Effectiveness of nature-based solutions to address water challenges in the Greater Mekong Subregion: a systematic mapping

The Greater Mekong Subregion (GMS) faces escalating water-related challenges, including floods, droughts, sea-level rise, and coastal erosion. Nature-based Solutions (NbS) offer a promising approach to address these challenges, yet their long-term effectiveness is difficult to evaluate and remains under-monitored, limiting policy uptake. This systematic mapping reviews scientific evidence from 2012 to 2023 on NbS implemented for water challenges in the GMS.

This study performs a systematic mapping of NbS interventions implemented to address water challenges in the Mekong Region. The review intends to delineate the current state of evidence on NbS effectiveness including the type of NbS applied, water challenges addressed and the effectiveness of these solutions. The effectiveness of NbS includes environmental, physical, social and economic elements [37] along with its capacity to deliver multiple co-benefits [38]. This review addresses the following research questions:

• What is the current state of research on NbS in the Mekong Region?
• What types of NbS intervention are applied and which water challenges are targeted?
• What are the reported co-benefits and level of effectiveness of NbS interventions

Findings reveal a regional imbalance, with most studies in Vietnam and Thailand, and limited representation in Myanmar, Lao PDR, and Cambodia. NbS interventions most documented include mangrove protection or restoration (13 %), forest protection or restoration (13 %), and wetland creation or restoration (11 %). Coastal protection (31 %) and flood management (25 %) are the primary challenges addressed, while fewer studies focus on water quality, storage, or supply. About half of the studies assessed multiple outcomes; 33 % focused only on ecological outcomes, with fewer examining social (14 %) or economic outcomes (9 %), though co-benefits such as recreation and thermal comfort were noted. Over half of the studies (55 %) met criteria for socioeconomic benefits, sustainability, natural resource conservation, and multifunctionality, while 45 % did not fully address these.

Research gaps remain in underrepresented countries and less-studied outcomes, including the role and implications of revitalizing traditional knowledge within NbS framework, highlighting the need for more comprehensive evaluation to support integration of NbS into national and regional water management strategies.

Citation: Khaing Su Lwin, Ridhi Saluja, Sushmita Mandal, Chayanis Krittasudthacheewa,
Effectiveness of nature-based solutions to address water challenges in the Greater Mekong Subregion: a systematic mapping of nature-based solutions, Volume 8, 2025, 100283, ISSN 2772-4115,
https://doi.org/10.1016/j.nbsj.2025.100283.
(https://www.sciencedirect.com/science/article/pii/S2772411525000710)