Tendências de variações climáticas e suscetibilidade á desertificação na bacia hidrográfica no rio Moxotó

Abstract

Desertification has been one of the most challenging environmental problems in recent times, the subject of studies aiming to analyze and identify its origin, progression, intensity, space-time variation, and classification. Climatic trends and susceptibility to desertification are environmental concerns in the State of Pernambuco. Thus, the objective was to evaluate the variation in the Aridity Index (AI) and the tendency towards susceptibility to desertification for the Moxotó river basin. To achieve this, the monthly and annual potential evapotranspiration (PET) was estimated, and its space time variability was analyzed. The aridity index was determined, identifying the areas most susceptible to desertification. Trends in changes in aridity index climatic patterns were also examined. Monthly average precipitation values from the historical series from 1989 to 2018 were used, obtained from sixteen (16) rainfall stations governed by the Pernambuco Water and Climate Agency (APAC). Average air temperature data for the same period and location of the stations were obtained using the Estima_T software. The aridity index classification and desertification susceptibility levels for the Moxotó river basin were obtained from the aridity index. The results indicate significant space-time irregularity in the distribution of air temperature, PET, precipitation, and AI parameters. The average air temperature is 24°C, showing a significant increase with the arrival of summer (26°C) and variation depending on the local geomorphology. Potential evapotranspiration is around 1,271 mm, irregularly distributed, with prominent values in areas with low precipitation and high temperatures. Precipitation is concentrated in the early months of the year, reducing the annual rainfall total from east to west, thereby advancing water deficiency (DEF). Finally, it is revealed that the Moxotó river basin is highly susceptible to the desertification process due to the hydroclimatic characteristics of the semi-arid geosystem.