Publication Date
5-2020
Abstract
Puerto Rico is an oceanic tropical archipelago with about 3.2 million inhabitants, located between the Caribbean Sea and the Atlantic Ocean. It has a land area of 9104 km2. Groundwater provides about 15 percent of the freshwater used in Puerto Rico and is an important reserve during droughts. A monthly groundwater level index was calculated for Puerto Rico from 1982 to 2017. Sub-indices were calculated for the karst North Coast Limestone aquifer, the non-karst South Coastal Plain aquifer, and for the non-karst Rest of Puerto Rico. The index was calculated with data from 80 non-pumping observation wells operated by the United States Geological Survey. Each station has more than 100 water levels on the Internet. The study also looks at rainfall and demographic data that affects groundwater.
Groundwater levels in Puerto Rico, the North Coast Limestone and the Rest of Puerto Rico are rising. Groundwater levels in the South Coastal Plain aquifer are falling. The declining water levels on the south coast are probably due to changing pumping and recharge patterns and not climate change. The island shows spatial correlation. High levels of the index are associated with landslides in areas without aquifers. Low levels of the index are associated with water rationing. The index shows temporal correlation with the index rising or falling for years at a time. The index rose between 1994 and 2011. The all-time maximum was a massive rainfall event in August 2011. The second highest peak of the index was caused by Hurricane Maria on 20 September 2017. Hurricane Maria was the largest single recharge event in the 36-year period of the index. The minima of the index in 1994 and 2015 are associated with water rationing in the San Juan metropolitan area. In the final analysis, based on demographics, precipitation, and groundwater levels, the current pattern in the karst North Coast Limestone is more sustainable than in the non karst South Coastal Plain.
DOI
https://doi.org/10.5038/9781733375313.1054
Are the groundwater levels falling in Puerto Rico between 1982 and 2017: comparing a karst aquifer with non-karst aquifers
Puerto Rico is an oceanic tropical archipelago with about 3.2 million inhabitants, located between the Caribbean Sea and the Atlantic Ocean. It has a land area of 9104 km2. Groundwater provides about 15 percent of the freshwater used in Puerto Rico and is an important reserve during droughts. A monthly groundwater level index was calculated for Puerto Rico from 1982 to 2017. Sub-indices were calculated for the karst North Coast Limestone aquifer, the non-karst South Coastal Plain aquifer, and for the non-karst Rest of Puerto Rico. The index was calculated with data from 80 non-pumping observation wells operated by the United States Geological Survey. Each station has more than 100 water levels on the Internet. The study also looks at rainfall and demographic data that affects groundwater.
Groundwater levels in Puerto Rico, the North Coast Limestone and the Rest of Puerto Rico are rising. Groundwater levels in the South Coastal Plain aquifer are falling. The declining water levels on the south coast are probably due to changing pumping and recharge patterns and not climate change. The island shows spatial correlation. High levels of the index are associated with landslides in areas without aquifers. Low levels of the index are associated with water rationing. The index shows temporal correlation with the index rising or falling for years at a time. The index rose between 1994 and 2011. The all-time maximum was a massive rainfall event in August 2011. The second highest peak of the index was caused by Hurricane Maria on 20 September 2017. Hurricane Maria was the largest single recharge event in the 36-year period of the index. The minima of the index in 1994 and 2015 are associated with water rationing in the San Juan metropolitan area. In the final analysis, based on demographics, precipitation, and groundwater levels, the current pattern in the karst North Coast Limestone is more sustainable than in the non karst South Coastal Plain.
