Skip to content

Study of the Relationship between Procurement Duration and Project Performance in Design-Build Projects: Comparison between Water/Wastewater and Transportation Sectors

Bogus, Susan M.; Migliaccio, Giovanni C.; Jin, Ruoyu. (2013). Study of the Relationship between Procurement Duration and Project Performance in Design-Build Projects: Comparison between Water/Wastewater and Transportation Sectors. Journal Of Management In Engineering, 29(4), 382 – 391.

View Publication

Abstract

Previous studies on building, industrial, and transportation projects found that projects delivered using design-build tend to perform better than projects delivered with the traditional design-bid-build method. However, performance of design-build projects is affected by various factors, with procurement-related factors being among the most influential. Whereas other aspects of procurement have been largely investigated, the effect of procurement duration on project performance has been studied only for design-build transportation projects. In addition, few studies have focused specifically on the delivery of water/wastewater projects. This paper includes the results of a study on the relationship between procurement duration and performance of water/wastewater design-build projects. The study methodology was based on regression analysis of data from a sample of water/wastewater design-build projects. The results show that unlike the transportation sector, procurement duration has little effect on either schedule or cost performance in the water/wastewater sector. Likely reasons for this difference were then explored through a content analysis of procurement documents. (C) 2013 American Society of Civil Engineers.

Keywords

Design Engineering; Procurement; Project Management; Regression Analysis; Transportation; Waste Management; Procurement Documents; Schedule Performance; Cost Performance; Design-build Transportation Projects; Procurement-related Factors; Design-bid-build Method; Water-wastewater Sectors; Transportation Sectors; Project Performance; Procurement Duration; Design/build; Project Delivery; Water; Wastewater

Deriving a Long-Term Pan Evaporation Reanalysis Dataset for Two Chinese Pan Types

Wang, Kaiwen; Liu, Xiaomang; Li, Yuqi; Yang, Xiaohua; Bai, Peng; Liu, Changming; Chen, Fei. (2019). Deriving a Long-Term Pan Evaporation Reanalysis Dataset for Two Chinese Pan Types. Journal Of Hydrology, 579.

View Publication

Abstract

A long-term continuous and consistent pan evaporation (E-pan) reanalysis dataset will augment the analysis of E-pan distributions when the observation network is discontinuous or inconsistent, and assist in the evaluation of the outputs of General Circulation Models (GCMs) and Land Surface Models (LSMs). From the 1950s to early 2000s, China had a continuous observation of the D20 pan, but this was replaced by the 601B pan across China around 2002, and thus the E-pan observation network became discontinuous and inconsistent. This study developed a long-term monthly, 0.05 degrees, continuous and consistent reanalysis dataset for both D20 and 6018 pans covering mainland China throughout 1960-2014, based on meteorological data homogenization and interpolation and E-pan assimilation. The PenPan-V3 model used inE(pan) assimilation was successfully validated by observations at 767 and 591 stations for D20 and 601B pans, respectively. Comprehensively considering the physical influence of elevation, radiation, wind speed, humidity, and air temperature, the average annual and seasonal gridded E-pan reanalyses show significant spatial dependent on proximity to the ocean and latitude, consistent with previous studies. The reanalysis dataset can be used to analyze E-pan distributions across China, including the areas without observations, and to estimate the representativeness of E-pan to atmospheric evaporative demand. The dataset has been released in two cloud servers in China and the United States, and it will continue to be maintained and updated.

Keywords

General Circulation Model; Evaporation (meteorology); Atmospheric Temperature; Wind Speed; China; Long-term Continuous And Consistent Dataset; Pan Evaporation Reanalysis Dataset; Representativeness To Atmospheric Evaporative Demand; Maximal T-test; Reference Evapotranspiration; Climate Data; Energy-balance; Reference Crop; Trends; Water; Model; Demand; General Circulation Models; Air Temperature; Data Collection; Evaporation; Evaporative Demand; Humidity; Latitude; Meteorological Data; United States

Symbiotic And Regenerative Sustainability Frameworks: Moving Towards Circular City Implementation

Horn, Erin; Proksch, Gundula. (2022). Symbiotic And Regenerative Sustainability Frameworks: Moving Towards Circular City Implementation. Frontiers In Built Environment, 7.

View Publication

Abstract

Growing in popularity, the circular city framework is at the leading-edge of a larger and older transitional dialogue which envisions regenerative, circular, and symbiotic systems as the future of urban sustainability. The need for more research supporting the implementation of such concepts has been often noted in literature. To help address this gap, this holistic review assesses a range of pertinent sustainability frameworks as a platform to identify actionable strategies which can be leveraged to support and implement circular city goals. This assessment is grounded in a holistic overview of related frameworks across interdisciplinary and scalar domains including circular city, the food-water-energy nexus, circular economy, bioeconomy, industrial symbiosis, regenerative design, and others. Building on these interrelationships, the applied strategies espoused within these publications are synthesized and assessed in the context of circular city implementation. From an initial 250 strategies identified in literature, thirty-four general implementation strategies across six thematic areas are distinguished and discussed, finding strong overlaps in implementation strategies between frameworks, and opportunities to further develop and harness these synergies to advance circular city toward sustainable urban futures.

Keywords

Circular City; Implementation Strategies; Literature Review; Circular Economy; Fwe-nexus; Regenerative Design; Systems Integration; Environmental Assessment; Rooftop Greenhouses; Anaerobic-digestion; Urban Agriculture; Built Environment; Waste Management; Climate-change; Carbon Nexus; Food Nexus; Economy

uilding Watershed Narratives: An Approach for Broadening the Scope of Success in Urban Stream Restoration

Yocom, Ken. (2014). Building Watershed Narratives: An Approach for Broadening the Scope of Success in Urban Stream Restoration. Landscape Research, 39(6), 698 – 714.

View Publication

Abstract

The success of urban stream restoration is often measured through biophysical attributes, or the progress towards restoration of a notionally intact section of landscape. What remains understudied is how success can be defined across social, economic, as well as ecological parameters. This research offers a narrative approach for urban restoration research that serves as a chronotope for untangling the biophysical and sociocultural complexities of the contemporary urban environment. The framework of this approach is presented through a case study of a recent stream restoration project in Seattle, Washington. The findings highlight the need for urban stream restoration processes to be grounded within a sociocultural context that is interdependent with biophysical conditions, and recommends measures of project success to include community, educational and participatory goals.

Keywords

River Restoration; Landscape; Management; Catchment; Systems; History; People; Restoration; Success; Watershed; Narrative; Urban

The Unignorable Impacts of Pan Wall on Pan Evaporation Dynamics

Wang, Kaiwen; Liu, Xiaomang; Liu, Changming; Yang, Xiaohua; Bai, Peng; Li, Yuqi; Pan, Zharong. (2019). The Unignorable Impacts of Pan Wall on Pan Evaporation Dynamics. Agricultural & Forest Meteorology, 274, 42 – 50.

View Publication

Abstract

Open water evaporation (E-ow), such as evaporation of lake and reservoir, is typically estimated by observations of different pans. The observation networks of pan evaporation (E-pan) were established and maintained worldwide for a long history. All the pans in the world consist of water body and pan wall, which includes side wall, pan rim and (if any) pan bottom. Since the pan wall will affect E-pan by radiation absorption and heat conduction, once pan wall absorbs and conducts more heat for vaporizing than water body in a pan, observed E-pan dynamics will greatly deviate E-ow causing uncertainties and errors in estimating E-ow. Thus, this study calculated E-pan at 767 meteorological stations in China and quantified the contributions of water body and pan wall on E-pan trends. For China as a whole, E-pan decreased at -3.75 mm/a(2) and increased at 3.68 mm/a(2) during 1960-1993 and 1993-2016, respectively. 84% of E-pan trends were contributed by water body. For 767 stations, E-pan trends of 84 and 96 stations were dominated by pan wall during 1960-1993 and 1993-2016, respectively. Since pan wall contributed more than half of E-pan trends for (similar to)23% of the stations in China, the impacts of pan wall on E-pan dynamics cannot be ignored.

Keywords

Heat Radiation & Absorption; Heat Conduction; Meteorological Stations; Bodies Of Water; Dynamics; Water Diversion; China; Pan Evaporation Dynamics; Pan Wall; Radiation Absorption And Heat Conduction; Trends; Sensitivity; Demand; Model; Absorption; Evaporation; Heat Transfer; Lakes; Surface Water; Uncertainty

Tsunami Preparedness And Resilience: Evacuation Logistics And Time Estimations

Chen, Chen; Wang, Haizhong; Lindell, Michael K.; Jung, Meen Chel; Siam, M. R. K. (2022). Tsunami Preparedness And Resilience: Evacuation Logistics And Time Estimations. Transportation Research Part D-transport And Environment, 109.

View Publication

Abstract

Extensive research has studied the near-field tsunami threat in the Cascadia Subduction Zone (CSZ), but little research has examined the ability to evacuate the inundation zone before the first tsunami wave arrives. To address this gap, this study provides empirical evidence about people's expectations about hazard onset and evacuation logistics when a tsunami threatens. We surveyed households in five CSZ communities to assess residents' expected first wave arrival time, as well as their expectations about evacuation destinations, route choices, preparation times, travel times, and clearance times. Heatmaps are used to summarize residents' evacuation destinations and route choices, and probabilistic functions are used to model evacuation distances and time estimates. The results suggest that respondents have similar patterns of time estimates, but a few plan to evacuate within the inundation zone, and some plan to evacuate on routes that were congested in a previous event and end their evacuations at destinations within the inundation zone.

Keywords

Disaster; Tsunami Evacuation; Time Estimate; Cascadia Subduction Zone; Behavior; Decision-making; American-samoa; Earthquake; Oregon; Washington; Wellington; Responses; Hazard; Model

Ecological Design For Urban Waterfronts

Dyson, Karen; Yocom, Ken. (2015). Ecological Design For Urban Waterfronts. Urban Ecosystems, 18(1), 189 – 208.

View Publication

Abstract

Urban waterfronts are rarely designed to support biodiversity and other ecosystem services, yet have the potential to provide these services. New approaches that integrate ecological research into the design of docks and seawalls provide opportunities to mitigate the environmental impacts of urbanization and recover ecosystem function in urban waterfronts. A review of current examples of ecological design in temperate cities informs suggestions for future action. Conventional infrastructures have significant and diverse impacts on aquatic ecosystems. The impacts of conventional infrastructure are reduced where ecological designs have been implemented, particularly by projects adding microhabitat, creating more shallow water habitat, and reconstructing missing or altered rocky benthic habitats. Opportunities for future research include expanding current research into additional ecosystems, examining ecological processes and emergent properties to better address ecosystem function in ecological design, and addressing the impact of and best practices for continuing maintenance. Planned ecological infrastructure to replace aging and obsolete structures will benefit from design feedback derived from carefully executed in situ pilot studies.

Keywords

Coastal Defense Structures; Fixed Artificial Habitats; Marine Habitats; Intertidal Seawalls; Benthic Communities; Reconciliation Ecology; Subtidal Epibiota; Rocky Shores; Reef; Biodiversity; Ecological Design; Seawalls; Habitat; Waterfront; Urban Infrastructure; Aquatic Ecology

Pan Coefficient Sensitivity to Environment Variables across China

Wang, Kaiwen; Liu, Xiaomang; Tian, Wei; Li, Yanzhong; Liang, Kang; Liu, Changming; Li, Yuqi; Yang, Xiaohua. (2019). Pan Coefficient Sensitivity to Environment Variables across China. Journal Of Hydrology, 572, 582 – 591.

View Publication

Abstract

Data of open water evaporation (E-ow), such as evaporation of lake and reservoir, have been widely used in hydraulic and hydrological engineering projects, and water resources planning and management in agriculture, forestry and ecology. Because of the low-cost and maneuverability, measuring the evaporation of a pan has been widely regarded as a reliable approach to estimate E-ow through multiplying an appropriate pan coefficient (K-p). K-p is affected by geometry and materials of a pan, and complex surrounding environment variables. However, the relationship between K-p and different environment variables is unknown. Thus, this study chose China D20 pan as an example, used meteorological observations from 767 stations and introduced the latest PenPan model to analyze the sensitivity of K-p to different environment variables. The results show that, the distribution of annual K-p had a strong spatial gradient. For all the stations, annual K-p ranged from 0.31 to 0.89, and decreased gradually from southeast to northwest. The sensitivity analysis shows that for China as a whole, K-p was most sensitive to relative humidity, followed by air temperature, wind speed and sunshine duration. For 767 stations in China, K-p was most sensitive to relative humidity for almost all the stations. For stations north of Yellow River, wind speed and sunshine duration were the next sensitive variables; while for stations south of Yellow River, air temperature was the next sensitive variable. The method introduced in this study could benefit estimating and predicting K-p under future changing environment.

Keywords

Atmospheric Temperature; Hydraulic Engineering; Meteorological Observations; Humidity; Water Supply; Evaporation (meteorology); Sunshine; Lake Management; China; Kp Most Sensitive To Relative Humidity; Open Water Evaporation; Pan Coefficient (kp); Pan Evaporation; Sensitivity Analysis; Reference Evapotranspiration; Reference Crop; Evaporation; Water; Model; Pan Coefficient (k-p); K-p Most Sensitive To Relative Humidity; Air Temperature; Ecology; Forestry; Geometry; Hydrologic Engineering; Lakes; Maneuverability; Meteorological Data; Models; Planning; Prediction; Relative Humidity; Solar Radiation; Wind Speed; Yellow River

Exposure Path Perceptions and Protective Actions in Biological Water Contamination Emergencies

Lindell, Michael K.; Mumpower, Jeryl L.; Huang, Shih-kai; Wu, Hao-che; Samuelson, Charles D. (2015). Exposure Path Perceptions and Protective Actions in Biological Water Contamination Emergencies. Environmental Health Insights, 9, 13 – 21.

View Publication

Abstract

This study extends the Protective Action Decision Model, developed to address disaster warning responses in the context of natural hazards, to boil water advisories. The study examined 110 Boston residents' and 203 Texas students' expectations of getting sick through different exposure paths for contact with contaminated water. In addition, the study assessed respondents' actual implementation (for residents) or behavioral expectations (for students) of three different protective actions - bottled water, boiled water, and personally chlorinated water - as well as their demographic characteristics and previous experience with water contamination. The results indicate that people distinguish among the exposure paths, but the differences are small (one-third to one-half of the response scale). Nonetheless, the perceived risk from the exposure paths helps to explain why people are expected to consume (or actually consumed) bottled water rather than boiled or personally chlorinated water. Overall, these results indicate that local authorities should take care to communicate the relative risks of different exposure paths and should expect that people will respond to a boil water order primarily by consuming bottled water. Thus, they should make special efforts to increase supplies of bottled water in their communities during water contamination emergencies.

Keywords

Water Contamination; Exposure Paths; Risk Perception; Protective Action

Ancient and Current Resilience in the Chengdu Plain: Agropolitan Development Re-‘Revisited’

Abramson, Daniel B. (2020). Ancient and Current Resilience in the Chengdu Plain: Agropolitan Development Re-‘Revisited’. Urban Studies (sage Publications, Ltd.), 57(7), 1372 – 1397.

View Publication

Abstract

The Dujiangyan irrigation system, China's largest, is one of the world's most important examples of sustainable agropolitan development, maintained by a relatively decentralised system of governance that minimises bureaucratic oversight and depends on significant local autonomy at many scales down to the household. At its historic core in the Chengdu Plain, the system has supported over 2000 years of near-continuously stable urban culture, as well as some of the world's highest sustained long-term per-hectare productivity and diversity of grain and other crops, especially considering its high population density, forest cover, general biodiversity and flood management success. During the past decade, rapid urban expansion has turned the Chengdu Plain from a net grain exporter into a grain importer, and has radically transformed its productive functioning and distinctive scattered settlement pattern, reorganising much of the landscape into larger, corporately-managed farms, and more concentrated and infrastructure-intensive settlements of non-farming as well as farming households. Community-scale case studies of spatial-morphological and household socio-economic variants on the regional trend help to articulate what is at stake. Neither market-driven 'laissez-faire' rural development nor local state-driven spatial settlement consolidation and corporatisation of production seem to correlate well with important factors of resilience: landscape heterogeneity; crop diversity and food production; permaculture; and flexibility in household independence and choice of livelihood. Management of the irrigation system should be linked to community-based agricultural landscape preservation and productive dwelling, as sources of adaptive capacity crucial to the social-ecological resilience of the city-region, the nation and perhaps all humanity.

Keywords

Urbanization; Economies Of Agglomeration; Agricultural Ecology; Sustainability; Urban Planning; Land Use; China; Agglomeration/urbanisation; Agroecosystems; Environment/sustainability; History/heritage/memory; Redevelopment/regeneration; Cultivated Land; Countryside; Expansion; State; Rise; Modernization; Conservation; Integration; Earthquake; Agglomeration; Urbanisation; Environment; History; Heritage; Memory; Redevelopment; Regeneration; Population Density; Production; Farming; Agriculture; Decentralization; Autonomy; Food Production; Households; Landscape; Resilience; Rural Development; Food; Farms; Regional Development; Productivity; Economic Development; Case Studies; Agricultural Production; Biodiversity; Sustainable Development; Governance; Preservation; Crops; Flood Management; Irrigation; Permaculture; Radicalism; Socioeconomic Factors; Grain; Flexibility; Heterogeneity; Variants; Urban Areas; Irrigation Systems; Rural Communities; Bureaucracy; Landscape Preservation; Agricultural Land; Flood Control; Density; Infrastructure; Urban Sprawl; Livelihood; Farm Management; Rural Areas; Urban Farming; Settlement Patterns; Agribusiness; Market Economies