A Continuous Multisite Multivariate Generator for Daily Temperature Conditioned by Precipitation Occurrence

Temperature is one of the most influential weather variables necessary for numerous studies, such as climate change, integrated water resources management, and water scarcity, among others. The temperature and precipitation are relevant in river basins because they may be particularly affected by modifications in the variability, for example, due to climate change. We developed a stochastic model for daily precipitation occurrences and their influence on maximum and minimum temperatures with a straightforward approach. The Markov model has been used to determine everyday occurrences of rainfall. Moreover, we developed a multisite multivariate autoregressive model to represent the short-term memory of daily temperature, called MASCV. The reduction of parameters is an essential factor addressed in this approach. For this reason, the normalization of the temperatures was performed through different nonparametric transformations. The case study is the Jucar River Basin in Spain. The multisite multivariate stochastic model of two states and a lag-one accurately represents both occurrences as well as maximum and minimum temperature. The simulation and generation of occurrences and temperature is considered a continuous multivariate stochastic process. Additionally, time series of multiple correlated climate variables are completed. Therefore, we simplify the complexity and reduce the computational time for the simulation.

Automated summary

This study developed a novel stochastic model to analyze the impact of temperature and precipitation on river basins, and conducted a case study on the Jucar River Basin in Spain. We used a Markov model to determine daily rainfall occurrences and developed a multisite multivariate autoregressive model to represent the short-term memory of temperature. The reduction of parameters and normalization of temperature were important factors in this approach.