Robert Vertessy

University of Melbourne | MSD · Department of Infrastructure Engineering

Wood et al. (2008; FPB 35) concluded their measurements of evapotranspiration (ET) in Eucalyptus regnans F.Muell. forest at Wallaby Creek, Victoria showed that ET differs only slightly between regrowth and oldgrowth, contrary to the findings of previous research. We assert that the conclusions of Wood et al. are invalid and argue that Wood et al. s...

Australia is facing an unprecedented water scarcity crisis and governments are responding with major policy, regulatory, market and infrastructure interventions. No matter what facet of water reform one is talking about, good intelligence on the country’s water resource base and how it is trending is a vital ingredient for good decision making. Tho...

Of concern to the environmental modelling community is the proliferation of individual, and individualistic, models and the time associated with common model development tasks such as data transformation, coding of models, and visualisation. One way of addressing this problem is the adoption of modelling frameworks. These frameworks, or environment...

Paired catchment studies have been widely used as a means of determining the magnitude of water yield changes resulting from changes in vegetation. This review focuses on the use of paired catchment studies for determining the changes in water yield at various time scales resulting from permanent changes in vegetation. The review considers long ter...

Despite widespread bench-terracing, stream sediment yields from agricultural hillsides in upland West Java remain high. We studied the causes of this lack of effect by combining measurements at different spatial scales using an erosion process model. Event runoff and sediment yield from two 4-ha terraced hillside subcatchments were measured and fie...

The Rainfall Runoff Library (RRL) provides a convenient platform for implementing environment modelling components such as rainfall runoff models, calibration tools, and objective functions. A rainfall-runoff model widely known and used in South Korea, TANK, is added to the RRL, and used along with the models AWBM and SIMHYD to reproduce the histor...

This paper presents an overview of the ‘downward approach’ to hydrologic prediction and attempts to provide a context for the papers appearing in this special issue. The downward approach is seen as a necessary counterpoint to the mechanistic ‘reductionist’ approach that dominates current hydrological model development. It provides a systematic fra...

Large-scale plantation development will exert additional pressure on a water resource system that is already under considerable stress. Tree planting will reduce river flows and recharge to groundwater and, in certain circumstances, may lead to short-term worsening of river salinity prior to any improvement. Reductions in flow will be particularly...

Since 1999 the CRC for Catchment Hydrology has been developing a modelling toolkit for the prediction of catchment behaviour. The modelling toolkit is underlain by a development, management and deployment environment that supports module-based modelling services such as data loading, computation and analysis, and display. Modules are constructed th...

The Australian CRC for Catchment Hydrology has developed a software environment for integrating models of various aspects of catchments. Effective use of the resulting complex models requires knowledge of the sensitivity of their outcomes to variations in parameters or inputs, and hence to the underlying data and assumptions. Sensitivity assessment...

We discuss the motivations for, and software design concepts underpinning, the development of a regional water quality model. The Environmental Management Support System (EMSS) was developed to predict daily fluxes of runoff, total suspended sediment, total nitrogen and total phosphorous through a large-scale river network. It was built using a cus...

Preface

The water supply of Launceston, Tasmania is partially provided by a run of the river diversion from the North Esk River. The magnitude of future impacts on the level of summer low flows due to land use and land cover changes in the North Esk catchment are important for planning the reliable provision of Launceston's water supply. The Macaque model...

We evaluated the performance of nine published pedotransfer functions (PTFs) for estimating saturated hydraulic conductivity (Ks) in modeling the stormflow generated in a rainforest catchment. Using available input data consisting of particle size distribution, bulk density, and saturated moisture content information, these empirically-based PTFs w...

We conducted thinning trials in a 5-year-old Eucalyptus globulus ssp. globulus Labill plantation near Warrenbayne, northeastern Victoria, Australia, where soil salinization and waterlogging are common, and assessed treatment effects on tree growth, water use and survival. Half-hectare plots were thinned from the original density of 1100 stems ha(-1...

We measured transpiration, sapwood areas, and leaf areas of individual trees in three stands of Eucalyptus sieberi, aged 14, 45, and 160 years. Transpiration was calculated from estimates of sap velocity made by the heat-pulse method. Sapwood and leaf areas were determined by destructive sampling. Leaf area index (LAI), sapwood area and transpirati...

The statistical methods underpinning analysis of streamflow data from paired-catchment studies have not changed much since the 1960s. Whilst such analyses are widespread in hydrologic practice and research, attention is rarely given to the problems of heteroscedacity, seasonality, serial correlation, and non-normally distributed variates. Each of t...

There is a well-documented empirical relationship between stand age and water yield for mountain ash (Eucalyptus regnans) forested catchments in the Central Highlands of Victoria, Australia. Catchments covered with old-growth stands of mountain ash yield almost twice the amount of water annually as those covered with re-growth stands aged 25 years....

Water yields in a regrowth eucalypt forest were found to increase initially and then to decline below pre-treatment levels during the 16-year period which followed the logging of a moist old-growth eucalypt forest in Eastern Australia. Both regrowth and old-growth stands were dominated by Sydney Blue Gum (Eucalyptus saligna Smith) and Silvertop Str...

: Rivers, streams and wetlands provide people with a wide range of benefits often referred to as "Ecosystem Services" (Cork et al. this volume). These services include maintenance of atmosphere and climates suitable for human life; filtration, purification and delivery of water; maintenance of soil fertility and structure; pollination of crops and...

The division of large landscapes into 'hillslopes' is an attractive concept in hydrologic modelling. It essentially reduces the dimensionality of the landscape from three dimensions to two: vertical and lateral. This results in economy with respect to both conceptual and computational complexity. The evolution of a hillslope hydrologic model is des...

total nitrogen and total phosphorous from 175 different sub-catchments within the 22,670 km2 region. The model predictions are sensitive to changes in climate, storage operations, land use and land management practices, including point- and diffuse-source loadings and treatments. The EMSS is deployed in a GIS-like environment on a PC and has been d...

This paper addresses the problem of designing belts of trees on a hillslope, strategically placed to intercept water flowing from upslope preventing it reaching the problem areas characterised by waterlogging and salinity. In a companion paper to this, the huge range of possibilities for agroforestry plantings is discussed. A sophisticated biophysi...

This paper presents the results of an investigation involving the calibration and testing of an ecohydrologic model, TOPOG-Dynamic. The model was used to simulate the water use and growth of an agroforestry plantation on a hill-slope. Model results were compared to measured leaf area index, wood volume, and pasture and plantation transpiration. The...

The Amazon basin covers an area of roughly 7 × 106 km2 and encompasses diverse soil – landscape types with potentially differing hydrological behaviour. This study was conducted in the Ultisol landscape of the western Amazon basin in Peru. Processes of stormflow generation were investigated on an event basis in a first-order rainforest catchment to...

Break of slope (BOS) plantations are advocated as a means of water table control in areas where groundwater flows through colluvial deposits overlying low permeability bedrock. It is also believed that BOS plantations can supplement their water use requirements by exploiting shallow groundwater at the breaks in topographic slope. We compared measur...

Models used in catchment prediction have often been developed for specific research problems or locations by individuals using software engineering practices that are now considered obsolete. The legacy of this is a range of models dealing with similar problems, using similar data input and output interpretation, but with a high diversity of operat...

A canvassed option for watertable control in shallow watertable areas is the establishment of tree plantations. Proponents expect that the trees will provide a direct financial return to the grower through wood production, and lead to lowered watertables through groundwater uptake by trees. The feasibility of this concept depends on achievable grow...

The Thomson reservoir catchment area is one of few Melbourne water supply catchments where forest harvesting is permitted. The region is also at risk of bush-fire. Macaque, a large-scale, long-term, physically based, water balance model developed by Watson (1999) and Watson et al. (1998 & 1999) was applied to the Thomson catchment in order to predi...

There are many sound reasons for increasing the area of plantations in Australia. However, catchment managers should carefully assess the water use requirements of downstream users and the aquatic environment before committing to any major afforestation initiative that is concentrated geographically. MAYA can assist catchment planners in this regar...

We describe a process-based storm flow generation model, Topog_SBM consisting of a simple bucket model for soil water accounting, a one-dimensional kinematic wave overland flow scheme, and a contour-based element network for routing surface and subsurface flows. Aside from topographic data and rainfall the model has only six input parameters: soil...

A water balance model was used to simulate the long-term increases in water yield with forest age which are observed in the mountain ash (Eucalyptus regnans) forests of Victoria, Australia. Specifically, the hypothesis was tested that water yield changes could be explained by changes in evapotranspiration resulting from changes in leaf area index (...

Most studies on the use of physically based hydrological models have identified saturated hydraulic conductivity (Ksat) as one of the most sensitive input parameters. However, Ksat is also one of the most difficult landscape properties to measure accurately, casting doubt on the ability of modellers to estimate this parameter a priori for catchment...

This paper discusses the growth and hydrologic impact of a small (2 ha) 21-year old plantation growing over a shallow saline water table at Kyabram, in the Shepparton irrigation area. Using TOPOG_Dynamic, an ecohydrological model, we simulate leaf and stem growth, water use and salt accumulation of the plantation, and assess likely future trends. T...

It is somewhat ironic that in the driest inhabited continent, two of Australia's major environmental and agricultural problems stem from a surplus of water. Large areas of agricultural land and natural ecosystems are under threat from waterlogging and salinisation, which will jeopardise all productivity if better land management is not achieved. Th...

Australia is beset by enormous environmental problems caused by an hydrological imbalance that has resulted from the extensive clearing of native vegetation for agriculture. There is now a focus on redesigning our agricultural systems, returning trees to the landscape, and thereby restoring the water balance. We need agroforestry design criteria ac...

Planting of trees has been proposed as a means of addressing problems in areas with shallow saline watertables. In irrigation areas water is usually added to the surface at a rate exceeding that used by the plants, to ensure that any salt that accumulates in the soil near the surface as a result of evaporation and soil water extraction by roots is...

A large-scale distribution function model was used to investigate the effect of differing parameter mapping schemes on the quality of hydrological predictions.Precipitation was mapped over a large forested catchment area (163 km2) using both one-dimensional linear and three-dimensional non-linear interpolation schemes. Lumped stream flow prediction...

Weighing lysimeters, large-tree potometers, ventilated chambers, radioisotopes, stable isotopes and an array of heat balance/heat dissipation methods have been used to provide quantitative estimates of whole-tree water use. A survey of 52 studies conducted since 1970 indicated that rates of water use ranged from 10 kg day(-1) for trees in a 32-year...

Mountain ash (Eucalyptus regnans F.J. Muell.) forest catchments exhibit a strong relationship between stand age and runoff, attributed inter alia to differences in tree water use. However, the tree water use component of the mountain ash forest water balance is poorly quantified. We have used the sap flow technique to obtain estimates of daily wate...

SoLIM (Soil Land Inference Model) is a fuzzy inference scheme for estimating and representing the spatial distribution of soil types in a landscape. This study developed the inference method a step further to derive continuous soil property maps through two case studies. The first case illustrates the derivation of soil A horizon depth in a mountai...

A regional scale, process based model of forest hydrology has been developed as part of research into water production in managed forests. The model, named Macaque, allows spatial predictions of water balance for entire water supply catchments (c. 1000 km2 in area). It is intended that this model will help improve water supply catchment management...

Three techniques were used to measure saturatcd hydraulic conductivity (Ksat) in an upland forest soil; each employed a different scale of measurement in an attempt to investigate the consequences of the heterogeneities present. All measurements were conducted within a 50 m x 50 m field plot on a ridge top site in 1939 regrowth Mountain Ash forest....

We used a physically based ecohydrological model to predict the water balance and growth responses of a mountain ash (Eucalyptus regnans F. Muell.) forest catchment to clear-felling and regeneration. The model, Topog-IRM, was applied to a 0.53 km(2) catchment for a 3-year pretreatment period, and a 20-year period following clear-felling and reseedi...

The parameterization of a large-scale hydrological model (RHESSys) for a forested region is described. Using the GRASS GIS, a range of topographic, vegetative, climatic, and edaphic parameters were mapped over the region. A regional DEM was validated by ground-truthing and shown to give an excessively smooth representation of the terrain which infl...

Establishment of broad-scale plantations is being considered in many areas of Australia as a way of remediating land-degradation problems brought about by the clearing of native forests for agriculture. In this paper we summarise our experience in the development and application of a model, Topog-Dynamic, which is well suited to predicting the carb...

We examined relationships between stem diameter, sapwood area, leaf area and transpiration in a 15-year-old mountain ash (Eucalyptus regnans F. Muell.) forest containing silver wattle (Acacia dealbata Link.) as a suppressed overstory species and mountain hickory (Acacia frigescens J.H. Willis) as an understory species. Stem diameter explained 93% o...

This book presents the integrated contributions of hydrologists, meteorologists and ecologists to the first IHP/IAHS George Kovacs Colloquium in connection with the study of global hydrology and climate change. The atmospherical, hydrological and terrestrial components of the Earth's systems operate on different time and space scales. Resolving the...

Process-based models of soil-vegetation-atmosphere interactions developed for small plots (points) define vertical transfers of water and energy. One can attempt to scale to larger heterogeneous land units by disaggregating the landscape into a set of elements and applying a vertical SVAT model independently to each element (Running et al., 1989; P...

The effects of digital elevation model (DEM) resolution on raster and vector terrain data are investigated for the computation of hydrological terrain-soils indices. Cumulative distribution functions of ln(a/tanβ), where a is the area drained per unit contour length and β is the surface gradient, were computed by two different grid-based methods an...

The structure, capabilities and performance of a distributed parameter hydrologic model are described. The model, called Topog-Yield, permits a transient analysis of unsaturated-saturated flow and evapotranspiration to be performed across complex terrain using a one-dimensional framework. It is applied to a 0.32 km2 mountain ash (Eucalyptus regnans...

Soil water balance studies can be used to directly calculate groundwater recharge. Soil hydraulic properties of volumetric water content, soil suction and hydraulic conductivity must be measured to solve Darcian flux equations. Experimental plots and hydraulic conductivity tests have been placed in landscape positions to measure spatially and tempo...

A small forested catchment in southwest Western Australia was thinned to study the effect on hydrology, wood production and disease escalation. This paper deals primarily with the hydrological aspects. The uniform, intensive thinning treatment reduced crown cover from 60 to 14%, which resulted in an increase in streamflow of approximately 20% of an...

This thesis compares the morphodynamic behaviour of the South Alligator, Daly and Adelaide rivers in far north Northern Territory, Australia. These three macrotidal rivers bave formed under similar boundary conditions of climate and sea level rise, but exhibit dissimilar plan and cross-sectional morphometries, hydrodynamic behaviour, bed sediment c...

The heat pulse method was used to estimate stand transpiration from a radiata pine (Pinus radiata) plantation in southeastern Australia over a period of four days. The diurnal pattern of sapflow was related to net radiation with a time lag of about 1.5 hours. Despite high soil moisture levels, sapflow did not keep up with evaporative demand in the...

The heat pulse technique provides an estimate of sapflow velocity at one position within the xylem of an individual plant. Previous experience has shown that the velocity profile across the conducting area cannot be assumed to be constant, necessitating several such point estimates for a reasonable characterization of the velocity profile with dept...

The application of an integrated terrain analysis and hydrologic modelling package to problems of erosion in semi-arid tropical pasturelands is described. The model, knwon as TOPOG, focusses on describing the complex interrelationships which exist between topography, soils, climate and vegetation. The calculation of a steady-state erosion hazard in...

The South Alligator River, located in the Northern Territory, Australia, is a macrotidal estuary with suspended sediment concentration values reaching 10 gl-1. In September 1986, in the dry season, the estuary was well mixed in temperature and salinity. While the vertical gradients in suspended sediment concentration were small at flood tides, for...

Large-scale plantation development will have significant impact on mean annual water yield and hence affect water allocation. In the Goulburn-Broken catchments there are plans to convert large areas of pastures to forestry plantations in the coming decades. There is a range of commercial and environmental considerations that motivate these plans. A...

The mission of the CRC for Catchment Hydrology is 'To deliver to resource managers the capability to assess the hydrologic impact of land-use and water management decisions at whole-of- catchment scale'. The primary method for delivery of this capability is a suite of software products known as the "Catchment Modelling Toolkit". The CRCCH is now in...

Lumped-conceptual rainfall-runoff models are a 'stock in trade' tool for those working in the water industry and allied fields. However, there are many alternative models available, and sometimes multiple implementations of the same model. The consequence of this is a plethora of models with different operational features and different access arran...