensing approaches.
The reference evapotranspiration(ETo) calculated by using the FAO56 Penman-Monteith equation at selected growing stages from flowering to harvest ranged from 2.8 mm d‑1 in September 2022 to 3.7 mm d‑1 in March 2023. In contrast, ETo estimated using remote sensing-based eeflux ranged from 3.2 to 5.5 mm d‑1, respectively.
The NDVI was calculated based on Landsat 8 satellite data downloaded from USGS website and analysed using QGIS. The output from Landsat data indicated that the highest NDVI value of 0.6 was obtained during December and the lowest value of 0.3 in March, and NDVI estimated by eeflux indicated 0.7 and 0.6 respectively, during the growing season.
There was a moderate correlation relationship between estimates of both methods for ETo (r=0.67) and NDVI (r=0.54).
Authors
R.L. Kgaphola, P.C. Tharaga, T. Volschenk, S. Dzikiti
Keywords
eeflux, irrigation, QGIS, reference evapotranspiration, water use
Groups involved
- Division Temperate Tree Nuts
- Division Vine and Berry Fruits
- Division Temperate Tree Fruits
- Division Precision Horticulture and Engineering
- Division Plant-Environment Interactions in Field Systems
- Division Tropical and Subtropical Fruit and Nuts
- Working Group Precision Management of Orchards and Vineyards
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