Mark Trigg

University of Leeds · School of Civil Engineering

Uses the MODIS surface water product observations of the 2011 Bangkok flood.A data gap filling method is developed to better preserve the dynamics of the event.We quantify surface water connectivity geostatistically to give new flood insights.There is a clear structure to the connectivity of the event through time and space.Changes and thresholds i...

Floodplain channels are important components of river-floodplain systems and are known to play a key role in hydrodynamic exchange and sediment transport. The Amazon floodplain exhibits complex networks of these channels, and despite their potential importance to this globally important wetland system, these floodplain channels are relatively unstu...

In this paper a systematic approach to the optimization of 2D blade profiles is presented. A genetic optimizer has been developed which modifies the blade profile and calculates its profile loss. This process is automatic, producing profile designs significantly faster and with significantly lower loss than has previously been possible. The optimiz...

A bathymetric survey of 575 km of the central Amazon River and one of its tributaries, the Purus, are combined with gauged data to characterise the Amazon flood wave, and for hydraulic modelling of the main channel for the period June 1995–March 1997 with the LISFLOOD-FP and HEC-RAS hydraulic models.Our investigations show that the Amazon flood wav...

The research focuses on estimating bathymetry in extensive and ungauged river systems through entropy theory. This method was utilized in the central segment of the Congo River, spanning 1740 km and encompassing vast sections of up to 6 km, as well as in areas with highly intricate watercourse morphology, such as multi-thread reaches.

This study implements an entropy theory-based approach to infer bathymetry for 29 selected cross-sections along a 1740 km reach of the Congo River. A genetic algorithm optimization approach is used based on an analysis of near-surface velocity measurements to generate a random sample of 1000 bathymetry profiles from which the analysis is carried ou...

In this article, we examine the scientific and sustainable research capacity outcomes of the ‘Congo River: user Hydraulics and Morphology’ or CRuHM project, a six-year effort supported by the Royal Society’s Africa Capacity Building Initiative. This project brought together a consortium of African and UK universities to undertake the first large-sc...

The formation and failure of landslide dams is an important and understudied, multi-hazard topic. A framework of landslide dam formation susceptibility evaluation was designed for large-scale studies to avoid the traditional dependence on landslide volume calculations based on empirical relationships, which requires comprehensive local inventories...

Adequate monitoring of river discharge is crucial for effective water resource management. However, this objective remains difficult to achieve in the context of large and ungauged river basins. This study assesses the performance of remote sensing applications for discharge monitoring in the lower reach of the Congo River, where daily discharge in...

Surface water flooding (SWF) is a severe hazard associated with extreme convective rainfall, whose spatial and temporal sparsity belie the significant impacts it has on populations and infrastructure. Forecasting the intense convective rainfall that causes most SWF on the temporal and spatial scales required for effective flood forecasting remains...

Water resource modelling plays a crucial role in water resources management, but it involves many inherent uncertainties. This research investigates how epistemic uncertainties affect reservoir water budgets, projecting forward over a 30 year period using Monte Carlo simulation. It encompasses long-term variations in water demand, reservoir volume,...

Introduction: Cities located in lower income countries are global flood risk hotspots. Assessment and management of these risks forms a key part of global climate adaptation efforts. City scale flood risk assessments necessitate flood hazard information, which is challenging to obtain in these localities because of data quality/scarcity issues, and...

Household water demand has increased dramatically in Kuwait over the last few decades, due to rapid population growth and changing lifestyles. Avoiding a water deficit through a supply-side approach has been the default strategy in Kuwait, yet this approach is unsustainable, associated with declining groundwater levels, and reliance on desalination...

Surface water flooding (SWF) is a severe hazard associated with extreme convective rainfall, whose spatial and temporal sparsity belies the significant impacts it has on populations and infrastructure. Forecasting the intense convective rainfall that causes most SWF on the temporal and spatial scales required for effective flood forecasting remains...

The number of global refugees has been rising annually for the last decade. Many of these refugees are housed within camps, in temporary structures, vulnerable to the impacts of flooding. The flood risk of refugees is not well understood. Flood risk guidance available for camp planners and managers is vague, and existing flood risk data is often la...

Small Island Developing States (SIDS) are acknowledged as particularly vulnerable to extreme climate events; however, the realities for transport infrastructure and bridges are still poorly studied. Assessing bridges in this context can be challenging due to data scarcity, a lack of local standards, and uncertainty due to climate change. While brid...

Here we show how major rivers can efficiently connect to the deep-sea, by analysing the longest runout sediment flows (of any type) yet measured in action on Earth. These seafloor turbidity currents originated from the Congo River-mouth, with one flow travelling >1,130 km whilst accelerating from 5.2 to 8.0 m/s. In one year, these turbidity current...

Non-intrusive image-based techniques for measuring surface river velocities have rapidly evolved as a cost-effective and safe means for quantifying flow patterns. Large-scale particle image velocimetry (LSPIV) can provide instantaneous surface velocities over a large spatial footprint rapidly and with little pre-calibration as compared to tradition...

In the sparsely investigated region of the Congo Basin (CB), flood seasonality and flood regime shift are established through relative frequency, cluster analysis, directional statistics, and non-overlapping block methods based on block maxima and peak over threshold (POT) series. Two months of significantly rich floods are observed at all gauging...

The resources of small‐scale community‐based flood risk action groups are often limited, hence studies to model and predict the effects of Natural Flood Management are often restrained by time and lack of empirical data to validate results. As a result, representations of hillslope leaky barriers are largely modelled as several equifinal approaches...

The African continent hosts some of the largest freshwater systems worldwide, characterized by a large distribution and variability of surface waters that play a key role in the water, energy and carbon cycles and are of major importance to the global climate and water resources. Freshwater availability in Africa has now become of major concern und...

Over the last two decades, several data sets have been developed to assess flood risk at the global scale. In recent years, some of these data sets have become detailed enough to be informative at national scales. The use of these data sets nationally could have enormous benefits in areas lacking existing flood risk information and allow better flo...

Household water demand has dramatically increased in Gulf Cooperation Council (GCC) countries in the last few decades, due to rapid population growth and changing lifestyles. Growing demand has been met by increasing supply capacity, largely via new desalination plants and over-abstracting groundwater. The continuous investment in water supply to a...

The Sentinel-1 SAR dataset provides the opportunity to monitor floods at unprecedentedly high spatial and temporal resolutions. However, the accuracy of the flood maps can be affected by the image polarization, the flood detection method used, and the reference data. This research compared change detection and histogram thresholding methods using c...

Avec les récents développements des technologies pour étudier le transport des sédiments dans les plans d'eau, comme la télédétection et les améliorations des modèles de prédiction de l'érosion, les mesures de concentration des sédiments sur le terrain sont toujours nécessaires pour calibrer et valider les résultats de ces études. Les détails de l'...

The Congo River provides a huge potential for socio‐economic growth at the regional scale, but with limited information on the river dynamics it is difficult for basin countries to benefit from this potential, and to invest in the development of water resources. Accurate information is needed to support adequate management strategies such as predic...

The need for a catchment classification framework for the Congo Basin is obvious given the basin's inherent heterogeneities, the ungauged nature of the basin, and the pressing needs for water resources management that include the quantification of current and future supplies and demands, which also encompass the impacts of future changes associated...

Flood disasters have regularly been reported in the Congo Basin with significant damage to human lives, food production systems, and infrastructure. Losses incurred by these damages are huge and represent a major challenge for economic expansion in developing nations. In the Congo River Basin, where availability of in situ data is a significant cha...

La navigation fluviale est un élément crucial de l'économie des pays qui partagent le Bassin du Congo. Le transport fluvial n'est pas à la hauteur du rôle qu'il pourrait jouer dans le développement de la région, et il a décliné au cours des dernières décennies. Les cartes de navigation fluviale sont des cartes spécialisées conçues pour aider à la s...

Des inondations ont été régulièrement signalées dans le Bassin du Fleuve Congo (BFC) avec des dommages importants pour la vie humaine, les systèmes de production alimentaire et infrastructures. Les pertes encourues par ces dommages sont énormes et représentent un défi majeur pour les économiques des nations en développement. Dans le BFC, où la disp...

Bathymetry is a key input into numerical models that simulate river hydrodynamics, but it is particularly challenging to obtain on multichannel rivers where mid‐channel islands prevent survey boats from undertaking bank‐to‐bank navigation. This is problematic, as there is a need to explicitly represent individual channel threads in hydrodynamic mod...

The Congo River is navigable along much of its length and plays a crucial role in the economies of nine basin countries. River users rely on river transport for access to markets, resources, and key services. These users range from millions of small‐scale informal users, to industrial‐scale users such as mining and logging companies. Without a func...

La nécessité de mettre en place un cadre de classification des unités hydrologiques est évidente dans le Bassin du Congo à cause de ses hétérogénéités, de sa nature non jaugée et des besoins pressants d'utilisation des ressources en eau. Ces besoins comprennent la quantification des approvisionnements et des demandes actuels et futures, qui incluen...

Le fleuve Congo offre un potentiel important pour la croissance économique à l’échelle régionale, mais avec des informations limitées sur la dynamique des cours d'eau, il est difficile pour les pays riverains de tirer profit de ce potentiel et d'investir dans le développement des ressources en eau. Des informations précises sont nécessaires pour so...

Le fleuve Congo est navigable sur une grande partie de sa longueur et il joue un rôle crucial dans les économies de neuf pays du bassin. Les usagers du fleuve dépendent du transport fluvial pour accéder aux marchés, aux ressources et aux services essentiels. Ces utilisateurs vont des millions de petits utilisateurs informels aux utilisateurs indust...

La bathymétrie est un élément clé des modèles numériques qui simulent l'hydrodynamique des rivières, mais elle est particulièrement difficile à obtenir sur les rivières multicanaux où les îles du milieu du canal empêchent les bateaux de reconnaissance d'entreprendre une navigation de rive à rive. Cela est problématique car il est nécessaire de repr...

To address the current data and understanding knowledge gap in landslide dam inventories related to geomorphological parameters, a new global-scale landslide dam dataset named River Augmented Global Landslide Dams (RAGLAD) was created. RAG-LAD is a collection of landslide dam records from multiple data sources published in various languages and man...

Here we document for the first time how major rivers connect directly to the deep-sea, by analysing the longest runout sediment flows (of any type) yet measured in action. These seafloor turbidity currents originated from the Congo River-mouth, with one flow travelling >1,130 km whilst accelerating from 5.2 to 8.0 m/s. In one year, these turbidity...

Landslide dams can result in substantial flood hazards caused by dam formation, overtopping, and dam failure. Previous studies have established datasets on a regional or global scale and identified indices to estimate the probability of landslide dam formation. These datasets are collections of landslide dam records from multiple data sources. Howe...

The characteristics of a sub-basin's long-term hydrological behaviour are used as multiple constraint filters for constraining hydrological model simulations in the Congo Basin using the monthly time step Pitman model. The results suggest that the constraints are appropriate in many sub-basins (≥20 gauging stations), but not all. Detailed examinati...

There is now a wealth of data to calculate global flood exposure. Available datasets differ in detail and representation of both global population distribution and global flood hazard. Previous studies of global flood risk have used datasets interchangeably without addressing the impacts using different datasets could have on exposure estimates. By...

Urban flood models that use Digital Elevation Models (DEMs) to simulate extent and depth of flood inundation rely on the accuracy of DEMs for predicting flood events. Despite recent advances in developing vegetation corrected DEMs, the effect of building height and density errors in global DEMs in urban areas are still poorly understood, and their...

Flooding is an important global hazard that causes an average annual loss of over 40 billion USD and affects a population of over 250 million globally. The complex process of flooding depends on spatial and temporal factors such as weather patterns, topography, and geomorphology. In urban environments where the landscape is ever-changing, spatial f...

There is now a wealth of data to calculate global flood exposure. Available datasets differ in detail and representation of both global population distribution and global flood hazard. Previous studies of global flood risk have used datasets interchangeably without addressing the impacts using different datasets could have on exposure estimates. By...

The risk of surface water flooding (SWF) in England is already high and its frequency and severity is projected to increase in the future. SWF generally occurs due to intense, highly localised rainfall, which is challenging to forecast with sufficient accuracy to take proactive action ahead of flood events. Being able to manage the risk effectively...

River navigation is a crucial part of the economy for countries that share the Congo Basin. River transport falls short of the role it could play in the region's development, and has declined in recent decades. River navigation charts are specialist maps designed to assist in the safe navigation of river traffic. In the DRC, navigation charts for t...

With recent developments in technologies to study sediment transport in water bodies, such as remote sensing and improvements in erosion prediction models, field‐derived sediment concentration measurements are still required to calibrate and validate the results of such studies. The details of the establishment of a high‐frequency sediment sampling...

Although the Congo Basin is still one of the least studied river basins in the world, this paper attempts to provide a multidisciplinary but non-exhaustive synthesis on the general hydrology of the Congo River by highlighting some points of interest and some particular results obtained over a century of surveys and scientific studies. The Congo Riv...

Continental-scale models of malaria climate suitability typically couple well-established temperature-response models with basic estimates of vector habitat availability using rainfall as a proxy. Here we show that across continental Africa, the estimated geographic range of climatic suitability for malaria transmission is more sensitive to the pre...

Study region The five drainage systems of the Congo River Basin in central Africa. Study focus This study aims to establish uncertainty ranges of hydrologic indices and to provide a basis for transferring hydrologic indices from gauged to ungauged sub-basins by identifying the most influential climate and physiographic attributes. New insights fo...

The coastal state of Kerala, India experienced unprecedented levels of rainfall and flooding in August 2018, resulting in huge life and property loss. Since then the impact reservoir management may have had on the severity of the 2018 Kerala floods has been in question. This study presents a novel approach to developing a reservoir model using HEC-...

The coastal state of Kerala, India experienced unprecedented levels of rainfall and flooding in August 2018, resulting in huge life and property loss. Since then the impact reservoir management may have had on the severity of the 2018 Kerala floods has been in question. This study presents a novel approach to developing a reservoir model using HECH...

Landslide dams are a common hazard reported in mountainous areas around the world, where the dams block the normal flow of the river and can cause catastrophic flooding downstream when the temporary dam subsequently fails. Most of the research that couples landslide dams and fluvial systems have been concentrated on a site-specific scale and thus l...

Every year riverine flooding affects millions of people in developing countries, due to the large population exposure in the floodplains and the lack of adequate flood protection. Preparedness and monitoring are effective ways to reduce flood risk. State‐of‐the‐art technologies relying on satellite remote sensing as well as numerical hydrological a...

The Congo Basin is a unique freshwater ecosystem supporting hundreds of millions of people and a crucial part of regulating Earth’s water cycle. Increasing international attention on its resource potential brings worrying pressures to this understudied region. Equitable collaboration is the key to understanding this complex, interconnected system a...