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The objective of this paper is to assess the impact of proposed Canadian climate change mitigation policies (discounting and carbon pricing) on cost, energy use, and greenhouse gas (GHG) emissions in the single-objective design/expansion optimization of the Amherstview water distribution system in Amherstview, Ontario, Canada. The single-objective optimization problem is solved with the elitist genetic algorithm (EGA). The optimization approach is used in a parametric analysis to examine the impact of discounting and carbon pricing on GHG reductions for cement-mortar ductile iron and polyvinyl chloride pipe materials. Preliminary results indicate that the discount rate and carbon prices investigated had no significant influence on energy use and GHG mass in the Amherstview system and did not meet the emission-reduction targets set by the Canadian government. This result was attributed to a number of factors, including adequately installed hydraulic capacity in the Amherstview system, the use of a time-declining GHG emission intensity factor, and the scope of the expansion problem. [ABSTRACT FROM AUTHOR]

The climate impact studies in hydrology often rely on climate change information at fine spatial resolution. Because general circulation models (GCMs) operate on a coarse scale, the output from a GCM has to be downscaled to obtain the information relevant to hydrologic studies. In this paper, downscaling models are developed using the state-of-the-art nonparametric method K-Nearest Neighbor (K-NN) approach, with an emphasis on optimal choice in selection of nearest neighbors for obtaining simultaneous projections of mean monthly maximum and minimum temperatures (Tmax and Tmin) as well as monthly precipitation and pan evaporation to lake-basin scale in a semiarid region that is considered to be a climatically sensitive region in India. The performance of the K-NN approach was evaluated based on several statistical performance indicators. A comparison of K-NN has been made with a linear multiple regression (LMR)-based downscaling model. Also, the prevailing view in the literature regarding optimal choice of selection of nearest neighbors is checked with different perturbations. A simple multiplicative shift was used for correcting predictand values. The K-NN-based models are found to be superior to LMR-based models, and, subsequently, the K-NN-based model is applied to obtain future climate projections of the predictands. An increasing trend is observed for Tmaxand Tmin for A1B, A2, and B1 scenarios, and the precipitation is projected to increase in the future for A2 and A1B scenarios, whereas no trend has been observed for pan evaporation in future. [ABSTRACT FROM AUTHOR]

Building regulations and governmental policies create pressure on the construction industry to minimize the environmental impacts that are caused by buildings. Achieving energy efficiency, and thereby low-carbon construction, is only possible by cooperation among the participants in the construction supply chain. Clients in particular have an important role in promoting environmental sustainability. In this paper, the carbon-reduction process is analyzed from a construction client's perspective. A framework is developed to analyze the interrelated components of this process, including the drivers, initiatives, challenges, facilitators, solutions, and achievements. A qualitative case study methodology was employed to gain a better understanding of the project-based practices and corporate policies in achieving energy efficiency. The study presents the results of three award-winning construction projects from the U.K. in which innovations for improving environmental sustainability were based on the Code for Sustainable Homes. The study outlines the initiatives and strategies of clients for carbon reduction, obstacles faced by project teams, mechanisms that helped overcome the difficulties, and low-carbon solutions applied to design, construction, and operation in the selected cases. Effective leadership, corporate responsibility, a focus on end users, repeatable nature of projects, and integrated teams are found to be the main success factors. The findings of this study are expected to guide construction professionals in implementing innovative low-carbon practices in collaborative project environments. The proposed framework can be used to better understand the carbon-reduction process in other projects and other countries where different regulations and conditions prevail. [ABSTRACT FROM AUTHOR]

Coastal freshwater aquifers are highly vulnerable to climate change and other anthropogenic environmental impacts. Therefore, managing coastal freshwater for future use requires critical planning. This is especially true for small barrier islands where, in most cases, groundwater could be the only freshwater resource. In this study, the combined effects of climate change, land-use changes, and increased groundwater pumping on freshwater resources of a barrier island were studied. A case study was completed using the field data available for Dauphin Island, a small barrier island located in Alabama, U.S., and by using the simulation data generated from multiple water-resource-management models. Soil and Water Assessment Tool (SWAT) simulations provided recharge estimates under various future land use/land cover and climate-change scenarios. Downscaled global circulation model provided precipitation and temperature patterns for the period 2011–2030. The recharge estimates from SWAT were then used as input in a numerical groundwater model to evaluate saltwater-intrusion effects and forecast the changes in freshwater storage within the island aquifer system. Various groundwater-management scenarios were simulated using the MODFLOW-family computer code SEAWAT to assess the sensitivity of the groundwater system to increased pumping rates and decreased recharge due to climate change and/or future developments. SEAWAT was used to predict the lateral saltwater-intrusion effects and its impacts on groundwater quality and freshwater volume. The simulation results show that the saltwater wedge would advance laterally under all future climate-change scenarios. These results indicate that the shallow unconfined aquifer might not be able to sustain any significant future population growth, especially under adverse climate-change conditions. Analysis of changes in the volume of freshwater lens provided a broader understanding of the coupled effects of climatic and anthropogenic changes on freshwater storage and this information can be used to better manage Dauphin Island’s unconfined groundwater system. [ABSTRACT FROM AUTHOR]

This study presents a methodology for assessing impacts of climate change in regional-scale hydrology using the K-nearest neighbor weather generator (WG) model in combination with the outputs of global circulation models (GCMs) and hydrologic rainfall-runoff model. The Nakdong River Basin in Korea is used as a case study. The study applies a systematic approach to select the variables for the WG model from five meteorological variables available in the basin. In addition, the GCMs' projections based on a B1 emission scenario are incorporated into the proposed WG model to reflect the impacts of climate change, consequently generating the meteorological series for 60 years. Meteorological data for historic and two climate scenarios (dry and wet) are generated. The generated time series of meteorological variables are used with the streamflow synthesis and reservoir regulation rainfall-runoff model to calculate the streamflow at 25 sub-basins. The results demonstrate that the WG models combined with the GCMs' outputs are able to provide future weather conditions for the assessment of climate change impacts. One of the major findings of the study is the potential severity of drought impacts that may increase the historical drought duration in the basin up to three times. [ABSTRACT FROM AUTHOR]