Mott MacDonald Group

An investigation was undertaken into the potential advantages and challenges of using small-scale modular sustainable drainage systems combined with real-time control systems as flood mitigation measures in public urban areas. By using case studies and undertaking a high-level local hydraulic assessment based on historic rainfall data, the flood mitigation benefits of various solutions were assessed. The paper aims to provide further evidence of the practicality and benefits of using green and smart surface water management systems in urban areas, ultimately leading to more sustainable and resilient communities.

It has been proposed that climate change and the arrival of modern humans in Europe affected the disappearance of Neanderthals due to their impact on trophic resources; however, it has remained challenging to quantify the effect of these factors. By using Bayesian age models to derive the chronology of the European Middle to Upper Paleolithic transition, followed by a dynamic vegetation model that provides the Net Primary Productivity, and a macroecological model to compute herbivore abundance, we show that in continental regions where the ecosystem productivity was low or unstable, Neanderthals disappeared before or just after the arrival of Homo sapiens . In contrast, regions with high and stable productivity witnessed a prolonged coexistence between both species. The temporal overlap between Neanderthals and H. sapiens is significantly correlated with the carrying capacity of small- and medium-sized herbivores. These results suggest that herbivore abundance released the trophic pressure of the secondary consumers guild, which affected the coexistence likelihood between both human species.

A derelict 150-year-old railway station building in Northern Ireland has been reborn as a state-of-the-art multimodal transport hub with integrated rail, bus and active travel facilities. The 1875 Waterside Station in Londonderry was abandoned after bomb damage in the 1970s, and its hastily built replacement nearby soon reached capacity. A European-Union-funded project has restored the old rail terminus to its former role and added a bus station, park-and-ride facility and links to the city’s greenways for cyclists and pedestrians. This paper provides an overview of the North West Transport Hub project, from inception to completion in 2022.

Over the past three decades, China's government has implemented many projects under its ecological compensation policy, including paying compensation fees for habitat creation to redress natural habitat losses caused by development. However, a critical evaluation of both the policy design and its ecological outcomes, has not previously been carried out. We assemble diverse data sources to provide the first evaluation of China's eco‐compensation policy and practice, identifying several challenges. In policy, the pricing of forest restoration fees is insufficient in several provinces, and there is no requirement for use of biodiversity metrics or for ecological equivalence of compensation and losses. In practice, only 23% of a sample of 31 developments applied quantitative biodiversity metrics, and fewer than 1% of China's local governments have disclosed information regarding compensation implementation. Thus, to improve the validity of its compensation policy and practice to better secure biodiversity, China may need to embrace higher compensation standards, having first prevented ecological losses where possible. Equally important, China may also need to improve compensation governance for data tracking and conservation effectiveness monitoring.

Industrial processes generate various quantities of waste that can be contaminated with radionuclides of natural origin (naturally occurring radioactive material ('NORM waste')). The efficient management of this waste is essential for any industries affected by NORM waste generation. To obtain an overview of current practices and approaches in Europe, the IRPA Task Group on NORM conducted a survey among task group members and other experts from European countries. The results revealed significant differences in methods and approaches in the European countries. In many countries, landfills are used to dispose of small- and medium-sized quantities of NORM waste with limited activity concentration. But our survey indicated that despite a uniform reference basis for national legislation in Europe, there are different framework conditions for the disposal of NORM waste in practice. In some countries, the disposal is hampered because the interface between the radiation protection system and the waste regime is not yet clearly regulated. Particular practical problems include the lack of acceptance of waste because of the 'radioactivity' stigma and only vague specifications by the legislators on acceptance obligations of the waste management sector.

The paper provides an overview of ICOLD Congresses, the typical content of Congress proceedings and how this is disseminated. The most recent ICOLD Congress was held in Marseilles in June 2022. Notes from sessions of all the four Questions (themes) of the 2022 ICOLD Congress are provided, either providing an overview of the presentations and discussions, or providing details of a particular presentation. Themes include concrete dams, incidents and accidents, surveillance and monitoring, and climate change.

Limit state design codes such as Eurocode 7 require good estimates of displacement to be made for serviceability checks. It is known that the stiffness of over-consolidated soils and weak rocks is highly non-linear and this needs to be taken into account for reliable displacements to be calculated. This paper outlines a relatively simple means of characterising the undrained and drained non-linear stiffness of a wide range of soils and rocks. A series of practical applications are described where the calculated stiffness non-linearity is compared with high quality field and laboratory test data, including back-analysis of full-scale structures. The non-linear stiffness function requires just four inputs: shear modulus at small-strain, shear strength, failure strain, and elastic threshold strain. Applications include: checking advanced test data and calibration of non-linear constitutive models; derivation of field stiffness, including variations with depth, non-linear stiffness curves, and assessing the potential effects of stiffness anisotropy.

The 2022 Binnie lecture was delivered to the British Dam Society on 16 September 2022. I began by looking at my introduction to reservoirs as a teenager. I then reviewed a variety of reservoir projects that have impacted my career and, more particularly, how they were shaped by social and environmental issues. Finally, I examined how my experience can influence the future of dam building in the UK.

Managing thermal loss is a key topic that needs further investigation as it has a direct link to reducing the energy load in buildings. One of these thermal loss management methods can be the use of shading devices. Dynamic thermal models normally used at the early stages of the building design can play an important role in the decision-making process regarding the use of shading devices. This paper presents the results of a real-world study assessing the potential of using a sealed cellular blind as a passive energy conservation method, where the real-world results are compared with the simulated results generated with environmental design solutions limited thermal analysis software (EDSL Tas) and integrated environmental solutions virtual environment (IES VE). During the real-world study, a positive impact of having blinds was seen whereby the window surface temperature increased and office heating energy consumption was lowered. Both software tools were able to predict a similar trend of results for the window surface temperature in with and without blind scenarios whereas for energy consumption although in the presence of a blind a consistent correlation is seen between measured and calculated values but not without a blind. This can be attributed to the inability of the software tools in demonstrating the effect of infiltration in the absence of a blind or shading device i.e., a clear window scenario. The performance gap analysis regarding thermal loss between dynamic thermal models and real-world settings within buildings can enhance the predictability of the building energy software tools used by designers. Early design inputs within buildings can prevent costly building re-work to improve the building’s energy performance. This can also improve the understanding within the building industry of the importance of reducing thermal loss through the use of shading devices and ensuring the software tools used to model these devices are as close to real-world settings as possible.

Background: Antimicrobial resistance (AMR) in Gram-negative bacteria-causing bloodstream infections (BSIs), such as Klebsiella pneumoniae and non-typhoidal Salmonella (NTS), is a major public health concern. Nonetheless, AMR surveillance remains scarce in sub-Saharan Africa, where BSI treatment is largely empirical. The aim of the study was to determine the distribution and AMR patterns of BSI-causing NTS, K. pneumoniae, and other Gram-negative bacteria in Ghana. Methods: A cross-sectional study was conducted between April and December 2021 at eleven sentinel health facilities across Ghana as part of a pilot study on the feasibility and implementation of the human sector AMR surveillance harmonized protocol in sub-Saharan Africa. Gram-negative bacteria recovered from blood specimens of febrile patients were identified using MALDI-TOF and evaluated for antimicrobial resistance using the BD Phoenix M50 analyzer and Kirby-Bauer disc diffusion. The Department of Medical Microbiology at the University of Ghana served as the reference laboratory. Results: Out of 334 Gram-negative blood isolates, there were 18 (5.4%) NTS, 85 (25.5%) K. pneumoniae, 88 (26.4%) Escherichia coli, 40 (12.0%) Acinetobacter baumannii, 25 (7.5%) Pseudomonas aeruginosa, and 77 (23.1%) other Gram-negative bacteria. As a composite, the isolates displayed high resistance to the antibiotics tested-amoxicillin (89.3%), tetracycline (76.1%), trimethoprim-sulfamethoxazole (71.5%), and chloramphenicol (59.7%). Resistance to third-generation cephalosporins [ceftriaxone (73.7%), cefotaxime (77.8%), and ceftazidime (56.3%)] and fluoroquinolones [ciprofloxacin (55.3%)] was also high; 88% of the isolates were multidrug resistant, and the rate of extended-spectrum beta-lactamase (ESBL) production was 44.6%. Antibiotic resistance in K. pneumoniae followed the pattern of all Gram-negative isolates. Antibiotic resistance was lower in NTS blood isolates, ranging between 16.7-38.9% resistance to the tested antibiotics. Resistance rates of 38.9%, 22.2%, and 27.8% were found for cefotaxime, ceftriaxone, and ceftazidime, respectively, and 27.8% and 23.8% for ciprofloxacin and azithromycin, respectively, which are used in the treatment of invasive NTS. The prevalence of multidrug resistance in NTS isolates was 38.9%. Conclusions: Multicenter AMR surveillance of Gram-negative blood isolates from febrile patients was well-received in Ghana, and the implementation of a harmonized protocol was feasible. High resistance and multidrug resistance to first- or second-choice antibiotics, including penicillins, third-generation cephalosporins, and fluoroquinolones, were found, implying that these antibiotics might have limited effectiveness in BSI treatment in the country. Continuation of AMR surveillance in Gram-negative blood isolates is essential for a better understanding of the extent of AMR in these pathogens and to guide clinical practice and policymaking.

Groundwater’s role in maintaining the well-being of the planet is increasingly acknowledged. Only recently has society recognised groundwater as a key component of the water cycle. To improve public understanding and the proper use of groundwater, the hydrogeological community must expand its efforts in groundwater assessment, management, and communication. The International Association of Hydrogeologists (IAH) intends to help achieve the United Nation’s water-related Sustainable Development Goals (SDGs) by the adoption of innovative hydrogeological strategies. This essay introduces a topical collection that encapsulates IAH’s 2022 ‘Year for Groundwater’.

Redundant reservoirs, whether they are subject to the provisions of reservoir legislation or not, have an ongoing maintenance requirement that places a burden on reservoir owners. Reservoirs upstream of communities also pose a risk to life. For these reasons, reservoir owners often consider discontinuing redundant assets; however, reservoirs can deliver amenity value for local communities as well as contributing to a desirable environmental habitat. Careful consideration should therefore be given to balancing the advantages and disadvantages when deciding whether to discontinue a reservoir. This paper will draw on case studies of five Scottish Water reservoir sites where the merits of discontinuance have been assessed. Two have been retained; and three have been discontinued. Key influences and lessons learned will be presented including identifying and mitigating environmental aspects; the findings from public consultations; the approach to whole life cost estimates; the benefits or otherwise of carrying ground investigations; the approach to dealing with sediment issues; the approach to managing flood risk during removal of the reservoir; and the approach to managing downstream flood risk following removal of the reservoir. The peculiarities of the Reservoirs (Scotland) Act 2011 (HMG, 2011) will be touched upon, as complete removal of a reservoir is termed abandonment!

Deep excavations in over-consolidated clays lead to swelling of the clay, which can exert large swell pressures on the basement slabs. In this paper, four prototype scenarios of basement construction in over-consolidated clay were investigated using both centrifuge modelling and finite element modelling. The main aim was to discern the effects of two aspects of embedment on long-term heave behaviour when relatively flexible and relatively stiff slabs were employed. The extension of diaphragm side walls below the formation level and the presence of a drainage layer between the slab and the clay were investigated. The results confirm that the use of a drainage layer would shorten the time of consolidation as expected. The variations in embedment conditions would also cause some redistribution of heave displacements, though the magnitude of such redistribution is relatively small, both when compared to the overall magnitudes of heave displacement and when compared to the effect of varying base slab stiffness on heave displacement.

Improving our understanding of groundwater quality threats to human health and the environment is essential to protect and manage groundwater resources effectively. This essay highlights some global groundwater quality challenges, describes key contaminant groups and threats of emerging concern, including antimicrobial resistance, and discusses novel approaches to assessing groundwater quality. Groundwater quality monitoring needs to improve significantly in order to effectively identify and mitigate threats to groundwater from historical, current and future pollution.

The effect of steel corrosion on the structural performance of reinforced concrete (RC) beams is a complex phenomenon concerning all types of reinforcing steel (tension, compression, and shear reinforcement) which has not been fully investigated experimentally or through modelling. The parameters used in models have not been fully employed in the non-uniform corrosion of steel bar, the buckling effect of corroded compression reinforcement or bond slip at the steel to concrete interface due to the combined effects of longitudinal and shear reinforcement corrosion. The objectives of this paper are i) to experimentally investigate the effect of three corrosion schemes (tension reinforcement corrosion; tension and compression reinforcement corrosion; tension, compression and shear reinforcement corrosion) on the structural performance of RC beams through the investigation nine beams, each with dimension of 150 mm width, 200 mm height and 2100 mm length ii) to employ a finite element method (FEM) to model both the control and corroded RC beams in which non-uniform corrosion of steel bars has been modelled by varying the bar diameters and the locations of corrosion pits including the buckling effect of compressive reinforcing steel bar, iii) to propose a modified bond slip model at the longitudinal steel–concrete interface due to the combined effect of longitudinal and shear reinforcement corrosion. The experimental results show that the yield and ultimate strength of the RC beams reduced under the three corrosion schemes. The yield strength of corroded RC beams is affected by the tension reinforcement corrosion while the ultimate strength is influenced by both the tension and compression reinforcement corrosion. Shear reinforcement corrosion contributes to the reduction in flexural strength of the RC beams due to the reduction in confinement of concrete. The failure modes and the ductility of the corroded RC beams are influenced by the non-uniformed corrosion and its distribution along the steel bars. The proposed FEM demonstrates good correlation with the experimental results, with the difference in ultimate flexural strength from the FEM and the experimental test in the range of 0.1 % to about 4 % for small pitting corrosion beams and up to 10 % for critical pitting corrosion beams.