On-site sanitation systems (OSS), such as pit latrines, are an important source of methane (CH₄), with emissions increasing when they are wet, and this occurs when anaerobic conditions dominate. This paper presents the development of a model, which uses seasonal changes in groundwater to account for the fluctuating inundation of pit latrines, and, therefore, the associated CH₄ emissions from varying degrees of anerobic conditions are examined. Given that observed timeseries of groundwater table depth at high enough spatial and temporal resolutions are often difficult to obtain in low- and middle-income countries (LMICs), inverse distance weighted (IDW) interpolation is used to generate values for a whole region, which is then used, alongside average pit latrine depth, to determine areas of pit latrine inundation. Outcomes are further informed with open-source contextual data, covering population, urban/rural split, and sanitation facility data, before using methodologies from the Intergovernmental Panel on Climate Change (IPCC) to generate CH₄ emissions data. As a case study, we use data from Senegal to illustrate how this model works. Results show total CH₄ emissions for the month of January to be ~1.69 kt CH₄. We have also discussed the potential use of satellite remote sensing data in regions where access to historical groundwater data is limited. Understanding when the pit conditions are most likely to change could lead to incentives for better management strategies, as well as a reduction in CH₄ production.

Understanding the resilience of water supplies to climate change is becoming an urgent priority to ensure health targets are met. Addressing systemic issues and building the resilience of community‐managed supplies, which serve millions of people in rural LMIC settings, will be critical to improve access to safe drinking water. The How Tough is WASH (HTIW) framework to assess resilience was applied to community‐managed water supplies in Ethiopia and Nepal to assess the effectiveness of this framework in field conditions. The resilience of these water supplies was meas-ured along six domains—the environment, infrastructure, management, institutional support, community governance and supply chains—that can affect how they respond to climate change effects. We found that the HTIW framework provided an objective measure of resilience and could be used to rank water supplies in order of priority for action. We also found that systemic issues could be identified. The tools and methods used in the framework were easy to deploy by field research teams. The water supplies studied in Ethiopia and Nepal had low to moderate resilience to climate change. Service management and institutional support were weak in both countries. The data from Ethiopia and Nepal suggests that many water supplies in rural and small‐town communities are unlikely to be resilient to future climate change without increased investment and support. The use of simple frameworks such as HTIW will be important in supporting decisions around such invest-ments by identifying priority communities and actions.

Climate change presents a major threat to water and sanitation services. There is an urgent need to understand and improve resilience, particularly in rural communities and small towns in low- and middle-income countries that already struggle to provide universal access to services and face increasing threats from climate change. To date, there is a lack of a simple framework to assess the resilience of water and sanitation services which hinders the development of strategies to improve services. An interdisciplinary team of engineers and environmental and social scientists were brought together to investigate the development of a resilience measurement framework for use in low- and middle-income countries. Six domains of interest were identified based on a literature review, expert opinion, and limited field assessments in two countries. A scoring system using a Likert scale is proposed to assess the resilience of services and allow analysis at local and national levels to support improvements in individual supplies, identifying systematic faults, and support prioritisation for action. This is a simple, multi-dimensional framework for assessing the resilience of rural and small-town water and sanitation services in LMICs. The framework is being further tested in Nepal and Ethiopia and future results will be reported on its application.