Quantification of potable water savings by residential water conservation and reuse - A case study

To demonstrate the benefits of water conservation at the household level in regional Victoria in Australia, a family house “Sharland Oasis” was designed and built according to an ecologically sustainable design for improved water and energy efficiency. This study has demonstrated that the combined use of alternative water supplies together with water efficient appliances can save up to 77% of total potable water use compared to the average 1990s household water use in the same region considering the location and differing in water use approach. The use of rainwater inside the home alone saved up to 40% of potable water use. In addition to the water savings, there is a significant wastewater discharge saving achieved through the use of water conservation strategies and greywater reuse. A community survey undertaken in regional Victoria revealed that community receptivity for reusing greywater is highest for uses, such as watering gardens and flushing toilets; but it progressively decreased with increasing personal contact with greywater. Positive perception of greywater reuse needs to be encouraged through programs targeted at developing resources, skills and motivation for new water reuse practices and technologies, across a diverse range of social groups.     

Environmental benefits from the use of the residual biomass in nurseries

Every year, nurseries waste about 40 t of residual biomass for each ha of potted plants cultivation. The European nursery sector deals with about 90,000 ha of cultivated land and 120,000 ha of nurseries, with a turnover of 19.8 billion Euros in 2011. In recent years, a number of Italian projects highlighted that GHG (greenhouse gas) emissions for the nursery sector range between 37 tCO₂eq/ha/year and 45 tCO₂eq/ha/year for potted plants, mainly due to the consumption of electric energy, plastics and peat. Moreover, other studies analyse the impacts associated to nurseries, recommending best practices for energy reductions and waste recycle or reuse. Therefore, the present work focused its attention to the possible environmental benefits associated to the reuse of residues (wood and substrate) of potted plants that are discarded from the nursery production chain. GHG emissions and fossil energy requirement were quantified by considering the CO₂eq (CO₂ equivalent) and the CER (cumulative energy requirement) respectively, in order to assess the environmental impacts of two different scenarios proposed for the materials recovery. Final results highlighted that the solutions which are able to recover the substrate and the wood allow impact reductions compared to landfill disposal. In particular, the scenario consisting in the immediate separation of the substrate from the root-plant system and the successive chipping of wood for energetic reuse, allows higher savings than those obtainable through shredding and subsequent wind separation. Moreover, for what concerns the CO₂eq, an adequate use of the residual biomass make it possible to compensate the GHG emissions of the nurseries up to 15%.     

Modeling Energy Savings from Urban Shade Trees: An Assessment of the CITYgreen® Energy Conservation Module

CITYgreen® software has become a commonly used tool to quantify the benefits of urban shade trees. Despite its frequent use, little research has been conducted to validate results of the CITYgreen energy conservation module. The first objective of this study is to perform a familiar application of CITYgreen software to predict the potential energy savings contribution of existing tree canopies in residential neighborhoods during peak cooling summer months. Unlike previous studies utilizing CITYgreen, this study also seeks to assess the software’s performance by comparing model results (i.e., predicted energy savings) with actual savings (i.e., savings derived directly from energy consumption data provided by the electric utility provider). Homeowners in an older neighborhood with established trees were found to use less energy for air-conditioning than homeowners in a recently developed site. Results from the assessment of model performance indicated that CITYgreen more accurately estimated the energy savings in the highly vegetated, older neighborhood.     

New insights into the benefits of flood warnings: Results from a household survey in England and Wales

The flood defence agency in England and Wales has been pursuing a programme of flood warning system enhancement, engaging householders at risk in improving their warning responses. The immediate aim of this paper is to test and revise a model of economic benefits of warnings, but the survey data also generate insights into the constraints acting upon flood warning responses. Damage saving is less than previously anticipated: warning reliability and householder availability problems limit savings. Warnings are less likely to be received by those in lower social grades, and flood warning lead time is a factor in avoiding damage. The survey data indicate the complexities involved in improving flood warning response, and provide policy pointers.     

道地药材分布特点的研究

经初步整理研究表明.中国有道地药材约208种,按其自然地理分布,试将其划分为八大区,并进行了分区论述.本文着重分析和研究了道地药材的分布规律及分布特点     

EFFECT OF INFLUENT PHOSPHORUS REDUCTIONS ON GREAT LAKES SEWAGE TREATMENT COSTS1

ABSTRACT: Controlling phosphorus sources, such as laundry detergents, for eutrophication control has been the aim of water resources management in many areas. However, the advisability of limiting phosphorus in raw wastewater continues to be debated. One aspect that has received little attention is the cost savings at sewage treatment plants practing phosphorus removal. It is estimated, based on available data and observations where detergent phosphorus has been reduced, that cost savings could range from about $0.20 to $1.70 per capita per year for an influent reduction of about 1.5 mg/L of phosphorus. These savings result mostly from a decrease in the amount of chemicals needed to remove phosphorus at the plant as well as a decrease in sludge production. For the U.S. Great Lakes basin, total annual savings amounting to several million dollars are projected given a basin-wide ban. Although estimates of cost savings are presented for the Great Lakes basin, the results are applicable to other areas where phosphorus controls are being considered.     

The capital gains from trade are not enough: evidence from the environmental accounts of Venezuela and Mexico

In principle, a country cannot endure negative genuine savings for long periods of time without experiencing declining consumption. Nevertheless, theoreticians envisage two alternatives to explain how an exporter of non-renewable natural resources could experience permanent negative genuine savings and still ensure sustainability. The first one alleges that the capital gains arising from the expected improvement in the terms of trade would suffice to compensate for the negative savings of the resource exporter. The second alternative points at technological change as a way to avoid economic collapse. This paper uses the data of Venezuela and Mexico to empirically test the first of these two hypotheses. The results presented here prove that the terms of trade do not suffice to compensate the depletion of oil reserves in these two open economies.     

能源转型影响中国经济增长潜力的模拟研究——基于"弱可持续性"视角

能源需求的高增长和化石能源的高占比导致了日益严峻的环境退化问题.均衡状态下,用于环境治理的资本投入实质上是对储蓄的一种扣除,这会降低生产性资本总量的积累速度,导致经济增长潜力下滑.本文构建了一个包含能源转型与真实储蓄量的DSGE模型,结合最新相关文献和中国经济数据校准模型,模拟研究了能源转型对中国经济增长潜力的影响以及相关政策效应.结论表明:能源转型发挥出一种"刹车"效应,将逐渐减缓经济增长潜力的下滑趋势;能源转型的持续推进,有望在2030年左右逆转其趋势;能源转型相关政策会改变"刹车"期的时长和弱化经济潜力的下滑程度.政策启示方面,能源转型是扭转经济增长潜力下滑趋势的有效手段,政府可通过政策"组合拳"的方式来干预能源转型过程,将有助于缩短"刹车"期和相对增强经济增长潜力.     

Optimal design for water conservation and energy savings using green roofs in a green building under mixed uncertainties

Most water conservation and energy saving strategies for residential homes and commercial buildings have higher initial capital investment than traditional ones. Yet, the added benefits of these “green” building strategies should outweigh the increase of initial capital cost at the end of the house lifetime. Using green roof systems to cool houses gives rise to uncertainties from local precipitation patterns and the unstable market related costs and benefits. The optimal area of green roof to balance cost, benefit, and risk remains unknown. To achieve such a complex systems analysis, a grey stochastic programming model was prepared to address the optimal design strategies under mixed uncertainties. Such a cost-benefit-risk trade-off model was formulated for this study through an optimization framework to retrieve the optimal design strategies with respect to a typical Florida residential home (shingle and metal roofs). It is particularly designed to synergistically integrate a green roof with beneficial reuse of gray water and stormwater while achieving some degree of energy savings. The study identifies the optimal green roof area that keeps within the cost of a conventional home over a specific life time, such as 50 years. Research findings show that as the reliability level associated with the chance constraint was decreased, the upper bound of the green roof area did not vary much for either shingle or metal roofs. The lower bound was found to decrease in the same situation, however, due to the higher minimum cost of the cistern in relation to the greater volume of expected rainfall, forcing the required green roof area to decrease.     

Testing genuine savings as a forward-looking indicator of future well-being over the (very) long-run

Genuine Savings (GS) have been much used in recent years as an indicator of a country's sustainability. According to some theorists (e.g. Arrow et al., 2012), under certain conditions a country with a positive level of GS should experience non-declining future utility, given the assumption of unlimited substitutability among all forms of capital (sometimes called “weak” sustainability). This paper reports the first very long-run tests of GS (also called comprehensive investment or adjusted net savings) as a forward-looking indicator of future well-being. We assemble data for British capital back to 1765, and construct several net investment measures which are used as indicators of two alternative measures of future well-being: consumption per capita and real wages. An allowance for a “value of time” due to exogenous technological progress is included in some GS measures, and we demonstrate the importance of this measure and the choice of discount rate over the very long-run. On the whole, our results do not reject the postulated relationship between GS and future well-being, and show GS can be a forward looking indicator of future well-being for periods of up to 100 years.