The Danube Delta, Europe’s largest natural delta and a UNESCO World Heritage Site, was formed over the past 11,500 years through the interaction of riverine sediment supply and Black Sea coastal dynamics. Its development depended on the formation of the Zhebriiany (Jibrieni)-Letea-Caraorman coastal barrier ridge system, which enabled sediment accumulation and lagoon formation.

The Red River Delta in Vietnam exemplifies the complex challenges facing sustainable development in vulnerable coastal regions. Despite occupying only 5% of Vietnam's territory, this densely populated delta supports approximately one-third of the national population and serves as the backbone of the country's agricultural and aquacultural sectors.

In providing high spatial resolution land subsidence velocities for the 48 largest coastal cities worldwide which represent 20% of the global urban population, Tay et al. (2022) show that delta cities experiencing the fastest subsidence are concentrated in Asia.  In China, urban floods have become a major concern due to climate change and rapid urbanization on deltas. Major cities are affected e.g., Beijing (2012), Guangzhou (2014, 2015, 2020), Shenzhen (2014, 2020), Ningbo (2013) and Wuhan (2016, 2020).

Major risks facing by the Río de la Plata (RdlP) Estuary against climate change and human pressures are sea level rise, coastal flooding linked to El Niño Southern Oscillation warm phase, which produces increased rainfall and river discharge, wind-induced storm surges, eutrophication and pollution (Venturini et al., 2024 and references therein).

Delta communities are doing the work of adaptation despite little access to funding “because they must”.  Indigenous communities receive less than 1% of all climate funding. The Regranting model is an example of an innovative finance mechanism that can facilitate quicker action on the ground with wider reach to fast-track adaptation and resilience benefits.

Over the past fifty years, the Indus delta has lost approximately 92% of its active area, resulting in the conversion of fertile farmland into saline soils, the destruction of fisheries, and the displacement of local communities. The disappearance of mangroves, which serve as the delta’s primary coastal defense, has increased vulnerability to storms and flooding.

Watershed-scale threats including climate change, deforestation, mining, hydropower dams and pollution related to intensive agriculture are driving serious riverbank erosion in the Amazon River Delta (ARD) region in northern Brazil. Riverbank erosion occurs due to natural tidal-fluvial sedimentary dynamics, but is enhanced by removal of floodplain vegetation, inland sediment trapping due to damming, increasing frequency of extreme floods and drought and sea level rise.

The Pointe-Au-Chien Indian Tribe, located in the Terrebonne Basin of coastal Louisiana, has lived for generations in close relationship with the Mississippi River Delta. The wetlands sustained traditional fishing, shrimping, and crabbing, while also buffering homes and sacred sites from storms.

Sediment fluxes in the Nile river system have been drastically modified by human impact through the last century, until now almost no sediments reach the delta region. Consequently, the Nile River Delta suffers severe erosion along its northern coast due to wave action, currents, and other coastal processes. This erosion has been exacerbated since the construction of the Aswan high dam in 1964 where the Nile River’s sediments became trapped within the artificial reservoirs.

Akassa is a low-lying coastal clan in Bayelsa State, within the Niger Delta. Its communities face accelerating sea-level rise, shoreline erosion, saline intrusion, mangrove loss, declining fisheries, and increased flooding. These pressures are intensified by climate change and compounded by long-standing governance gaps, limited public investment, and fragmented coordination among government agencies.

The Pampanga delta, located in northern Manila Bay, has been experiencing human-accelerated subsidence for several decades, predominantly driven by groundwater overextraction, with present sinking rates locally reaching up to 15 cm/yr (Sulapas et al., 2024). As a result large parts of the delta have been lost to the sea in only a few years time, causing population displacement and irreversible landscape changes with attendant impacts of delta livelihoods.