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The monitoring of flooded and waterlogged areas is essential for the Argentinean Pampas, an extensive flat region of high agricultural, livestock and industrial productivity. Areas within the Argentinean Pampas have experienced a rise of the water table in recent years, a key factor contributing to the development and persistence of flooding. The monitoring of these extreme environmental events is essential for long-term objectives, e.g. increasing knowledge to model and predict the occurrence and evolution of extreme events; as well as for short-term objectives, e.g. to provide producers potential field management options in a flood emergency. Therefore, the main objective of this work is to develop a simple method for monitoring affected areas, using accessible tools. A 160 km2 region of southeastern Cordoba for which data on water table height and daily precipitation are available, was chosen as a study site. To determine the flooded areas of the site, 18 Landsat-8/OLI images from September 2019 - April 2021 were used. On each of these images, pixels were labeled according to three categories: Open Water, Mixed-Water and Non-Water by applying unsupervised classification of the mNDWI and NDWI water indices. Despite the lack of scenes due to cloud cover the scenes may suffer, the Open Water category, and to a lower degree the Mixed-Water category, are able to capture the changes in the water table height due to precipitation. [ABSTRACT FROM AUTHOR]

Recently, vegetation indices have been used in order to determine the type of cover, with the interest of its temporal variation evaluation, or with the aim of determining the status of the health of crops from estimation of some characteristics such as plant vigor, chlorophyll content, nutritional or water status. Several studies have put forward a range of vegetation indices that use different bands in the visible and near-infrared spectrum, to obtain characteristics of interest. In this study, statistical differences between the NDVI, GNDVI, and NDRE vegetation indices, estimated from aerial images taken at 30 m above the canopy of an experimental Coffea arabica crop, were evaluated. Spearman correlation coefficient showed a higher correlation between the NDVI and GNDVI indices, compared to that found between either of them and NDRE. In addition to this, it was observed that, according to the values of the coefficient of variation, and the subsequent analysis of the histograms, the NDRE index presented a greater sensitivity to variation in plant vigor, which would suggest a greater potential to characterize the state of development of coffee cultivation, compared to other studied indices. [ABSTRACT FROM AUTHOR]

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