Análise preliminar do potencial agrícola da região semiárida alagoana

Abstract

The 2017 IBGE Census showed that more than 75% of agricultural activities in the Brazilian semi-arid region are related to family farming, therefore, monitoring systems are essential to understand the general distribution pattern of time of use and changes in vegetation cover, precipitation and conditions from soil. Agroecological zoning is a scientific technical tool based on understanding the environmental potential and vulnerability of a specific area, in particular the behavior and characteristics of climate, soil, vegetation, geomorphology, with an emphasis on the suitability of agricultural land. In March 2005, the Ministry of National Integration (MI) defined 38 municipalities as being at some stage of environmental degradation. This methodology aimed to evaluate the agricultural potential of the semi-arid region of Alagoas, based on a time series of satellite images, analyzing agrometeorological variables. Analyzing the interannual average of NDVI, it is possible to note that the medium and high hinterlands present, almost in their entirety, values below 0.5, with the exception of only a few areas that presented higher values, between 0.5 and 0.7, as can be seen in the municipality of Mata Grande. According to Koppen's classification, rainfall in the semi-arid region of Alagoas varies between 250 mm and 750 mm per year, which can be observed in the interannual average of the spatial distribution of precipitation. When analyzing the interannual average of soil moisture, it is possible to notice that the lowest values of water retained in the soil were found in the Sertão Alagoano region. Whether native vegetation or plantations, precipitation and soil moisture strongly influence the health of vegetation. It is possible to observe that the areas where the lowest NDVI values are observed are associated with a low volume of rainfall and a low amount of water retained in the soil, which indicates the strong influence of climate on the response obtained from vegetation. The results obtained were satisfactory, highlighting the scarcity of water in the semi-arid region, which resulted in the response of the vegetation.