Assessing sectoral water stress states from the demand-side perspective through water footprint dimensions decomposition.

Due to its essentiality and scarcity, water is subject to stress from the supply and demand side. The SDG and many methods for assessing water stress (WS) are based on water supply, even though the total water supply is uncontrollable by humans in the short term. Conversely, from a water demand perspective, WS arises from the deliberate and manageable use of water to produce goods and services, with few methods proposing to evaluate WS. We propose a method to assess the sectoral demand-side water stress states (DWSS) to fill this gap. The method comprises a quantitative step followed by a qualitative analysis. Quantitatively, an environmentally extended input-output model integrated Brazilian water resource and economic data for 2010 and 2015, including the imported virtual water in the water footprint calculation. Three dimensions of water footprint (DWF) were calculated: consumptive use of water (CUWF), water consumption (CWF), and return to the environment (REWF). The variations in DWFs over time were used as criteria to define five DWSS ranging from weak to strong. Brazilian economy as a whole presented a moderately weak DWSS. Among economic sectors, the most frequent DWSS was moderately weak, with sixteen sectors. The Livestock and Forestry, fishing, and aquaculture sectors had a strong DWSS, while the Slaughter, meat, and dairy and Public administration sectors had weak DWSS. Despite its limitations, the demand-side analysis can complement the usual method from a supply perspective.

Emergy unsustainability index for agricultural systems assessment: A proposal based on the laws of thermodynamics.

The anthropic effects of agriculture call for more sustainable systems. Agricultural sustainability conventionally communicates an idea of perennity. However, the sustainability of living open systems, like agricultural systems, can be regarded as a mere utopian idea when the effects of the laws of thermodynamics are taken into account. Under such physical laws, what really exists is the fact that any system alone has the property of unsustainability. The rate of entropy production can denote the potential level of the unsustainability of a system. The higher the rate of entropy production in an agricultural system, the higher its potential for unsustainability. Directly measuring entropy in living open systems is unfeasible. Even so, such systems are subject to the laws of thermodynamics. Indirect measurements of entropy in living open systems can be assessed by approximation through an analysis of the energy flows of the system. We used emergy analysis to account for the energy flows and compare the unsustainability among agricultural systems. However, the indicators proposed by emergy analysts have been more aligned with the perspective of sustainability. To change this perspective, we propose an emergy unsustainability index applied in this paper specifically to agricultural systems (EUIAS). EUIAS is not a simple inversion of the ESI obtained by the ratio between the Emergy Yield Ratio (EYR) and the Environmental Loading Ratio (ELR). The use of renewable exergy stored from one production cycle to another is one of the peculiarities of long-term agricultural systems. Therefore, quantifying the renewable and non-renewable fractions of resources used is fundamental to the EUIAS. A higher EUIAS means that an agricultural system is more dependent on non-renewable economic resources than renewable resources, and, in general, environmental impacts are higher due to the use of non-renewable resources.

Avaliação quantitativa e do grau de segregação dos resíduos sólidos orgânicos gerados em serviços de alimentação de um shopping center em Porto Alegre ­ RS / Quantitative evaluation and segregation of organic solid waste generated in food services of a shopping center in Porto Alegre - RS

O objetivo do presente estudo foi avaliar a quantidade e o grau de segregação dos resíduos sólidos orgânicos (RSO) gerados em 14 estabelecimentos que preparam e servem alimentos em um shopping center no município de Porto Alegre - RS. Em quatro dias não consecutivos, os resíduos gerados nos estabelecimentos foram coletados para avaliação, resultando em 180 amostras e geração diária média de 421kg de RSO. Considerando que estes resíduos são destinados à alimentação animal, determinou-se o grau de conformidade na sua segregação, através da observação e manuseio dos conteúdos de cada amostra. Verificou-se que apenas 82 (46%) amostras estavam de acordo com os critérios de segregação previamente estabelecidos, não sendo observada diferença (P=0,189) entre os estabelecimentos. O alto índice de segregação em desacordo demonstra que há necessidade de capacitação continuada junto às pessoas que atuam nestes ambientes.

This study aimed at quantitatively and qualitatively assessing the solid organic waste (SOW) produced by 14 food establishments in a shopping center. In 4 days, 180 samples were collected, with each establishment generating a daily average of 421 Kg. Considering that these SOW are destined to feed animals, the conformity degree in their segregation was determined, through observation and handling of the contents of each sample. We verified that only 82 (46%) of the samples were compliant with the segregation criteria established and that this percentage was similar (P=0.189) between the establishments. The high level of deviation demonstrates that the persons working in such environments need continuous training.