Tsunami risk reduction for densely populated Southeast Asian cities: analysis of vehicular and pedestrian evacuation for the city of Padang, Indonesia, and assessment of interventions     

Manuela Di Mauro  Kusnowidjaia Megawati  Veronica Cedillos  Brian Tucker 《Natural Hazards》2013,68(2):373-404

A major tsunamigenic earthquake is expected in the near future along the coast of West Sumatra Province of Indonesia. In the city of Padang, the arrival time of the tsunami is expected to be ~30 min. Currently, there are approximately 400,000 people in the city living within the potential inundation zone. This study aimed to complement the existing research in appraising possible risk reduction interventions, specifically looking at enabling the timely evacuation of the area. This research, developed in consultation with national and local authorities, emergency planners and NGOs, analysed interventions for tsunami risk reduction in Padang through the development of a pedestrian and vehicular evacuation model and the appraisal of possible solutions to enhance the evacuation rates. Some of the conclusions from this research can be applied to other areas in Southeast Asia where the traffic patterns are similar to those in Padang and where the distance to safety is greater than 4–5 km. For the case of Padang, the results show that pedestrian evacuation is strongly preferable to vehicular evacuation due to the limited road capacity and the high population density. In the present situation, however, 70–80 % of the population in Padang could not evacuate within 30 min, even by foot. Common interventions such as widening roads and building bridges prove to be relatively ineffective in this case due to the large distance that has to be covered in a short time. These interventions would only have a decisive impact if a longer evacuation time was available (more than 60 min). In the case of Padang, the evacuation rate in the first 30 min is strongly dependent on the presence/absence of evacuation shelters, whose effectiveness is limited by the capacity of the structures. Building a few high-capacity and high-resilience structures such as evacuation hills is a more effective and robust evacuation strategy than constructing many small high-raised buildings. Even with evacuation structures, wider roads and bridges, about 20 % of the population would still be unable to reach safety by the time the tsunami arrives. This means about 70,000 people of Padang’s current population, which is rapidly increasing. The building of evacuation shelters may be a viable option for saving lives in the short term, but it is not a sustainable option in the medium to long term. It is therefore also necessary to set up and enforce regulations for land use planning that take into account the tsunami risk and prevent further urban development for the areas that may be affected by a tsunami.  相似文献   

Effect of the dilution process on the attenuation of contaminants in aquifers   总被引：1，自引：1，他引：0  

Manuela Lasagna  Domenico Antonio De Luca  Laura Debernardi  Paolo Clemente 《Environmental Earth Sciences》2013,70(6):2767-2784

This paper discusses the effects of the dilution process on levels of aquifer contamination attenuation, developing analytical equations for application in theoretical and practical cases. The key finding is that, in aquifers, the dilution process causes a reduction of the contaminant concentration. Analytical equations for the assessment of the contaminant attenuation capacity, by means of the dilution process in an aquifer, are put forward. In particular, the attenuation of the contaminant concentration in an aquifer, and thus the dilution, is described by the volumetric flow rate per unit width perpendicular to the flow direction (q _u). Moreover, a classification of q _u was developed, considering six classes of attenuation capacity due to dilution. For the equations validation, nitrate contamination attenuation due to dilution was analysed in two sample areas in Piedmont (North-West Italy). The results confirmed the hypothesis, evidencing high nitrate concentrations in areas with low q _u values, connected to low dilution rate of the contaminant in the groundwater; vice versa, low nitrate concentrations were evidenced in areas with high q _u values, due to a high nitrate dilution rate.  相似文献   

Retrograde resonance in the planar three-body problem     

M. H. M. Morais  F. Namouni 《Celestial Mechanics and Dynamical Astronomy》2013,117(4):405-421

We continue the investigation of the dynamics of retrograde resonances initiated in Morais and Giuppone (Mon Notices R Astron Soc 424:52–64, doi:10.1111/j.1365-2966.2012.21151.x, 2012). After deriving a procedure to deduce the retrograde resonance terms from the standard expansion of the three-dimensional disturbing function, we concentrate on the planar problem and construct surfaces of section that explore phase-space in the vicinity of the main retrograde resonances (2/ $-$ 1, 1/ $-$ 1 and 1/ $-$ 2). In the case of the 1/ $-$ 1 resonance for which the standard expansion is not adequate to describe the dynamics, we develop a semi-analytic model based on numerical averaging of the unexpanded disturbing function, and show that the predicted libration modes are in agreement with the behavior seen in the surfaces of section.  相似文献   

Late Pleistocene–Holocene environmental and climatic history of a freshwater paramo ecosystem in the northern Andes     

Luisa Patiño  Maria Isabel Velez  Marion Weber  César A. Velásquez-r  Santiago David  Manuela Rueda  Ivonne Castañeda  Diana Arboleda 《第四纪科学杂志》2020,35(8):1046-1056

This study presents the first multi-proxy palaeoenvironmental and palaeoclimatic history for northern South America based on the palaeolimnological reconstruction of a pond located in a dry paramo at 3570 masl. During the Last Glacial Maximum (LGM), the study area was under glacial conditions, then during global events Heinrich Stadial 1 (HS1), Bølling–Allerød (BA), and the Younger Dryas (YD), the pond expanded, accumulation rates and proxies for erosion reached the highest values, indicative of humid conditions, with maxima in humidity during the BA and YD. Dry conditions and pond desiccation occurred in the Greenlandian–Northgrippian and by 6010 cal a bp the area was transformed into the mire of today. Comparisons with records from other sites in South America indicate that changes in humidity are most likely controlled by the Intertropical Convergence Zone, mainly during the glacial and postglacial, and by changes in the Pacific Ocean, more pronounced after the YD.  相似文献   

Diel variation in the vertical distribution and schooling behaviour of sardine (Sardina pilchardus) off Portugal     

Zwolinski  Juan; Morais  Alexandre; Marques  Vitor; Stratoudakis  Yorgos; Fernandes  Paul G. 《ICES Journal of Marine Science》2007,64(5):963-972

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Gastric Evacuation in the Juveniles of two Flatfish from a Western Mediterranean Bay     

L. Tito de  Morais 《Marine Ecology》1986,7(3):255-264

Abstract. The gastric evacuation (at 11 ^oC and 19 ^oC) and the relation between prey size and fish size of juveniles of Buglossidium luteum and Arnoglossus thori (Pisces, Heterosomata) are studied. The fish were collected at 20 m depth in the Banyuls Bay (France, Western Mediterranean). B. luteum showed a very rapid evacuation rate at 19 ^oC (2h to 4h for a IgDW meal) and a slower one at 11^oC (9h 30min for a IgDW meal). A. thori showed similar rates at both temperatures (6h 20min to 7 h 30 min for a IgDW meal). The relationship between prey size and predator size showed that A. thori always took larger prey than B. luteum. The diet of the latter changes only slightly with the increasing size of the fish. In contrast, the diet of A. thori changes more rapidly towards larger prey. A hypothesis explaining the contradictory evidence concerning the effect of fish and meal size on gastric evacuation is proposed.  相似文献   

Study of the growth of southern black and white monkfish stocks   总被引：1，自引：0，他引：1  

Duarte  Rafael; Azevedo  Manuela; Pereda  Pilar 《ICES Journal of Marine Science》1997,54(5):866-874

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Past surface instability of Miage debris‐covered glacier tongue (Mont Blanc Massif,Italy): a decadal‐scale tree‐ring‐based reconstruction     

Giovanni Leonelli  Manuela Pelfini 《Boreas: An International Journal of Quaternary Research》2013,42(3):613-622

Debris‐covered glaciers may host several biological forms that colonize the debris cover, especially if the glacier tongue reaches sufficiently low altitudes (down to about 1700 m a.s.l. at Miage Glacier, Western Italian Alps) thus allowing also tree growth. Supraglacial trees colonizing the debris‐covered tongue are strongly influenced in growth and distribution by substrate characteristics and instability. The tree age distribution at Miage Glacier presents a positive gradient towards the glacier terminus, which was found to be related to the decreasing glacier surface velocity. By analysing tree‐ring growth anomalies on the glacier and at a control site at the tree line over the 20‐year period 1987–2006, it was found that trees growing on the glacier presented the highest percentages of abrupt growth changes (AGCs)>+70% with respect to the four previous years. Considering tree displacement on the glacier surface over the same 20‐year period and the recorded AGCs, it was found that the central‐lower portion of the southern lobe towards the margins was the most unstable. The temporal analysis of AGC>+40% confirmed a period of higher glacier surface instability, reaching a maximum in the years 1988 (on lobe S) and 1989 (on lobe N), probably related to the passage of a kinematic wave in the glacier tongue. Our analysis suggests that supraglacial trees hold useful information on the glacier tongue dynamics and that both AGC>+70% and AGC>+40% may be used as a proxy for substrate instability in spatio‐temporal reconstructions in the Alpine environment.  相似文献   

Tellurium isotope compositions of calcium‐aluminum‐rich inclusions     

Manuela A. FEHR  Mark REHKÁMPER  Alex N. HALLIDAY  Bodo HATTENDORF  Detlef GÜNTHER 《Meteoritics & planetary science》2009,44(7):971-984

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Periodic Appearance of Coronal Holes and the Related Variation of Solar Wind Parameters   总被引：1，自引：0，他引：1  

Manuela Temmer  Bojan Vršnak  Astrid M. Veronig 《Solar physics》2007,241(2):371-383

We compared the variability of coronal hole (CH) areas (determined from daily GOES/SXI images) with solar wind (daily ACE data) and geomagnetic parameters for the time span 25 January 2005 until 11 September 2005 (late declining phase of solar cycle 23). Applying wavelet spectral analysis, a clear 9-day period is found in the CH time series. The GOES/SXI image sequence suggests that this periodic variation is caused by a mutual triangular distribution of CHs ∼120° apart in longitude. From solar wind parameters a 9-day periodicity was obtained as well, simultaneously with the 9-day period in the CH area time series. These findings provide strong evidence that the 9-day period in solar wind parameters, showing up as higher harmonic of the solar rotation frequency, is caused by the “periodic” longitudinal distribution of CHs on the Sun recurring for several solar rotations. The shape of the wavelet spectrum from the Dst index matches only weakly with that from the CH areas and is more similar to the wavelet spectrum of the solar wind magnetic field magnitude. The distinct 9-day period does not show up in sunspot group areas which gives further evidence that the solar wind modulation is strongly related to CH areas but not to active region complexes. The wavelet power spectra for the whole ACE data range (∼1998 – 2006) suggest that the 9-day period is not a singular phenomenon occurring only during a specific time range close to solar minimum but is occasionally also present during the maximum and decay phase of solar cycle 23. The main periods correspond to the solar rotation (27^d) as well as to the second (13.5^d) and third (9^d) harmonic. Electronic Supplementary Material The online version of this article () contains supplementary material, which is available to authorized users.  相似文献