The study investigates groundwater storage and behavior in order to meet the water demand for irrigated agriculture in Buriti Vermelho, Brazil.
How to meet water supply and demand in Buriti Vermelho, Brazil?
Supervisors: Roel Dijksma, Jos van Dam, Lineu N. Rodrigues
In Brazil, an increasing middle class has raised the food demand substantially. To meet this demand, the agriculture sector is facing several challenges. Certainly, water limits the food production in the Brazilians savannahs, also known as Cerrados. This increases the opportunities for irrigated agriculture to develop. Moreover, in light of increasing water need in near future, researchers started to develop strategies to expand agriculture within sustainable limits of water use. Water conflicts occur already in some watersheds of the Cerrados, which may jeopardise agriculture and decrease the livelihood of rural communities. Therefore, it is important to investigate other sources of water, like groundwater.
The objective of this study is to investigate groundwater storage in the catchment of the Buriti Vermelho, with respect to a possible expansion in irrigated agriculture. Therefore, the current water demand was investigated, and simulated by an Irrigation Strategies Simulation Model (MSEI). A daily water balance was computed, which quantified catchments storage over time. In addition, groundwater behaviour and availability was investigated by a recession analysis and analysis of groundwater levels fluctuations. Literature was used to specify its hydrogeology.
With these results, three scenarios were made by modifying the water balance. Additionally, the effect is shown for the groundwater tables by the recession characteristics. Thereby, it was examined how catchment’s hydrology responds to expanded irrigation. The results show that groundwater is an important source of water in the region. Hence, the phreatic aquifer is directly affected by irrigation expansion. The scenarios indicate a serious decline to discharge and groundwater levels. However, the role of the deeper aquifers remains unknown. As groundwater is a scarce water source in the Cerrados, it is important to manage groundwater carefully and adapt cultivation practices to increase crop water productivity.