STUDY OF PRECIPITATION AND EXTREME DROUGHT: AN ANALYSIS FOR A POTENTIAL AGRICULTURAL REGION IN THE BRAZILIAN SOUTHERN AMAZON

Soybean, corn, and cotton are the main agricultural commodities in the state of Mato Grosso. However, regardless of the technological level, the region's climate, including the rainfall regime, influences the increase in production. The objective of this study was to define the behavior of monthly and annual precipitation variability in the northwest region of Mato Grosso. Daily precipitation records were collected, calculating the totals for each month of the historical series for each of the four rainfall stations of the National Water and Sanitation Agency (ANA): Aripuanã (1985–2020), Colniza (2001–2020), Cotriguaçu (2004–2020), and Juína (1985–2020). The annual distribution of rainfall during the studied periods ranged from 1,376.2 to 3,017.3 mm. The monthly SPI-1 index revealed a total of 56 months affected by very dry events and 34 extreme drought events. The annual SPI-12 index indicated 7 very dry years and 5 extremely dry years.