A simplified procedure to improve the usability of hydrodynamic modelling software in regenerative urban design

Densely urbanized areas are greatly exposed to the risks from climate change as reported by IPCC in 2018. In particular, compact urban settings afflicted by heavy storms and droughts, coupled with the intensification of the Urban Heat Island (UHI) effect and incremental heat waves require a requalification of the outdoor environment that accommodates for both strategic water management and enhanced microclimatic conditions. The present study proposes simplified procedures to enable the application of complex hydrodynamic modelling software (SWMM), by non-expert users (such as planners and designers), in the preliminary phases of an urban space project according to a water-sensitive urban design approach. In the paper, Italian multi-level regulations aimed at controlling the impacts of excessive rainfall in urban areas are taken into account as well as the integration of circular water management systems with evaporative cooling strategies. The proposed procedure is focused on two aspects: 1- to simplify the steps needed to convert the existing climatic data to provide a numerical sequence, to insert into the software; 2- to define a set of pre-compiled and multi-purposed solutions toolkits for the design of urban spaces that can be imported into the software through an external database.

Using the Goldilocks Principle to model coral ecosystem engineering

The occurrence and proliferation of reef-forming corals is of vast importance in terms of the biodiversity they support and the ecosystem services they provide. The complex three-dimensional structures engineered by corals are comprised of both live and dead coral, and the function, growth and stability of these systems will depend on the ratio of both. To model how the ratio of live : dead coral may change, the ‘Goldilocks Principle’ can be used, where organisms will only flourish if conditions are ‘just right’. With data from particle imaging velocimetry and numerical smooth particle hydrodynamic modelling with two simple rules, we demonstrate how this principle can be applied to a model reef system, and how corals are effectively optimizing their own local flow requirements through habitat engineering. Building on advances here, these approaches can be used in conjunction with numerical modelling to investigate the growth and mortality of biodiversity supporting framework in present-day and future coral reef structures.

Non-invasive hydrodynamic imaging in plant roots at cellular resolution

A key impediment to studying water-related mechanisms in plants is the inability to non-invasively image water fluxes in cells at high temporal and spatial resolution. Here, we report that Raman microspectroscopy, complemented by hydrodynamic modelling, can achieve this goal - monitoring hydrodynamics within living root tissues at cell- and sub-second-scale resolutions. Raman imaging of water-transporting xylem vessels in Arabidopsis thaliana mutant roots reveals faster xylem water transport in endodermal diffusion barrier mutants. Furthermore, transverse line scans across the root suggest water transported via the root xylem does not re-enter outer root tissues nor the surrounding soil when en-route to shoot tissues if endodermal diffusion barriers are intact, thereby separating ‘two water worlds’.