Lake Guidimouni, a designated Ramsar wetland in Niger's Zinder Region, represents a keystone socio-ecological system whose ecological functions, cultural heritage, and local livelihoods are tightly interwoven. Yet, this emblematic dryland lake is increasingly destabilised by intensifying climatic extremes-prolonged droughts and recurrent floods-and by accelerating anthropogenic pressures. To provide a more rigorous and climate-centred diagnosis of these transformations, we developed and operationalized a spatially explicit, participatory and statistically validated DPSIR-GIS framework integrating object-based image analysis, spatial autocorrelation modelling and NDVI-based carbon proxies. This combined approach enabled the development of a fine-scale vulnerability map of the lake and its periphery, capturing both biophysical and socio-economic dimensions of change. Our findings reveal two converging threats jeopardising ecosystem sustainability: (i) extensive inundation of agricultural lands and (ii) the massive proliferation of the invasive macrophyte Typha domingensis. Land-use analysis demonstrates that approximately 77.2 ha of irrigated croplands have transitioned into aquatic grasslands, signalling a structural ecological shift tightly linked to hydrological stress and climate variability. Moreover, 42.5% of irrigated agriculture is now exposed to flooding and exhibits high susceptibility to vegetative invasion. In response to these pressures, we identify targeted, science-based strategies-such as selective mechanical harvesting, hydrological regulation, and adaptive local governance-as priority resilience levers capable of restoring ecological balance and safeguarding ecosystem services. These findings underline the urgent need for integrated natural-resource management in Sahelian drylands. The analysis further integrates convergent stakeholder perceptions collected through participatory co-production, which were systematically embedded within the DPSIR framework to triangulate and validate spatial and remote-sensing evidence.