Delineation of homogeneous management zones through EMI and multispectral data for a vineyard in northern Italy
Abstract
Data di Pubblicazione:
2018
Citazione:
Delineation of homogeneous management zones through EMI and multispectral data for a vineyard in northern Italy / B. Ortuani, G. Sona, G. Ronchetti, A. Facchi. - In: GEOPHYSICAL RESEARCH ABSTRACTS. - ISSN 1607-7962. - 20:(2018 Apr). ((Intervento presentato al convegno EGU General Assembly tenutosi a Vienna nel 2018.
Abstract:
Homogeneous site-specific management zones (SSMZ) used in Precision Agriculture for the optimization of
water and nutrient management are usually delineated from soil electrical conductivity (EC) maps obtained
through geophysical proximal soil sensors. To improve SSMZ delineation, the recent literature recommends the
integration of geophysical soil monitoring data with crop information acquired through multispectral (VIS-NIR
data) imaging. In non-flat areas, topography can influence the soil water condition and consequently the crop
water status; in this situations SSMZ delineation may be improved by taking into account the topography (which
can be investigated through VIS surveys) in addition to soil and crop data. On the other hand, it is now widely
recognized that thermal infrared (TIR) can be used to produce indices, e.g. Crop Water Stress Index (CWSI), well
correlated with the crop water status.
Objective of this study is the fusion of EC and VIS-NIR data to delineate SSMZs in a rainfed vineyard of 1.5
ha located in northern Italy (Franciacorta), and the assessment of the obtained SSMZ map through a TIR survey
carried out in a hot and dry period of the agricultural season 2017. In the literature, the delineation of SSMZs is
usually validated through a distributed crop yield map. In this study, in absence of this type of information, it is
assumed that the crop water status may summarize the effect of the principal environmental factors acting on the
crop production. EC data were collected in May with a multi-frequency electro-magnetic induction (EMI) sensor.
The EMI sensor worked with three different frequencies, corresponding to increasing depths of exploration up
to 3 - 4 meters. Data for each frequency were interpolated to obtain EC maps. VIS-NIR and TIR images were
acquired in late July with multispectral and thermal cameras mounted on an Unmanned Aerial Vehicle (UAV),
during two separate flights. Photogrammetric processing was performed, producing the digital terrain model
(DTM), four orthophotos from VIS-NIR data (one for each channel), and one orthophoto from TIR data. After
radiometric and atmospheric corrections, VIS-NIR and TIR orthophotos were used to retrieve the Normalized
Difference Vegetation Index (NDVI) and the CWSI. The post processing of the different data, the data fusion procedure
and the results obtained in term of SSMZ map and its assessment will be presented and discussed in the poster.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
geophysical data, multispectral data, thermal imaging, data fusion, homogeneous management
zone, crop water stress
Elenco autori:
B. Ortuani, G. Sona, G. Ronchetti, A. Facchi
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