Representative benchmark site identification for soil moisture storage

Non-Peer ReviewedSoil moisture limits agricultural production in semi-arid prairies and is a key hydrological factor affecting the fate and transport of pollutants in soils. Spatial and temporal variability in soil water requires monitoring many locations to capture the salient features of soil water in the field. The objective of this study was to examine whether there are temporally stable soil moisture patterns in a field and whether a representative moisture benchmark site can be identified from these patterns. The experiments were conducted on a black soil at Alvena, northwest of Saskatoon, Canada. Soil moisture was monitored at 95 measurement sites with a portable Capacitance Probe (CP) along a 612m rolling transect, from April to September in 2001 and 2002. Temporal stability of spatial patterns in soil moisture for depths of 30, 60, 90, 120 and 160cm were determined using temporal means and standard deviations of the differences between individual and spatial average values of soil moisture along the transect. The spatial patterns of soil water storage were stable in different locations for each depth. Spatial variations in soil moisture with daily soil moisture means of >0.20 and <0.20 showed poor correlations with soil texture (R2 < 0.1) and topographical variables (R2 < 0.3). Clay content showed the least amount of control of spatial patterns with only one day with R2 (=0.08) greater than 0.01. Coefficient of variation and standard deviation of soil moisture both decreased with increasing soil moisture. For depths of 30, 90, and 120cm, benchmark sites had a difference of less than 1% in soil moisture storage from both measured field mean and a composite sample obtained using the conventional random sample method, indicating the three methods are equivalent to each other. Soil moisture benchmark sites identified in this study represent field mean soil moistur

Preferential transport of Escherichia coli through soil

Non-Peer ReviewedContamination of water sources resulting from Escherichia coli 0157:H7 movement through the soil requires knowledge of the transport mechanisms. The objective of this study was to examine the effect of initial soil water content on the preferential transport of E. coli through the soil. The study was conducted on a heavy clay soil near Plenty, SK. Escherichia coli as well as conservative and adsorptive tracers were applied to treatments that were initially dry, partially wet, and initially wet. Relative breakthroughs of E. coli and Cl- were similar for all three treatments, showing a large proportion of the mass applied remained in the top 10 cm of soil, indicating transport through the soil matrix. Beyond this depth, E. coli: Cl- ratios remained consistent, suggesting transport along preferential pathways. The lack of differences between treatments may suggest that irrespective of the transport pathway, the end result is the same. This study is important for semi-arid areas where dry cracked soils can receive intense thunderstorms that provide enough water to transport E. coli to substantial depths

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Intensively monitoring cover system thermal properties with distributed temperature sensing

Reclamation soil cover systems can range in size from hundreds of square metres at the pilot scale to tens of hectares at the commercial scale. Performance of cover systems is typically conducted using point scale monitoring stations. While vertically intensive, a point-source monitoring profile is inadequate for characterizing the spatial and temporal variations of the cover that exist at the landscape scale of interest. Distributed temperature sensing is a technology that intensively measures temperature at 1 m resolutions over distances between 5,000 to 10,000 m. This paper presents a series of case studies that detail how the technology can be used to the fieldscale performance of cover systems through measurement of thermal properties.Non UBCUnreviewedOthe

Estabilidade temporal do conteúdo de água em três condições de uso do solo, em uma bacia hidrográfica da região da Serra da Mantiqueira, MG

A descrição de processos hidrológicos é relativamente complexa, principalmente da variação do conteúdo de água no solo, devido à influência de fatores edáficos, topográficos, climáticos e de vegetação. Em condições de campo, a estimativa do conteúdo de água no solo requer um plano de amostragem adequado, considerando as variações no tempo e no espaço. Visando representar adequadamente o conteúdo de água no solo com reduzido esforço amostral e custo, o conceito de estabilidade temporal tem sido muitas vezes empregado. Este estudo foi realizado com o objetivo de analisar a estabilidade temporal do conteúdo de água na camada superficial do solo (0-0,20 m de profundidade), sob diferentes usos do solo, em uma bacia hidrográfica experimental da região da Serra da Mantiqueira, Minas Gerais, nos períodos de estiagem e chuvoso, estimando os pontos mais representativos para essa determinação. Houve maior estabilidade temporal do conteúdo de água no solo na área de vegetação de várzea, menor na área ocupada por Mata Atlântica e intermediária na área de pastagem. Ocorreram, também, variações significativas da diferença relativa média entre os períodos de medição, concluindo-se que as características de cada área devem ser consideradas particularmente para escolha dos pontos. Na área de pastagem, foi possível identificar apenas um ponto para monitoramento tanto para o período chuvoso como para o de estiagem. Por outro lado, nas áreas de Mata Atlântica e vegetação de várzea foram identificados dois pontos, sendo um especificamente para o período chuvoso e outro para o período de estiagem, sendo recomendada uma análise individual específica para cada estação