Resumen

SALVO, C.S.; BALDASSINI, P.  y  DI BELLA, C.. Identificación de campos de precipitación mediante el uso de radares meteorológicos: una alternativa para mejorar las estimaciones espaciales de las lluvias. RIA. Rev. investig. agropecu. [online]. 2021, vol.47, n.2, pp.240-248.  Epub 08-Sep-2021. ISSN 1669-2314.

The spatial interpolation of point measurement from meteorological stations is a recurring way of estimating precipitation at a given site. However, as the distance to the specific measurement site increases, these estimates tend to differ greatly in the amount of water that actually precipitates. Optical remote sensors on board satellites allow to increase the spatial extent with an adequate temporal resolution, although they have a low spatial resolution. The terrestrial weather radars present greater spatial and temporal resolution but previous works have shown a significant gap between the estimated precipitation values and those recorded in rain gauges. Given the limited punctual precipitation information and its variable distribution in the territory, the identification of precipitation fields (that is, the area where the precipitating event actually occurs) using radars can be an important alternative to increase the accuracy of the estimates based in conventional interpolations. The objective of this work was to delimit precipitation fields from the use of the INTA weather radar network in order to complement rainfall estimates in large areas of the territory based on data from punctual interpolations. For this, data from October and November 2016 were considered for the analysis, including a total of 8784 images. The spatial interpolation of the daily rainfall records measured at the meteorological stations was performed and the weather radars were used to recognize the spatial distribution of precipitation events. For that, a precipitation detection threshold of 3,125 mm was defined. The precipitation fields were delimited and the product of “Spatial Interpolation using Radar (IER)” was generated on a daily and monthly scale. It was observed that events of daily precipitation actually occurred only in 55% of the studied area, so that conventional spatial interpolations generate an overestimation in the area of occurrence of this event. This would generate a mean overestimation of precipitated water for the study area of 91,1 mm y 35,2 mm for the months of October and November respectively, which could seriously affect the decision-making related to this resource. The radar turned out to be a practical and complementary tool for the delimitation of those areas that were affected by the precipitation event and that are overestimated by the discontinuous recording in the spatial interpolations, even more in distant areas from meteorological stations.

Palabras clave : spatial interpolation; remote sensing; radar.

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