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Many countries encourage brownfield regeneration as a means of sustainable development but define "brownfield" differently. Specifically, the definitions of brownfield in the regeneration policies of countries with higher population densities usually promote recycling land that is previously developed, whether or not there is chemical contamination. Further, the de facto definition of brownfield used by the UK government focuses on previously developed land that is unused or underused. The ANOVA in this study revealed that local authorities in England (n = 296) with higher percentages of derelict and vacant land tended to be more deprived based on the English Indices of Multiple Deprivation, which evaluate deprivation from the aspects of income, employment, health, education, housing, crime, and living environment. However, the percentage of previously developed land in use but with further development potential had no significant effect on the deprivation conditions. The Blair-Brown Government (1997~2010) encouraged more than 60% of new dwellings to be established on the previously developed land in England. The analyses in this study showed that this target, combined with the definition of brownfield in the policy, may have facilitated higher densities of residential development on previously developed land but without addressing the deprivation problems. These observations indicate that a definition of brownfield in regeneration policies should focus on previously developed land that is now vacant or derelict if land recycling is to contribute to sustainable communities.

Abstract. A GIS-based method for the assessment of landslide susceptibility in a selected area of Qingchuan County in China is proposed by using the back-propagation Artificial Neural Network model (ANN). Landslide inventory was derived from field investigation and aerial photo interpretation. 473 landslides occurred before the Wenchuan earthquake (which were thought as rainfall-induced landslides (RIL) in this study), and 885 earthquake-induced landslides (EIL) were recorded into the landslide inventory map. To understand the different impacts of rainfall and earthquake on landslide occurrence, we first compared the variations between landslide spatial distribution and conditioning factors. Then, we compared the weight variation of each conditioning factor derived by adjusting ANN structure and factors combination respectively. Last, the weight of each factor derived from the best prediction model was applied to the entire study area to produce landslide susceptibility maps. Results show that slope gradient has the highest weight for landslide susceptibility mapping for both RIL and EIL. The RIL model built with four different factors (slope gradient, elevation, slope height and distance to the stream) shows the best success rate of 93%; the EIL model built with five different factors (slope gradient, elevation, slope height, distance to the stream and distance to the fault) has the best success rate of 98%. Furthermore, the EIL data was used to verify the RIL model and the success rate is 92%; the RIL data was used to verify the EIL model and the success rate is 53%.

Abstract. Floods from failures of landslide dams can pose a hazard to people and property downstream, which have to be rapidly assessed and mitigated in order to reduce the potential risk. The Tangjiashan landslide dam induced by the Mw = 7.9 2008 Wenchuan earthquake had impounded the largest lake in the earthquake affected area with an estimated volume of 3 × 108 m3, and the potential catastrophic dam breach posed a serious threat to more than 2.5 million people in downstream towns and Mianyang city, located 85 km downstream. Chinese authorities had to evacuate parts of the city until the Tangjiashan landslide dam was artificially breached by a spillway, and the lake was drained. We propose an integrated approach to simulate the dam-breach floods for a number of possible scenarios, to evaluate the severity of the threat to Mianyang city. Firstly, the physically-based BREACH model was applied to predict the flood hydrographs at the dam location, which were calibrated with observational data of the flood resulting from the artificial breaching. The output hydrographs from this model were inputted into the 1-D–2-D SOBEK hydrodynamic model to simulate the spatial variations in flood parameters. The simulated flood hydrograph, peak discharge and peak arrival time at the downstream towns fit the observations. Thus this approach is capable of providing reliable predictions for the decision makers to determine the mitigation plans. The sensitivity analysis of the BREACH model input parameters reveals that the average grain size, the unit weight and porosity of the dam materials are the most sensitive parameters. The variability of the dam material properties causes a large uncertainty in the estimation of the peak flood discharge and peak arrival time, but has little influence on the flood inundation area and flood depth downstream. The effect of cascading breaches of smaller dams downstream of the Tangjiashan dam was insignificant, due to their rather small volumes, which were only 2% of the volume of the Tangjiashan lake. The construction of the spillway was proven to have played a crucial role in reducing the dam-breach flood, because all the other natural breach scenarios would have caused the flooding of the downstream towns and parts of Mianyang city. However, in retrospect improvements on the spillway design and the evacuation planning would have been possible. The dam-break flood risk will be better controlled by reducing the spillway channel gradient and the porosity of the coating of the channel bottom. The experience and lessons we learned from the Tangjiashan case will contribute to improving the hazard mitigation and risk management planning of similar events in future.

Abstract. The huge Donghekou landslide was triggered by the Wenchuan earthquake in 2008 with about 2.4 × 107 m3 of rock displaced. The landslide is considered as an example of an earthquake-induced "ejection" event, where dislocated slope materials was expelled over a section of the slope, but the kinematic processes are not well understood. We used the 2-D granular discrete element method to characterize the kinematic behavior and mechanics of this "ejection landslide". The initial boundary conditions were applied along the ball–wall contacts by using derived velocities integrated from strong motion data with a duration of 125 s, including the peak acceleration near the Donghekou area. The constraints were primarily determined from the final geometry of the landslide and geological structures to account for the actual landslide characteristics. Simulated results showed that the large local seismic acceleration and a free face under the sliding body, caused by the dip difference between the upper slide face and the natural slope, originated from the activation of the landslide. For the lower sliding body, its kinematic mechanism was changed during sliding. Initially it was a push-type landslide, and then gradually changed to a retrogressive landslide. The eroded bed on the slope during the landslide had the potential of slightly increasing the runout distance from 1435 to 1519 m, and was predicted in the numerical simulation.

8 pags., 7 figs., 3 tabs.-- Parts of this work have been presented at XI Reunión Nacional de Óptica in Self-calibration of silicon photodiodes internal quantum efficiency by using temperature sensors, 2015. ; Predictable quantum efficient detectors (PQEDs), based on photoelectric effect in silicon semiconductor, have proved their potential as optical radiant power primary standard. At present, simulations for semiconductor devices are the common method to predict the response of a PQED. As an alternative, this work investigates the feasibility of an experimental technique, the self-calibration of silicon photodiodes at room temperature by means of temperature sensors. A device which compares two physics principles by optical power, working both as a photodetector and a radiometer based on electrical substitution, was made. The device allows for measuring the current generated under irradiation (in photocurrent mode) and the heating of the system, induced by a laser or forward biasing, to determine the optical power (in thermal mode). The feasibility study consists of testing the equivalence between both modes and establishing the suitable range of optical power. The range of optimum optical power level, where both modes run in the linear domain at the present configuration, is from 300 μW up to 1 mW. Within this range, the optical power experimental uncertainty is lower than 1%. ; This work has been supported by the European Commission through the project SIB57-NEWSTAR under the European Metrology Research Programme (EMRP). The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. The authors of CSIC acknowledge support from the Comunidad de Madrid and the European Union under program SINFOTON-CM (S2013/MIT-2790). ; Peer Reviewed