Simulating Discharge in a Non-Dammed River of Southeastern South America Using SWAT Model

Abstract

Within a single region, it is possible to identify opposite changes in flow production. This proved to be the case for several basins in southeastern South America. It remains challenging to the causes this behavior and whether changes in streamflow will continue at current levels or decline in the coming decades. In this study, we used the Soil Water Assessment Tool to simulate monthly river discharge in the Ivaí River Basin, an unregulated medium-sized catchment and tributary of the Upper Paraná River Basin. After calibration, the simulated flow regime for the five streamflow stations based on the Nash-Sutcliffe Efficiency index (NSE) rated four of the streamflow stations Very Good (NSE between 0.86 and 0.89) and only one in the Good index (0.70). The overall flow behavior was well represented, although an underestimation was identified in four monitoring stations. Through assessment of its functionality and limitations in terms of specific flow duration curves percentages, the calibrated model could provide (to managers) the reliability needed for a realistic intervention. The results of this study may assist managers and support public policies for the use of water resources at the Ivaí River basin.

Insights to the water balance of a Boreal watershed using a SWAT model

“…This underprediction highlights the need for further investigation and fine-tuning of the model to improve its performance in accurately simulating baseflow conditions. FDCs provide valuable insights into the frequency and magnitude of flows, making them essential for climate change impacts, water resource management, environmental planning, and flood control efforts (Vogel and Fennessey 1994, Daraio 2017, Fujita et al 2022. The successful estimation of peak and low flows in the UHRW using the SWAT model reaffirms its ability to represent the hydrological dynamics of the region effectively.…”

“…Variations in the supply and demand of water may also threaten the food security of global communities (Nechifor and Winning 2018). To address upcoming challenges in watershed water management, it is crucial to conduct a local assessment of the hydrological cycle (Raihan et al 2020, Fujita et al 2022.…”

“…SWAT is also open access, meaning anyone can use it for free and efficiently, meaning it can handle large amounts of information without slowing down (Arnold et al 2012b). These features make SWAT an excellent choice for understanding complex interactions in watersheds, predicting hydrological components, and determining how they will change over time (Fujita et al 2022).…”

Metrics Assessment and Streamflow Modeling under Changing Climate in a Data-Scarce Heterogeneous Region: A Case Study of the Kabul River Basin

“…Ref. [15] reports a rather high NSE, in the range of 0.86-0.89, while still underestimating the river discharge at four stations of the Ivaí River basin.…”