Climate trends and variabilities in regions with different classes of use and land cover in Rio Grande do Sul

Abstract

This study aims analyse the climatic trend of rainfall and temperature and the variability of drought events in four regions of Rio Grande do Sul. Monthly temperature and rainfall data from 1970 and 2020 were used, and the analysis performed in relation to drought months and drought events were on the decadal scale. The Mann-Kendall test was used to assess the monthly trend of temperature and rainfall, while drought events were analyzed by frequency. The drought characteristics studied were: the number of months and dry events, the greatest number of consecutive drought months (maximum duration), the average of drought months (average duration) and its maximum intensity. With the trend of increasing temperatures and the greater frequency of longer and more intense drought events, associated with the almost non-existence of monthly trends in rainfall, it is assumed that the mesoclimate of these regions is changing, tending towards a warmer, drier environment with irregular rainfall in the temporal and spatial scales