Ecological responses of three urban watercourse stretches after implementation of one-off recovering interventions: an integrated assessment

Faced with the anthropic activities of urban streams stretches through rectification with concrete, there is a concern about the modifications of the aquatic habitats and consequent ecological damages to the ecosystems. Based on biophilic engineering, there is a great opportunity to idealize and test interventions to revitalize such hampered ecosystems. Hence, we verified the performance of biological and organic factors, after the implementation of one-off interventions in three rivers using biophilic handmade materials and structural elements in their fixation. We carried out the project in urban stretches of concrete bed streams, located in Sorocaba-SP, Southeast of Brazil. In two years, we conducted biweekly in situ and laboratory measurements to characterize the study sites, idealize, scale, implement the projects, and, evaluate the ecological responses of the implementations. We collected sampling in two points: upstream and downstream interventions. We evaluated the performance of the interventions through the analysis of SWOT (Strengths, Weaknesses, Opportunities, and Threats) factors and by using the Analytic Hierarchy Process (AHP). We presented the results through a decision-making matrix for stakeholders, which indicated that our ideas are of low cost and easy to implement. Then, we got the following scenario of SWOT priorities: opportunity (58.55%), strength (24.71%), threat (10.74%), and weakness (6.00%). They demand constant efforts for maintenances and they need adjustments to a better understood by residents and the watershed management. We concluded that the strengths observed in the project turn our idea replicable in any part because it attaches the idea of caring about the environment through biophilic techniques, and the weaknesses are liable to modifications (improvements) in future projects that consider such proposal.

Measurement and Modelling of Moisture Distribution and Water Binding Energy of Dredged Sludge

The dewatering of dredged sludge is a critical step in the minimization and reutilization of this solid waste. However, there is a lack of available literature on the fundamental drying characteristics of dredged sludge. In this work, two kinds of typical sludge dredged from an urban watercourse were tested by low-field NMR to investigate the water distribution in sludge and it was found that water contained in sludge can be classified into three categories: free water, capillary water and bound water. In addition, a novel model was proposed based on the Lennard-Jones equation and Kelvin law to quantitatively evaluate the binding energy during drying. Further, the model results were experimentally verified by thermogravimetry differential thermal analysis (TG-DTA). Results show that the trends of the model are consistent with the experimental values and the gradient of energy consumption during dehydration can be divided into three main stages. In stage 1, the total energy required for dewatering equals the latent heat of free water. In stage 2, binding energy reaches dozens to hundreds of kJ/kg accounting for capillary action. In stage 3, binding energy increases steeply reaching almost thousands of kJ/kg due to intermolecular interactions. All the discovered aspects could improve the management and disposal of dredged sludge from an energy cost perspective.

Multi-Criteria Decision Method for Sustainable Watercourse Management in Urban Areas

The rapid urban growth followed by disordered occupation has been generating significant impacts on cities, bringing losses of an economic and social nature that directly interfere with the well-being of the population. In this work, a proposal for local urban infrastructure problems associated with watercourse management is presented, comparing Sustainable Drainage System (SuDS) techniques and Low-Impact Development (LID) concepts with alternative traditional interventions. The study addresses sustainable alternatives to cope with the urbanization of the Cehab’s open channel, which is an important urban watercourse tributary of the Muriaé River, at the municipality of Itaperuna, Rio de Janeiro—Brazil. The multi-criteria decision-making method called Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was applied here. The results highlighted the better performance of sustainable techniques when compared to the traditional ones, with an overall advantage of the geogrids and geocells for this case study. The obtained TOPSIS coefficients-C for these techniques were higher (0.59488, for Reach 1; and 0.68656, for Reach 2) than those for the others. This research, therefore, presented an important urban watercourse management methodology that can be further applied to guide sustainable investments and help the decision-making associated with the development of territories.

Properties of the urban watercourse composition under anthropogenic load

The anthropogenic impact on urban rivers is very significant. Industrial enterprises, municipal, and agricultural organizations discharge wastewater directly into the rivers. In the samples of the studied water, certain properties were found. The water in the river is cloudy, brown in color, and in some places has a sharp smell. Extraneous impurities and foam were detected in water. Moreover, various chemicals were found, which are not characteristic to natural waters. The analyzed water is highly polluted as shown by the following chemical indicators, which reported results higher than the Maximum Allowable Concentration: Fe concentration is 24 times higher than standard, Cu is 5 times higher, Mn is 6 times higher, Al is 366 times higher, Hg is 3 times higher, Zn is 4 times higher, NO2 is 2.5 times higher, hydrocarbon pollution is 2.8 times higher, NH4 is 1.9 times higher. Therefore, it is necessary to immediately develop effective methods for monitoring the state of the watercourse, both economic and energetic. To save the sustainable development of the natural system.

Water, society and urbanization in the 19th century Belgrade: Lessons for adaptation to the climate change

This paper traces urban history of Belgrade in the 19th century by looking into its waterscape in the context of its transformation as the capital of the Princedom of Serbia. Aiming to underline the importance of water as a resource, with the view to contemporary environmental concerns, we explore how citizens historically related to waterscape in everyday life and created a specific socio-spatial water network through use of public baths on the river banks and public fountains, water features and devices in the city. The paper outlines the process of establishing the first modern public water supply system on the foundations of the city?s historical Roman, Austrian and Ottoman waterworks. It also looks at the Topcider River as the most telling example of degradation of a culturally and historically significant urban watercourse from its natural, pastoral and civic past to its current polluted and hazardous state. Could the restitution of the Topcider River be considered as a legacy of sustainability for future generations, and are there lessons to be learned from the urban history which can point to methods of contemporary water management?