Frugality is a core notion of sustainability, and responsible resource management should be prioritized in urban planning and landscape architecture. Low-budget strategies as a deliberate means of creating valuable, attractive, well-used, sociable public spaces are recognized by some influential designers using the "Light, cheap, quick" methodology. Unused spaces, just like objects and waste, can be creatively changed, reinvented with little resource input through a circular solution of upcycling. Case study methodology was predominantly used in the inquiry with three new parks, built after the year 2004, in Faro, Portugal. The study examined how the success rate and the current state of these public green areas correlates with the amount of financial resources invested in each of the projects. The case studies show key aspects in the building of the three spaces including: urban context, management and community participation. The success rate of a place is established based on user activity observations, user counts and questionnaires-conveyed amongst both experts and local residents. Results illustrate how low-budget strategies and limited use of funds and resources can be translated into a successful project of a public greenery. Comparative studies from Warsaw and Berlin further extend the discussion to the concept of upcycling as a sustainable solution for landscape architecture.

How can the governance of nature areas foster the sustainability of ecosystems? This is discussed with regard to larger threats on ecosystems despite larger global nature areas that reach 19 million km2 of land along with larger costs per area unit. Moreover, monetization of nature with payments for ecosystem services is sometimes demanded for justification of the nature areas; however, this does not resolve the threats but faces scientific and ethical scrutiny. An alternative is the governance that incubates sustainable innovations in the nature areas for broad dissemination which generates interests in the sustainability of ecosystems. Opportunities are due to demands for ethical products, ecotourism and images of nature which generate USD 1100 billion in global markets. Sustainable innovations of using reed for insulation walls, furniture panels and upholstery in the EU can generate a few hundred million dollars in addition to present roof thatching, fodder and fuels if good functional qualities of the reed products are developed. Their functionalities can be supported by the inclusive economics, CO2 storage, treatment of water pollution, richer biodiversity, and other ethical qualities. The governance of nature areas can prevent the present deadlock but needs the development of technical and entrepreneurial capabilities.

The biophilic design promotes specific principles and patterns of nature-based solutions for health and well-being in the spaces we live and work. A growing body of literature advocates a more prominent role of nature in urban design and architecture, emphasizing the necessity of maintaining, enhancing, and restoring the beneficial experience of nature in the cities. Biophilia and nature-based solutions can improve the quality of built environment design and bring new opportunities to restore urban ecosystems and smart thinking for sustainable cities. The paper concludes that adopting biophilic principles in urban planning will lead to cities that can regenerate life and nurture end-users' health and well-being. Moreover, bring forward ways to transfer human nature ties' knowledge into restorative approaches to design the built environment.

The Danube Delta is the newest land formed by both transporting sediments brought by Danube River, which flows into the Black Sea and by traversing an inland region where water spreads and deposits sediments. Diurnal tidal action is low (only 8–9 cm), therefore the sediments would wash out into the water body faster than the river deposits it. However, a seasonal fluctuation of water level of 20 cm was observed in the Black Sea, contributing to alluvial landscape evolution in the Danube Delta. The Danube Delta is a very low flat plain, lying 0.52 m above Mean Black Sea Level with a general gradient of 0.006 m/km and only 20% of the delta area is below zero level. The main control on deposition, which is a combination of river, wind-generated waves, and tidal processes, depends on the strength of each one. The other two factors that play a major role are landscape position and the grain size distribution of the source sediment entering the delta from the river. The Danube Delta is a natural protected area in the South-Eastern part of Romania, declared a Biosphere Reserve through the UNESCO “Man and Biosphere” Programme. Water is a determining factor for all the human settlements in the Biosphere Reserve, the whole Danube Delta being structured by the three branches of the Danube (Chilia, Sulina and Sfantu Gheorghe (Saint George)). Our case study is focused on the Sulina branch, also named Sulina Channel, which offers the shortest distance between the Black Sea (trough Sulina Port) and Tulcea (the most important city of the Danube Delta from economic, social and cultural points of view) for both fluvial and marine ships. The improvement of water resources management is the main topic of this chapter, in terms of water quality indicators, which will be presented in twenty-nine monitoring points, starting since a few years ago and updated to nowadays. During the study period, significant exceedances of the limit value were detected in case of nitrate-N (3.9–4.6 mg/L) at the confluence (CEATAL 2) with the Saint George branch and in the Sulina Channel after the Wastewaters Treatment Plant (WWTP) discharge area, as well as near two settlements, namely Gorgova and Maliuc. The higher concentrations of Nitrogen-based nutrients were caused by the leakage from the old sewage systems (where these exist) and the diffuse loads.