ABSTRACT
Aims: To evaluate the potential for substituting green roof mains water irrigation by irrigation using lightly loaded synthetic greywater. Study Design: The planted green roof system was designed to be operated and tested within a glasshouse. Place and Duration of Study: Schools of Engineering, and Plant Sciences, The University of Reading, for 28 days commencing 28th of May 2012. Methodology: A trial was conducted for comparing two planting schemes using Sedum and Stachys Byzantina and a third unplanted control. The three sets of growing boxes were subdivided between substrate depths of 10 cm and 20 cm. By further subdivision, half of each set were watered using mains water, and half using a synthetic greywater. The soil composition and water quality of the drainage (filtrate) water were monitored. Statistical analysis of the results was conducted. Results: Consistency was observed in influent pH and EC, in both mains and greywater samples. Influent Na concentrations were higher in the greywater samples due to detergent content. The Na mass balance calculations for all boxes showed that some Na mass was unaccounted for when comparing aggregated concentrations in influent, plant tissue and soil with the aggregated Na mass in filtrate, plant tissue and soil water. It was concluded that this was likely to be due to retained/ponded irrigation water in the boxes, difficulties in attaining homogenous box flushing and the underestimation of soil Na. The variation in substrate depth affected all results. The plants themselves seemed to have little significant influence on the measured parameters, with the exception of the accumulation of Na mass in plants irrigated with greywater. Conclusion: No improvement was observed in the quality of the greywater following filtration through the soil matrix. For longer term watering using greywater, a choice of Na resistant species should be considered, although the Sedum species used in this trial showed no recorded adverse growth effects due to Na accumulation.
ABSTRACT
Aims: In recent decades, Ho Chi Minh City, Vietnam, frequently has been affected by local floods and inundation from heavy rainfall. Conventional flood mitigation measures such as building flood gates and upgrading sewerage systems have been implemented but problems persist. The objective of this research is to assess another approach for flood control measures, namely Sustainable Urban Drainage Systems (SUDS), with application to the Nhieu Loc - Thi Nghe Basin, located in the central part of Ho Chi Minh City. Methodology: A combination of the Stormwater Management Model (PCSWMM) and interviews with 140 households was used to assess the efficacy and acceptability of four of the most popular SUDS: Rainwater harvesting, green roofs, urban green space and pervious pavement. Thirteen SUDS and urban build-out scenarios were simulated under 6 design storm conditions. Results: PCSWMM results showed that inundation from intense rainfall could be reduced with proper land-use control, specifically by maintaining imperviousness at 65% or less of the surface area. With respect to SUDS performance, green roofs were best at reducing peak runoff (22% reduction), followed by pervious pavement, urban green space, and rainwater harvesting systems. Regarding environmental improvements, as represented by reduction in total suspended solids load, urban green space was best with 20% of the solids load removed compared to the base case scenario, followed by green roofs, pervious pavement, and rainwater harvesting. The household interviews revealed the majority of people preferred pervious pavement to the other SUDS options and the least preferred option was green roof technology. Conclusion: Considering the combination of water quantity and water quality controls, it seems that green roof technology was the best performer for this area of Ho Chi Minh City, followed by urban green space, pervious pavement and rainwater harvesting. However, green roof technology also was the least favored option for the public and stakeholder acceptance will impact SUDS implementation.
ABSTRACT
Purpose The purpose of this study was to determine the relaxing effects of a hospital rooftop forest on healthcare workers and to assess the influence of trait anxiety. Methods Sixteen male workers (aged 37.1±10.6years, mean±SD) and 56 female workers (aged 43.5±11.2years) participated in this study. Females were divided into 32low-to medium-anxiety and high-anxiety groups according to their trait anxiety as per the State Trait Anxiety Inventory-Form JYZ (STAI-Form JYZ). The experimental site was a rooftop forest, which covered an area of 122 m2, on the fourth storey of a health service facility. An outdoor car park area of 170m2, near the same facility, was used as a control. All participants were assessed individually at 3 sites: pre-room, rooftop forest, and outdoor car park area. Participants sat still in a wheelchair and viewed the scenery for 5minutes in each experimental area. The subjective effect was analyzed using the state anxiety as per the STAI-Form JYZ and the Profile of Mood States (POMS). The data between the rooftop forest and the control was compared within each participant. The participants were also divided into sex- and age-matched groups: A and B. Group A moved to the rooftop forest from the pre-room and group B first moved to the control area to eliminate the order effect. Results and Discussion After viewing the rooftop forest, the mean values of state anxiety as per the STAY-Form JYZ showed a significant (p<0.01) decrease to 34.6±8.1 (43.4±8.4for control) in males and to 36.3±10.2 (45.8±8.8) in females. In low- to medium-anxiety females, state anxiety significantly (p<0.01) decreased to a“very low”anxiety state (“low” for control), and in high-anxiety females, it significantly (p<0.01) decreased to a “low” anxiety state (“intermediate” for control). As per the T-score of POMS, in males, “Fatigue” significantly (p<0.01) decreased to 39.0±7.5 (41.1±7.0) and “Vigor” significantly (p<0.01) increased to 43.3±10.4 (37.9±8.1). In females, “Tension-Anxiety” significantly (p<0.01) decreased to 39.7±7.7 (43.7±8.8), “Depression-Dejection” significantly (p<0.01) decreased to 43.5±6.3 (45.4±7.6), “Fatigue” significantly (p<0.01) decreased to 40.7±7.3 (43.6±8.5), and “Vigor” significantly (p<0.01) increased to 46.2±10.8 (38.9±8.0). After viewing the rooftop forest, the “iceberg profile” observed in the visual pattern of low- to medium-anxiety females indicated positive feelings. The “negative wing” indicating negative feelings observed in high-anxiety females in the pre-room disappeared after viewing the rooftop forest. Conclusion We demonstrated that a short exposure to a rooftop forest environment induces a significant subjective relaxation effect in healthcare workers and that this effect is influenced by individual trait anxiety.
ABSTRACT
<B>Purpose</B><BR> The purpose of this study was to determine the relaxing effects of a hospital rooftop forest on healthcare workers and to assess the influence of trait anxiety.<BR><B>Methods</B><BR> Sixteen male workers (aged 37.1±10.6years, mean±SD) and 56 female workers (aged 43.5±11.2years) participated in this study. Females were divided into 32low-to medium-anxiety and high-anxiety groups according to their trait anxiety as per the State Trait Anxiety Inventory-Form JYZ (STAI-Form JYZ). The experimental site was a rooftop forest, which covered an area of 122 m<SUP>2</SUP>, on the fourth storey of a health service facility. An outdoor car park area of 170m<SUP>2</SUP>, near the same facility, was used as a control. All participants were assessed individually at 3 sites: pre-room, rooftop forest, and outdoor car park area. Participants sat still in a wheelchair and viewed the scenery for 5minutes in each experimental area. The subjective effect was analyzed using the state anxiety as per the STAI-Form JYZ and the Profile of Mood States (POMS). The data between the rooftop forest and the control was compared within each participant. The participants were also divided into sex- and age-matched groups: A and B. Group A moved to the rooftop forest from the pre-room and group B first moved to the control area to eliminate the order effect.<BR><B>Results and Discussion</B><BR> After viewing the rooftop forest, the mean values of state anxiety as per the STAY-Form JYZ showed a significant (<I>p</I><0.01) decrease to 34.6±8.1 (43.4±8.4for control) in males and to 36.3±10.2 (45.8±8.8) in females. In low- to medium-anxiety females, state anxiety significantly (<I>p</I><0.01) decreased to a“very low”anxiety state (“low” for control), and in high-anxiety females, it significantly (<I>p</I><0.01) decreased to a “low” anxiety state (“intermediate” for control). As per the T-score of POMS, in males, “Fatigue” significantly (<I>p</I><0.01) decreased to 39.0±7.5 (41.1±7.0) and “Vigor” significantly (<I>p</I><0.01) increased to 43.3±10.4 (37.9±8.1). In females, “Tension-Anxiety” significantly (<I>p</I><0.01) decreased to 39.7±7.7 (43.7±8.8), “Depression-Dejection” significantly (<I>p</I><0.01) decreased to 43.5±6.3 (45.4±7.6), “Fatigue” significantly (<I>p</I><0.01) decreased to 40.7±7.3 (43.6±8.5), and “Vigor” significantly (<I>p</I><0.01) increased to 46.2±10.8 (38.9±8.0). After viewing the rooftop forest, the “iceberg profile” observed in the visual pattern of low- to medium-anxiety females indicated positive feelings. The “negative wing” indicating negative feelings observed in high-anxiety females in the pre-room disappeared after viewing the rooftop forest.<BR><B>Conclusion</B><BR> We demonstrated that a short exposure to a rooftop forest environment induces a significant subjective relaxation effect in healthcare workers and that this effect is influenced by individual trait anxiety.