Suchergebnisse

Current paper analyzes the reservoir´s useful water volume for hydropower efficiency in water supply systems. Data, retrieved from the Guanabara Water Supply System of the municipality of Ananindeua, state of Pará, Brazil, were analyzed. Two useful volume sizes were determined following recommendations by NBR 12.217/1994 "Project on the water distribution reservoir for public supply". The former featured the time curve of water consumption and the latter the rate of maximum daily discharge. The latter stage assessed the most adequate useful water volume from the point of view of hydropower efficiency by Epanet 2.0. Dimensions with or without water consumption curve provided useful volumes of 838 m3 and 2.043 m3, respectively. In the case of the lowest volume, 47 hours/day of CMB functioning and 987 kWh/day of electric power consumption in EAT were detected. Volume increase to 2,043 m3 was positive, followed by 30 hours/day of functioning of CMB and consumption at 818 kWh/day in EAT. Hydropower costs were reduced by R$ 35,903.00/year, from R$ 143,108.00/year, with a useful volume of 838 m³, to R$ 107,205.00/year with 2,043 m³. Research revealed the importance of computerized simulation in decision-taking and the need for the updating of NBR 12.217/1994 by criteria of hydropower efficiency in the preparation of projects involving water supply reservoir systems.

Blue and green ecosystems are considered a key for the improvement of cities sustainability, providing numerous ecosystem services and habitat for many species. However, urban streams are still neglected and degraded, specially in southern European countries. One important step towards the rehabilitation of these ecosystems is the awareness of their importance by citizens. This study aimed to assess the effect of 1-year of activities (field and laboratory) of an environmental education project on primary school children, in improving their knowledge on urban stream ecosystems and their problems. We analyzed students' questionnaires before and after field and laboratory activities, drawings and group interviews. Initially, most children had incipient contact with rivers and streams, showing fears and lack of knowledge about them. As the project progressed, their perceptions changed, with a clear increase in the proportion of students recognizing the biodiversity associated to rivers (e.g., names of riparian trees, aquatic plants and invertebrates). Also, their fears decreased significantly, while their awareness to the impacts of artificialization and lack of riparian vegetation increased. Our results show that direct contact with nature have a positive role in the way it is understood by children, as well as promoting responsible and sustainable behaviors, being effective from the early primary-school years. ; Funding: SRQS was financed by a post-doc grant in the Project "PHARA-ON: Pilots for Healthy and Active Ageing" funded by the European Union's Horizon 2020 research and innovation programme (H2020-SC1-FA-DTS-2018-2); ARC by a posdoc grant of project RIVEAL - RIparian forest Values and Ecosystem services in uncertain freshwater futures and Altered Landscapes (LISBOA-01-0145-FEDER-029790; FCT). MJF by FCT through Norma Transitória do DL 57/2016 changed by law 57/2017). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.