Andrew Mark Ireson

University of Saskatchewan | U of S · Global Institute for Water Security

Root‐zone soil moisture (0–110 cm) was monitored at 21 sites within a cold‐region semiarid prairie grazing pasture over multiple growing seasons. There were large differences in the moisture dynamics for different sites, which was related to local‐scale impacts of sodium‐induced clay dispersion. Sites with high exchangeable sodium percentages, indi...

Stable isotopes have been used to quantify lake and wetland pond water loss to evaporation by applying the modified Craig and Gordon (1965) model. This model and its derivatives employ simplifying assumptions that ignore the additions of precipitation and infiltration outputs and assume evaporation is the only loss term over the prediction period....

Long-term meteorological, soil moisture, surface water, and groundwater data provide information on past climate change, most notably information that can be used to analyze past changes in precipitation and groundwater availability in a region. These data are also valuable to test, calibrate and validate hydrological and climate models. CCRN (Chan...

Numerical models of soil-water dynamics have been widely used in the design of soil cover systems for mine site reclamation; however, in most cases these models only consider water dynamics without consideration of heat dynamics. For cover systems in northern climates, such as those associated with oil sands mines in northern Alberta, Canada, freez...

Mine waste rock dumps have highly variable flowpaths caused by contrasting textures and geometry of materials laid down during the ‘plug dumping’ process. Numerical experiments were conducted to investigate how these characteristics control unsaturated zone flow and transport. Hypothetical profiles of inner-lift structure were generated with multip...

Hydrological water balance closure is a simple concept, yet in practice it is uncommon to measure every significant term independently in the field. Here we demonstrate the degree to which the field-scale water balance can be closed using only routine field observations in a seasonally frozen prairie pasture field site in Saskatchewan, Canada. Arra...

Hydrological water balance closure is a simple concept, yet in practice it is usually impossible to measure every significant term independently in the field. Here we explore field scale water balance closure in a prairie pasture field site in Saskatchewan, Canada. The area is cold, flat and semi-arid, with snowmelt-dominated runoff. Arrays of snow...

Many practical hydrological, meteorological, and agricultural management problems require estimates of soil moisture with an areal footprint equivalent to field scale, integrated over the entire root zone. The cosmic-ray neutron probe is a promising instrument to provide field-scale areal coverage, but these observations are shallow and require dep...

Many practical hydrological, meteorological and agricultural management problems require estimates of soil moisture with an areal footprint equivalent to "field scale", integrated over the entire root zone. The cosmic-ray neutron probe is a promising instrument to provide field scale areal coverage, but these observations are shallow and require de...

Temporal and spatial patterns of active layer thaw depth were measured during the 2015 thaw period at a small test basin in the Canadian arctic. Measurements were obtained at eight creek hill slope transects and two tundra site grids within the Siksik Creek Basin located 45 km north of Inuvik within the Beaufort Mackenzie Delta Region in the Northw...

The Boreal Plains Ecozone (BPE) in Western Canada is expected to be an area of maximum ecological sensitivity in the 21st century. Successful climate adaptation and sustainable forest management require a better understanding of the interactions between hydrology, climate, and vegetation. This paper provides a perspective on the changing water cycl...

Linkages between the controls on surface storage and catchment streamflow response were examined in a wetland dominated basin in the Canadian Prairie Pothole region. Snowmelt, surface storage, water table elevation, atmospheric fluxes, and streamflow were monitored during spring snowmelt and summer in a 1 km2 sub-catchment containing a semi-permane...

Heat dissipation sensors are used to measure matric potential in soils. A van Genuchten equation can be used to fit the relationship between measured heat dissipation and matric potential. Calibration is required for each probe because of intrinsic variability in the properties of the porous material. However, calibration is time-consuming (months)...

Global and regional climate is influenced by the heterogeneity of the land surface. The land surface is responsible for partitioning of net radiation into latent heat and sensible heat and precipitation into infiltration, evapotranspiration and streamflow. Evapotranspiration is a dominant component of the hydrological cycle and accurate modeling of...

The prairie region of Canada and the United States is characterized by millions of small depressions of glacial origin called prairie potholes. The transfer of surface runoff in this landscape is mainly through a “fill and spill” mechanism among neighboring potholes. While non-contributing areas, that is small internally drained basins, are common...

The glaciated plains of the North American continent, also known as the "prairies", are a complex hydrological system characterized by hummocky terrain, where wetlands, containing seasonal or semi-permanent ponds, occupy the numerous topographic depressions. The prairie subsoil and many of its water bodies contain high salt concentrations, in parti...

Numerical models are frequently used for the regional quantification of groundwater recharge. However there is a wide range of potential models available that represent the land surface with varying degrees of complexity, but which are rarely tested against observations at the field scale. We compared four models that simulate potential recharge at...

Models for the soil-plant-atmosphere system, especially large scale models, frequently ignore interactions with underlying groundwater, and ignore fractures or macropores which may strongly influence the system response. Unsaturated fractured porous media can exhibit a range of behavior, depending on both the characteristics of the porous matrix an...

The glaciated plains of the North American continent, also known as the "prairies", are a complex hydrological system characterized by hummocky terrain, where wetlands, containing seasonal or semi-permanent ponds, occupy the numerous topographic depressions. The prairie subsoil and many of its water bodies contain high salt concentrations, in parti...

Experimental and modeling results were used to develop a conceptual understanding of the process of pervaporative irrigation in dry soils. When irrigating in this way, a pervaporative membrane is formed into a tube, buried in the soil, and filled with water. If the surrounding soil is dry, a chemical potential gradient across the membrane draws wat...

The semiarid glaciated plains of the North American continent, known as the prairies, are characterized by an undulating terrain rich in sulfate salts in the subsurface, with ephemeral streams and large numbers of wetlands containing seasonal or semi-permanent ponds. Salinization is a potential concern for the diverse community of vegetation, aquat...

A novel method for irrigation with saline water uses a polymer membrane, formed into a tube, to treat and distribute the water simultaneously. The flux of water across the membrane occurs by the process of pervaporation, during which a phase change from liquid to vapor occurs. Thus, water arrives in the soil in the vapor phase. The experimental res...

Quantification of the timing and magnitude of point-scale groundwater recharge is challenging, but possible at specific sites given sufficient high spatial and temporal resolution field observations, and a suitable physically based model. Such models are generally too computationally intensive and have too many unknown parameters to be practically...

Serving as a link between the land surface and the planetary boundary layer, evapotranspiration constitutes a key component of the water cycle and of atmospheric energy and moisture processes. Hence, accurate estimation of basin-scale evapotranspiration is crucial for hydrological models and for weather and climate models. An extensive set of meteo...

The groundwater regime in seasonally frozen regions of the world exhibits distinct behavior. This paper presents an overview of flow and associated heat and solute transport processes in the subsurface, from the soil/vadose zone, through groundwater recharge to groundwater discharge processes in these areas. Theoretical developments, field studies...

A framework for the rigorous quantification of the timing and magnitude of groundwater recharge is proposed. This involves developing a physically based model for the flow processes in the unsaturated and saturated zones that is consistent with the conceptualisation of the system, and with field observations. Subsequently, the essential behaviour o...

Two distinct types of fracture flow can occur in unsaturated fractured porous media: non-preferential flow, whereby the fractures and matrix wet up in equilibrium, and preferential flow, whereby water in the fractures bypasses the matrix. This has important implications for how infiltration, recharge, groundwater flooding and contaminant transport...

Groundwater in Chalk catchments is a major resource that also helps support internationally important habitats and ecosystems. Its dual porosity and dual permeability properties, coupled with large-scale structural features (such as hard rock layers and marls), produce a highly complex hydrogeological system. Recent impacts from groundwater floodin...

Pervaporative irrigation allows in-situ treatment of low quality water (e.g. saline water) whilst simultaneously distributing water throughout the soil. The system is also low energy, requiring only that a positive head of water is maintained in a supply tank. To irrigate using this method a pervaporative polymer membrane is formed into a pipe, bur...

One of the fundamental challenges for quantifying the timing and magnitude of groundwater recharge is that there remains no direct, non-destructive method for measuring this flux. As a result, recharge is indirectly inferred, requiring a conceptual model (that is a set of assumptions about the system processes), a mathematical model (providing quan...

In dry soils hydraulic connectivity within the liquid water phase decreases and vapour flow becomes a significant transport mechanism for water. The temperature or solute concentration of the liquid phase affects the vapour pressure of the surrounding air, thus temperature or solute gradients can drive vapour flows. However, in extremely dry soils...

Groundwater flooding has moved up the policy-makers' agenda as a result of the United Kingdom experiencing extensive groundwater flooding in winter 2000/2001. However, there is a lack of appropriate methods and data to support groundwater flood risk assessment. The implications for flood risk assessment of groundwater flooding are outlined using a...

Background: Drinking water from natural sources in coastal Bangladesh has become contaminated by varying degrees of salinity due to saltwater intrusion from rising sea levels, cyclone and storm surges, and upstream withdrawal of freshwater. Objective: Our objective was to estimate salt intake from drinking water sources and examine environmental fa...

There is evidence that, under certain conditions, rapid preferential recharge via the fracture network can occur in Chalk aquifers. This has potentially important implications for contaminant migration through the Chalk unsaturated zone, CUZ, and for groundwater flooding in Chalk catchments. In the case of groundwater flooding, deficiencies in mode...

The fractured porous Chalk aquifers underlying south east England constitute the UK's single most important groundwater resource, but understanding and modelling the flow and transport processes that govern recharge, nutrient transport and response to extremes have remained a challenge. Rushton (2005) provides an authoritative summary of convention...

Peatlands cover ca. 3% of the land surface yet account for ca. 30% of the global soil carbon sink. As climate conditions are known to control carbon accumulation in peatlands, future projections of increased temperatures and decreased summer precipitation could alter peatland carbon fluxes by influencing the water table dynamics in these saturated...

Precipitation downscaling improves the coarse res-olution and poor representation of precipitation in global climate models, and helps end users to as-sess the likely hydrological impacts of climate change. This paper integrates perspectives from meteorolo-gists, climatologists, statisticians and hydrologists, to identify generic end user (in parti...

Serious groundwater flooding events have occurred on Chalk catchments in both the UK and north west Europe in the last decade, causing substantial amounts of disruption and economic damage. These fractured, permeable catchments are characterized by low surface runoff, high baseflow indices and strongly attenuated streamflow hydrographs. They have a...

Groundwater from unconfined chalk aquifers constitutes a major water resource in the UK. The unsaturated zone in such systems plays a crucial role in the hydrological cycle, determining the timing and magnitude of recharge, and the transport and fate of nutrients. However, despite more than three decades of study, our physical understanding of this...

Current interest in groundwater flooding follows the events of 2000/01 when extreme long duration rainfall caused the water tables in Chalk catchments in South East England and Northern France to rise to unusually high levels. Individual rainfall events, and even monthly totals were unexceptional. By contrast, in July 2007, an extreme short-duratio...

Unsaturated vegetated soils are an important component in performance assessment models used to quantify risks associated with deep engineered repositories for underground radioactive waste disposal. Therefore, experimental studies, funded by Nirex over nearly 20 years, have been undertaken at Imperial College to study the transfer of radionuclides...

The unsaturated zone exerts a major control on the delivery of nutrients to Chalk streams, yet flow and transport processes in this complex, dual-porosity medium have remained controversial. A major challenge arises in characterising these processes, both at the detailed mechanistic level and at an appropriate level for inclusion within catchment-s...

The Chalk unsaturated zone is crucial in controlling the delivery of nitrate to Chalk streams and groundwater abstraction wells. In this paper, results from a dual-permeability numerical model of the Chalk unsaturated zone are used to illustrate the relative roles of matrix and fracture flow. A major challenge arises in representing the Chalk unsat...

As part of the NERC lowland catchment research programme (LOCAR), the Pang-Lambourn catchments (Berkshire, UK) have been extensively instrumented to provide an improved understanding of the hydrological processes in the unsaturated zone of the Chalk – a subject of much debate over the past 30 years. To quantify the movement of water through the uns...

The Water Framework Directive calls for strategic water resources planning at a catchment level, yet data and information are scarce in the areas where they are most needed: in the new EU Member States and Third Counties trying to assess the impact of EU environmental legislation in their water resources management policy. The research presented he...

Despite many decades study, quantification of water movement through the Chalk unsaturated zone has proved difficult, due to its particular properties. Chalk comprises a fine grained porous matrix intersected by a fracture network. In much of the unsaturated zone, for most of the time, matric potentials remain between -20 and -0.5 m. Thus the matri...

PREFACE This report has been prepared by Imperial College, London under contract to Nirex and forms part of an ongoing programme of research commissioned by Nirex to underpin the long-term safety of a geological disposal facility for higher-active radioactive wastes. Before it was pub-lished Nirex was subsumed into the Nuclear Decommissioning Autho...