On fair-weather summer days an intense southerly lake breeze blows across the northern shorelines of Lake Garda (Italy). This wind, known as Ora del Garda, arises regularly in the late morning, and then channels northward into the adjacent Sarca Valley and Lakes Valley, coupling with the local up-valley flow. In the early afternoon, after flowing over an elevated (~400 m high) saddle, the Ora del Garda wind breaks into the Adige Valley north of Trento city; there it flows down on the valley floor, interacting with the local up-valley wind and creating a strongly turbulent flow. The characteristic diurnal cycle of surface meteorological variables determined by the lake-valley coupled circulation is rather well-known, on the basis of climatological analyses of data from surface automatic weather stations operated in the area by local institutions; on the contrary, the valley upper atmosphere structure, i.e. the structure of the atmospheric boundary-layer (ABL), associated with the Ora del Garda development has not yet been investigated. Indeed, in such a complex terrain area, the characterization of the typical structure, spatial variation and depth of the ABL, as well as a sound knowledge of local atmospheric circulation patterns, are of crucial importance for the understanding of the local climate and of air pollution transport and dispersion processes. To meet this lack of knowledge, a series of targeted measurement campaigns, including both intensive surface observations and research flights, were carried out by the Atmospheric Physics Group of the University of Trento in the study area between 1998 and 2001, providing the database for the present work. Five flights of an instrumented motorglider explored specific sections of the valley atmosphere, namely at Lake Garda’s shoreline, in the lower Sarca Valley, in the Lakes Valley, and where the Ora del Garda and the Adige Valley up-valley flow interact. Position, pressure, temperature and relative humidity were measured along spiralling trajectories performed over the above mentioned target areas. Surface observations from a number of weather stations disseminated along the valley floor provided a picture of the diurnal cycles of meteorological quantities determined at the surface by the development of the investigated wind on the flight days. The preliminary processing of the experimental dataset included the application of a suitable procedure to correct airborne temperature data for the time-delay effect induced by the slow-response behavior of the sensor, and required the determination of a proper time constant. The dominant vertical structure of the valley ABL was then deciphered on the basis of vertical “pseudo-soundings” (i.e. mean vertical profiles) of potential temperature and water vapour mixing ratio extracted from airborne data. Shallow mixed layers, surmounted by deeper stable layers, likely to be produced by local subsidence associated with up-slope flows, were detected up-valley. This characteristic pattern is indeed in good accord with ABL structures typically observed in deep Alpine valleys in connection with up-valley winds, as reported in the literature. On the other hand, closer to the lake the potential temperature profile was typically stabilized down to lower heights, due to the onshore advection of colder air from above the water surface. A residual kriging (RK) technique was adopted to map potential temperature fields over 3D high-resolution grids for each explored section of the valley atmosphere, integrating both surface and airborne observations. Exploiting a test-bed database, RK method was preliminarly tested against the interpolation methods commonly used in the literature for mapping airborne data, namely inverse distance, inverse squared distance and natural neighbor methods. The predictive performance of the different methods was assessed by means of a cross-validation procedure, and a critical comparison of the different interpolation results was carried out. Finally, RK resulted the best-performing technique for the specific application. RK-interpolated fields revealed fine-scale local features of the complex ABL thermal structures determined by the Ora del Garda in the study area valleys, revealing at the same time macroscopic features of the thermo-topographically driven wind field, mainly amenable to irregular topography and land cover heterogeneities. In particular, a non-homogeneous penetration of the lake-breeze front across the flat basin facing Lake Garda was detected in the morning, while in the afternoon the presence of a sharp discontinuity in the upper-level vertical stratification, originated by updrafts and downdrafts associated with the lake breeze circulation, was observed. Moreover, a strongly asymmetric potential temperature field, resulting from the contrast between the stable core of the Ora del Garda up-valley flow and an intense up-slope flow layer developing along a bare-rock valley sidewall, was detected in the area of Cavedine Lake in the Lakes Valley. Further up-valley, RK-interpolated fields displayed a thermal structure compatible with the occurrence of a single-cell cross-valley circulation, likely to be originated by asymmetric solar irradiation and by the local valley curvature. The valley curvature was also found to induce a preferential channeling of the up-valley flow along the northwestern sidewall at the valley end, in proximity of the elevated saddle from where the Ora del Garda overflows into the underlying Adige Valley, giving origin to an anomalous, strong katabatic wind that hinders the regular development of the local up-valley wind in the area north of Trento. Here the westerly inflow from the Lakes Valley feeds a denser wedge of potentially cooler air, which forces the local up-valley (i.e. southerly) wind to flow over it. Regridded potential temperature fields provided further insight into this flow pattern, revealing the occurrence in the area of a hydraulic jump structure, due to the blocking exerted on the flow by the eastern Adige Valley sidewall. This induced a pronounced deepening of the local mixed layer, which was likely produced by the highly-turbulent flow conditions that usually develop here following the Ora del Garda outbreak.

In the current era of the Anthropocene, human activities are powerful forces that affect the geosphere, atmosphere, and biosphere – globally, fundamentally, and in most cases irreversibly. In freshwaters, land use change, chemical pollution, decline in biodiversity, spread of invasive species, climate change, and shifts in the hydrological regime are among the key drivers of changes. In the 21st century, major water engineering projects such as large dams and water diversion schemes will fundamentally alter the natural hydrological regime of entire landscapes and even continents. At the same time, the hydrological regime is the governing variable for biodiversity, ecosystem functions and services in river networks. Indeed, there will be an increasing conflict between managing water as a resource for human use and waters as highly valuable ecosystems. Therefore, research needs to unravel the challenges that the freshwaters are facing, understand their potential drivers and impacts, and develop sustainable management practices – for the benefit of humans and ecosystems alike. The present thesis focuses on three currently understudied alterations in flow and material dynamics within river networks, namely (i) on the dynamics of floating organic matter (FOM) and its modification in dammed rivers, (ii) on river intermittency and its effects on nutrient and organic matter (OM) dynamics, and (iii) on major future water transfer schemes. Massive construction and operation of dams cause modification of water flow and material fluxes in rivers, such as of FOM. FOM serves as an essential component of river integrity, but a comprehensive understanding of its dynamics is still lacking. River damming, climate change and water extraction for human needs lead to a rapid expansion in number and extent of intermittent rivers worldwide, with major biogeochemical consequences on both regional and global scales. Increased intermittency of river networks also forces people to implement engineering solutions, such as water transfer schemes, which help to supply water to places of demand. Water transfer projects introduce artificial links among freshwater bodies modifying the hydrological balance. Impacts of abovementioned activities on freshwaters have been assessed in single case studies. However, the current knowledge does not allow a generalization of their globally applicable meaning for ecosystems. Furthermore, mostly neglected aspects of these alterations, such as the potential consequences of FOM extraction from rivers, the biogeochemical role of intermittent rivers upon rewetting, and the current scale of water transfers require better understanding before bold conclusions could be made. By combining research methods such as extensive literature reviews, laboratory experiments and quantitative analyses including spatial analyses with Geographic Information Systems, I investigated (1) the natural cycle, functions, and amounts of FOM in rivers fragmented by dams, (2) effects of rewetting events on the pulsed release of nutrients and OM in intermittent rivers and ephemeral streams (IRES), and (3) the potential extent of water transfer megaprojects (WTMP) that are currently under construction or in the planning phase and their role in modifying the global freshwater landscape. In all three cases, I provide a global perspective. The role of FOM in rivers as a geomorphological agent, a resource, a dispersal vector and a biogeochemical component was investigated based on an extensive literature review. Collected information allowed for conceptualizing its natural cycle and dynamics, applicable to a wide range of rivers. Data on FOM accumulations at 31 dams located within catchments of 13 rivers showed that damming leads to FOM entrapment (partly or completely) and modifies its natural cycling. The results of a spatial analysis considering environmental properties revealed that catchment characteristics can explain around 57% in the variation of amounts of trapped FOM. Effects of rewetting events on the release of nutrients and OM from bed sediments and course particulate organic materials (CPOM) accumulated in IRES was studied in laboratory experiments. Using a large set of samples collected from 205 rivers, located in 27 countries and distributed across five major climate zones, I determined the concentrations and qualitative characteristics of nutrients and OM released from sediments and CPOM. I also assessed how these characteristics can be predicted based on environmental variables within sampled IRES. In addition, I calculated area-specific fluxes of nutrients and OM from dry river beds. I found that the characteristics of released substances are climate specific. In the Continental zone I found the highest concentrations of released nutrients, but the lowest quality of OM in terms of its potential bioavailability. In contrast, in the Arid zone the concentrations of released nutrients were the lowest, but the quality of OM the highest. The effect of environmental variables on the concentrations of nutrients and the quality of OM was better predicted for sediments than for other substrates with the highest share of explained variance in the Continental and Tropical zones. On the global scale, dissolved organic carbon, phenolics, and nitrate dominate fluxes released during rewetting events. Overall, this study emphasized that on the global scale rewetting events in IRES represent biogeochemical “hot moments†, but characteristics of released nutrients and OM differ greatly among climate zones. The present thesis fills also a major knowledge gap on the global distribution of large water transfer schemes (referred to as “megaprojects†) that are actually planned or under construction. To provide an inventory of WTMP, I collected data from various literature sources, ranging from published academic studies, the official web-sites of water transfer projects, environmental impact assessments, reports of non-governmental organizations, and information available in on-line newspapers. In total, 60 WTMP were identified. Information on spatial location, distances and volumes of water transfer, costs, and purposes of WTMP was collected and compared with those of existing schemes. The results showed that North America, Asia and Africa will be the most affected by future WTMP having the highest densities of projects and the largest water transfer distances and volumes. If all projects were completed by 2050, the total water transfer distances would reach 77,063 km transferring more than 1,249 km3 per year, which corresponds to about 20 times the annual flow of the river Rhine. The outcomes of the thesis provide major implications for environmental management. Natural FOM is an important component for sustaining the ecological and geomorphic integrity of rivers and, therefore, should be managed appropriately. Intermittent rivers must be considered in models quantifying nutrient and OM fluxes in river networks. First flush events in particular release huge amounts of nutrients and OM, which may cause dramatic metabolic effects on downstream receiving waters. Finally, the future WTMP alter the hydrological balance of entire river basins and continents. They require multiple assessments before construction and careful management practices for sustainable operation in order to consider both freshwater as a resource as well as freshwaters as pivotal ecosystems.

This research tries to fill a gap between two very different scales of enquiry: the local (i.e. hillslope) scale, where detailed investigations are possible but difficult to generalize over large areas, and the landscape (i.e., catchment) scale, where representation of the physics is minimised, the resolution in space and time is maximised, and the focus is upon predicting emergent properties rather than system details. Specifically, this Thesis focused on an aspect of the geosciences that is of critical current concern: the representation of the interface between hydrological response and geomorphic processes, notable mass movements. At present there remains a great difficulty at this interface: detailed geotechnical and hydrological studies of mass movements reveal exceptionally complex interlinkages between water and the surface sediment mass, notably dynamically at the onset and during mass release; but these kinds of studies are only possible with a very detailed description of the three-dimensional structure of the porous media and its hydrological and mechanical response during (and after) rainfall events. Such analyses are feasible but tend to result in analyses that are restricted in terms of geographical generalisation. On the other hand, approaches that apply to larger spatial scales tend to over-simplify the representation of critical failure processes, such as in the assumptions that infinite slope stability analysis can be applied to failures that are finite in their slope length, or that upslope contributing area can always act as a surrogate for the hydrologic response at a point in the watershed. The innovative element in this research lies on the assessment of rainfall-induced shallow landslide occurrence over large spatial scales, whilst accepting that shallow landslides triggering may be influenced by processes that operate over much smaller scales. Specifically, this Thesis focuses upon connection by subsurface flow pathways. New model approaches that incorporate connectivity are required to address the findings of field hydrologists. Thus, this Thesis starts from the understanding of small-scale hydrological processes to develop a large-scale topographic index-based shallow landslide model that includes the concept of subsurface hydrological connectivity. The research aims to provide a tool for more realistic assessments of when shallow landslides may occur and where landsliding may occur at the catchment scale to support decision makers in developing more accurate land-use maps and landslide hazard mitigation plans and procedures.

No description available.

No description available.

Engineering and technical challenges exist with the material transport of natural resources in space. One aspect of this transport problem is the design of an orbit architecture in the Earth-Moon system (EMS) that facilitates these resources through the mining cycle. In this thesis, it is proposed to use the Circular Restricted 3-Body Problem (CR3BP) to design an orbit architecture composed of L3 Lyapunov orbits, hyperbolic invariant stable and unstable manifolds, and geosynchronous (GEO) orbits. A single shooting method (SSM) and natural parameter continuation (NPC) numerical algorithm is used to compute a family of L3 Lyapunov orbits. Invariant Manifold Theory (IMT) is leveraged to find the set of feasible hyperbolic invariant stable and unstable manifolds associated with a L3 Lyapunov orbit. Ideal L3 Lyapunov orbits are chosen to construct an orbit architecture based off favorable metrics like orbital period, Jacobi Constant, and stability index. Manifolds that enter the GEO and xGEO (beyond GEO) volumes are identified. Finally, a ∆V analysis for GEO to manifold transfer is conducted. An achievement of this study is the computation of stable L3 Lyapunov orbits. The primary contribution of this paper lies in its modeling of a L3 Lyapunov orbit architecture using the CR3BP. / Master of Science / Engineering and technical challenges exist with the material transport of natural resources in space. One aspect of this transport problem is the design of an orbit architecture in the Earth-Moon system (EMS) that facilitates these resources through the mining cycle. In this thesis, it is proposed to use the Circular Restricted 3-Body Problem (CR3BP) to design an orbit architecture composed of L3 Lyapunov orbits, hyperbolic invariant stable and unstable manifolds, and geosynchronous (GEO) orbits. L3 is a unique point in space in a rotating frame of reference where the gravity of the Earth and Moon create a dynamical equilibrium point. Due to its location in a rotating frame of reference relative to the Earth and the Moon, orbits around L3 tend to greater stability than L1 or L2. A single shooting method (SSM) and natural parameter continuation (NPC), which are computational methods for finding solutions that connect discrete boundary conditions, numerical algorithm is used to compute a family of L3 Lyapunov orbits. Invariant Manifold Theory (IMT), which is a dynamical system structure that is invariant throughout the action of the system, is leveraged to find the set of feasible hyperbolic invariant stable and unstable manifolds associated with L3 Lyapunov orbits. Ideal L3 Lyapunov orbits and manifolds are chosen to construct an orbit architecture based off favorable metrics like orbital period, Jacobi Constant, and stability index. Manifolds that enter the GEO and xGEO (beyond GEO) volumes are identified. Finally, a ∆V analysis for GEO to manifold transfer is conducted. An achievement of this study is the computation of stable L3 Lyapunov orbits. The primary contribution of this paper lies in its modeling of a L3 Lyapunov orbit architecture using the CR3BP.

This thesis investigates global fight against terrorism in North West Pakistan and Afghanistan from a 21st century perspective in 2018. It focuses on local attitudes towards the War on Terror and their interplay with geo-strategic, regional, international and Pakistan’s domestic landscapes. In doing so, it questions the efficacy of existing academic and policy approaches towards achieving sustainable peace in North West Pakistan in particular and South Asia in general. It also evaluates the impact of regional rivalries especially in between Pakistan and India on the achievement of US foreign policy interests. Part-1 reviews existing literature on terrorism especially in post 9/11 setting. It examines the international discord of agreeing on a single definition of terrorism and its ramifications. It sequentially focuses on character of security in North West Pakistan and neighbouring Afghanistan since colonial times. It also identifies various traditional, religious and societal angles of Pashtun tribes; which always inspired them to fight against external powers. Part-2 combines academic investigations with empirical evidence. The results are correlated with current discussions on modern terrorism, geopolitical pulls and regional rivalries to create a holistic picture. It identifies local attitudes and regional rivalries as major impediments towards achievement of sustainable peace. Research findings indicated that predominant Western academic debates on the conflict were foreign policy inspired with little local and veteran input. By adapting a pragmatic approach the terrorism challenge can be addressed and the region can contribute towards the continuation of ‘Rules Based Order’ within the current phase of Great Power Rivalry.

Many tools exist to assist law enforcement agencies in mitigating criminal activity. For centuries, academics used statistics in the study of crime and criminals, and more recently, police departments make use of spatial statistics and geographic information systems in that pursuit. Clustering and hot spot methods of analysis are popular in this application for their relative simplicity of interpretation and ease of process. With recent advancements in geospatial technology, it is easier than ever to publicly share data through visual communication tools like web applications and dashboards. Sharing data and results of analyses boosts transparency and the public image of police agencies, an image important to maintaining public trust in law enforcement and active participation in community safety.

Els datasets geogràfics representen la realitat mitjançant un conjunt d'entitats temàtiques que sovint no estan definides d'una manera precisa i que diferents persones poden entendre de diferents formes. La integració d'informació geogràfica provinent de diverses fonts presenta un important repte des del punt de vista semàntic. En aquesta tesi es proposa una solució a aquest problema basada en la definició d'un marc semàntic el nucli del qual és una ontologia que representa els conceptes temàtics en un repositori de datasets, així com les relacions entre aquests conceptes. També es proposa un mètode semi-automàtic per fusionar les ontologies d'aplicació dels datasets en el repositori. El marc semàntic permet també la definició de serveis semàntics, en concret la integració en un nou dataset d'informació temàtica provinent de diverses fonts. Finalment, el marc semàntic i els seus serveis s'utilitzaran en un sistema d'indexació i recuperació d'elements multimèdia geo-referenciats a partir del seu contingut geogràfic temàtic. / Los datasets geográficos representan la realidad mediante un conjunto de entidades temáticas que a menudo no están definidas de una manera precisa y que diferentes sujetos pueden entender de distintas formas. La integración de información geográfica proveniente de diversas fuentes presenta un importante reto desde el punto de vista semántico. En esta tesis se propone una solución a este problema basada en la definición de un marco semántico cuyo núcleo es una ontología que representa los conceptos temáticos en un repositorio de datasets, así como las relaciones entre dichos conceptos. También se propone un método semi-automático para fusionar las ontologías de aplicación de los datasets en el repositorio. El marco semántico permite además la definición de servicios semánticos, en concreto la integración en un nuevo dataset de información temática proveniente de diversas fuentes. Finalmente, el marco semántico y sus servicios se utilizarán en un sistema de indexación y recuperación de elementos multimedia geo-referenciados a partir de su contenido geográfico temático. / Geographic datasets represent reality through a set of thematic entities that are often not precisely defined and that may be understood in different ways by different subjects. Integrating geographic information from diverse datasets presents an important challenge from the semantic point of view. A solution to this problem is proposed in this thesis based on the definition of a semantic framework whose core is an ontology that represents the thematic concepts in a repository of datasets as well as their relations. A semi-automatic method is also proposed to merge the application ontologies of the datasets in the repository. The semantic framework supports the definition of semantic services, particularly the integration of the thematic information from diverse datasets in a new one. Finally, the semantic framework and its services have been used in the context of indexing and retrieving geo-referenced multimedia elements based on their thematic geographic content.

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / Universal acceptance of the Windows NT operating system has made utilization of the personal computer (PC) platform for critical space operations a reality. The software attributes of the operating system allow PC products to attain the reliability necessary for secure control of on-orbit assets. Not only is the software more reliable, it supports better networking interfaces at higher speeds. The software upgrades that the Microsoft Corporation generates on a regular basis allow PCs to offer capabilities previously available only with UNIX-based solutions. As technology matures, PCs will operate faster, offer more graphical user interfaces, and give customers a lower cost versus performance choice. These reasons, and others to be discussed further, clearly demonstrate that PCs will soon take their place at the forefront of mission-critical ground station applications.