Analyzing Trends in Rainfall and Their Impacts in Water Management in a Cerrado Region in Brazil

Abstract

Abstract This study presents a trend analysis related to a Cerrado Region in Brazil surrounded by multiple climatic influences and which lived a recent water crisis (2016-2018). This crisis could be associated with climatic changes or population growth. To verify the first possibility, an analysis was performed on a series of rainfall data (21 rain gauges spread throughout the region) divided by season periods (December/January/February – DJF, March/April/May – MAM, June/July/August – JJA, September/October/November – SON, and Water Year – WY) to provide information about the presence of trends or lack thereof. Four statistics tests were used in this procedure: Cox-Stuart, Mann-Kendall, Spearman, and Wald-Wolfowitz. The overall results indicate that the percentage of gauges/periods displaying trends by the Mann-Kendall was 10.48%, Cox-Stuart 9.52%, Spearman 12.38, and Wald-Wolfowitz 8.57%. Of these gauges/periods, 70% were classified as highly skewed, 10% as moderately skewed, and 20% as symmetric. Most of the trends are concentrated in the JJA period where it registered about 22 mm of rainfall average while the annual mean total precipitation is ~1500 mm.