## 1 Introduction  
The changes arising from global environmental change have generated significant interest within both governmental [1] bodies and the scientific community, as it has become increasingly evident that this phenomenon poses a threat to numerous populations across the globe [2, 3]. The utilization of water is contingent upon its availability, and in semi-arid regions, this factor demonstrates temporal and spatial variability, particularly within small watersheds [4]. According to the National Water Agency (ANA) [5], the PISF (Sao Francisco River Integration Project) aims to enhance the security of water supply in reservoirs within the semi-arid region. Consequently, monitoring the water availability of semi-arid river basins is of utmost importance to ensure water security for the population [6]. Water security is intricately linked to chronic actions and extreme events [7]. In semi-arid areas, water security is perpetually a contentious and vital subject. A comprehensive understanding of the region's hydrological characteristics is imperative for informed public policy decisions. On certain occasions, acquiring detailed on-site data can be financially prohibitive. Therefore, hydrological modeling becomes a valuable and essential tool for accurately assessing water conditions in a given region [8]. Thus, hydrological modeling plays a pivotal role in the management and decision-making processes related to water security in semi-arid areas, aiding in the optimization of the utilization of the limited water resources available. The hydrological model Soil Water Assessment Tools-SWAT is very widespread in Brazil and due to the need for adjustments in the results obtained through modeling and the observed data, it is necessary to carry out a calibration. Different studies have been developed to calibrate the swat model to Brazil [9], including [10; 11; 12], and for the northeast of Brazil [13], and for the Pernambuco basins [14; 15; 16]. The intention was and is to provide a system that can facilitate the monitoring and planning of watersheds. This system is called the SUPER-System of Hydrological Response Units for Pernambuco. Watersheds can be regarded as natural systems that play a pivotal role in the hydrological cycle. It is essential to underscore that water flow may constitute the most critical component of the hydrological cycle and can be influenced by climate change and human activities [17]. Climate change and human activities are determinants of both the quantity and quality of water, and the analysis of these two factors is exceedingly important in the formulation of public policies [18]. In Brazil, the River Basin Committees (CBHs) were established to implement the provisions of the Water Law [19]. These committees consist of individuals with diverse interests who advocate for, analyze and deliberate on the programs included in the Basin Plans, representing a significant initiative for the entire civil community. A hydrographic basin is responsible for receiving rainwater that falls on the surface, which can be captured and stored in reservoirs, lakes, soil and underground aquifers, as demonstrated by [20]. Studies that investigate the behavior of precipitation and flow in a watershed have garnered the attention of researchers worldwide [21]. The quantity and temporal distribution of precipitation are of utmost importance in determining the flow regime of rivers, which directly impacts water availability. Studies such as [22] elucidate the significance of precipitation in conjunction with extreme events that have a direct bearing on the lives of people residing in a specific watershed. Another highly pertinent process within the hydrological cycle is evapotranspiration, which has become the second most critical variable within the hydrological cycle [18]. When the atmospheric demand for evapotranspiration (ET) surpasses the supply of precipitation, it leads to indicators of water deficit, potentially exacerbating social vulnerability through reduced water availability and limited access [23].