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The biodegradation and settlement of two consolidating municipal solid waste (MSW) anaerobic reactors operated at Southampton University, UK, were modelled with the Moduelo landfill simulation tool. This paper presents the fundamental concepts of the model, the difficulties found in its application to the studied case and the simulation results obtained. The significant difference found between the rates of anaerobic processes that took place in the field in relation to those in the laboratory required the reduction of the default simulation time step of the model and the introduction of a new parameter to represent the delay in the onset of methanogenesis so that it became predominant after rapid hydrolysis was experienced. Once calibrated by fitting the evolution of the organic content of the leachate during the start-up period (the first 77 days), the model was used to predict leachate concentration, gas generation and composition and settlement of the waste mass throughout the experimental period (919 days). The predicted results will be compared with actual data and discussed in another paper. The exercise here constitutes a basis for reflection on the model's structure and applicability, and serves as a reminder of the difficulty of representing field (landfill) conditions in a laboratory.

A generalized methodology to characterize the bio-chemical properties of waste results is of great interest in waste management. The chemical and physical methods traditionally used to determine the organic content of solids, such as volatile solids content (VS), total organic carbon content (TOC), cellulose (CEL), hemicellulose (HEM), lignin (LIG), and leaching tests with later analyses of the eluate are easy to perform and to reproduce, but they do not give enough information about the rate of waste stabilization. On account of this, more specific assays like Biochemical Methane Potential (BMP) or respirometry assays are nowadays being performed. These biodegradation assays are more complex because they require extensive time and specific equipments and a number of influencing parameters have to be considered. These difficulties promoted the interest in looking for correlations between "conventional", simpler analyses and biodegradation assays. Based on characterization results obtained by different authors in old waste, ratios between BMP and several parameters are studied in this paper, showing significant correlations in most cases. As a theoretical analysis indicates, only for CEL and CEL+HEM laws that can be generalized to other cases were obtained. VS and (CEL+HEM)/LIG are indicators of the degradation state too, but only with regard to samples of the same type of waste. Since VS content does not inform about organic matter biodegradability and (CEL+HEM)/LIG is independent of the inorganic fraction of waste, the laws BMP/VS and BMP/[(CEL+HEM)/LIG] obtained are different for each studied data series.

Floods are one of the most common and harmful natural disasters worldwide, especially in cities, due to the high concentration of people and goods in these areas.This research aims to provide an accessible and accurate means to model risks associated with floods in urban spaces using open data about a series of susceptibility and impact contributing factors. Hence, a methodology combining geoprocessing tools, additive weighting, dependence measures, and optimisation was designed to generate spatial information, aggregating the factors according to their weights and optimising the modelling of their relationships to flood risk, respectively. The application of the proposed approach to the city of Santander (Spain) yielded a flood risk map providing an accurate assessment of the ranking of flood zones reported by its City Council. The results suggested that flood mitigation might focus on the implementation of permeable pavements, due to their ease of integration in urban environments. K E Y W O R D S additive weighting, contributing factors, open data, optimisation, risk assessment, urban flooding