Rutger Willem Vervoort

• Professor at The University of Sydney

Optical-based remote sensing techniques can be an effective means to monitor surface water extent (SWE) in wetlands. However, these techniques have limitations which arise due to omission errors caused by cloud coverage, shadows, vegetation canopy above the water and the presence of water and vegetation within the pixel (mixed pixels). Moreover, re...

The Millennium Drought lasted more than a decade, and is notable for causing persistent shifts in the relationship between rainfall and runoff in many south-east Australian catchments. Research to date has successfully characterised where and when shifts occurred and explored relationships with potential drivers, but a convincing physical explanati...

Numerical models of groundwater flow play a critical role for water management scenarios under climate extremes. Large-scale models play a key role in determining long range flow pathways from continental interiors to the oceans, yet struggle to simulate the local flow patterns offered by small-scale models. We have developed a highly scalable nume...

Drought is the most expensive natural hazard and one of the deadliest. While drought propagation through standardised indices has been extensively studied at the regional scale, global scale drought propagation, and particularly quantifying the space and time variability, is still a challenging task. Quantifying the space time variability is crucia...

Soil water is a critical component of the water balance to make water management decisions at multiple scales. While soil water can be sensed remotely, this is generally at coarse scales (> 12.5 km). In addition, soil moisture products developed at field scale resolutions (< 250 m) have been mostly limited to shallow observations (up to 10 cm depth...

To increase water productivity and assess water footprints in irrigated systems, there is a need to develop cheap and readily available estimates of components of water balance at fine spatial scales. Recent developments in satellite remote sensing platforms and modelling capacities have opened opportunities to address this need, such as those bein...

Storage and subsequent release of water is a key function of catchments that moderates the impact of meteorological and climate extremes. Despite the fact that many key hydrological processes depend upon storage, there are relatively few studies that focus on storage itself. Storage is difficult to quantify due to catchment heterogeneity and the pa...

There is considerable interest and value in identifying the gap between crop yields that have actually been achieved, and yields that could have potentially been achieved. A suite of methods currently exist to estimate the yield potential of a crop, but there are no approaches that predict the site- and season-specific yield potential using dataset...

Accurate estimates of water volumes are crucial for water management. This study applies an automated methodology to detect small-scale on-farm dams and develops a novel application of Bayesian inference to jointly simulate volumes and uncertainties. A linear relationship was assumed between flooded pixel area images derived from LiDAR datasets and...

Black Box (Eucalyptus largiflorens F. Muell.), is a keystone tree species of lowland semi-arid floodplain ecosystems in south-eastern Australia. E. largiflorens woodlands are of high conservation value and threatened by climate change-induced drought and irrigation water diversions due to their location on upper floodplain areas where flood frequen...

Management of water, regionally, nationally and globally will continue to be a priority and complex undertaking. In riverine systems, biotic components like flora and fauna play critical roles in filtering water so it is available for human use and consumption. Preservation of ecosystems and associated ecosystem functions is therefore vital. In hig...

Climate change together with changes in land cover and water allocations are expected to affect water resources availability. The long-term effect of these changes on available water resources in central Chile was comprehensively evaluated through climatic trends from 1982, land cover changes from 2001, and water allocations from 1980. Trends in cl...

Soil salinization resulting from shallow saline groundwater is a major global environmental issue causing land degradation, especially in semi-arid regions such as Australia. The adverse impact of shallow saline groundwater on soil salinization varies in space and time due to the variation in groundwater levels and salt concentration. Understanding...

Hydrological extremes are complex phenomena that will intensify in the future as a result of the changing climate. Seasonal forecasts are one of a multitude of tools that can be used to support an early warning system to monitor hydrological extremes, such as droughts. In this study different drought indices were calculated for regions around Fiji...

The inherent complexity of numerical models and the diversity of stakeholders in integrated water resources management (IWRM) create challenges in achieving credibility, salience and legitimacy to develop trust in model-based scenarios. In Uruguay, there has been significant debate on increasing agricultural production while managing agriculture’s...

The effect of climate change on water resources has been an area of continued research, especially in Australia. Previous studies have suggested significant trends in rainfall, and these are amplified causing larger changes in streamflow. However, most of the previous analysis was based on annual time scales or modelled data and did not account for...

Forecasts of crop yield are an important tool for a variety of stakeholders, but most studies produce large-scale, late-season yield forecasts that are not appropriate for farmers. Farmers require forecasts of crop yield mid-season and at fine spatial resolutions to guide site-specific adaptive crop management practices. This study created empirica...

Improving our knowledge of the travel times of water through catchments is critical for the management and protection of water resources and to improve our understanding of fundamental catchment behaviour. In this study we use the age‐ranked storage framework StorAge Selection (SAS) to investigate travel times in the Corin catchment, a headwater ca...

Trifluralin is a widely used dinitroaniline herbicide, which can persist in the environment and has substantial ecotoxicity, especially to aquatic organisms. Trifluralin is very insoluble in water (0.22 mg/L at 20○C) and highly volatile (vapour pressure of 6.7 mPa at 20○C); these physicochemical properties determine a large part of its environmenta...

In recent years the exponential growth in digital data and the expansion of machine learning have fostered the development of new applications in geosciences. Natural Language Processing (NLP) tackles various issues that arise from using human language data. In this study, NLP is applied to classify and map lithological descriptions in a three dime...

In recent years the exponential growth in digital data and the expansion of machine learning have fostered the development of new applications in geosciences. Natural Language Processing (NLP) tackles various issues that arise from using human language data. In this study, NLP is applied to classify and map lithological descriptions in a three dime...

Economic pressures on natural resources have led to a modification of natural surface water patterns. This has affected the hydrologic cycle at a global scale with multiple environmental and socioeconomic implications. This study evaluates long-term trends in surface water occurrence and related climate variables in a large agricultural catchment o...

Study region This study was conducted in the Namoi catchment, Australia. Study focus Managed aquifer recharge (MAR) site suitability has been widely studied through multicriteria decision analysis (MCDA). However, the selection of areas for MAR project implementation can be a vague process with different validation approaches. The aim of this stud...

Uncertainty communication is too frequently approached as a linear task from "experts" to their audience, though admittedly sometimes with feedback and dialogue. From a system-wide perspective, uncertainty is managed and communicated in many ways by many people and groups both within organisations and in society generally. In the water sector, the...

Many lumped rainfall-runoff models are available but no single model can account for the uniqueness and variability of all catchments. While there has been progress in developing frameworks for optimal model selection, the process currently selects a range of model structures a priori rather than starting from the hydrological data and processes. I...

CTED Models are playing an increasingly prominent role in watershed management, and environmental management more generally. To successfully utilize model-based tools for governing water resources, modelling timelines must match decision making timelines, and modelling costs must fall within budget constraints. Clarity on management options for mod...

La escorrentía de fuentes difusas representa gran parte las descargas de nutrientes y pesticidas hacia los ecosistemas de agua dulce. En particular, el herbicida glifosato constituye el pesticida más extensamente aplicado en Uruguaydesde la introducción de cultivos genéticamente modificados con tolerancia al mismo. Escasos estudios existen en nuest...

Analysis of observational data to pinpoint impact of land cover change on local rainfall is difficult due to multiple environmental factors that cannot be strictly controlled. In this study we use a statistical approach to identify the relationship between removal of tree cover and rainfall with data from best available sources for two large areas...

In this study, we extend our earlier work presented in the 22nd International Congress on Modelling and Simulation (MODSIM 2017) and propose a simple parametric pre-factor (the biodegradation potential ψB), which can be used to estimate the biodegraded fraction of a contaminant in soil. ψB can be determined based on either first-order or Michaelis–...

Land use change is an important driver of trends in streamflow. However, the effects are often difficult to disentangle from climate effects. The aim of this paper is to demonstrate that trends in streamflow can be identified by analysing residuals of rainfall-runoff simulations using a Generalized Additive Mixed Model. This assumes that the rainfa...

Compared with larger nations, small island developing states (SIDS) are disproportionately affected by natural disasters relative to size and frequency. Social, environmental and economic complexities are integral in making SIDS more vulnerable to such catastrophes. Floods and droughts have drastic impacts on societies; however, few studies have...

Quality and reliable drought prediction is essential for mitigation strategies and planning in disaster-stricken regions globally. Prediction models such as empirical or data-driven models play a fundamental role in forecasting drought. However, selecting a suitable prediction model remains a challenge because of the lack of succinct information av...

Uncertainty about global change requires alternatives to quantify the availability of water resources and their dynamics. A methodology based on different satellite imagery and surface elevation models to estimate surface water volumes would be useful to monitor flood events and reservoir storages. In this study, reservoirs with associated digital...

Accurate spatiotemporal analysis of surface water is important for managing water resources. The main objectives of this study were: 1) to assess different remote sensing algorithms’ ability to accurately determine flood extent using MODIS imagery, and 2) to study the temporal dynamics of inundated areas and corresponding return periods in a large...

An improved understanding of the drivers controlling infiltration patterns in semiarid regions is of key importance, as they have important implications for ecosystem productivity, retention of resources and the restoration of degraded areas. The infiltration depth variability (ΔInf) in vegetation patches at the hillslope scale can be driven by dif...

Glyphosate (GLP) is one of the most widely-used herbicides globally and its toxicity to humans and the environment is controversial. GLP is biodegradable, but little is known about the importance of site exposure history and other environmental variables on the rate and pathway of biodegradation. Here, GLP was added to microcosms of soils and sedim...

The Santa Lucía river is the main source of potable water for Uruguay, representing more than 60% of the country’s population water supply. After 1995, some of the upstream areas have been characterized by substantive land use change (mostly agricultural intensification and afforestation), which along with climate change, can cause trends in hydrol...

Biodegradation of glyphosate (GLP) and its metabolite aminomethylphosphonic acid (AMPA) was numerically assessed for a vineyard and a wheat field in the Po Valley, Italy. Calculation of the Hazard Quotient suggested that GLP and AMPA can pose a risk of aquifer contamination in the top 1.5 m depth within 50 years of GLP use. Numerical results relati...

Episodic flood events have a significant impact on ecosystems and human settlements, and can be important drivers for the water availability. This study maps the flood extension at a catchment scale, and determines the volumes associated with inundation events for selected return periods by coupling a water detection algorithm and three methods for...

Hydro-metrological hazards are a prevalent issue in the Pacific. Although hazards are inevitable, proactive approaches to efficiently manage its consequences can significantly alleviate risks. The cognizance of climate change has raised a serious need for further modelling, risk management discussions and tools, as it can potentially exacerbate wea...

Empirical evidence from Australia shows that fuel reduction burning significantly reduces the incidence and extent of unplanned fires. However, the integration of environmental values into fire management operations is not yet well-defined and requires further research and development. WAVES, a plant growth model that incorporates Soil-Vegetation-A...

Identifying physical catchment processes from streamflow data, such as quick- and slow-flow paths, remains challenging. This study is designed to explore whether a flexible nonparametric regression model (generalized additive model, GAM) can be used to infer different flow paths. This assumes that the data relationship in data-driven models is also...

Remotely sensed (RS) data can add value to a hydrological model calibration. Among this, RS soil moisture (SM) data have mostly been assimilated into conceptual hydrological models using various transformed variable or indices. In this study, raw RS surface SM is used as a calibration variable in the Soil and Water Assessment Tool (SWAT) model. Thi...

This paper aims to evaluate sources of uncertainty in projected hydrological changes under climate change in twelve large-scale river basins worldwide, considering the mean flow and the two runoff quantiles Q10 (high flow), and Q90 (low flow). First, changes in annual low flow, annual high flow and mean annual runoff were evaluated using simulation...

Remotely sensed (RS) data have additive value in calibrating a hydrological model. In this regard, RS soil moisture data were mostly assimilated into conceptual hydrological model by changing the entity of the product. In this study, raw remotely sensed (RS) surface soil moisture (SM) is used as the only calibration variable in the Soil water asses...

This paper discusses an innovative framework to use crop models which combines sensitivity analysis, uncertainty analysis and constrained optimisation runs for irrigation optimisation purposes, facing competing constraints on several agricultural variables (e.g. crop yield, total irrigation amount, financial expectations). For simplicity, this ex-p...

The consistency of calibrated hydrological models (whether the model is internally consistent) is often ignored as model calibration generally only evaluates performance. A correlation matrix is developed in this paper to assess model consistency by comparing different flow dynamics combined with a stepwise calibration approach targeting different...

Knowledge of temporal and spatial variability of climate and rainfall can improve agriculture production and can help to manage risks caused by climate variability. Available high-quality monthly rainfall data from the Australian Bureau of Meteorology for 1907-2011 was used to investigate the leading seasonal mode of the long-term rainfall variabil...

The height variability of Lake Patzcuaro, in central Mexico, remained constant for several decades, and during that period, the lake maintained its functionality and environmental services. However, in the last twenty years, there has been a significant decrease in the variability range. In order to estimate the water balance, in this work, an appr...

Rainfall is a major driver for dryland wheat yields across Australia. Many authors have covered issues such as rainfall trends in Australia, and much of this information has been reviewed and updated in recent years in relation to the Millennium drought and associated concerns about climate change. However, despite a long history of work relating r...

Generalized additive model in Hydrology

Much of India’s agricultural production is reliant on groundwater for irrigation, which has led to declining water tables. Rainwater harvesting (RWH), the small-scale collection and storage of run-off to augment groundwater stores through recharge, is an important supply-side management tool to sustain this precious resource. Understanding the impa...

Hydrological models are common tool now-a-days to assess, explore and manage our environment and water resources. Sophistication of the hydrological models over the past years have led us to better assessment and management of resources through improved predictions. However, such predictions are often masked by the data availability both in spatial...

Forecasts can be an important component of water cycle management and farm decision making, particularly where rainfall is uncertain. In Kenya, the use of informal or indigenous forecasting ( IF ) is known to be widespread, but farmers also use more formal seasonal forecasting ( SF ) to make decisions in relation to the water cycle. A review of lit...

Farmer perceptions clearly influence the adoption of technology and adaptation to climate change, but may not be consistent with or captured by scientific measurements. There has been a significant research on how perceptions influence water resource management and adaptation to climate, but conclusions are unclear or contradictory. This research a...

Knowledge about future rainfall is important for agriculture management and planning in arid and semi-arid regions. Australia has complex variations in rainfall patterns in time and space, arising from the combination of the geographic structure and the dual effects of Indian and Pacific Ocean. This study aims to develop a forecasting model of spat...

http://www.pik-potsdam.de/~valen/ISI-MIP2/Calib_Valid_Res/Murray-Darling/SWAT_MDB_Warrego-calib.pdf

Soil sodicity, where the soil cation exchange complex is occupied for a significant fraction by Na+, may lead to vulnerability to soil structure deterioration. With a root zone flow and salt transport model, we modeled the feedback effects of salt concentration (C) and exchangeable sodium percentage (ESP) on saturated hydraulic conductivity Ks(C,ES...

Peri-urban growth can affect local flood and drought risks, which are exacerbated by climate change. Research into optimal planning and arrangement of landscape functions is needed to manage local flood and drought risks. As a first step, simple hydrological models are required to study the range of feedbacks and interactions within the peri-urban...

Deep drainage can contribute to groundwater table rises and salinity, and is a complex function of rainfall, land management and soil hydraulic properties. Each of these components is uncertain and variable in space and time. This study quantifies the associated uncertainty using a Monte Carlo simulation to calculate deep drainage and estimate deep...

Regional climactic variability coupled with an increasing demand on water has placed an even greater pressure on managers to understand the complex relationships between surface water and groundwater in the Murray–Darling Basin. Based on limited soil sampling combined with geophysical observations, past research has suggested that relic subsurface...

In recent ecohydrological modelling, a common basis has been found in methodology and axiomas, such as the minimalist, systems analysis approach and a piecewise linear root zone water loss function. In this paper, we consider the loss function for root zones in contact with ground water through capillary upflow and including deep root systems. The...

â–º We use a bio-physical model to estimate the cost of environmental policies based on a case study catchment. â–º We compare settings where irrigators have access to frictionless water markets and invest in water efficient technologies. â–º Water markets and irrigation technologies increase basin profit and achieve environmentally desirable outco...

Agricultural production in India has become increasingly reliant on groundwater and this has resulted in depletion of groundwater resources. Rainwater harvesting (RWH) for groundwater recharge is seen as one of the solutions to solve the groundwater problem. This is reflected in an increase in watershed development programs, in which RWH is an impo...

ABSTRACT ONLY: Important agricultural areas in Kenya and the Murray Darling Basin (MDB) in Australia are largely semi-arid to arid. Persistent dry periods and timing of dry spells directly impact the availability of soil moisture and hence crop production in these regions. Most studies focus on the analysis of dry spell lengths at an annual scale....

Fire can considerably change hydrological processes, increasing the risk of extreme flooding and erosion events. Although hydrological processes are largely affected by scale, catchment-scale studies on the hydrological impact of fire in Europe are scarce, and nested approaches are rarely used. We performed a catchment-scale experimental fire to im...

Salinity in South Western Sydney, NSW is a major emerging urban problem. The occurrence of salinity is affected by climate variability as well as human management. Any change in the hydrological balance, either natural or induced by land management, is likely to affect the extent and severity of salinity occurrence. The primary objective of this st...

Water management is a topic of great importance in Australia. Future and current professionals specifically need quantitative skills in Hydrology due to the increase in available data (remote sensing and dataloggers). In addition, numerical models have become the main tool for prediction and forecasting in operational hydrology. Hydrology is taught...

Saline groundwater has been recognised as a problem in Western Sydney for many years, yet its true extent is unknown as little work on the hydrogeology of the region has occurred, and that which has is often contained in unpublished reports. In this study the salinity of groundwater in Western Sydney was mapped at discrete depth intervals regardles...

Seasonal rainfall and temperature classification is important for strategic and tactical decision making in agriculture and land and water resource management. This study aims to apply optimal data-driven techniques to extract patterns from historical climate data and develop a fine resolution rainfall and climate classification over the Southeast...

Variable source area (VSA) hydrology is a useful tool to discriminate between areas in a catchment that do and do not make a significant contribution to streamflow. Saturation excess runoff is an important factor in VSA that has often been determined by topography. Recent investigations that indicate wet and dry states (where flow is assumed to be...

Better forecasts of locally detailed seasonal rainfall and temperature estimates are needed to improve how agricultural producers adapt to climate change and climate variability. We propose a spatially explicit seasonal forecasting system, based on the Fuzzy Classification of long-term (40 years) daily rainfall and temperature data to create climat...

Fire can significantly increase a landscape's vulnerability to flooding and erosion events, which is often attributed to the impact of fire and soil heating on soil physical properties and soil water repellency. Although it is acknowledged that loss of vegetative cover plays a role after fire, the effects of litter and vegetation removal have recei...

The curve number method is a simple one parameter (the curve number) rainfall runoff model. While its theoretical underpinning has been questioned it remains a powerful hydrological tool in the absence of detailed data and is therefore used extensively in hydrological models. This study aims to characterize the variation in maximum retention values...

Long-range forecasting of intermittent streamflow in semi-arid Australia poses a number of major challenges. One of the challenges relates to modelling zero, skewed, non-stationary, and non-linear data. To address this, a probabilistic statistical model to forecast streamflow 12 months ahead is applied to five semi-arid catchments in South Western...

Long-range forecasting of intermittent streamflow in semi-arid Australia poses a number of major challenges. One of the challenges relates to modelling zero, skewed, non-stationary, and non-linear data. To address this, a statistical model to forecast streamflow up to 12 months ahead is applied to five semi-arid catchments in South Western Queensla...

Groundwater can be a source of both water and salts in semiarid areas, and therefore, capillary pressure-induced upward water flow may cause root zone salinization. To identify which conditions result in hazardous salt concentrations in the root zone, we combined the mass balance equations for salt and water, further assuming a Poisson-distributed...

Fire can considerably change hydrological processes, increasing the risk of extreme flooding and erosion events. Although hydrological processes are largely affected by scale, catchment-scale studies on the hydrological impact of fire are scarce, and nested approaches are rarely used. Taking a unique approach, we performed a catchment-scale experim...

A key question in relation to rainwater harvesting (RWH) is whether the technique increases the sustainability of irrigated agriculture. A conceptual water balance model, based on field data from the Arvari River catchment, was developed to study and understand catchment-scale trade-offs of rainwater harvesting (RWH). The model incorporates an effe...

http://web.natur.cuni.cz/hydroeco2011/download/presentations/poster/A/45_sessionA_PAPER%28not_poster%29_D_Berhane_W_Vervoort_P_Serov_Thermograph_analysis_etc.pdf

Rainwater harvesting (RWH), the small-scale collection and storage of runoff to augment groundwater stores, has been seen as a solution to the deepening groundwater crisis in India. However, hydrological impacts of RWH in India are not well understood, particularly at the larger catchment-scale. A key element to grasping RWH impact involves underst...

Leaf area index (LAI) has been linked to catchment processes and geomorphology, such as precipitation and elevation. Hence, satellite derived LAI, in particular, is a suitable resource for water balance modeling in large catchments due to extensive, instantaneous coverage. Using the Corin Catchment in eastern Australia (CC) as a case study, we init...

The vegetation layer can, to a certain extent, modify the soil-atmosphere feedback. This is partly through efficient soil water uptake and controlled transpiration. At the same time, the presence of vegetation alters the surface albedo depending on the density of the vegetation cover. Some other vegetation properties such as carbon uptake and surfa...

As the direct uptake of deep groundwater by vegetation may be essential in semiarid regions, we incorporated this process in stochastic root zone water balance models. The direct water uptake by vegetation via deep tap roots is simulated using one additional empirical parameter. This is considered for the case of feedback with root zone saturation...

Understanding the process by which nutrients and solids enter waterways from pastures in the Great Lakes district, New South Wales, Australia, may assist in maintaining water quality to ensure ongoing environmental and economic sustainability of the region. Rainfall simulations, using a 100-year return storm event, were conducted to determine nutri...

As the direct uptake of deep groundwater by vegetation may be essential in semiarid regions, we incorporated this process in stochastic root zone water balance models. The direct water uptake by vegetation via deep tap roots is simulated using one additional empirical parameter. This is considered for the case of feedback with root zone saturation...

Ecohydrological research on the water balance has given little consideration to the replenishment of rootzone water by capillary upflow from groundwater. Depending on climate, vegetation, soil, and ground water parameters, such upflow can be important. Hence, a model approach to quantify this aspect is developed, after making a comparison of altern...

Existing research in soil moisture atmosphere feedbacks suggests that large irrigation areas are likely to have an impact on local precipitation, due to increased levels of soil moisture. However, some of the past research attempting to prove this has been inconclusive. Using a simplifi ed analytical model, the infl uence of different land uses, cl...

During the last decade there has been an increase in the utilisation of heat as a groundwater tracer in surface/ground water interactions and streambed zone studies. Temperature is one of the cheapest hydrologic parameters to measure with a relatively high degree of accuracy. For this study, the Cockburn River, a tributary of the Peel River, was se...

Groundwater uptake can play a major role in the survival of vegetation in semiarid areas, but this has not yet been included in an earlier developed ecohydrological stochastic framework. In this paper we provide a piecewise linear equation which includes capillary fluxes from shallow groundwater in the loss function of the ecohydrological stochasti...

A major limitation of statistical forecasts for specific weather station sites is that they are not spatial in the true sense. And while spatial predictions have been studied, their results have indicated a lack of seasonality. Global Circulation Models (GCMs) are spatial, but their spatial resolution is rather coarse. Here we propose spatially exp...

http://search.informit.com.au/documentSummary;dn=588199357701888;res=IELENG Berhane, Dawit; Vervoort, Willem and Serov, Peter. Analysis of Groundwater Thermographs and Hydrographs at Different Time/Spatial Scales: Headwaters of the Namoi River, NSW [online]. In: Lambert, Martin (Editor); Daniell, TM (Editor); Leonard, Michael (Editor). Proceedings...