Sustainable, Just, Equal, and Optimal Groundwater Management Strategies to Cope with Climate Change: Insights from Brazil

Abstract

This paper applies optimal-control theory to develop groundwater exploitation strategies that account for potential climate change patterns in Brazil. Numerical experiments showed that whether climate change only affects groundwater quantity or whether it affects both groundwater quantity and quality, Brazilian water institutions will be able to implement optimal, equitable groundwater management strategies. However, they may be unable to achieve justice between current generations, while the economic, social, and environmental sustainability is likely to be favoured by a large regional groundwater availability. Institutional sustainability is ensured by the principles and institutions established by Brazil's 1988 Constitution and by Law 9.433/97. Some sources of misunderstandings between managers and the research community are dealt with by suggesting directly applicable management strategies that accommodate stakeholder perceptions and desires. Some potential water policies based on the modelling results are discussed, with water conservation and water subsidies turning out to be beneficial for current and detrimental for future generations, respectively; in contrast, current generations paying for water at its social opportunity cost and being more concerned for future generations would benefit current generations.

Potential climate change impacts on the water balance of regional unconfined aquifer systems in south-western Australia

“…Almost all GCMs project a further reduction in rainfall in south-western Australia by 2030. Reductions in mean annual rainfall have major implications for groundwater management as it reduces recharge and affects other components of the water balance (Zagonari, 2010). This study and others (Candela et al, 2009;Sandstorm, 1995) show that the projected reduction in recharge is 2 to 4 times the reduction in rainfall.…”

“…Both the temperature rise and rainfall decline due to climate change affects various components of the groundwater balance by directly and indirectly affecting multiple factors (Zagonari, 2010) such as groundwater recharge (Ng et al, 2010) due to rainfall decline, potential evapotranspiration due to temperature and vapour pressure deficits rise, and groundwater discharge to drains due to groundwater levels decline. It can increase seawater intrusion risks in coastal aquifers and affect inter-aquifer leakage rates and flow direction.…”

Hydrogeological characterisation of groundwater over Brazil using remotely sensed and model products

“…and conditions (i.e., rock types and elevation) could be critical factors for understanding the 46 nature of groundwater storage behaviour across Brazil (e.g., Zagonari, 2010).…”

Soil‐Hydrological Responses to Rainfall Variation in a Subtropical Australian Landscape

“…These results suggest an increasing ID with time for the Lockyer Valley, as also predicted for other areas of Australia . These increases in ID due to a decrease in rainfall can have major implications for farming and groundwater management (Zagonari, 2010;Ali et al, 2012). In contrast, a higher rainfall period such as 2008-2011 (Figure 2) is promising for meeting water demands.…”