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<p>Ecosystems have been profoundly shaped by unusually rapid climate change effects largely driven by human activities that release heat-trapping greenhouse gases into the atmosphere. The goal of this research is to develop a strategy to measure the direct effects of climate change on the value of natural resources, particularly Great Lakes water resources; and how humans control these resources through management decisions. This base will assist in developing and supplying the tools and information necessary for decision-making to facilitate enhancements and thus policy revision. The Canada-US Great Lakes Water Quality Agreement (GLWQA) had substantial influence on the cleanup and restoration of the region, however, threats to the Great Lakes in the face of climate change demand a renewal of program and policy approaches to the restoration of beneficial uses as identified in Annex 2. To remedy this, climate models including Statistical Downscaling (SDSM) and Artificial Neural Network (ANN) are developed to produce daily predictions of future climate variables at the regional scale. In this study, separate downscaled precipitation and temperature scenarios are generated using the SDSM and ANN with the calibrations and validations derived from CGCM and Hadley models for Canadian Areas of Concern. Then the Delphi Survey Method was designed and administered participants to verify on significant pressures associated with climate change on related beneficial uses of the Great Lakes. Collaborating both data sets allows for a thorough picture of the effects of climate change and possible adaptation strategies in the Great Lakes required to develop management and sustainable public policies</p> / Doctor of Science (PhD)

General Circulation Models (GCMs), which are mathematical models based on principles of fluid dynamics, thermodynamics and radiative transfer, are the most reliable tools available for projecting climate change. However, the spatial scale on which typical GCMs operate is very coarse as compared to that of a hydrologic process and hence, the output from a GCM cannot be directly used in hydrologic models. Statistical Downscaling (SD) derives a statistical or empirical relationship between the variables simulated by the GCM (predictors) and a point-scale meteorological series (predictand). In this work, a new downscaling model called CRF-downscaling model, is developed where the conditional distribution of the hydrologic predictand sequence, given atmospheric predictor variables, is represented as a conditional random field (CRF) to downscale the predictand in a probabilistic framework. Features defined in the downscaling model capture information about various factors influencing precipitation such as circulation patterns, temperature and pressure gradients and specific humidity levels. Uncertainty in prediction is addressed by projecting future cumulative distribution functions (CDFs) for a number of most likely precipitation sequences. Direct classification of dry/wet days as well as precipitation amount is achieved within a single modeling framework, and changes in the non-parametric distribution of precipitation and dry and wet spell lengths are projected. Application of the method is demonstrated with the case study of downscaling to daily precipitation in the Mahanadi basin in Orissa, with the A1B scenario of the MIROC3.2 GCM from the Center for Climate System Research (CCSR), Japan. An uncertainty modeling framework is presented in this work, which combines GCM, scenario and downscaling uncertainty using the Dempster-Shafer (D-S) evidence theory for representing and combining uncertainty. The methodology for combining uncertainties is applied to projections of hydrologic drought in terms of monsoon standardized streamflow index (SSFI-4) from streamflow projections for the Mahanadi river at Hirakud. The results from the work indicate an increasing probability of extreme, severe and moderate drought and decreasing probability of normal to wet conditions, as a result of a decrease in monsoon streamflow in the Mahanadi river due to climate change. In most studies to date, the nature of the downscaling relationship is assumed stationary, or remaining unchanged in a future climate. In this work, an uncertainty modeling framework is presented in which, in addition to GCM and scenario uncertainty, uncertainty in the downscaling relationship itself is explored by linking downscaling with changes in frequencies of modes of natural variability. Downscaling relationships are derived for each natural variability cluster and used for projections of hydrologic drought. Each projection is weighted with the future projected frequency of occurrence of that cluster, called ‘cluster-linking’, and scaled by the GCM performance with respect to the associated cluster for the present period, called ‘frequency scaling’. The uncertainty modeling framework is applied to a case study of projections of hydrologic drought or SSFI-4 classifications, using projected streamflows for the Mahanadi river at Hirakud. It is shown that a stationary downscaling relationship will either over- or under-predict downscaled hydrologic variable values and associated uncertainty. Results from the work show improved agreement between GCM predictions at the regional scale, which are validated for the 20th century, implying that frequency scaling and cluster-linking may indeed be a valid method for constraining uncertainty. To assess the impact of climate change on reservoir performance, in this study, a range of integrated hydrologic scenarios are projected for the future. The hydrologic scenarios incorporate increased irrigation demands; rule curves dictated by increased need for flood storage and downscaled projections of streamflow from an ensemble of GCMs and emission scenarios. The impact of climate change on multipurpose reservoir performance is quantified, using annual hydropower and RRV criteria, under GCM and scenario uncertainty. The ‘business-as-usual’ case using Standard Operating Policy (SOP) is studied initially for quantifying impacts. Adaptive Stochastic Dynamic Programming (SDP) policies are subsequently derived for the range of future hydrologic scenarios, with the objective of maximizing reliabilities with respect to multiple reservoir purposes of hydropower, irrigation and flood control. It is shown that the hydrologic impact of climate change is likely to result in decreases in performance criteria and annual hydropower generation for Hirakud reservoir. Adaptive policies show that a marginal reduction in irrigation and flood control reliability can achieve increased hydropower reliability in future. Hence, reservoir rules for flood control may have to be revised in the future.

L'analyse de la climatologie des aléas océano-météorologiques tels que les états de mer est fondamentale pour comprendre l'évolution et la dynamique des zones côtières, estimer les risques naturels survenant lors d'événements de tempête majeurs, définir les moyens optimaux de protection des ports et infrastructures onshore et offshore, caractériser la ressource houlomotrice pour des projets de récupération d'énergie des vagues, comprendre les processus d'érosion et accrétion des plages, etc. Pour répondre à ces problématiques dans un contexte de questionnement croissant sur les conséquences potentielles associées au changement climatique, le travail de thèse s'inscrit dans une démarche double : (i) approfondissement de la connaissance du climat de vagues actuel le long des côtes Atlantique, Manche et Mer du Nord en France d'une part, et (ii) estimation des évolutions futures potentielles de cette climatologie des vagues pour différents scénarios d'évolution climatique. L'estimation de l'impact du changement climatique sur le climat de vague se compose de trois éléments principaux : (i) une connaissance détaillée de la variabilité climatique actuelle des états de mer, (ii) l'utilisation de scénarios de changement climatique à l'horizon 2100 et (iii) la définition d'une méthodologie de descente d'échelle adaptée. Pour appréhender ces sujets, l'Atlas Numérique d'Etats de Mer Océanique et Côtier ANEMOC-2 a été construit à l'aide du modèle spectral de 3ème génération TOMAWAC (Benoit et al., 1996) sur la période 1979-2009 et le climat de vagues futur a été simulé à l'horizon 2100 par des méthodes de descente d'échelle dynamique et statistique en considérant les scénarios de changement climatique du quatrième rapport du GIEC (IPCC, 2007).En particulier, un travail original de comparaison de projections d'états de mer par approche dynamique et par approche statistique des types de temps a été réalisé sur la période 2061-2100 pour les scénarios B1, A1B et A2 simulés par le modèle ARPEGE-CLIMAT de Météo-France (Salas-Mélia, et al. 2005). Les résultats des deux approches (à savoir hauteur significative, période moyenne, direction moyenne et flux d'énergie des vagues) ont été comparés en termes de valeurs moyennes, écarts-types, distributions jointes et variabilités saisonnière et interannuelle. Ce travail a abouti à une estimation de l'impact du changement climatique sur la climatologie des états de mer le long des côtes Atlantique, Manche et Mer du Nord françaises sur la période 2061-2100 en tenant compte des incertitudes intrinsèques aux méthodes de descente d'échelle et aux scénarios de changement climatique. En hiver par exemple, nous observons une augmentation des valeurs moyennes et de la variabilité des paramètres de hauteur significative, période moyenne et flux d'énergie des vagues, notamment en Mer du Nord (pour les scénarios B1, A1B et A2) et dans le Golfe de Gascogne pour le scénario B1. En complément, ces paramètres d'états de mer ont tendance à diminuer dans le Golfe de Gascogne pour les saisons printemps, été et automne. Enfin, les paramètres d'états de mer associés aux hauteurs de vagues du quantile 95 tendent à augmenter sur une large emprise de l'Atlantique nord-est / Wave climate analysis is of utmost importance to understand the evolution and dynamics of coastal zones, to estimate the occurrence of extreme events, to design protections for ports, onshore and offshore infrastructure, to characterize wave resources for wave energy conversion, to quantify sediment erosion and accretion processes, et cetera. Thus, this thesis project aims to improve knowledge of wave climatology in the growing context of climate change prediction with a two-step approach: (i) enhancement of the understanding of the present wave climate along the French coastline facing the Atlantic Ocean, English Channel and North Sea and (ii) estimation of possible future wave climate evolution. For this purpose, the estimation of climate change impacts on the wave climate requires three key parameters: (i) detailed knowledge of current wave climate variability, (ii) the application of climate change scenarios from Global Climate Models and (iii) the definition of an appropriate downscaling method. To answer these questions, ANEMOC-2, a hindcast sea-state data base has been built based on the third-generation spectral wave model TOMAWAC (Benoit et al., 1996) over the period 1979-2009, and the future wave climate has been simulated over the period 2061-2100 by means of dynamical and statistical downscaling methods. In particular, an original approach comparing sea-state projections obtained from dynamical and statistical downscaling methods has been applied over the period 2061-2100 for B1, A1B and A2 scenarios (Forth Assessments Reports, IPCC, 2007), based on the ARPEGE-CLIMAT (Salas-Mélia et al., 2005) model simulations. The wave spectral parameters resulting from the projections (i.e. significant wave height, mean period, mean direction and wave energy flux) have been compared in term of mean, joint distribution and seasonal and interannual variability.The possible climate change impacts on the wave climate along the Atlantic, English Channel and North Sea French coastline have also been evaluated. The analysis provides estimations of the inherent uncertainties of climate change scenarios and downscaling methods. Wave climate evolution trends are presented in terms of the mean, joint distribution, and seasonal and interannual variability of significant wave height, mean period, mean direction and wave energy flux

Environmental monitoring of Earth from space has provided invaluable information for understanding the land-atmosphere water and energy exchanges. However, the use of satellite observations in hydrologic applications is often limited by coarse space-time resolutions. This study aims to develop a data assimilation system that integrates remotely-sensed precipitation and soil moisture observations into physically-based models to produce fine-scale precipitation, soil moisture, and other relevant hydrometeorological variables. This is particularly useful with the active Global Precipitation Measurement and Soil Moisture Active Passive missions. The system consists of two major components: (1) a framework for dynamic downscaling of satellite precipitation products using the Weather Research and Forecasting (WRF) model with four-dimensional variational data assimilation (4D-Var) and (2) a variational data assimilation system using spatio-temporally varying background error covariance for directly assimilating satellite soil moisture data into the Noah land surface model coupled with the WRF model. The WRF 4D-Var system can effectively assimilate and downscale six-hour precipitation products of a spatial resolution of about 20 km (i.e., those derived from the National Centers for Environmental Prediction Stage IV data and the Tropical Rainfall Measuring Mission (TRMM) 3B42 dataset) to hourly precipitation with a spatial resolution of less than 10 km. The system is able to assimilate and downscale daily soil moisture products at a gridded 36-km resolution obtained from the Soil Moisture and Ocean Salinity (SMOS) mission to produce hourly 4-by-4 km surface soil moisture forecasts with a reduction of mean absolute error by 35% on average. The results from the system with coupled components show that assimilation of the TRMM 3B42 precipitation improves the quality of both downscaled precipitation and soil moisture analyses, while the effect of SMOS soil moisture data assimilation is largely on the soil moisture analyses. The downscaled WRF precipitation, with and without assimilation of TRMM precipitation, was preliminarily tested with a spatially distributed simulation of streamflow using the TIN (Triangular Irregular Network)-based Real-time Integrated Basin Simulator (tRIBS).

Cyclones distribution and intensities impact directly on human activities, mainly due to their associated intense precipitation and winds. The main aim of this thesis is to understand changes in the cyclones originated in the South Atlantic focusing on their genesis and intensifying mechanisms. Cyclones are identified and tracked based on the relative vorticity field at 850 hPa computed from the winds. The characteristics of the cyclones are obtained by diagnostic variables sampled within a radial distance from each cyclone center and to produce a spatial distribution of the cyclone properties at the time of genesis. Also, cyclone centered composites are used to analyze the cyclone structure and the evolution of cyclones during their genesis. The climatology of cyclones was done using NCEP-CFSR and shows four main cyclogenesis regions in the South Atlantic Ocean: on the Southern Brazilian coast (SE-BR, 30°S), over the continent near the La Plata river discharge region (LA PLATA, 35°S), on the southeastern coast of Argentina (ARG, 40°S-55°S) and on the Southeastern Atlantic (SE-SAO, centered at 55°S and 10°W). To access changes in cyclone development, we used the CMIP5 HadGEM2-ES historical experiment (1980-2005) and RCP8.5 future projection (2074-2099). The HadGEM2-ES can represent the main South Atlantic characteristics of cyclones according to NCEP-CFSR climatology. However, there is an underestimation in cyclone frequency in the equatorward side of the storm track, particularly in the LA PLATA region. The HadGEM2-ES RCP8.5 future projection shows a general decrease of approximately 10% of cyclogenesis in the South Atlantic domain, which is mainly related to the poleward shift of the storm track. However, LA PLATA region presents a slight increase in its cyclogenetic activity (6.1 and 3.6%), in the summer and winter, respectively). The increase in genesis at 30°S over the continent is associated with the strengthening of the upper-level jet and the increase of warm and moisture advections at the same location. The enhance in the moisture transport from the tropics is also related to the intensification of the cyclone in the domain, mainly northward of 35°S. Finally, a downscaling using WRF was performed in an attempt to improve the climate model resolution. However the downscaling produces less and weaker cyclones in the NCEP-CFSR and HadGEM2-ES runs. The only region that presented an improvement was LA PLATA, due to the better representation of local features related to orography and moisture processes. The downscaled HadGEM2-ES RCP8.5 also shows an increase in cyclogenesis in the LA PLATA region and other locations. The HadGEM2-ES RCP8.5 projection and its downscaling shows that the cyclogenesis in some locations of South America is increasing, mainly due to the increase in the low-level moisture content and the strengthening of the equatorward flank of the upper-level jet. The cyclones in this locations will be slightly intense (between 20°S and 30°S) and will affect a narrow area close to the South American coast. / A distribuição e intensidade dos ciclones afeta diretamente as atividades humanas devido a precipitação e fortes ventos associados a esses sistemas. O objetivo principal deste trabalho é entender as mudanças nos ciclones gerados no Atlântico Sul devido às mudanças climáticas, focando em seus mecanismos geradores e intensificadores. Os ciclones foram identificados e rastreados utilizando a vorticidade relativa em 850hPa, calculada a partir do campo de ventos horizontal. Também foram usadas composições centradas para a análise da estrutura e evolução dos ciclones durante seu desenvolvimento. A climatologia de ciclones feita com o NCEP-CFSR mostra quatro regiões ciclogenéticas principais no Oceano Atlântico Sul: na costa sul do Brasil (SE-BR, 30°S), sobre o continente próximo da desembocadura do Rio da Prata (LA PLATA, 35°S), na costa sudeste da Argentina (ARG, 40°S-55°S) e no Sudeste do Atlântico (SE-SAO, centrada em 55°S, 10°W). Para analisar as mudanças no desenvolvimento dos ciclones, nós utilizamos os experimentos histórico (1980-2005) e RCP8.5 (2074-2099) do HadGEM2-ES (CMIP5). O HadGEM2-ES é capaz de reapresentar as principais características dos ciclones do Atlântico Sul, quando comparado à climatologia. No entanto, existe uma subestimativa do número de ciclones no lado equatorial da região de máxima atividade ciclônica, principalmente na região LA PLATA. A projeção futura HadGEM2-ES no cenário RCP8.5 mostra uma redução de aproximadamente 10% na ciclogêneses no domínio do Atlântico Sul, principalmente associada ao deslocamento em direção ao polo da região de máxima atividade ciclônica. Porém, a região LA PLATA apresenta um pequeno aumento em sua atividade ciclogenética (6.1 e 3.6%), no verão e inverno, respectivamente). O aumento na ciclogênese em 30°S está associada ao fortalecimento do jato de altos níveis e ao aumento da advecção quente e de umidade nessa localidade. O aumento do transporte de umidade dos trópicos está associado também à intensificação dos ciclones observada na projeção futura, principalmente ao norte de 35°S. Por fim, uma regionalização com o modelo WRF foi usada para melhorar a resolução do modelo climático. Porém, as simulações regionais subestimaram os ciclones em número e intensidade. A única região que em as regionalizações apresentaram melhor desempenho foi a LA PLATA, devido a uma melhor representação de feições locais associadas a orografia e processos úmidos. A regionalização do cenário futuro RCP8.5 também apresentou aumento da ciclogênese do LA PLATA, mas para o inverno. Tanto a projeção RCP8.5 do HadGEM2-ES quanto sua regionalização mostram que a ciclogênese em algumas regiões da América do Sul está aumentando, principalmente devido ao aumento de umidade em baixos níveis da atmosfera e fortalecimento do lado ramo equatorial do jato de altos níveis. Os ciclones nessas localidades serão intensos (entre 20°S e 30°S) e tendem a afetar uma região mais próxima à costa.

Cyclones distribution and intensities impact directly on human activities, mainly due to their associated intense precipitation and winds. The main aim of this thesis is to understand changes in the cyclones originated in the South Atlantic focusing on their genesis and intensifying mechanisms. Cyclones are identified and tracked based on the relative vorticity field at 850 hPa computed from the winds. The characteristics of the cyclones are obtained by diagnostic variables sampled within a radial distance from each cyclone center and to produce a spatial distribution of the cyclone properties at the time of genesis. Also, cyclone centered composites are used to analyze the cyclone structure and the evolution of cyclones during their genesis. The climatology of cyclones was done using NCEP-CFSR and shows four main cyclogenesis regions in the South Atlantic Ocean: on the Southern Brazilian coast (SE-BR, 30°S), over the continent near the La Plata river discharge region (LA PLATA, 35°S), on the southeastern coast of Argentina (ARG, 40°S-55°S) and on the Southeastern Atlantic (SE-SAO, centered at 55°S and 10°W). To access changes in cyclone development, we used the CMIP5 HadGEM2-ES historical experiment (1980-2005) and RCP8.5 future projection (2074-2099). The HadGEM2-ES can represent the main South Atlantic characteristics of cyclones according to NCEP-CFSR climatology. However, there is an underestimation in cyclone frequency in the equatorward side of the storm track, particularly in the LA PLATA region. The HadGEM2-ES RCP8.5 future projection shows a general decrease of approximately 10% of cyclogenesis in the South Atlantic domain, which is mainly related to the poleward shift of the storm track. However, LA PLATA region presents a slight increase in its cyclogenetic activity (6.1 and 3.6%), in the summer and winter, respectively). The increase in genesis at 30°S over the continent is associated with the strengthening of the upper-level jet and the increase of warm and moisture advections at the same location. The enhance in the moisture transport from the tropics is also related to the intensification of the cyclone in the domain, mainly northward of 35°S. Finally, a downscaling using WRF was performed in an attempt to improve the climate model resolution. However the downscaling produces less and weaker cyclones in the NCEP-CFSR and HadGEM2-ES runs. The only region that presented an improvement was LA PLATA, due to the better representation of local features related to orography and moisture processes. The downscaled HadGEM2-ES RCP8.5 also shows an increase in cyclogenesis in the LA PLATA region and other locations. The HadGEM2-ES RCP8.5 projection and its downscaling shows that the cyclogenesis in some locations of South America is increasing, mainly due to the increase in the low-level moisture content and the strengthening of the equatorward flank of the upper-level jet. The cyclones in this locations will be slightly intense (between 20°S and 30°S) and will affect a narrow area close to the South American coast. / A distribuição e intensidade dos ciclones afeta diretamente as atividades humanas devido a precipitação e fortes ventos associados a esses sistemas. O objetivo principal deste trabalho é entender as mudanças nos ciclones gerados no Atlântico Sul devido às mudanças climáticas, focando em seus mecanismos geradores e intensificadores. Os ciclones foram identificados e rastreados utilizando a vorticidade relativa em 850hPa, calculada a partir do campo de ventos horizontal. Também foram usadas composições centradas para a análise da estrutura e evolução dos ciclones durante seu desenvolvimento. A climatologia de ciclones feita com o NCEP-CFSR mostra quatro regiões ciclogenéticas principais no Oceano Atlântico Sul: na costa sul do Brasil (SE-BR, 30°S), sobre o continente próximo da desembocadura do Rio da Prata (LA PLATA, 35°S), na costa sudeste da Argentina (ARG, 40°S-55°S) e no Sudeste do Atlântico (SE-SAO, centrada em 55°S, 10°W). Para analisar as mudanças no desenvolvimento dos ciclones, nós utilizamos os experimentos histórico (1980-2005) e RCP8.5 (2074-2099) do HadGEM2-ES (CMIP5). O HadGEM2-ES é capaz de reapresentar as principais características dos ciclones do Atlântico Sul, quando comparado à climatologia. No entanto, existe uma subestimativa do número de ciclones no lado equatorial da região de máxima atividade ciclônica, principalmente na região LA PLATA. A projeção futura HadGEM2-ES no cenário RCP8.5 mostra uma redução de aproximadamente 10% na ciclogêneses no domínio do Atlântico Sul, principalmente associada ao deslocamento em direção ao polo da região de máxima atividade ciclônica. Porém, a região LA PLATA apresenta um pequeno aumento em sua atividade ciclogenética (6.1 e 3.6%), no verão e inverno, respectivamente). O aumento na ciclogênese em 30°S está associada ao fortalecimento do jato de altos níveis e ao aumento da advecção quente e de umidade nessa localidade. O aumento do transporte de umidade dos trópicos está associado também à intensificação dos ciclones observada na projeção futura, principalmente ao norte de 35°S. Por fim, uma regionalização com o modelo WRF foi usada para melhorar a resolução do modelo climático. Porém, as simulações regionais subestimaram os ciclones em número e intensidade. A única região que em as regionalizações apresentaram melhor desempenho foi a LA PLATA, devido a uma melhor representação de feições locais associadas a orografia e processos úmidos. A regionalização do cenário futuro RCP8.5 também apresentou aumento da ciclogênese do LA PLATA, mas para o inverno. Tanto a projeção RCP8.5 do HadGEM2-ES quanto sua regionalização mostram que a ciclogênese em algumas regiões da América do Sul está aumentando, principalmente devido ao aumento de umidade em baixos níveis da atmosfera e fortalecimento do lado ramo equatorial do jato de altos níveis. Os ciclones nessas localidades serão intensos (entre 20°S e 30°S) e tendem a afetar uma região mais próxima à costa.

<p>A global climate change may have large impacts on water resources on regional and global scales. General circulation models (GCMs) are the most used tools to evaluate climate-change scenarios on a global scale. They are, however, insufficiently describing the effects at the local scale. This thesis evaluates different approaches of statistical downscaling of precipitation from large-scale circulation variables, both concerning the method performance and the optimum choice of predictor variables. </p><p>The analogue downscaling method (AM) was found to work well as “benchmark” method in comparison to more complicated methods. AM was implemented using principal component analysis (PCA) and Teweles-Wobus Scores (TWS). Statistical properties of daily and monthly precipitation on a catchment in south-central Sweden, as well as daily precipitation in three catchments in China were acceptably downscaled.</p><p>A regression method conditioning a weather generator (SDSM) as well as a fuzzy-rule based circulation-pattern classification method conditioning a stochastical precipitation model (MOFRBC) gave good results when applied on Swedish and Chinese catchments. Statistical downscaling with MOFRBC from GMC (HADAM3P) output improved the statistical properties as well as the intra-annual variation of precipitation.</p><p>The studies show that temporal and areal settings of the predictor are important factors concerning the success of precipitation modelling. The MOFRCB and SDSM are generally performing better than the AM, and the best choice of method is depending on the purpose of the study. MOFRBC applied on output from a GCM future scenario indicates that the large-scale circulation will not be significantly affected. Adding humidity flux as predictor indicated an increased intensity both in extreme events and daily amounts in central and northern Sweden.</p>

A global climate change may have large impacts on water resources on regional and global scales. General circulation models (GCMs) are the most used tools to evaluate climate-change scenarios on a global scale. They are, however, insufficiently describing the effects at the local scale. This thesis evaluates different approaches of statistical downscaling of precipitation from large-scale circulation variables, both concerning the method performance and the optimum choice of predictor variables. The analogue downscaling method (AM) was found to work well as “benchmark” method in comparison to more complicated methods. AM was implemented using principal component analysis (PCA) and Teweles-Wobus Scores (TWS). Statistical properties of daily and monthly precipitation on a catchment in south-central Sweden, as well as daily precipitation in three catchments in China were acceptably downscaled. A regression method conditioning a weather generator (SDSM) as well as a fuzzy-rule based circulation-pattern classification method conditioning a stochastical precipitation model (MOFRBC) gave good results when applied on Swedish and Chinese catchments. Statistical downscaling with MOFRBC from GMC (HADAM3P) output improved the statistical properties as well as the intra-annual variation of precipitation. The studies show that temporal and areal settings of the predictor are important factors concerning the success of precipitation modelling. The MOFRCB and SDSM are generally performing better than the AM, and the best choice of method is depending on the purpose of the study. MOFRBC applied on output from a GCM future scenario indicates that the large-scale circulation will not be significantly affected. Adding humidity flux as predictor indicated an increased intensity both in extreme events and daily amounts in central and northern Sweden.