Groundwater resources of low-lying atoll islands are threatened due to short-term and long-
term changes in rainfall, wave climate, and sea level. A better understanding of how these
forcings affect the limited groundwater resources was explored on Roi-Namur in the
Republic of the Marshall Islands. As part of a 16-month study, a rarely recorded island-
overwash event occurred and the island's aquifer's response was measured. The findings
suggest that small-scale overwash events cause an increase in salinity of the freshwater …