Starting with the meanings of the terms “risk” and “uncertainty,””he paper compares uncertainty management with risk management in project management. We bring some doubt to the use of “risk” and “uncertainty...Starting with the meanings of the terms “risk” and “uncertainty,””he paper compares uncertainty management with risk management in project management. We bring some doubt to the use of “risk” and “uncertainty” interchangeably in project management and deem their scope, methods, responses, monitoring and controlling should be different too. Illustrations are given covering terminology, description, and treatment from different perspectives of uncertainty management and risk management. Furthermore, the paper retains that project risk management (PRM) processes might be modified to facilitate an uncertainty management perspective, and we support that project uncertainty management (PUM) can enlarge its contribution to improving project management performance, which will result in a significant change in emphasis compared with most risk management.展开更多
Most researchers agree that pedogenesis plays a significant role in determining thevertical distribution of magnetic susceptibility in soils and in the loess/paleosol sequences found inthe People’s Republic of China....Most researchers agree that pedogenesis plays a significant role in determining thevertical distribution of magnetic susceptibility in soils and in the loess/paleosol sequences found inthe People’s Republic of China. Magnetic susceptibility distribution from Jiaodao on the Chinesecentral loess plateau matches other published magnetic susceptibility curves. Using the CBDmethod and a mixing model, the lithogenic and pedogenic components of magnetic susceptibilityfrom Jiaodao were quantified. The estimated lithogenic component showed a long-term decreasewith depth and had short-term periodic fluctuations in tune with the occurrence of paleosol andloess strata. The results of the mixing model suggest that interpretations based only on fluctuationsin total magnetic susceptibility will be in error and that a single estimate of average lithogenicsusceptibility is not an accurate basis for adjustment of the total susceptibility.展开更多
The degradation of agricultural terraces is considered a major challenge to soil and water conservation in steep-slope viticulture.Although terracing is a widespread conservation practice,its sustainability is threate...The degradation of agricultural terraces is considered a major challenge to soil and water conservation in steep-slope viticulture.Although terracing is a widespread conservation practice,its sustainability is threatened by adverse climatic and man-made conditions.Previous studies have shown the impact of terrace designs on the formation of runoff pathways,causing degradation processes on terrace platforms(e.g.sheet erosion)and walls(e.g.piping,landslides,collapse).This study evaluates a remote sensing versus a field-based approach to monitor hydrological processes responsible for terrace degradation,as tested in a north-Italian vineyard.The field-based approach was based on spatially measured Soil Moisture Content(SMC)using a Time Domain Reflectometry(TDR)instrument,which clearly revealed saturation hotspots around two damaged terraces in the study area.Moreover,these zones showed a particular cross-sectional SMC profile,with the highest saturation close to the terrace platform edges.The remote sensing approach was based on aerial imagery acquired by an Unmanned Aerial Vehicle(UAV)and photogrammetric reconstruction of the vineyard geomorphology,allowing terrain-based analysis and physical erosion modelling.In this approach,simulations indicated that terrace damages could be partly explained by the formation of preferential runoff pathways caused by the terrace design.This parallel methodology allowed a comparison of the merits and limitations of either approach,as done in light of published work.The occurrence of two SMC hotspots at terrace edges(and their non-typical cross-sectional profiles)could be better understood from simulated surface flow paths.While the causal relationship between heterogeneous soil saturation and terrace instability has been previously reported in literature,the novelty of the presented study is the use of topsoil SMC as an indicator of potential damages,favouring the scalability compared to fixed,local and often intrusive terrace sub-surface ex-periments.Remote sensing based approaches,however,tend to offer the most time-efficient solution on larger scales,and aerial acquisition of SMC distribution could thus potentially offer a powerful integrated methodology.展开更多
文摘Starting with the meanings of the terms “risk” and “uncertainty,””he paper compares uncertainty management with risk management in project management. We bring some doubt to the use of “risk” and “uncertainty” interchangeably in project management and deem their scope, methods, responses, monitoring and controlling should be different too. Illustrations are given covering terminology, description, and treatment from different perspectives of uncertainty management and risk management. Furthermore, the paper retains that project risk management (PRM) processes might be modified to facilitate an uncertainty management perspective, and we support that project uncertainty management (PUM) can enlarge its contribution to improving project management performance, which will result in a significant change in emphasis compared with most risk management.
文摘Most researchers agree that pedogenesis plays a significant role in determining thevertical distribution of magnetic susceptibility in soils and in the loess/paleosol sequences found inthe People’s Republic of China. Magnetic susceptibility distribution from Jiaodao on the Chinesecentral loess plateau matches other published magnetic susceptibility curves. Using the CBDmethod and a mixing model, the lithogenic and pedogenic components of magnetic susceptibilityfrom Jiaodao were quantified. The estimated lithogenic component showed a long-term decreasewith depth and had short-term periodic fluctuations in tune with the occurrence of paleosol andloess strata. The results of the mixing model suggest that interpretations based only on fluctuationsin total magnetic susceptibility will be in error and that a single estimate of average lithogenicsusceptibility is not an accurate basis for adjustment of the total susceptibility.
基金supported by University of Padova research projects“ViTE-Vineyard terraced landscapes:understanding the environmental constraints to improve sustainable management”(DALL_FINAC_P14_02)“Evaluation of the effectiveness of drainage systems in an agricultural context”(DOR1948955/19)。
文摘The degradation of agricultural terraces is considered a major challenge to soil and water conservation in steep-slope viticulture.Although terracing is a widespread conservation practice,its sustainability is threatened by adverse climatic and man-made conditions.Previous studies have shown the impact of terrace designs on the formation of runoff pathways,causing degradation processes on terrace platforms(e.g.sheet erosion)and walls(e.g.piping,landslides,collapse).This study evaluates a remote sensing versus a field-based approach to monitor hydrological processes responsible for terrace degradation,as tested in a north-Italian vineyard.The field-based approach was based on spatially measured Soil Moisture Content(SMC)using a Time Domain Reflectometry(TDR)instrument,which clearly revealed saturation hotspots around two damaged terraces in the study area.Moreover,these zones showed a particular cross-sectional SMC profile,with the highest saturation close to the terrace platform edges.The remote sensing approach was based on aerial imagery acquired by an Unmanned Aerial Vehicle(UAV)and photogrammetric reconstruction of the vineyard geomorphology,allowing terrain-based analysis and physical erosion modelling.In this approach,simulations indicated that terrace damages could be partly explained by the formation of preferential runoff pathways caused by the terrace design.This parallel methodology allowed a comparison of the merits and limitations of either approach,as done in light of published work.The occurrence of two SMC hotspots at terrace edges(and their non-typical cross-sectional profiles)could be better understood from simulated surface flow paths.While the causal relationship between heterogeneous soil saturation and terrace instability has been previously reported in literature,the novelty of the presented study is the use of topsoil SMC as an indicator of potential damages,favouring the scalability compared to fixed,local and often intrusive terrace sub-surface ex-periments.Remote sensing based approaches,however,tend to offer the most time-efficient solution on larger scales,and aerial acquisition of SMC distribution could thus potentially offer a powerful integrated methodology.
