In the Fall of 2014, I spent a sabbatical leave at the Technical University of Loja, in Loja, Ecuador, researching the new subject of ecohydroclimatology.¹ With the assistance of a local colleague, we examined the available local climatological and surface-water data, which led to the paper "Ecohydroclimatological research along the Catacocha-Zamora transect, Loja and Zamora-Chichipe, Ecuador." ²

After examining the surface-water data, I asked my colleague about the groundwater data. To my surprise, he answered:

"There is no groundwater data because we do not pump groundwater in the Loja valley."

I immediately realized that, historically, there has been no need to pump groundwater in the Loja valley. The available surface water has been sufficient to satisfy all needs, natural and anthropogenic. With 900 mm of mean annual precipitation, i.e., a subhumid climate, the Loja valley sits near the middle of the climatic precipitation spectrum. ^{3, 4}

Reflecting on the experience, I realized that groundwater is typically used where surface water is scarce, particularly in semiarid and arid regions, or where intense water development is based on the use of groundwater, as is the practice of many developed countries.⁵ I could not help but ponder society's predicament regarding groundwater use: Where it is most needed, i.e, in arid regions, its replenishment is slowest.⁶ In many instances, this duality has led to groundwater depletion, which is clearly unsustainable.⁷ Moreover, intensive groundwater development surely carries with it the specter of baseflow loss in the regional vicinity.

¹ Ponce, V. M. 2015. Ecohydroclimatological research: The case for geomorphology. http://ponce.sdsu.edu/ecohydroclimatology.html

² Oņate, F, and V. M. Ponce. 2015. Ecohydroclimatological research along the Catacocha-Zamora transect, Loja and Zamora-Chichipe, Ecuador, Tecnología y Ciencias de Agua, Vol. VI, No. 6, November-December.

³ Ponce, V. M., R. Pandey, and S. Ercan. 2000. Characterization of drought across climatic spectrum. Journal of Hydrologic Engineering, Vol. 5, No. 2, April, 222-224. (republished online 2015).

⁴ Ponce, V. M. 2014. The 800-mm isohyet: Health and hope. EWRI Congress: International Perspectives on Water Resources and the Environment, Quito, Ecuador, January 8-10, 2014. Also on video.

⁵ Alley, W. M., T. E. Reilly, and O. L. Franke. 1999. Sustainability of ground-water resources. U.S. Geological Survey Circular 1186.

⁶ Scanlon, B. R., K. E. Keese, A. L. Flint, L. E. Flint, C. B. Gaye, W. M. Edmunds, and I. Simmers. 2006. Global synthesis of groundwater recharge in semiarid and arid regions. Hydrological Processes, 20, 3335-3370.

⁷ Ponce, V. M. 2007. Sustainable yield of groundwater. http://ponce.sdsu.edu/groundwater_sustainable_yield.html