Research Gaps and Priorities for Terrestrial Water and Earth System Connections From Catchment to Global Scale

Abstract

The out‐of‐sight groundwater and visible but much less extensive surface waters on land constitute a linked terrestrial water system around the planet. Research is crucial for our understanding of these terrestrial water system links and interactions with other geosystems and key challenges of Earth System change. This study uses a scoping review approach to discuss and identify topical, methodological and geographical gaps and priorities for research on these links and interactions of the coupled ground‐ and surface water (GSW) system at scales of whole‐catchments or greater. Results show that the large‐scale GSW system is considered in just a small part (0.4%–0.8%) of all studies (order of 105 for each topic) of either groundwater or surface water flow, storage, or quality at any scale. While relatively many of the large‐scale GSW studies consider links with the atmosphere or climate (8%–43%), considerably fewer address links with: (a) the cryosphere or coastal ocean as additional interacting geosystems (5%–9%); (b) change drivers/pressures of land‐use, water use, or the energy or food nexus (2%–12%); (c) change impacts related to health, biodiversity or ecosystem services (1%–4%). Methodologically, use of remote sensing data and participatory methods is small, while South America and Africa emerge as the least studied geographic regions. The paper discusses why these topical, methodological and geographical findings indicate important research gaps and priorities for the large‐scale coupled terrestrial GSW system and its roles in the future of the Earth System.

Hydrological Research Evolution: A Large Language Model‐Based Analysis of 310,000 Studies Published Globally Between 1980 and 2023

“…And how has the given scientific domain evolved over time (Waltman et al, 2010)? To provide more accurate answers to these questions, methods such as bibliometrics (Ning et al, 2019;Rahman et al, 2022;Xu et al, 2018), meta-analyses (Song et al, 2019;Sun et al, 2024), and scoping reviews (Zarei & Destouni, 2024) are employed for quantitative literature analysis. However, meta-analyses are mostly limited to a relatively small number of publications (typically a few hundred), while bibliometric analysis is constrained to information such as authors and keywords, making it difficult to discover new knowledge in specific fields (Z.…”

“…Xia et al (2021) elaborated on the progress and challenges in the field of ecohydrology and suggested future development directions, including the development of various large-scale ecohydrological process models, the promotion of interdisciplinary integration through comprehensive monitoring of ecohydrological variables, and the exploration of multi-process interaction mechanisms. Zarei and Destouni (2024) reviewed the coupling of groundwater and surface water, and the links and interactions of the coupled water system at whole-basin and larger, multi-basin scales with other geosystems and key challenges of Earth System change, to identify and discuss topical, methodological and geographical gaps and priorities for hydrological research. While researchers have provided insightful summaries of the field's development and offered forward-looking perspectives on its future, it is crucial to acknowledge that traditional reviews inherently reflect the qualitative assessment of researchers.…”