Debris flows can be considered the most significant geological hazard in areas of high relief in Scotland having impacted upon slope foot infrastructure several times in recent years. The potency of this geohazard is anticipated to increase over the coming decades due to a climatologically enforced upturn in debris flow frequency. In thisresearch material and topographic controls on debris flow activity are investigated using a combination of field and laboratory based analysis of debris flows at six study sites across upland Scotland. Centrifuge modelling is also used to simulate theinitiation of debris flows in soils with varying particle size distributions.Spatial densities of debris flow measured in the field indicate that hillslopes underlain by sandstone and granitic bedrocks, which tend to be mantled by coarser sand rich soils, have a greater frequency of flows than those underlain by schist andextrusive lava bedrocks. Higher debris flow densities on slopes underlain by sandstone and granite lithologies are facilitated by high permeability in overlying regolith matrixes allowing more rapid increase in pore water pressures duringrainstorms although this is likely to be further influenced by packing and organic content. Centrifuge modelling of hillslope debris flows also demonstrate that sandier soils are generally geotechnically more susceptible to slope failure.The susceptibility of a hillslope to debris flow is strongly influenced by slope geometry and morphology. Hillslopes with persistently steep slopes and a high incidence of concavities, gullies and couloirs are topographically more predisposed todebris flow activity due to greater shear stresses and morphologically controlled, gravity induced concentrations of hillslope hydrology. The majority of material in channelised debris flows is entrained during the gully propagation stage of the massmovement. Consequently, such events can be considered accumulative channelised debris flows. Longer and steeper gullies with greater sediment capacities are more likely to yield larger flow mass movements. Coupling between open hillslopes andbedrock gullies is shown to be an essential component for conceptualisation of the debris flow geohazard.Due to the role they play in amplifying debris flow magnitude, hazard management should be focussed around bedrock gullies and stream channels. Highesthazard rankings should be assigned to slope foot infrastructure in proximity to gullied stream channels with high sediment capacities and long, steep profiles conducive to large accumulative channelised debris flows. To avoid detrimental aesthetic impact, hazard management should be strongly geared towards utilisation of lower impactexposure reduction techniques and less visually intrusive engineering approaches such as increasing culvert capacity to accommodate debris flows. During realignment or the planning of future transport infrastructure, culverts with capacities significantly exceeding those required for purely hydrodynamic considerations should be placed straight on to stream channels avoiding proximal gully bends.

Matagorda Peninsula is located along an interfluvial region of the central Texas coast in the northwestern Gulf of Mexico. The Pleistocene Beaumont Clay underlies the coastal plain and inner continental shelf and controls the general slope of the coast in this region. This clay surface also creates low accommodation space for the preservation of modern sediments. As a result, only a thin (1 m) layer of transgressive Holocene muddy sand extends throughout the lower shoreface. On 15 July, 2003, Hurricane Claudette (Category 1) made landfall on the peninsula. Following the storm, the shoreface was found to be an extensively eroded surface. Most obvious on this surface was an area containing numerous scour pits on the lower shoreface. These pits extended through the Holocene sediment and into the underlying Beaumont Clay. By the following July, the shoreface exhibited a relatively flat and featureless appearance. Rapid infilling of the pits was attributed to the high sediment supply to the area from converging longshore currents and by the relatively high accommodation space offered by the scoured areas. A large amount of sediment was removed from the lower shoreface where the formation of scour pits occurred. This sediment would have been available for depositionin storm layers both inshore and offshore of the scoured area. Within scour pits, accommodation space was high, resulting in sediment deposition and rapid infilling of the pits. Outside of the scour pits, accommodation space remained low and sediment deposition did not occur. Preservation potential of the sediment record on the shoreface was low and was controlled by cycles of erosion and deposition during storm events. Antecedent geology of the shoreface and the sedimentary processes occurring during and after the storm supported arguments against the assumptions used by the classic "profile of equilibrium" model. Finally, the heavily scoured surface represents a geohazard to development of nearshore regions.

Matagorda Peninsula is located along an interfluvial region of the central Texas coast in the northwestern Gulf of Mexico. The Pleistocene Beaumont Clay underlies the coastal plain and inner continental shelf and controls the general slope of the coast in this region. This clay surface also creates low accommodation space for the preservation of modern sediments. As a result, only a thin (1 m) layer of transgressive Holocene muddy sand extends throughout the lower shoreface. On 15 July, 2003, Hurricane Claudette (Category 1) made landfall on the peninsula. Following the storm, the shoreface was found to be an extensively eroded surface. Most obvious on this surface was an area containing numerous scour pits on the lower shoreface. These pits extended through the Holocene sediment and into the underlying Beaumont Clay. By the following July, the shoreface exhibited a relatively flat and featureless appearance. Rapid infilling of the pits was attributed to the high sediment supply to the area from converging longshore currents and by the relatively high accommodation space offered by the scoured areas. A large amount of sediment was removed from the lower shoreface where the formation of scour pits occurred. This sediment would have been available for depositionin storm layers both inshore and offshore of the scoured area. Within scour pits, accommodation space was high, resulting in sediment deposition and rapid infilling of the pits. Outside of the scour pits, accommodation space remained low and sediment deposition did not occur. Preservation potential of the sediment record on the shoreface was low and was controlled by cycles of erosion and deposition during storm events. Antecedent geology of the shoreface and the sedimentary processes occurring during and after the storm supported arguments against the assumptions used by the classic "profile of equilibrium" model. Finally, the heavily scoured surface represents a geohazard to development of nearshore regions.

Gas hydrates in near-mudline subsea sediments present significant challenges in the production of underlying hydrocarbons, impacting wellbore integrity and placement of subsea equipment. As the fluids of an underlying reservoir flow to the mudline, heat carried by the fluids warms nearwell sediments and dissociates hydrates, which releases gas that can displace and fracture near well soil. This gas release may be calculated with numerical simulations that model heat and mass transfer in hydrate-bearing sediments. The nature and distribution of hydrates within the sediments, the melting behavior of the hydrates, the thermal and mechanical properties of these shallow sediments, and the amount of hydrates contained in the sediments are required for the model simulations. Such information can be costly to acquire and characterize with certainty for an offshore development. In this information environment, it is critical to understand what information, processes, and calculations are required in order to ensure safe, robust systems, that are not overly conservative, to produce the hydrocarbon reservoirs far below the hydrates.

This thesis is focused on natural elements in the microregion Bechynsko,it describes and localizes geohazards (ecological hazards) and natural risks, It designs solutions for elimination of this problems. Designed management of this area leads to sustainable development and it is outlined on the basis of the own SWOT anylyze. In the end of my work I prepared sample case studies which are focused on special geohazards and natural risks and I suggest suitable landscape management and its recultivation.

This thesis is a landscape study of Milevsko region. It is aimed at the characteristic of natural conditions in this area. The next part focuses on description, localization of geohazards (ecological hazards) and natural risks and proposes steps towards their elimination. Based on the SWOT analysis of the region the management of the territory is made in a way leading to a sustainable development. The last part focuses on the case studies of the areas which merit special attention.

In the late spring of 2008, the Chevron-led Gulf of Mexico Gas Hydrate Joint Industry Project (JIP) expects to conduct an exploratory drilling and logging campaign to better understand gas hydrate-bearing sands in the deepwater Gulf of Mexico. The JIP Site Selection team selected three areas to test alternative geological models and geophysical interpretations supporting the existence of potential high gas hydrate saturations in reservoir-quality sands. The three sites are near existing drill holes which provide geological and geophysical constraints in Alaminos Canyon (AC) lease block 818, Green Canyon (GC) 955, and Walker Ridge (WR) 313. At the AC818 site, gas hydrate is interpreted to occur within the Oligocene Frio volcaniclastic sand at the crest of a fold that is shallow enough to be in the hydrate stability zone. Drilling at GC955 will sample a faulted, buried Pleistocene channel-levee system in an area characterized by seafloor fluid expulsion features, structural closure associated with uplifted salt, and abundant seismic evidence for upward migration of fluids and gas into the sand-rich parts of the sedimentary section. Drilling at WR313 targets ponded sheet sands and associated channel/levee deposits within a minibasin, making this a non-structural play. The potential for gas hydrate occurrence at WR313 is supported by shingled phase reversals consistent with the transition from gas-charged sand to overlying gas-hydrate saturated sand. Drilling locations have been selected at each site to 1) test geological methods and models used to infer the occurrence of gas hydrate in sand reservoirs in different settings in the northern Gulf of Mexico; 2) calibrate geophysical models used to detect gas hydrate sands, map reservoir thicknesses, and estimate the degree of gas hydrate saturation; and 3) delineate potential locations for subsequent JIP drilling and coring operations that will collect samples for comprehensive physical property, geochemical and other analyses