This article is focused on the double complexity that takes place in emerging metropolitan deltas due to the coexistence of natural dynamics and urban processes, in a context of uncertainty regarding climate change and economic development. Within this scope, traditional planning turns ineffective to address current and future issues in a flexible and participatory way. In order to develop efficient planning methods and strategies, it is necessary to understand the structure and processes that define these systems. For that purpose, in this article the concept of emerging metropolitan deltas will be presented, deepening the understanding of these areas as complex adaptive systems. Then, the challenges of planning will be addressed by analysing the case of the Paraná Delta and presenting an adaptive and participatory planning method for the area.@en

Historically, both coastal areas and deltas have been attractive places for human settlements due to their natural wealth and strategic location. These qualities have made them suitable sites for the development of productive, industrial and commercial activities. Precisely, it is estimated that half of the world's population is located within a radius of 200 km from the coast, a figure that would double by 2025. The increase in the demand for land for residential and productive purposes causes a change in use that impacts the natural territory at different scales. Likewise, the natural dynamics of coastal zones and deltas, and those related to climate change, generate effects on the occupied territories, increasing their vulnerability to extreme hydrological events. Thus, these areas reach a double complexity, fundamentally derived from the coexistence of emergent processes, both natural and anthropic, in a context of continuous change and uncertainty regarding the future. It is necessary from the planning field to consider the complex reality of these areas in relation to future uncertainty, through the development and implementation of adaptive and participatory planning processes that allow these systems to increase their resilience. The presentation will delve into the analysis of emerging processes in metropolitan deltas, presenting examples from the international as well as the national sphere. Likewise, an adaptive and participatory planning tool applied in the Lower Paraná Delta will be presented.@en

The Parana River is the third largest river in the American continent, after the Mississippi and the Amazon. Instead of flowing directly to the sea, it flows to the Rio de la Plata (located between Argentina and Uruguay) through a complex delta system. This delta is a large and heterogeneous territory that spreads over three provinces of Argentina and that is characterized by different dichotomies along its extension. On the one hand, the islands of the delta are young alluvial lands in constant transformation due to the processes of sedimentation, and are subjected to pulses of floods influenced by the Paraná River streamflow, droughts, precipitations and strong southeastern winds coming from the Atlantic Ocean. Although these alluvial territories seem to be pristine, they have been moderately altered as a result of the development of economic activities. On the other hand, along the edges of the delta, we find the older territories of the mainland, created in the Pleistocene and less dynamic. Here is a network of cities of dissimilar sizes, that establishes the wealthiest corridor of the country. Conurbations such as Rosario (located in the province of San ta Fe) and the Metropolitan Area of Buenos Aires (located in the homonym province), exert different pressures over the territory, generating an increasing impact on the delta system. In other words, this delta shows a contrast between the wild and dynamic condition of the islands and the more stable but strongly urbanized edges. Nevertheless, this dichotomy is not the only one that can be found in the delta. On the contrary, there are other oppositions regarding economic, policy and social realms, expressed through a polarized, unsustainable and unplanned land use, which turns the area into a vulnerable place, given the uncertain context of climate change...@en

The effects of climate change have become increasingly visible in many coastal cities, where extreme hydrological events seem to occur more frequently causing severe flooding and other negative impacts over the territory and its communities. Although scientific evidence gives rise to predictions on the impacts of climate change, the level of uncertainty as to what these impacts are remains high, exhibiting a greater risk in areas where the planning process is fragmented and not coherent. This paper presents a reflection on the participatory processes used to address the potential of scenario development as a tool for integrating urban and environmental dimensions. Using this representative case study as an example, some methodological concerns about stakeholder participation and planning through scenarios were presented and tested as well. This is a study of the Lower Paraná Delta in Argentina, which is a complex estuarine delta and located near the Metropolitan Area of Buenos Aires, the country’s largest urban area, with more than 13 million inhabitants. There, lack of coordination and the disjointed management of urban and environmental issues turn participatory processes into an opportunity to build awareness and to set networks of communication up between different categories of active stakeholders. These stakeholders play a key role towards improving a set of informed common development goals to help face the climate change risk incurred within the area's metropolitan development.@en