IAHS2022-299
https://doi.org/10.5194/iahs2022-299
IAHS-AISH Scientific Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Impact of water demand for irrigation on the water availability of the Urubu River in Brazil 

Nicole John Volken1, Ricardo Tezini Minoti2, Conceição de Maria Albuquerque Alves3, and Fernan Enrique Vergara Figueroa4
Nicole John Volken et al.
  • 1University of Brasília, Technology College, Civil and Environmental Engineering, Florianópolis/SC, Brazil (nicolejvolken@gmail.com)
  • 2University of Brasília, Technology College, Civil and Environmental Engineering, Campus Universitário Darcy Ribeiro, Brasília/DF, Brazil (rtminoti@unb.br)
  • 3University of Brasília, Technology College, Civil and Environmental Engineering, Campus Universitário Darcy Ribeiro, Brasília/DF, Brazil (calves@unb.br)
  • 4Federal University of Tocantins Foundation, Palmas Campus, Environmental Engineering, ALC NO 14 NS 15, Centro, Palmas/TO, Brazil (vergara@mail.uft.edu.br)

There are 37 hydraulic water catchment pumps installed in the Urubu River hydrographic basin, located in an important agricultural area in the northern region of Brazil. The water is used to irrigate rice, which takes place between November and March, during the rainy season, and soy for seed, in the months of May to September, which include the dry season of the hydrological regime. In 2016, the region went through a water crisis that extended into the following years. The main causes were associated with a climatic extreme, caused by a prolonged dry season, high demand for irrigation and inefficient management of water resources, which resulted in the judicial suspension of water use permits and conflict between irrigators.

The objective of the study was to evaluate the water availability of the Urubu River in face of demand through the use of the Water Evaluation and Planning System (WEAP) model. The analysis period was from July 2018 to June 2019, focusing on the results for the months of July and August. The flow of the Urubu River was modeled in the WEAP using the Rainfall Runoff method. Three demand nodes (D1, D2, D3) were used to represent the water pumped for irrigation along the river. The pumped flow data for irrigation were obtained from the monitoring High Level Management Project (GAN) implemented in all hydraulic pumps.

The result showed that the demand for rice irrigation is compatible with the availability, however for the soybean crop the water demand exceeded the availability at many moments (Figure 1), causing the interruption of the river flow after node D2. The result shows that the high demand for water causes severe environmental impacts. In addition, the observed situation reflects in economic losses to farmers, decrease in the quality of the soy crop and increases conflicts between users.

Figure 1 - Urubu River flow after water demand for irrigation.

This study proves that it is necessary to change the irrigation techniques currently used to obtain a more efficient water management, preventing the environmental impacts caused by the unfavorable water balance from happening again.

How to cite: John Volken, N., Tezini Minoti, R., de Maria Albuquerque Alves, C., and Enrique Vergara Figueroa, F.: Impact of water demand for irrigation on the water availability of the Urubu River in Brazil , IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-299, https://doi.org/10.5194/iahs2022-299, 2022.