Tjahyo Nugroho Adji is a lecturer at the Department of Environmental Geography with a research interest in research related to groundwater in the karst area. The focus of the study he pursued was related to the hydrograph analysis dan hydrogeochemical methods and their relationship with rainfall (time-series analysis) to determine the development of a karst area. In addition, he also pursued the approach of hydrogeochemistry and its relation to the nature of the flow released by the karst aquifer. Some of the karst areas that have been studied include Gunungsewu karst (Central Java), Rengel karst (East Java), Jonggrangan Karst (Central Java), Gombong Karst (Central Java), Rembang karst (Central Java), karst area in Aceh (Sumatera), and Banggai Island karst (Celebes). Many research results have been published in several reputable international journals, including Acta Carsologica, Carbonates & Evaporates, Geosciences Journal, Environmental Earth Sciences, Environmental Processes, International Journal of Conservation Science, Aquatic Geochemistry, and Arabian Journal of Geosciences.