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Evaluating the sensitivity of vegetation and water indices to monitor drought for three Mediterranean crops
Author(s) -
Yildirim Tugba,
Zhou Yuting,
Flynn K. Colton,
Gowda Prasanna H.,
Ma Shengfang,
Moriasi Daniel N.
Publication year - 2021
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.1002/agj2.20475
Subject(s) - normalized difference vegetation index , environmental science , vegetation (pathology) , irrigation , enhanced vegetation index , mediterranean climate , crop , agronomy , leaf area index , vegetation index , biology , ecology , medicine , pathology
Understanding drought effects on vegetative health for crop producing locations, such as the Seferihisar‐Kavakdere region in western Turkey, is vital for water and crop management. This study used Landsat‐derived spectral vegetation indices, specifically normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), and land surface water index (LSWI) to evaluate and compare their performance and sensitivity for three major crops (citrus, grape, and olive) under dry (2008), wet (2010), and normal (2015) climatic conditions. Results showed that all three crops were affected by drought despite two (citrus and grape) being irrigated. However, grape and olive were more affected by drought than citrus. Drought conditions were exacerbated during September and October because of lack of precipitation and because irrigation is not a common practice during these months in this region. Therefore, this study aimed to use and compare drought sensitivities of Landsat‐derived spectral vegetation indices. All studied indices were closely related (.48 ≤ R 2 ≤ .98) for citrus, grape, and olive. The EVI and LSWI were greater than NDVI when NDVI values were greater than 0.65 for citrus, and LSWI values were larger than NDVI when NDVI values were greater than 0.6 for grape and olive during the wet year. The results showed that different vegetation indices are needed to detect drought from one crop to another under different climatic conditions. Our findings indicate that the irrigation applications in 2008 (drought year) were not sufficient to alleviate the severe drought stress experienced throughout the winter and growing seasons.