Rapid urbanisation and increasing heat extremes pose significant challenges for megacities in the Global South. This study develops a configuration-sensitive assessment of blue-green space (BGS) cooling in Delhi, a Global South megacity facing intensified heat. Using satellite imagery and statistical modelling, we quantify how land cover and patch structure regulate land surface temperature (LST). Satellite imagery was used to derive LST, and six land-cover classes were mapped using supervised classification. Spectral indices and proximity metrics were calculated, land-cover patches were delineated, and their thermal behaviour was analysed using patch-level LST statistics. Delhi exhibits a heterogeneous urban heat island (UHI) surface, with LST spanning 19.8–38.6 °C and built-up land dominating (743.50 km²), while BGS remains limited and fragmented. Warming scaled almost linearly with built-up patch size (R² = 0.98), with mean LST rising from 22.6 °C (500,000 m²). Cooling strengthened with BGS spatial dominance as dense vegetation declined from 23.8 to 22.1 °C (R² = 0.98), sparse vegetation from 24.3 to 22.2 °C, and water bodies from 21.4 to 18.8 °C (R² = 0.89) across increasing size classes. Correlations identified impervious surfaces as primary warming controls, while moisture and vegetation were cooling indicators. Random Forest-SHAP confirmed modified bare soil index (MBSI) and normalised difference built-up index (NDBI) as dominant predictors, with cooling from modified normalised difference water index (MNDWI) and comparatively conditional effects of normalised difference vegetation index (NDVI). Impervious and exposed surfaces govern Delhi’s thermal baseline, while BGS acts as a modifier whose benefits emerge when patches are large, connected, and integrated. These findings support shifting from area-based greening targets to morphology-based planning that protects connected blue-green corridors.

Rapid urbanisation in tropical megacities intensifies urban heat islands, especially during summer. Peri-urban wetlands help combat surface thermal stress through evapotranspiration, thermal inertia, and hydrological connectivity. However, their cooling effects are often oversimplified. This study assesses the complex cooling role of peri-urban wetlands, using a geospatial framework with Landsat imagery. We analyse land surface temperature (LST) variability and cooling patterns across the East Kolkata Wetlands (EKW). Results show a sharp thermal gradient, with waterbodies as the coolest surfaces (mean 25.4 °C) and dumping grounds as intense hotspots (mean 35.75 °C). Built-up areas adjacent to water are significantly cooler than urban cores. Cooling exhibits non-linear distance-decay and directional asymmetry, extending several kilometres but attenuated by dense western urban development. Internal thermal disruptions from dumping grounds create localised heat plumes. The findings demonstrate that wetland cooling is governed by hydrological connectivity and landscape permeability. Thus, conserving waterbody networks and mitigating thermally disruptive land uses are therefore critical. This positions peri-urban wetlands as dynamic climate-regulating infrastructure, offering a nature-based solution for urban heat adaptation that aligns with the sustainable development goals (SDGs).

Urban blue-green spaces (UBGS) are crucial nature-based solutions for enhancing urban resilience and improving public health. This study examined the experiential relationships linking BGS use to human well-being among users of five urban parks in Delhi, India. Using an integrated experience-centered framework, we collected in-situ survey data (n = 411) to profile usage patterns, assess environmental quality, and quantify restorative outcomes grounded in Attention Restoration Theory (ART) and Stress Reduction Theory (SRT). Advanced analytical techniques, including ordinal logistic regression and interpretable machine learning (SHAP), were used to identify the key factors associated with user satisfaction. The results revealed that for these respondents, BGS appeared to function as an essential neighbourhood, with over 40% visiting three or more times per week. Although visual attractiveness was rated positively, deficits in noise buffering and amenities indicated a gap between aesthetic and functional qualities. Restorative benefits, including emotional calmness, mood refreshment, and fatigue recovery, were consistently reported among respondents. Analyses showed that embodied experiences, particularly post-visit relaxation and physical comfort, were more strongly associated with user satisfaction. SHAP interpretation highlighted seating adequacy, routine use, and thermal comfort as prominent contributors, suggesting somatic relief may be particularly salient. This study provides exploratory evidence from a Global South megacity and context-sensitive insights into how restorative processes operate under high-density urban conditions. The findings show that routine accessibility, basic amenities, and thermal comfort are central to the everyday functioning of blue-green spaces as urban infrastructure, underscoring the need for experience-responsive and equity-oriented urban greening policies in high-density cities.