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J. C. Fontes
University of the Azores
8Publications
4H-index
67Citations
Publications 8
Newest
Published on Nov 1, 2018in Theoretical and Applied Climatology 2.32
Paula Paredes18
Estimated H-index: 18
(University of Lisbon),
J. C. Fontes4
Estimated H-index: 4
(University of the Azores)
+ 1 AuthorsLuis S. Pereira51
Estimated H-index: 51
(University of Lisbon)
Reference crop evapotranspiration (ETo) estimations using the FAO Penman-Monteith equation (PM-ETo) require a set of weather data including maximum and minimum air temperatures (T max, T min), actual vapor pressure (e a), solar radiation (R s), and wind speed (u 2). However, those data are often not available, or data sets are incomplete due to missing values. A set of procedures were proposed in FAO56 (Allen et al. 1998) to overcome these limitations, and which accuracy for estimating daily ETo...
4 Citations Source Cite
Published on Jan 1, 2011in Geoderma 3.74
J. C. Fontes4
Estimated H-index: 4
,
M.R. Cameira11
Estimated H-index: 11
(Technical University of Lisbon)
+ 2 AuthorsLuis S. Pereira51
Estimated H-index: 51
(Technical University of Lisbon)
Abstract In Terceira Island (Azores, Portugal), 87% of the agricultural land is used for permanent pasture under periodical grazing. The edaphoclimatic conditions promote nitrate leaching into the groundwater and runoff, which carries sediments and fertilizers into the surface waters. Of particular interest is the fact that volcanic Andosols are rarely study to analyze nitrogen dynamics. The soil capacity to provide mineral N from its organic matter pool through mineralization was estimated usin...
3 Citations Source Cite
Published on Apr 1, 2004in Catena 3.26
J. C. Fontes4
Estimated H-index: 4
,
Luis S. Pereira51
Estimated H-index: 51
(Technical University of Lisbon),
R.E Smith5
Estimated H-index: 5
(Colorado State University)
Abstract The islands of Azores are of very recent volcanic origin and their soils have special physical and chemical characteristics because of the specific circumstances of their formation from the volcanic materials, their young age and the presence of allophane. To assess and understand the hydrologic behavior of these soils under agricultural practices, the deterministic model OPUS was tested and calibrated using field data collected from 1996 to 1998 in two small basins of Terceira Island. ...
20 Citations Source Cite
Published on Apr 1, 2004in Catena 3.26
J. C. Fontes4
Estimated H-index: 4
,
Maria C. Gonçalves9
Estimated H-index: 9
,
Luis S. Pereira51
Estimated H-index: 51
(Technical University of Lisbon)
Abstract The Azores Islands are of recent volcanic origin and their soils, classified as Andosols, have characteristics peculiar to their formation and constituents. Several other areas in the world, including parts of Europe, have Andosols, but their hydraulic properties are not well known. To improve understanding of the hydrologic behaviour of these soils, two experimental sites were selected for in situ hydrological observations and sampling for laboratory analysis. The two studied soils are...
25 Citations Source Cite
Published on Jan 1, 2002
J. C. Fontes4
Estimated H-index: 4
,
Luis S. Pereira51
Estimated H-index: 51
+ 5 AuthorsV. Andreu
Published on Jan 1, 2000in Transactions of the ASABE 1.12
Isabel Alves12
Estimated H-index: 12
,
J. C. Fontes4
Estimated H-index: 4
,
Luis S. Pereira51
Estimated H-index: 51
Infrared surface temperature (T s ) has been considered a practical approximation of the true aerodynamic temperature (T o ). Once shown that the two temperatures are basically not the same, a new interpretation of T s became a necessity. Since T s reflects the evaporative cooling that occurs due to transpiration, the hypothesis that it represents a wet bulb temperature is tested. Mean absolute difference between measured and theoretically derived surface temperature was 0.79°C and maximum relat...
4 Citations Source Cite
Published on Jan 1, 2000in Transactions of the ASABE 1.12
Isabel Alves12
Estimated H-index: 12
,
J. C. Fontes4
Estimated H-index: 4
,
Luis S. Pereira51
Estimated H-index: 51
In many conditions, there is a need for simple yet accurate methods to estimate crop evapotranspiration. There is interest in the energy balance approach based on infrared surface temperature (T s ). However, the accuracy of the method relies on how closely T s approximates the true aerodynamic temperature (T o ). Several authors have reported a reasonable agreement between the two temperatures, allowing good estimates of latent heat flux. In this study, errors in T o were minimized by measuring...
6 Citations Source Cite
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