New developments in and reflections on, the use of visual literacy and environmental evaluation for the participation of community groups in design

Involving community groups in the design processes concerning their city or neighbourhood, can play a role in creating responsive environments and achieving a high level of satisfaction for communities.Interaction between clients and professionals is essential to encourage the resolution of disputes at the design stage rather than once actions have been taken, since their different roles and expertise could enrich the process of interaction.This study supports the idea of a form of participation based on research in environmental experience. Visual literacy is trained, and a combination of environmental assessment techniques and informative activities are linked to encourage community groups and professionals to work together on the generation and development of observational and analytical skills.The aim is to generate a structure for the involvement of local communities in urban renewal actions as an informed, organised and effective activity and then, to apply this approach in praxis.     

A new method for laboratory estimation of the transverse dispersion coefficient

We introduce a method for identifying the transverse dispersion coefficient in laboratory experiments based on the analytical solution of a pulse injection of a nonreactive solute in a soil column (cylindrical geometry) packed with a homogeneous porous medium. This method takes into account the effect of boundary conditions such as no flux on the column perimeter, and it does not need a priori knowledge of the longitudinal dispersion coefficient. Numerical applications of the method show that it is stable and robust and that the results are reasonably in accordance with those found using the classical maximum likelihood method.     

Analytical Solutions of Three‐Dimensional Contaminant Transport Models with Exponential Source Decay

Despite the availability of numerical models, interest in analytical solutions of multidimensional advection‐dispersion systems remains high. Such models are commonly used for performing Tier I risk analysis and are embedded in many regulatory frameworks dealing with groundwater contamination. In this work, we develop a closed‐form solution of the three‐dimensional advection‐dispersion equation with exponential source decay, first‐order reaction, and retardation, and present an approach based on some ease of use diagrams to compare it with the integral open form solution and with earlier versions of the closed‐form solution. The comparison approach focuses on the relative differences associated with source decay and the effect of simulation time. The analysis of concentration contours, longitudinal sections, and transverse sections confirms that the closed‐form solutions studied can be used with acceptable approximation in the central area of a plume bound transversely within the source width, both behind and beyond the advective front and for concentration values up to two orders of magnitude less than the initial source concentration. As the proposed closed‐form model can be evaluated without nested numerical computations and with simple mathematical functions, it can be very useful in risk assessment procedures.