RMAWGEN-package: R - Multi-site Autoregressive WEather Generator

Description Details Note Author(s) References

Description

Multi-site autoregressive Models for Daily Weather Generation. The modeling in climate change applications for agricultural or hydrological purposes often requires daily time-series of precipitation and temperature. This is the case of downscaled series from monthly or seasonal predictions of Global Climate Models (GCMs). The R package RMAWGEN (R Multi-Sites Auto regressive Weather GENerator) is built to generate daily temperature and precipitation time series in several sites by using the theory of vectorial autoregressive models (VAR). The VAR model is used because it is able to maintain the temporal and spatial correlations among the several series. In particular, observed time series of daily maximum and minimum temperature and precipitation are used to calibrate the parameters of a VAR model (saved as ”GPCAvarest2” or ”varest2” classes, which inherit the "varest" S3 class defined in the package vars [Pfaff, 2008]). Therefore the VAR model, coupled with monthly mean weather variables downscaled by GCM predictions, allows to generate several stochastic daily scenarios. The structure of the package consists in functions that transform precipitation and temperature time series into Gaussian-distributed random variables through deseasonalization and Principal Component Analysis. Then a VAR model is calibrated on transformed time series. The time series generated by VAR are then inversely re transformed into precipitation and/or temperature series. An application dateset is included in the RMAWGEN package as an example; it is presented by using a dataset with daily weather time series recorded in 59 different sites of Trentino (Italy) and its neighborhoods for the period 1958-2007. The software is distributed as a Free Software with General Public License (GPL) and is available on CRAN website. (https://cran.r-project.org/package=RMAWGEN) . A presentation of the package is available on https://docs.google.com/file/d/0B8xDtMCnW3dJU2JIemVqMnpKTHc/edit. Example script files about package usage are available on https://github.com/ecor/RMAWGENCodeCorner.

Details

Package: RMAWGEN
Type: Package
Version: 1.2.6
Date: 2014-04-27
License: GPL (>= 2)
LazyLoad: yes
Depends: R(>=2.12),time,chron,vars

Note

RMAWGEN has been created in the frame of ACE-SAP (http://www.ace-sap.it/) and ENVIROCHANGE (http://www.envirochange.eu/) projects funded by Provincia Autonoma di Trento (http://www.provincia.tn.it/).

RMAWGEN is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

RMAWGEN is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

Author(s)

Emanuele Cordano [email protected], Emanuele Eccel [email protected]

References

Bernhard Pfaff (2008). VAR, SVAR and SVEC Models: Implementation Within R Package vars. Journal of Statistical Software 27(4). http://www.jstatsoft.org/v27/i04/


RMAWGEN documentation built on May 29, 2017, 9:09 a.m.