Diving deep: Trends and gaps in Philippine groundwater research (1982–2024)

Groundwater in the Philippines, covering approximately 50,000 km² and holding an estimated 251 km³ of water, is a critical resource for communities, agriculture, and industry. Despite this reliance, the country’s groundwater faces mounting pressures from overextraction and pollution. To support its sustainable management, we conducted a bibliometric analysis of groundwater research in the Philippines from 1982 to 2024 using literature indexed in Scopus and Web of Science. Across four decades, we identified only 79 relevant publications, underscoring persistent research gaps in addressing groundwater challenges. Our findings show that international collaborations, particularly with partners from the USA and Japan, significantly enhance citation rates and research visibility, while local institutions play a pivotal role in building domestic expertise and setting focused research priorities. Groundwater contamination emerged as the most frequently studied topic, with growing attention to submarine groundwater discharge, reflecting evolving concerns about pollution pathways to coastal ecosystems. Although research output has increased in recent years, the overall volume remains limited, highlighting the need for a more proactive, interdisciplinary research agenda. We recommend prioritizing studies on biomonitoring, ecological assessments, remediation and recharge strategies, microplastic pollution, and standardized groundwater access, alongside efforts to enhance public awareness and policy development. These steps are essential for advancing groundwater research in the Philippines and ensuring its alignment with sustainable development goals