Global Warming, Evaporation, and Aquifer Recharge: A Case Study of South Maui

Global Warming, Evaporation, and Aquifer Recharge: A Case Study of South Maui

Global warming and climate change are having profound impacts on our planet’s water cycle, particularly in regions like South Maui, Hawaii. An increase in average temperatures, even by a few degrees, can significantly affect evaporation rates and reduce the amount of rainwater reaching aquifers123.

The Impact of Increased Temperatures on Evaporation

Increased global temperatures affect the hydrologic cycle, leading to changes in precipitation patterns and increases in the intensity and frequency of extreme events4. This results in altered soil moisture, runoff, and groundwater recharge4. In areas where the future climate becomes drier, reduced groundwater recharge could result in higher-salinity groundwater and reduced base flow in streams3.

The Effect on Rainwater and Aquifers

Less rainfall and increased evaporation due to rising temperatures put our drinking water supply at risk5. This means less groundwater, more risk of drought, and increased risk of wildfires5. Over the next 100 years, the full impact that climate change is having on groundwater resources will become apparent in half of the world’s aquifers1.

In South Maui, climate change not only increases the fire risk by driving up temperatures but also makes stronger hurricanes more likely678. These storms could fuel stronger wind events like the one behind the Maui fires678. That’s on top of other threats made worse by climate changes678.

The Negative Impacts on Aquifer Recharge

Aquifer recharge, the process by which water moves from the surface to groundwater, is significantly affected by these changes. Less rainfall and increased evaporation mean less water is available to replenish the aquifers123. In South Maui, this is particularly concerning as water resources are already scarce6.

Conclusion and Recommendations

The impacts of global warming on groundwater may be greatest through its indirect effects on irrigation water demand, potentially leading to depletion or contamination of groundwater resources2. Adaptations to climate-driven shortages in water supplies involve supply-side strategies that consider groundwater as a climate-resilient source of freshwater2.

It’s clear that global warming and increased temperatures are affecting evaporation rates and reducing the amount of rainwater reaching aquifers, particularly in regions like South Maui. As we continue to study and understand these impacts, it’s crucial that we also work towards solutions and adaptations to these changes123.

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Pictured: Waipuilani Gulch, Kihei
Drought Conditions and degraded ranchlands in South Maui.