Awareness of tsunami natural warning signs and intended evacuation behaviors in Java,Indonesia     

Hall  Sarah  Pettersson  Jessica  Meservy  William  Harris  Ron  Agustinawati  Diannitta  Olson  Jennie  McFarlane  Allayna 《Natural Hazards》2017,89(1):473-496

Natural Hazards - The south coast of Java has a long history of deadly seismogenic tsunamis. The most recent tsunami events in 1994 and 2006 killed hundreds due to lack of awareness and...  相似文献   

East African food security as influenced by future climate change and land use change at local to regional scales   总被引：3，自引：0，他引：3  

Nathan Moore  Gopal Alagarswamy  Bryan Pijanowski  Philip Thornton  Brent Lofgren  Jennifer Olson  Jeffrey Andresen  Pius Yanda  Jiaguo Qi 《Climatic change》2012,110(3-4):823-844

Climate change impacts food production systems, particularly in locations with large, vulnerable populations. Elevated greenhouse gases (GHG), as well as land cover/land use change (LCLUC), can influence regional climate dynamics. Biophysical factors such as topography, soil type, and seasonal rainfall can strongly affect crop yields. We used a regional climate model derived from the Regional Atmospheric Modeling System (RAMS) to compare the effects of projected future GHG and future LCLUC on spatial variability of crop yields in East Africa. Crop yields were estimated with a process-based simulation model. The results suggest that: (1) GHG-influenced and LCLUC-influenced yield changes are highly heterogeneous across this region; (2) LCLUC effects are significant drivers of yield change; and (3) high spatial variability in yield is indicated for several key agricultural sub-regions of East Africa. Food production risk when considered at the household scale is largely dependent on the occurrence of extremes, so mean yield in some cases may be an incomplete predictor of risk. The broad range of projected crop yields reflects enormous variability in key parameters that underlie regional food security; hence, donor institutions’ strategies and investments might benefit from considering the spatial distribution around mean impacts for a given region. Ultimately, global assessments of food security risk would benefit from including regional and local assessments of climate impacts on food production. This may be less of a consideration in other regions. This study supports the concept that LCLUC is a first-order factor in assessing food production risk.  相似文献   

Seeding nature, ceding culture: Redefining the boundaries of the marine commons through spatial management and GIS     

Julia Olson 《Geoforum》2010,41(2):293-303

The oceans are not only being transformed through privatization as management moves towards market mechanisms, the oceans are also being “zoned”, with zoning increasingly proposed as the ideal conduit for weighting different uses of the ocean. This is concomitant with a move towards ecosystem-based management that also partakes in a policy environment imbued with the commodification of nature, in which environmental services are ranked and valued according to neoliberal percepts. Crucial to these projects are the utilization of GIS technologies. This paper considers these zones of preservation and sites of conflict through an ethnographic case study of the scallop fisheries of New England, examining conflicts between harvesters, different projects to map the fishery, and ongoing efforts to reseed scallop beds. The paper explores how participants themselves articulate the changing practices of fishing and farming, redefining boundaries of nature and culture. While reseeding projects, for example, arguably participate in the market logic of neoliberalism, at the same time they may resist and redefine the terms, as communities see themselves sowing the seeds of their own sustainability and changing the terms of what counts, literally, as nature.  相似文献   

Monitoring food web changes in tide-restored salt marshes: A carbon stable isotope approach     

Andrew S. Wozniak  Charles T. Roman  Sam C. Wainright  Richard A. McKinney  Mary-Jane James-Pirri 《Estuaries and Coasts》2006,29(4):568-578

Primary producer (angiosperms, macroalgae, submerged aquatic vegetation), suspended particulate matter, andFundulus heteroclitus isotope values (δ¹³C, δ¹⁵N, δ³⁴S) were examined to assess their use as indicators for changes in food web support functions in tidally-restored salt marshes. Study sites, located throughout the southern New England region (USA), ranged fromSpartina alterniflora-dominated reference marshes, marshes under various regimes and histories of tide restoration, and a severely tide-restrictedPhragmites australis marsh.Fundulus δ¹³C values were greater for fish from referenceSpartina marshes than for fish from adjacent tide-restricted or tide-restored marshes where higher percent cover of C₃ plants, lower water column salinities, and more negative dissolved inorganic δ¹³C values were observed. The difference inFundulus δ¹³C values between a tide-restrictedPhragmites marsh and an adjacent referenceSpartina marsh was great compared to the difference between marshes at various stages of tide restoration and their respective reference marshes, suggesting that food web support functions are restored as the degree of tidal restriction is lessened. While a multiple isotopic approach can provide valuable information for determining specific food sources to consumers, this study demonstrates that monitoringFundulus δ¹³C values alone may be useful to evaluate the trajectory of ecological change for marshes undergoing tidal restoration.  相似文献   

Asymmetric continuum and anisotropy     

Roman Teisseyre 《Acta Geophysica》2006,54(3):225-238

We present a relation between stress moments and antisymmetric part of stresses and the related constitutive law joining those stresses with the particle/point rotations. Correspondence of the asymmetric continuum theory to the micromorphic theory is considered. An extension of the asymmetric continuum theory for the case of 2D anisotropy for antisymmetric stresses leads us to the problems of friction anisotropy and fracture pattern.  相似文献   

Aridic crusts and vein mineralisations in the playa Areg el Makrzene, South Tunisia     

Roman Fromm  Tarek Hachicha  Werner Smykatz-Kloss   《Chemie der Erde / Geochemistry》2005,65(4):357-373

The playa Areg el Makrzene is situated in the north of the escarpment of the Djebel Rehach in southern Tunisia. It is characterised by more than 70 spring mounds which are bound to faults in the Triassic sandstone, and by (sub-) recent calcareous and iron hydroxide precipitations. The artesian spring water contains high amounts of Na⁺, Ca²⁺, Mg²⁺ and Cl⁻, SO₄²⁻, and HCO₃, shows slightly alkaline character and a temperature of 25 °C. The spring mounds consist of porous travertine (calcite), goethite, gypsum and of Na–Mg evaporites and are up to 10 m high. Few metres away from the springs the amorphous iron hydroxides have altered to badly ordered goethite and ferrihydrite and finally to well ordered goethite. The muddy precipitate has altered to hard crusts (calcrete, ferricrete). The source of the precipitated material is discussed.

The faults in the sandstone are filled with (hydr-)oxides of iron and manganese, e.g. with goethite, hollandite and pyrolusite. The amount of Mn-oxides may reach 60 mass%.  相似文献   

Hazard assessment of the Tidal Inlet landslide and potential subsequent tsunami, Glacier Bay National Park, Alaska     

Gerald F. Wieczorek  Eric L. Geist  Roman J. Motyka  Matthias Jakob 《Landslides》2007,4(3):205-215

An unstable rock slump, estimated at 5 to 10 × 10⁶ m³, lies perched above the northern shore of Tidal Inlet in Glacier Bay National Park, Alaska. This landslide mass has the potential to rapidly move into Tidal Inlet and generate large, long-period-impulse tsunami waves. Field and photographic examination revealed that the landslide moved between 1892 and 1919 after the retreat of the Little Ice Age glaciers from Tidal Inlet in 1890. Global positioning system measurements over a 2-year period show that the perched mass is presently moving at 3–4 cm annually indicating the landslide remains unstable. Numerical simulations of landslide-generated waves suggest that in the western arm of Glacier Bay, wave amplitudes would be greatest near the mouth of Tidal Inlet and slightly decrease with water depth according to Green’s law. As a function of time, wave amplitude would be greatest within approximately 40 min of the landslide entering water, with significant wave activity continuing for potentially several hours.  相似文献   

In situ measurement of dissolved chloride in high temperature hydrothermal fluids     

B.I. Larson  E.J. Olson  M.D. Lilley 《Geochimica et cosmochimica acta》2007,71(10):2510-2523

The ability to continuously monitor chemical properties of hydrothermal vent effluents for extended periods of time is essential to understanding dynamic processes responsible for the temporally variable nature of mid-ocean ridge hydrothermal systems. Although instruments do exist for some parameters, there has been no sensor capable of measuring the chloride concentration, an indicator of possible phase separation, on a real-time and long-term basis. In this article, we discuss the construction of a novel instrument which measures solution resistance as a proxy for chloride concentration. The sensor consists of four gold electrodes embedded in a cylindrical ZrO₂ ceramic housing. It has been successfully deployed in several high temperature vents at the Main Endeavour Field (MEF) on the Juan de Fuca ridge in the NE Pacific, and calibrated under simulated hydrothermal conditions ranging up to 380 °C and 300 bar. The in situ data clearly demonstrate a tidal influence on the effluent from some high temperature vents possibly relating to a subsurface mixing process involving non-seawater end-members. Non-tidal changes are used to constrain the sequence and type of controls operating on fluids circulating within the subsurface.  相似文献   

Crystal structure of meteoritic schreibersites: determination of absolute structure     

Roman Skála  Ivana Císařová 《Physics and Chemistry of Minerals》2005,31(10):721-732

Minerals of the schreibersite–nickelphosphide series (Fe,Ni)₃P crystallize in the non-centrosymmetric space group . As a consequence, they can possess two different spatial arrangements of the constituting atoms within the unit cell, related by the inversion symmetry operation. Here, we present the crystal structure refinements from single crystal X-ray diffraction data for schreibersite grains from iron meteorites Acuña, Carlton, Hex River Mts. (three different crystals), Odessa (two different crystals), Sikhote Alin, and Toluca aiming for the determination of the absolute structure of the examined crystals. The crystals studied cover the composition range from ~58 mol% to ~80 mol% Fe₃P end-member. Unit-cell parameter a and volume of the unit cell V, as well as certain topological structural parameters tightly correlate with Fe₃P content. Unit-cell parameter c, on the other hand, does not show such strong correlation. Eight of the nine crystal structure refinements allowed unambiguous absolute structure assignment. The single crystal extracted from Toluca is, however, of poor quality and consequently the structure refinement did not provide as good results as the rest of the materials. Also, this crystal has only weak inversion distinguishing power to provide unequivocal absolute structure determination. Six of the eight unambiguous absolute structure determinations indicated inverted atomic arrangement compared to that reported in earlier structure refinements (here called standard). Only two grains, one taken from Odessa iron and the other from the Hex River Mts. meteorite, reveal the dominance of standard crystal structure setting.  相似文献   

An iterative algorithm for interactive multiobjective programming     

Shlomo P. Neuman  Roman Krzysztofowicz 《Advances in water resources》1977,1(1):1-14

A new iterative algorithm for interactive multiobjective programming is proposed. The algorithm is based on the Lagrange multiplier technique of generating noninferior solutions, and it is shown to converge under certain conditions. It reduces a complex multiobjective problem into a sequence of two-objective problems which the decision maker can handle more easily. The number of two-objective problems with which the decision maker is confronted, as well as the total number of noninferior solutions that must be generated, increase more or less linearly with the number of objectives. Computational efficiency is further enhanced by avoiding the need for regression. The decision maker interacts with the model directly in the functional space, and he is not required to translate his judgment of relative worth into numbers. Due to the iterative nature of the algorithm, the decision maker can articulate his preferences in a progressive manner. Furthermore, he may modify his attitude at any stage of the computation, based on partial results, without adversely affecting the quality of the solution. An example problem previously solved by other methods, including the surrogate worth trade-off approach, is used to illustrate the new algorithm.  相似文献