La hausse des températures et les modifications du régime des précipitations affectent les écosystèmes particulièrement fragiles des régions arctiques et subarctiques et ont des conséquences socio-économiques pour les populations locales. La perception et l'évaluation des opportunités et des risques qui y sont associés, dépendent des moyens de subsistance, des normes, des valeurs et des représentations du monde des individus qui y sont confrontés.La perception du climat est culturellement et socialement construite. Cette perception varie dans le temps et dans l'espace et, parfois même, diffère parmi différents groupes sociaux en fonction des valeurs et des modes de représentation du monde. Pour toutes ces raisons, nous avons non seulement étudié certains phénomènes météorologiques mais aussi intégré le cadre culturel, politique et historique dans lesquels ils s'inscrivent. Nous avons analysé l'environnement et le climat – et par extension, les événements météorologiques à forts impacts – comme des objets socio-culturels afin de mieux comprendre à la fois leurs impacts mais aussi leurs perceptions par les habitants. Ce travail se situe à la croisée de ces chemins, en confrontant l'observation, et donc les changements, et la perception qu'en ont différents acteurs, en considérant deux régions distinctes, les mers nordiques et la République de Touva.Dans une première partie, nous avons analysés l'impact des Polar Lows, d'intenses cyclones de méso-échelle qui se développent sur les mers libres de glace de l'Arctique pendant l'hiver, sur les régions côtières du nord de la Norvège. Ces systèmes sont associés à des vents de surface forts avec bien souvent des rafales qui peuvent être très violentes (Heinemann et Claud, 1997). Les conditions en mer lors du passage d'un PL peuvent s'avérer dangereuses avec des fortes vagues, des précipitations neigeuses brutales et du blizzard. Ces événements météorologiques extrêmes représentent un véritable risque pour les activités maritimes et côtières de la région, notamment pour le transport maritime, la pêche et les plateformes pétrolières et gazières offshore. En effet, les nouvelles zones libres de glace offrent de multiples opportunités économiques dans ces régions, en particulier en mer de Barents. Or dans le même temps, le recul de la banquise élargit mécaniquement les régions de formation des PLs.Dans une seconde partie, nous avons regardé les impacts du changement climatique et des événements météorologiques sévères en République de Touva. La République de Touva se localise entre 49°5 et 53°5 N en latitude, 88°5 et le 99°E en longitude, c'est par conséquent une région subarctique très méridionale. Le climat y est extrêmement continental et les précipitations ont tendance à être faibles en raison de la faible teneur en humidité dans l'air froid. La plupart du territoire est caractérisé par une végétation forestière de taïga ou de steppe semi-aride. Au cours du XXème siècle, la région a connu des changements socio-économiques majeurs, parfois brutaux, avec notamment le passage d'une société communiste à l'économie planifiée à une économie de marché au début des années 1990. Malgré ces récents bouleversements, les pasteurs nomades (chevaux, vaches, yaks, moutons, chameaux) en Touva occidentale et les chasseurs-cueilleurs éleveurs de rennes en Touva orientale, vivent toujours en étroite relation avec l’environnement naturel. Les populations autochtones de Touva, confrontées à un changement rapide de la société et à des changements globaux causés par certaines politiques régionales et nationales contemporaines, avec notamment l’expansion de l'industrie minière et par le développement de mégaprojets (complexe hydroéléctrique, construction d'une voie chemin de fer), offrent des points de vue variés, en fonction de leurs modes de vie, sur les changements environnementaux qu'ils observent et leurs impacts sur leurs activités quotidiennes. / The perception of the climate is culturally and socially constructed. For this reason, we have studied some weather events integrating the cultural, political and historical contexts in which they occur.In a first part, we analyzed the impact of Polar Lows, intense mesocyclones that develop over ice-free Arctic seas during winter time, on coastal regions of Norway. The passage of PL can provoke dangerous sea conditions with strong waves, sudden snowfall and blizzard. This phenomenon may represent a risk to maritime and coastal activities in the region, particularly for shipping, fishing and oil and gas offshore platforms.In a second part we studied the impacts of climate change and severe weather events in the Republic of Tuva. Tuva is a very southern subarctic region. Its climate is extremely continental and precipitation tend to be low due to the low moisture content in the cold air. During the twentieth century, the region has experienced major socio-economic changes, sometimes brutal, including the transition from a communist and planned economy to a market economy in the early 1990. Despite these recent changes, pastoralists in western Tuva (horses, cows, yaks, sheep, camels) and reindeer herders in eastern Tuva, still live in close contact with the natural environment. Indigenous peoples of Tuva are facing global changes caused by certain contemporary regional and national policies, including the expansion of the mining industry and the development of mega projects. They offer different points of view, describing environmental changes and their impact on their daily activities.

State Integrated Pest Management (IPM) programs are often called on to demonstrate their impacts. While many studies demonstrate techniques for assessing various economic and environmental effects of IPM, the literature provides little guidance on incorporating the techniques to perform complete assessments of IPM programs. This thesis begins with a discussion of relevant economic and environmental techniques for IPM impact assessment. Next, impact assessment techniques that are widely accepted and analytically feasible are identified. These techniques are incorporated into comprehensive impact assessment frameworks for use by individuals charged with the assessment of state level IPM programs. The study concludes with case studies which show how the assessment protocols were applied to estimate and describe the impacts of the Pennsylvania and Massachusetts sweet corn IPM programs. / Master of Science

Atmospheric aerosols are the largest remaining uncertainty in the Earth’s radiative budget and it is important that we improve our knowledge of aerosol processes if we are to understand current radiative forcing and accurately project changes in future climate. Aerosols affect the radiation balance directly through the absorption and scattering of incoming solar radiation and indirectly through the modification of cloud microphysical properties. Understanding aerosol forcing remains challenging due to the short atmospheric residence time of aerosols resulting in large spatial and temporal heterogeneity in aerosol loading and chemical composition. Satellite retrievals are becoming increasingly important to improving our knowledge of aerosol forcing. They provide regular global data at finer spatial and temporal resolution than available through sparse groundbased point measurements or localised aircraft campaigns, but cannot unambiguously determine aerosol speciation, relying heavily on a priori assumptions. In this thesis I use data from two satellite instruments: the Along Track Scanning Radiometer 2 (ATSR-2) and the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) interpreted using the Oxford-RAL Aerosol and Cloud (ORAC) retrieval scheme in three pieces of interrelated work. First I use satellite observations of aerosol optical depth a and cloud particle effective radius re from the ATSR-2 instrument in 1997 to investigate the Twomey indirect effect (IE, -δ ln re /δ ln τa) in regions of continental outflow. I generally find a negative correlation between τa and re with the strongest inverse relationships downwind of Africa. North America and eastern Asian continental outflow exhibits a strong seasonal dependence, as expected. Global values for IE range from 0.10 to 0.16, consistent with theoretical predictions. Downwind of Africa, I find that the IE is unphysically high but robust (r = −0.85) during JJA associated with high aerosol loading, and attribute this tentatively to the Twomey hypothesis accounting only for a limited number of physical properties of aerosols. Second, I test the response of the Oxford-RAL Aerosol and Cloud (ORAC) retrieval algorithm for MSG SEVIRI to changes in the aerosol properties used in the dust aerosol model, using data from the Dust Outflow and Deposition to the Ocean (DODO) flight campaign in August 2006. I find that using the observed DODO free tropospheric aerosol size distribution and refractive index compared with the dust aerosol properties from the Optical Properties of Aerosol and Cloud (OPAC) package, increases simulated top of the atmosphere radiance at 0.55 μm assuming a fixed aerosol optical depth of 0.5, by 10–15%, reaching a maximum difference at low solar zenith angles. This difference is sensitive to changes in AOD, increasing by ~2–4% between AOD of 0.4–0.6. I test the sensitivity of the retrieval to the vertical distribution of the aerosol and find that this is unimportant in determining simulated radiance at 0.55 μm. I also test the ability of the ORAC retrieval when used to produce the GlobAerosol dataset to correctly identify continental aerosol outflow from the African continent and I find that it poorly constrains aerosol speciation. I develop spatially and temporally resolved prior distributions of aerosols to inform the retrieval which incorporates five aerosol models: desert dust, maritime, biomass burning, urban and continental. I use a Saharan Dust Index and the GEOS-Chem chemistry transport model to describe dust and biomass burning aerosol outflow, and compare AOD using my speciation against the GlobAerosol retrieval during January and July 2006. I find AOD discrepancies of 0.2–1 over regions of biomass burning outflow, where AOD from my aerosol speciation and the GlobAerosol speciation can differ by as much as 50 - 70 %. Finally I use satellite observations of aerosol optical depth and cloud fraction from the MSG SEVIRI instrument to investigate the semi-direct effect of Saharan dust aerosol on marine stratocumulus cloud cover over the Atlantic during July 2006. I first use these data to study the spatial autocorrelation of aerosol optical depth and find that it is correlated over a lag of 0.1◦ (approximately 10 km at low latitudes), beyond which it rapidly decorrelates. I find a 15 % higher cloud fraction in regions with high dust loading (AOD > 0.5), compared with scenes with a lower dust loading (AOD < 0.5), which for high dust scenes increases with local static stability. I attribute this tentatively to aerosol solar shielding enhancing longwave cloud top radiative cooling which drives marine stratocumulus convection.

China has experienced high foreign direct investment (FDI) inflows for the past 30 years since it opened its door to foreign investors especially after the early 1990s. As a result, with more and more foreign invested enterprises in China, China has experienced dramatic changes in its economy and society. This study conducts an empirical analysis on the determinants of FDI regional and sectoral distribution in China and evaluates the impact of FDI on Chinese domestic investment. The dataset used for this study spans from 1990-2008 and involves both regional-level and sector-level data in China. The key findings of this thesis can be summarised into four points. First, on regional level, foreign investors base their investment decisions by tax rates, geography, labour costs and market size. Moreover, tax incentive effects are proved to be greater in the eastern areas than in the western areas. Second, at sectoral level, foreign investors are affected market size, employment, wage rate, exchange rate and state ownership degree, but not by the level of openness degree. Third, FDI has a significant crowding out effects on domestic investment on national level and in particular the eastern area, but has a crowding in effect in the middle area and no effect for the western area. Fourth, there is no significant evidence that FDI crowds out domestic investment on individual sector level. This study provides some valuable insights into foreign investors’ decision making and the economic costs/benefits of FDI, which have important implications for scholars, practitioners and policy makers alike.

Birding, the act of observing birds in the outdoors, is a form of nature recreation and traditionally considered ecologically benign. Unfortunately, birders, in the pursuit of interactions with wild birds, can have negative impacts on birds and critical bird habitat. Often, competition for space or resources can create conflict among recreational users and bird conservation initiatives. People involved in maintaining birding recreation as well as ecological conservation include stakeholders such as birders, birding guides, and natural resource managers. Comparisons of negative impact perceptions were investigated among birder specialization categories, and between birders and other stakeholders. This study is a comparative analysis of how birding's negative impacts are perceived by the people involved in recreation and conservation. Further examination of the recreational specialization theory as an indicator for birders? perceptions of birding's negative impacts was also conducted. The purpose of such comparisons is to gain an understanding of different stakeholder needs to better serve and utilize the resources available. Justification for the study came from a series of structured interviews. Preliminary interviews with birding stakeholders identified perceived negative impacts from birding and conservation strategies to address those impacts. Separate on-site surveys, tailored for each of the three stakeholder groups, were conducted to assess stakeholder perceptions of birding's negative impacts to the ecology of the Great Texas Coastal Birding Trail. Survey results indicate that as birders progress in increased specialization, they more often perceive birding's negative ecological impacts. This means that the most intense birders recognize negative ecological impacts from birding more frequently than birders with less experience, investment, or lifestyle tendencies. Additional results indicate that birders, in general, perceive negative ecological impacts less frequently than bird managers and birding guides. These results are indicative of experience or education as a means to facilitate increased ecological awareness. Finally, all stakeholders supported education and outreach strategies for bird and bird habitat conservation. This study has provided scientific data analysis of birding's perceived negative impacts, as well as strategies for bird conservation. This work provides needed data on the human dimension of natural resource use conflicts for natural resource managers, who require better understanding of their constituents to accomplish recreational and conservation conflict management.

This study investigates impacts on Western Canadas rural communities that may result from land usage change from conventional agriculture to that of forestry, in part or in whole. Many of Western Canadas rural communities in the agriculture regions near the tree line have developed around cash crops (cereal/oilseeds) and livestock production. Through the Government of Canadas commitments to achieve targeted greenhouse gas emission levels, a market may develop where landowners will be adequately compensated to initiate a switch from conventional agriculture to that of forestry. This study finds that forestry and agricultural regions have over time developed different business structures to support local industry demands. Because of this, converting land use to forestry from agriculture will likely have a significant impact on the rural communities that serve the local economy. Results also showed that population change is significantly influenced by the percentage of people employed in agricultural and by proximity to larger urban centres.

This study investigates impacts on Western Canadas rural communities that may result from land usage change from conventional agriculture to that of forestry, in part or in whole. Many of Western Canadas rural communities in the agriculture regions near the tree line have developed around cash crops (cereal/oilseeds) and livestock production. Through the Government of Canadas commitments to achieve targeted greenhouse gas emission levels, a market may develop where landowners will be adequately compensated to initiate a switch from conventional agriculture to that of forestry. This study finds that forestry and agricultural regions have over time developed different business structures to support local industry demands. Because of this, converting land use to forestry from agriculture will likely have a significant impact on the rural communities that serve the local economy. Results also showed that population change is significantly influenced by the percentage of people employed in agricultural and by proximity to larger urban centres.

Economic analyses of transportation investments are a common component of transportation planning. The profile of economic analyses has continued to rise due to increasing budget constraints and increasing emphasis on infrastructure's role in spurring economic development. One tool that has been developed specifically for transportation economic impact evaluation is the Transportation Economic Development Impact System (TREDIS). Common inputs for TREDIS are changes in travel characteristics caused by network improvements. Another commonly used planning tool is a travel demand model. Since 2003, the Texas Department of Transportation (TXDOT) has worked on the development of the Statewide Analysis Model (SAM) which estimates travel characteristics for passenger and freight modes. Together, the models have the potential to improve project evaluation and to highlight the roles that certain projects have in creating economic development. The hypothesis explored for this study is that SAM and TREDIS can be feasibly used together to help TXDOT evaluate the economic impacts of investments in freight corridors and other transportation investments. This report begins with general discussions of transportation economic analyses and the two models used. Then, the current SAM is evaluated using TREDIS followed by a discussion of the results and ways that this type of integrated planning can be incorporated by agencies. Through this study, key results include: the process of incorporating results from the SAM for use in TREDIS is feasible, an overall benefit-cost ratio of 4 for the entire set of long range roadway projects included in the SAM and 8 for only the interstate projects included in the SAM, rail and other transportation analyses are feasible using SAM and TREDIS. / text

Bloodstain pattern analysis is used in the investigation of a crime scene to infer the impact velocity and size of an impacting droplet and from these, the droplet’s point and cause of origin. The final pattern is the result of complex fluid dynamic processes involved in the impact and spreading of a blood drop on a surface with variable surface properties such as wettability and porosity. An experiment has been designed to study these processes and the resulting patterns for the case of a single Newtonian droplet impacting an inclined surface with variable roughness and wetting properties. An experimental apparatus, including a droplet generator, has been designed to produce droplets on-demand, and that impact an interchangeable surface. In addition, a blood-simulant liquid has been developed as a replacement for performing tests with real blood. With this apparatus and blood simulant, fluid dynamics concepts, such as contact line motion and wetting behavior are examined in the context of parameters of interest to the forensics community. These include eccentricity, spread factor and the number of spines formed on impact. The effect of varying dimensionless parameters including Reynolds number, Weber number and Laplace number, the angle of impact and surface properties is examined. Correlations are developed for predicting conditions at the point of impact from those observed later, as would be available to a forensics examiner, and the accuracy of the predictions developed in this thesis are evaluated.

In the stochastic hydrology literature, suitable time series modelling approaches have been developed for modelling daily streamflow. However, problems arise with this approach if changes are occurring to the precipitation regime generating the historic streamflow data, or if land-use changes are occurring within the catchment which may alter the water balance and the streamflow regime. Traditional time series modelling approaches employ historic streamflow data only and will generate synthetic data which are representative only of the historic conditions. It is not possible to predict how the model parameters should be changed to reflect changes in the climate (precipitation) and catchment response regimes. Developing a methodology to deal with the stochastic generation of daily streamflow that reflects changes to the catchment system and climatic inputs (rainfall and potential evapotranspiration) and then applying the corresponding methodology to a study catchment (upper Thames) in England is the focus of this study. To study the water resources impacts of land-use change on the daily streamflow regime of a catchment, a daily rainfall-runoff model is needed which can accommodate various land cover characteristics and provide separate estimates of potential and actual evapotranspiration in its evapotranspiration component for each land cover type. Given a model with this capability, the impacts of various land-use scenarios on daily streamflow can be investigated. In the case of climate change, since GCMs do not provide useable results on a short time scale such as a day and on a spatial scale such as a catchment of about 1000 km2, a methodology is required to predict the changes which may occur in the climate inputs of a catchment, and the resulting impacts on water resources. The approach developed here for water resources impact studies of land-use change and climate change has three main elements: (I) Two stochastic models, one for rainfall (Neyman-Scott Rectangular Pulses, NSRP, model) and the other for potential evapotranspiration (PET), are employed to generate daily rainfall and daily PET sequencesr,e spectively. Thesem odels have been validated using historic records for the study catchment. ABSTRACT ii (II) The ARNO model has been calibrated and validated using daily streamflow data for the study catchment. The evapotranspiration component of the model has been modified to obtain a satisfactory water balance. The model is then extended to include the explicit calculation of interception for different land cover types within the catchment. The runoff from these areas is then routed to the catchment outlet. The rainfall and PET models are used to generate synthetic daily input series to the modified ARNO model for present catchment land-use conditions, and overall procedure is validated using the historic streamflow record. This is then worked out using the extended model and referred to as the constructed` control' scenariow hich is used as a benchmarkf or assessingla nd-usec hange impacts on water resources for two different land-use scenarios. (III) The transient GCM climate scenarios are used as the starting point for assessing climate change impacts. Regression relationships are derived between atmospheric circulation variables and rainfall statistics used in fitting the NSRP model for present climate conditions and then used to predict the rainfall statistics for future conditions using GCM outputs. That is, the scenarios of a climate model are downscaled by a regression technique to a resolution sufficient to represent daily rainfall at the catchment scale. To generate potential evapotranspiration (PET) scenarios, an empirical equation is used to estimate PET daily values as a function of temperature, thus enabling future scenarios to be generated as a function of GCM temperature predictions. Generated rainfall and PET scenarios are used as inputs to the adapted ARNO catchment response model to generate daily streamflow data. Impact assessments using both land-use change and climate change scenarios are then carried out using a range of water resources assessment measures such as flow duration curves, cumulative run sums and storage/yield relationships, and the practical implications discussed.