An empirical attenuation relationship for Northwestern Turkey ground motion using a random effects approach

Using a random effects model that takes into consideration the correlation of data recorded by a single seismic event, a database consisting of 195 recordings from 17 recent events is employed to develop empirical attenuation relationships for the geometric mean of horizontal peak ground acceleration and 5-percent damped spectral acceleration (S_a). The recordings employed are obtained from strong motion stations operating in Northwestern Turkey and resulted from events that include the Kocaeli (M_w=7.4) and the Düzce (M_w=7.1) earthquakes and their aftershocks as well as other events. By studying differences in standard errors, the random effects model is compared with a fixed effects model that does not account for distinctions between intra- and inter-event variability. Effects of local site conditions are included in the empirical relationships developed. The dependence on frequency of the various model parameters is also studied. Frequency-dependent attenuation coefficients for the proposed random effects models developed are summarized in tables to facilitate their use.     

“Site & region-specific” response spectra: a probabilistic approach

Design seismic forces depend on Peak Ground Acceleration (PGA) values and on the shape of Response Spectrum (RS) curves dictated by Building Codes or which need to be evaluated in every particular case. The PGA values and RS curves strictly depend on earthquake magnitude and distance, as well as on the regional and local geological conditions. At present, there is no doubt that it is necessary to construct so-called “Site & Region-specific” Building Code provisions reflecting the influence of different magnitude events at different distances that may occur during the life time of the construction, as well as the variety of local ground conditions. A scheme of Uniform Hazard Response Spectra and PGA estimation considering local site response is described in this paper. The assessments of these design parameters are obtained on the basis of Uniform Hazard Fourier spectra using the conception of “dominant earthquakes”. The effect of local geology is included by means of the soil/reference site spectral ratios.     

The measurement of water losses from a forested area using a “natural” lysimeter

Water losses due to transpiration and evaporation of intercepted water were measured using a “natural” lysimeter in the Hafren forest of central Wales, and were compared with estimates of potential evaporation calculated from meteorological observations. Given certain assumptions concerning the forest canopy, the lysimeter observations were used to estimate runoff from the experimental catchment of the Upper Severn, within which the lysimeter is sited; this estimate agreed well with observation.     

Application of the Clean Development Mechanism in the Sanitation Sector: “Proof of Concept”

Greenhouse gas emissions from the waste sector account for only 4% of the total production, with wastewater management accounting for accurately 8 to 10% of this contribution. Wastewater disposal and treatment activities, mainly contributes to non‐CO₂ gases such as methane (CH₄) and nitrous oxide (N₂O). Capturing or avoiding these emissions is thus both a concern and an opportunity. The clean development mechanism (CDM) offers an instrument to internalize global climate concerns into the design of wastewater treatment facilities. Properly designed facilities could improve effluent quality and optimize the abatement of greenhouse gas emissions, thus ensuring additional revenues to pay for capital, operation and maintenance costs and possibly justify higher levels of wastewater treatment. This document summarizes the experience of the “Rio Frio CDM project” in Colombia, as an example of what is achievable through the CDM application in wastewater treatment upgrade in developing countries. This document summarizes the scope of the project, the methodology used to establish current greenhouse emissions and future reductions, and the estimated financial results.