RAFAEL PIMENTEL LEIVARAFAEL PIMENTEL LEIVAMARÍA JOSÉ POLO GÓMEZ2026-01-292026-01-29201910.1080/02626667.2019.16205072-s2.0-85068525773https://www.scopus.com/inward/record.uri?eid=2-s2.https://ucocris.uco.es/handle/123456789/30598Water Science and TechnologyWater Science and TechnologyTwenty-three unsolved problems in hydrology (UPH)–a community perspectiveresearch article