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Javier Pórtoles

Javier Pórtoles

About

29
Publications
14,286
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474
Citations
Introduction
Javier Pórtoles currently works in Computing in Mathematics, Statistics and Meteorology.

Publications

Publications (29)
Article
Full-text available
Diadromous species are particularly vulnerable to climate change because they utilize both marine and freshwater habitat to complete their life cycles. Dispersal plays an important role in restraining the distribution of plant and animal species, and is a key mechanism to allow diadromous species to adapt to changes in habitat suitability, but it i...
Presentation
Full-text available
Presentation made during the UHINAK IV the Cross-border conference on climate and coastal change that took place in Irún (Spain) during the days 4-5 of November 2020. The abstract works on a comparative study between the ECCLIPSE and CRISI-ADAPT II European projects regarding their respective local future climate scenarios in the Port of Valencia....
Article
Full-text available
Dynamical climate models present an initialisation problem due to the poor availability of deep oceanic data, which is required for the model assimilation process. In this sense, teleconnection indices, defined from spatial and temporal patterns of climatic variables, are conceived as useful tools to complement them. In this work, the near‐term cli...
Article
Heat- and cold-wave scenarios and temperature scenarios during the 21st century were obtained for Aragón (Spain), using, for the first time, nine Earth System Models (ESM) and two Representative Concentration Pathway (RCP) scenarios – RCP4.5 and RCP8.5 - belonging to the 5th Coupled Model Intercomparison Project (CMIP5). Local climate heat-wave sce...
Article
Full-text available
Dynamic Trees are a tree-based machine learning technique specially designed for online environments where data are to be analyzed sequentially as they arrive. Our purpose is to test this methodology for the very first time for Electricity Price Forecasting (EPF) by using data from the Iberian market. For benchmarking the results, we will compare t...
Article
Full-text available
A two-step statistical downscaling method has been reviewed and adapted to simulate twenty-first-century climate projections for the Gulf of Fonseca (Central America, Pacific Coast) using Coupled Model Intercomparison Project (CMIP5) climate models. The downscaling methodology is adjusted after looking for good predictor fields for this area (where...
Article
Full-text available
VALUE is an open European collaboration to intercompare downscaling approaches for climate change research, focusing on different validation aspects (marginal, temporal, extremes, spatial, process-based, etc.). Here we describe the participating methods and first results from the first experiment, using "perfect" reanalysis (and reanalysis-driven r...
Article
Probabilistic Neural Networks (PNNs) and Support Vector Machines (SVMs) are flexible classification techniques suited to render trustworthy species distribution and habitat suitability models. Although several alternatives to improve PNNs' reliability and performance and/or to reduce computational costs exist, PNNs are currently not well recognised...
Research
Supplement containing the detailed results from the simulations: expected relative seasonal changes in daily absolute precipitation (mm/day) and daily mean temperature (ºC) throughout the XXI century per meteorological station and each of the climate change studied scenarios, predicted daily mean air temperature; predicted daily mean streamflow, an...
Article
Full-text available
Climate changes affect aquatic ecosystems by altering temperatures and precipitation patterns, and the rear edges of the distributions of cold-water species are especially sensitive to these effects. The main goal of this study was to predict in detail how changes in air temperature and precipitation will affect streamflow, the thermal habitat of a...
Article
Full-text available
Climate change is gravely affecting forest ecosystems, resulting in large distribution shifts as well as in increasing infection diseases and biological invasions. Accordingly, forest management requires an evaluation of exposure to climate change that should integrate both its abiotic and biotic components. Here we address the implications of clim...
Data
Geographical representation and histogram of elevations of the meteorological stations from AEMET and WORLDCLIM. (DOCX)
Data
Selected environmental variables for Pinus pinaster Ait. (a) and pitch canker disease (b) to be included within their species distribution models. (DOCX)
Article
Full-text available
Climate change affects aquatic ecosystems altering temperature and precipitation patterns, and the rear edge of the distribution of cold-water species is especially sensitive to them. The main goal was to predict in detail how change in air temperature and precipitation will affect streamflow, the thermal habitat of a cold-water fish (brown trout,...
Conference Paper
Full-text available
RESUMEN La eficiencia en el uso de los recursos naturales es una prioridad para garantizar la sostenibilidad económica y ambiental de la agricultura. El proyecto Riego-Asesor analiza las relaciones entre la variabilidad climática y las necesidades requeridas en la gestión hídrica agrícola para así diseñar una batería de buenas prácticas de riego en...
Conference Paper
Full-text available
Streamflow and temperature regimes are well-known to influence on the availability of suitable physical habitat for instream biological communities. General Circulation Models (GCMs) have predicted significant changes in timing and geographic distribution of precipitation and atmospheric temperature for the ongoing century. However, differences in...
Article
Full-text available
This paper addresses the determination of the realized thermal niche and the effects of climate change on the range distribution of two brown trout populations inhabiting two streams in the Duero River basin (Iberian Peninsula) at the edge of the natural distribution area of this species. For reaching these goals, new methodological developments we...
Conference Paper
Full-text available
This study is aimed at forecasting the changes in the suitability of brown trout habitat (Salmo trutta L.), caused by alterations in the stream temperature and the flow regime under climate change scenarios. The stream temperature and instantaneous flow in several streams in Central Spain were modelled from daily temperature and precipitation data....
Article
Different epidemiological studies have shown that high temperatures are directly related to mortality, furthermore many studies on the effects of climate change on future mortality are being conducted. The objective of this study is to estimate the effect of extreme hot temperatures on daily mortality in Zaragoza (Spain) from 2014 to 2021, utilisin...
Article
Full-text available
The Mediterranean coast of Spain often experiences intense rainfall, sometimes reaching remarkable amounts of more than 400 mm in one day. The aim of this work is to study possible changes of extreme precipitation in Spain for this century, simulated from several Coupled Model Intercomparison Project Phase 5 (CMIP5) climate models. Eighteen climate...
Article
Full-text available
This study describes a two-step analogue statistical downscaling method for daily temperature and precipitation. The first step is an analogue approach: the “n” days most similar to the day to be downscaled are selected. In the second step, a multiple regression analysis using the “n” most analogous days is performed for temperature, whereas for pr...
Article
By applying a two-step statistical downscaling technique to four climate models under different future emission scenarios, we produced future projections of the daily precipitation and the maximum and minimum temperatures over the Spanish region of Aragón. The reliability of the downscaling technique was assessed by a verification process involving...
Conference Paper
Full-text available
Tenerife, the largest of the seven Canary Islands, has the highest elevation of Spain, the Teide volcano (3.718 m. – the third largest volcano in the world from its base). Its climate is hard influenced both for its tropical latitude and for its exposition to the Trade Winds (alisios), which blow from the northeast for almost the whole year. These...

Questions

Question (1)
Question
Does anyone know any implementation of Least-Squares Support Vector Machine (LS-SVM) for R environment?
The only one I know is the kernlab package, but it is not enough for me because, as it is detailed in the package documentation,
  1. "the solution is an approximation to the exact solution of the lssvm optimization problem".
  2. "regression - currently nor supported -", and I want to study regression problems.
Thank you.

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Cited By

Projects

Project (1)
Project
The recently launched RESCCUE project (“Resilience to cope with Climate Change in Urban Areas – a multisectorial approach focusing on water”) aims to provide practical and innovative models and tools to end-users facing climate change challenges to build more resilient cities. The project will provide tools to assess urban resilience from a multisectorial approach, for current and future climate scenarios and including multiple hazards. This holistic approach to urban resilience will enable city managers and urban systems operators to decide the optimal investments to cope with future situations. RESCCUE is a 48-month duration project built around three research sites (Barcelona, Lisbon and Bristol) coordinated by Aquatec and co-funded by the EU Horizon 2020 research and innovation programme under Grant Agreement no.700174.