Browsing by Subject "LOADS"

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  • Lötjönen, Sanna; Ollikainen, Markku (2019)
    We examine the abatement costs for water and climate pollutants and their respective policies while accounting for cobenefits. We construct private and social marginal cost curves for reducing greenhouse gas emissions and nutrient runoff in Finnish agriculture. We find that the social marginal costs of reducing emissions that reflect the cobenefits are lower than the private costs. Accounting for greenhouse gas cobenefits from nutrient load reduction or water cobenefits from climate emissions reduction creates a gap between privately and socially optimal reduction levels. This gap varies depending on the valuation of cobenefits. The cost-efficient reduction of the focus pollutant is increased when cobenefits from the other pollutant are accounted for. For policies, this implies a higher cap or tax on the focus pollutant. We decompose the optimal tax rate to a basic tax on the focus pollutant and on an additional tax component depending on the level of cobenefits.
  • Huang, Wenfeng; Li, Zhijun; Leppäranta, Matti; Han, Hongwei; Wang, Ni (2018)
    Ice strain dominates the ice thrust and dynamics on reservoir dams and retaining structures. An exclusively designed laser range finder was deployed to measure the surface ice displacements along six directions at a reservoir in northeastern China. The incompletely confined boundary (ice-boundary bonding), ice cracks development, water level fluctuations, parallel crack dynamics, and ice creep allow the surface ice to move rather than keep still in response to thermal deformation/pressure, and thus cause the ice strain to deviate from thermal strain. Consequently, a residual strain was introduced and calculated from the recorded displacements. Observations showed that the residual strains were anisotropic and showed diurnal patterns following the air/ice temperature. A scale-dependence of crack development was observed to cause potential scale-effects to residual strains. The real ice strain consists of thermal strain and residual strain. The proportion of the latter increased as time went by. A modified constitutive law accommodating the residual strains was developed to evaluate the impacts of the residual strains and to estimate the surface ice stresses. Modeling results underlined the role of the residual strain in determining both the principal stress and the stress perpendicular to and parallel with the dam face. The residual strain is probably the reason why the observed ice stress is always much lower than the single thermal stress. (C) 2018 American Society of Civil Engineers.