Access to surface water is limited in Australia and many regions rely on groundwater for all their water needs. Most of aquifers are already fully allocated and there is an increasing demand for more extraction. During drought, drop in rainfall can result in less recharge into groundwater system. Decrease in rainfall can cause direct and indirect impacts on groundwater. Drop in rainfall can result in less recharge into groundwater system. Moreover decreased rainfall can cause limited accessibility to surface water which results in increased demand for extraction. Understanding of groundwater recharge mechanism and quantifying how far climate change can influence groundwater, plays an important role for establishing sustainable extraction without causing any damage into environment. The CoupModel was selected as a tool to simulate groundwater behavior under different Scenarios. Model inputs are derived from actual observations, such as climatic data. Few assumptions were considered to conceptualize drainage system, such as soil hydraulic parameters, drainage system and evaporation procedure. The study period is 30 years between 1979 and 2008. Model was run for two 15-year periods to identify how far climate change can influence groundwater recharge in the study area. Eyre Peninsula area is highly dependent on groundwater for town water supply, Irrigation and industrial development. Therefore any science study would be definitely valuable for groundwater resource management of this area.

<p>Previous studies of agricultural conditions in the Mekong Delta (MD) have identified soil compaction as an obstacle to sustainable production. A conceptual model for soil formation was presented to demonstrate the link between soil hydrology and plant response. Detailed studies of soil moisture dynamics in agricultural fields were conducted using a dynamic process-orientated model. Pressure head and water flow were simulated for three selected sites during a year for which empirical data were available. Daily meteorological data were used as dynamic input and measured pressure head was used to estimate parameter values that satisfied various acceptance criteria. The Generalised Likelihood Uncertainty Estimation (GLUE) approach was applied for calibration procedures with 10,000 runs, each run using random values within the chosen range of parameter values. To evaluate model performance and uncertainty estimation, re-sampling was carried out using coefficient of determination (R2) and mean error (ME) as the criteria. Correlations between parameters and R2 (and ME) and among parameters were also considered to analyse the relationship of the selected parameter set in response to increases/decreases in the acceptable simulations. The method was successful for two of the three sites, with many accepted simulations. For these sites, the uncertainty was reduced and it was possible to quantify the importance of the different parameters.</p><p> </p>

High nitrous oxide (N2O) emission potential has been identified in hemiboreal forest on drained Histosols. However, the environmental factors regulating the emissions were unclear. To investigate the importance of different factors on the N2O emission, a modeling approach was accomplished, using CoupModel with Monti-Carlo based multi-criteria calibration method. The model was made to represent a forest on drained peat soil in south-west Sweden where data of fluxes combined with soil properties and plant conditions were used. The model outcome was consistent with measurements of abiotic (soil temperature, net radiation, groundwater level and soil moisture) and biotic responses (net ecosystem exchange and soil respiration). Both dynamics and magnitude of N2O emissions were well simulated compared to measurements (8.7 ± 2.1 kg N/ha/year). The performance indicators for an ensemble of accepted simulations of N2O emission dynamics and magnitudes were correlated to calibrated parameters related to soil anaerobic fraction and atmospheric nitrogen deposition (correlation coefficient, r ≥ 0.4). A weak correlation with N2O emission dynamics was also found for biotic responses (r ≥ 0.3). However, the ME of simulated and measured N2O emissions was better correlated to the ME of soil moisture (r = -0.6), and also to the ME of both the soil temperature (r = 0.53) and groundwater level (r = -0.7). Groundwater level (range from -0.8 m to -0.13 m) was identified as the most important environmental factor regulating the N2O emissions for present forest soil. Profile analysis indicated that N2O was mainly produced in the deeper layers (≥ 0.35 m) of the soil profile. The optimum soil moisture for N2O production was around 70%.

The impact of anthropogenic activities on environment, especially the effect of land-use and climate changes was investigated in a series of studies. A comprehensive study of 16 research sites in different parts of Sweden was evaluated by using one dimensional hydrological model (CoupModel) to represent water and heat dynamics in layered soil profile covered with vegetation. Simulations are based on daily values and the results are representatives of variations in daily values and changes over years. The models accuracies controlled by measured run-off and snow depth values. However, there are uncertainties in both input data and simulated parameters. The interaction between run-off and snow depth were obtained when the models constrained by both run-off and snow depth. Parameters values variations and models performances changes in different time domains indicate the changes in land-use and climate over time and the model ability to handle these changes respectively. The strong interaction between meteorological stations density and models performances were indicated by comparing results with interpolation radius used for input data preparation.

Previous studies of agricultural conditions in the Mekong Delta (MD) have identified soil compaction as an obstacle to sustainable production. A conceptual model for soil formation was presented to demonstrate the link between soil hydrology and plant response. Detailed studies of soil moisture dynamics in agricultural fields were conducted using a dynamic process-orientated model. Pressure head and water flow were simulated for three selected sites during a year for which empirical data were available. Daily meteorological data were used as dynamic input and measured pressure head was used to estimate parameter values that satisfied various acceptance criteria. The Generalised Likelihood Uncertainty Estimation (GLUE) approach was applied for calibration procedures with 10,000 runs, each run using random values within the chosen range of parameter values. To evaluate model performance and uncertainty estimation, re-sampling was carried out using coefficient of determination (R2) and mean error (ME) as the criteria. Correlations between parameters and R2 (and ME) and among parameters were also considered to analyse the relationship of the selected parameter set in response to increases/decreases in the acceptable simulations. The method was successful for two of the three sites, with many accepted simulations. For these sites, the uncertainty was reduced and it was possible to quantify the importance of the different parameters.

The Geological Survey of Sweden (SGU) has initiated a project to calibrate models to simulategroundwater levels in monitoring wells of their Groundwater Network, based on a commission fromthe Swedish Government after experiencing historically low groundwater levels and shortage in 2016and 2017. A version of the HBV model with 4 parameters, focusing on calculating groundwaterrecharge and levels, was manually calibrated to 119 groundwater stations in 2017 and the modelresults were classified according to a ‘good’, ‘poor’ or ‘bad’ visual fit to observations. In this thesis,the process-based model CoupModel, which allows the user to freely setup a model structure, wasused to simulate groundwater levels. The objectives of this thesis were to evaluate the usability of theCoupModel in groundwater level simulations and forecasting, and compare the results to previoussimulations using the HBV model. 22 groundwater stations of fast and slow responding aquifers, distributed all over Sweden, wereused to simulate groundwater levels with the CoupModel. A model structure with 11 parameters tocalibrate was constructed to represent all groundwater stations. A split-sample test was performed withcalibration of 10,000 Monte Carlo simulations and validation of the 10 simulations with the highestNash-Sutcliffe efficiency (NSE). The NSE performance was highest, and consistent through calibration and validation, for fastresponding aquifers using the CoupModel, whereas the performance of slow responding aquifers waslower. Residual analysis showed periodicity with under- and overestimations for low and highgroundwater levels, respectively, indicating that the model structure is not sufficient in representing allgroundwater stations. No relationship existed between CoupModel performance and HBV calibrationperformance, topographic position, aquifer type, location or distance to climate station. The HBVperformance was lower than for the CoupModel, with residuals of larger spread and periodicity. The CoupModel can be used for simulation and forecasting of groundwater levels, but a newmodel structure or individual structures for all groundwater stations must be constructed. A sensitivityanalysis of the parameters in the model structure must be performed to study the systematic under- andoverestimations. / Grundvatten har en stor betydelse för att upprätthålla ekosystem och försörja människor meddricksvatten, där grundvattentillgång och nivåer beror av bland annat nederbörd, temperatur,snösmältning, växtupptag och antropogen påverkan på jord och mark. Förändringar i temperatur- ochnederbördsmönster på grund av klimatförändringar och en större vattenförbrukning påverkargrundvattennivåernas variationer inom och mellan år. Den här studien syftar till att undersöka hur ochi vilken uträckning den konceptuella modellen CoupModel kan användas för simulering ochprognostisering av grundvattennivåer, samt hur den står sig i relation till en annan, tidigare studeradmodell (HBV-modellen). Studiens relevans uppdagades hos Sveriges geologiska undersökning (SGU)i samband med historiskt låga grundvattennivåer under 2016-2017, genom initiering av ett projekt medmålet att kalibrera grundvattenmodeller till mätstationer i SGUs grundvattennät. Appliceringen avmodeller har stor samhällsnytta då förebyggande av och åtgärder mot låga grundvattennivåer kanplaneras och vidtas utifrån väderprognoser och klimatscenarier. En modellstruktur skapades i CoupModel och användes för att simulera grundvattennivåer i 22grundvattenstationer av olika karaktär och modellen kalibrerades och validerades mot observationer avgrundvattennivå. Resultatet av studien visade att CoupModel kan användas som verktyg försimulering och prognostisering av grundvattennivåer, men att modellstrukturen som användes behöverutvecklas. Systematisk över- och underestimering av observerade nivåer förkommer hos allasimuleringar och ingen relation kunde ses mellan modellens prestation och plats eller typ avgrundvattenstation. CoupModel presterade i de flesta fall bättre än HBV-modellen, men kräversamtidigt mer information om en grundvattenstations jordprofil och fler parametrar att kalibrera.

<p>The removal of vegetation and overburden changes the naturalwater purifying processes and thus decreases the groundwaterprotection in gravel pit areas. The sand and gravel depositsusedfor aggregate extraction in Sweden are also often valuablefor extraction of groundwater as a drinking water resource. TheSwedish legislation requires that gravel pits be restored afterthe cessation of extraction, the aim being to reestablishvegetation and to reinstate groundwater purifyingprocesses.</p><p>The objective of this study was to improve our understandingof the processes governing groundwater protection andvegetation establishment so that these could be applied toimproving restoration methods for reestablishing naturalgroundwater protection. The focus was on the importance of soilphysical properties of the topsoil for vegetation establishmentand groundwater recharge.</p><p>Actual field methods for restoration were reviewed.Conflicts between aggregate extraction and groundwaterinterests were common. In many cases the actual restorationcarried out differed from pre-planned specifications in permitdocumentation.</p><p>Commonly available substrates that might be used forrestoration of gravel pits were investigated. The soils weredescribed as regards texture, organic content, porosity, waterretention and hydraulic conductivity. The way in which acombination of the water retention characteristic and theunsaturated conductivity influenced the behaviour of thesoil-plant-atmosphere system was demonstrated using aprocess-orientated simulation model. Plants with well-developedaboveground characteristics and shallow roots in particularexerted the highest requirements on the soil physicalproperties.</p><p><b>Key words:</b>groundwater protection, soil physicalproperties, CoupModel, unsaturated conductivity, waterretention, transpiration, soil evaporation</p>

<p>With the use of a process-orientated ecosystem model andmeasurements conducted at different Swedish coniferous forestsites, abiotic and biotic interactions between tree and soilwere identified and related to governing factors. Two differentmodelling approaches to describe soil temperatures at two sitesincluding hydrological transects were tested (I). The approachin which both canopy and soil were considered proved to be amore flexible tool to describe soil temperatures, especiallyduring snow-free winter periods. Five sites along a climatetransect covering Sweden were used to describe soil carbon poolchanges during an 80-year period simulation (II). The dynamicmodelling approach, with a feedback between abiotic and bioticsub-models, was successful in describing simplified patterns offorest stand dynamics and furthermore in differentiatingbetween climate and nitrogen availability factors. The largereffect of nitrogen availability compared to climate on soilcarbon pool changes was clearly shown.</p><p><b>Keywords:</b>SPAC; soil surface energy balance; Norwayspruce; canopy; LAI; climate; nitrogen; CoupModel</p>

The urban near surface atmosphere is of great concern since it affects the climate to which an increasing amount of people are immediately exposed. This study investigated the microclimate in central Stockholm in terms of the thermal conditions in the 0-2.5 m air layer and the water and heat exchange processes at different types of surfaces found within the urban environment. The main objective was to improve our understanding of the urban small-scale climate system. The urban microclimate was measured in terms of vertical air temperature profiles along a horizontal transect running through a vegetated park and its built-up surroundings during three clear and relatively calm summer days. The results showed that the air temperature at 1.2 m height within the park was 0.5 to 1.5 K lower than in the surrounding city blocks, and that the thermal stratification was generally stable (increasing temperature with height) in the park and unstable (decreasing temperature with height) in the built-up areas. In addition, there were a few examples of temperature gradients orientated in different directions within the lowest 2.5 m air layer, indicating horizontal advection between the park and the built-up areas. Climate conditions simulated with a three-dimensional microclimate model agreed well with observations and the model was therefore assumed to provide reasonable representations of important climate processes such as surface-air energy exchange processes. However, there were some discrepancies between observations and simulations that are discussed in terms of differences in real and modelled heat storage processes and wind conditions. Processes that need to be included for a more precise model description of areas such as the Stockholm environment include dynamic heat storage in buildings and dynamic wind forcing during the course of the simulation. A soil-vegetation-atmosphere transfer model was used to study soil water transport, the surface energy balance of an asphalt surface, and the impact of urban climate on evapotranspiration. Based on model calibration to field measurements of soil water content in a till catchment outside Stockholm, new parameter values were estimated that can be used for water flow modelling of till soils. The heat fluxes of an asphalt surface were reliably simulated without knowledge of site-specific calibration and the model was useful in identifying problems with energy balance closure based on measurements only. Simulations of ‘urban’ modifications to the forcing climate conditions demonstrated that increased air temperature, and thereby increased vapour pressure deficit, had most effect on evapotranspiration from tall vegetation, while increased long-wave radiation raised grass evapotranspiration the most. / QC 20100901

Carbon (C) pools and fluxes in northern hemisphere forest ecosystems are attracting increasing attention concerning predicted climate change. This thesis studied C fluxes, particularly soil C dynamics, in spruce forest ecosystems in relation to interactions between physical/biological processes using a process-based ecosystem model (CoupModel) with data for Swedish conditions. The model successfully described general patterns of C and N dynamics in managed spruce forest ecosystems with both tree and field layers. Using regional soil and plant data, the change in current soil C pools was -3 g C m-2 yr-1 in northern Sweden and +24 g C m-2 yr-1 in southern Sweden. Simulated climate change scenarios resulted in increased inflows of 16-38 g C m-2 yr-1 to forest ecosystems throughout Sweden, with the highest increase in the south and the lowest in the north. Along a north-south transect, this increased C sequestration mainly related to increased tree growth, as there were only minor decreases in soil C pools. Measurements at one northern site during 2001-2002 indicated large soil C losses (-96 g C m-2 yr-1), which the model successfully described. However, the discrepancy between these large losses and substantially smaller losses obtained in regional simulations was not explained. A simulation based on Bayesian calibration successfully reproduced measured C, water and energy fluxes, with estimated uncertainties for major components of the simulated C budget. Site-specific measurements indicated a large contribution from field layer fine roots to total litter production, particularly in northern Sweden. Mean annual tree litter production was 66% higher at the most southerly site (240 g C m-2 yr-1 compared with 145 g C m-2 yr-1 in the north), but when field and bottom layers were included the difference decreased to 16% (total litter production 276 g C m-2 yr-1 and 239 g C m-2 yr-1 respectively). Regional simulations showed that decomposition rate for the stable soil C fraction was three times higher in northern regions compared with southern, providing a possible explanation why soil C pools in southern Sweden are roughly twice as large as those in the north. / QC 20100922