Integration of landslide susceptibility maps for land use planning and civil protection emergency management

Landslides are one of the most relevant geomorphological hazards in Portugal, by the high levels of people affected, destruction of assets and disruption of economic and social activities. Regarding the Portuguese territorial land use planning and emergency management, regulation, practice, prevention and risk management have been promoted in different ways. In Portugal, the areas susceptible to landslides are included in the 'National Ecological Reserve', which is a public utility restriction legal figure that rules the land use planning at the municipal level. In addition, the Municipal Emergency Plans include landslide susceptibility maps that are combined with the map of the exposed elements, allowing the assessment of exposure to landslides. This study is applied to the Loures municipality located to the north of Lisbon. In this municipality 621 landslides registered in a landslide inventory (rotational slides, deep-seated translational slides and shallow translational slides) that affected 1,469,577 m2 (0.87 %) of the Loures territory. The final landslide susceptibility map shows that in Loures municipality 1,347 ha are associated to a Very high landslide susceptibility and 2,372 ha to High landslide susceptibility, which corresponds both to 22.1 % of the entire municipality, and constitutes the larger fraction of the National Ecological Reserve, related to landslides. These areas do not present geomorphological and geotechnical suitability for building structures or infrastructures. From the civil protection and emergency management point of views 34 classes of exposed elements were identified in the municipality, with point, linear and polygonal representations. The elements at risk located in the Very High or High landslide susceptibility classes were summarized and correspond to: high voltage poles; wind turbines; transmission/reception antennas; industrial areas; water tanks; silo; gas station/tank; service area; buildings of educational institutions; worship buildings; buildings of electricity facilities; regular buildings; gas pipeline; motorways; national roads; and municipal roads.info:eu-repo/semantics/publishedVersio

Assessment of physical vulnerability of buildings and analysis of landslide risk at the municipal scale: application to the Loures municipality, Portugal

This study offers a semi-quantitative assessment of the physical vulnerability of buildings to landslides in a Portuguese municipality (Loures), as well as the quantitative landslide risk analysis computed as the product of the landslide hazard by the vulnerability and the economic value of the buildings. The hazard was assessed by combining the spatiotemporal probability and the frequency–magnitude relationship of the landslides. The physical vulnerability assessment was based on an inquiry of a pool of European landslide experts and a sub-pool of landslide experts who know the study area, and the answers’ variability was assessed with standard deviation. The average vulnerability of the basic geographic entities was compared by changing the map unit and applying the vulnerability to all the buildings of a test site, the inventory of which was listed on the field. The economic value was calculated using an adaptation of the Portuguese Tax Services approach, and the risk was computed for different landslide magnitudes and different spatiotemporal probabilities. As a rule, the vulnerability values given by the sub-pool of experts who know the study area are higher than those given by the European experts, namely for the high-magnitude landslides. The obtained vulnerabilities vary from 0.2 to 1 as a function of the structural building types and the landslide magnitude, and are maximal for 10 and 20m landslide depths. However, the highest risk was found for the landslides that are 3m deep, because these landslides combine a relatively high frequency in the Loures municipality with a substantial potential damage.info:eu-repo/semantics/publishedVersio

Degradabilidade ruminal das silagens e produtividade de cultivares de sorgo de tipo forrageiro e granífero

Forages for feeding dairy cows should conciliate the potential for high dry matter yield per unit area, maximizing animal stocking rate, with high nutritive value, which enables decreasing the amount of concentrate feedstuffs per milk unit produced. Eighteen sorghum cultivars were cultivated 0.70 m apart and with 12 plants per linear meter. Plants harvested at the milk-to-dough stage were ensiled in the laboratory. Eleven agronomic and chemical traits were evaluated. Silage samples were incubated in situ and the effective ruminal dry matter degradation (DEF) was calculated assuming a fractional passage rate of -0.04 h-1. Dry matter yield was 13.0 ± 2.3 (mean ± S.D.) t ha-1. The neutral detergent fiber content was 50.3 ± 3.8 and the DEF was 48.8 ± 2.8% (dry matter basis). The average sorghum DEF was 84% of the DEF of a composite sample of 60 corn hybrids simultaneously cultivated, ensiled and ruminally incubated. The 12 forage-type cultivars were taller, more productive, had higher fiber content and lower DEF than the 6 grain and dual purpose-type cultivars. The acid detergent fiber content had the greatest correlation with DEF (r= -0.64). The linear model correlating DEF with productivity was: DEF=54.694 - 0.4449 x t of dry matter ha-1 (r²=0.14). Although there are cultivars that show high productivity and digestibility, it seems to be difficult to conciliate the maximum nutritive value with the maximum productivity of the sorghum crop.Forrageiras para alimentação de vacas leiteiras devem conciliar a alta produção de matéria seca por área, maximizando a taxa de lotação animal, com o alto valor nutritivo, capaz de reduzir a necessidade de alimentos concentrados por litro de leite produzido. Dezoito cultivares de sorgo foram cultivados com espaçamento de 0,70 m e 12 plantas por metro linear. As plantas colhidas ao atingirem o estádio leitoso-pastoso foram ensiladas em laboratório. Onze características agronômicas e químicas foram avaliadas. As silagens foram incubadas in situ e a degradabilidade efetiva da matéria seca no rúmen (DEF) foi calculada assumindo uma taxa de passagem de -0,04 h-1. A produção de matéria seca foi 13,0 ± 2,3 (média ± D.P.) t ha-1. O teor de fibra em detergente neutro foi 50,3 ± 3,8 e a DEF foi 48,8 ± 2,8 (% da matéria seca). A DEF média do sorgo foi 84% da DEF de uma amostra composta de 60 cultivares de milho simultaneamente cultivados, ensilados e incubados no rúmen. Os 12 cultivares do tipo forrageiro foram mais altos, produtivos e fibrosos e tiveram menor DEF que os 6 cultivares graníferos e de duplo propósito. O teor de fibra em detergente ácido foi a característica mais correlacionada à DEF (r=-0,64). O modelo linear correlacionando a DEF à produtividade foi: DEF=54,69 - 0,4449 x t de matéria seca ha-1 (r²=0,14). Apesar de existirem cultivares com alta produtividade e digestibilidade, pode ser difícil conciliar o máximo valor nutritivo com a máxima produtividade na planta de sorgo

Regional rainfall thresholds for landslide occurrence using a centenary database

This work proposes a comprehensive method to assess rainfall thresholds for landslide initiation using a centenary landslide database associated with a single centenary daily rainfall data set. The method is applied to the Lisbon region and includes the rainfall return period analysis that was used to identify the critical rainfall combination (cumulated rainfall duration) related to each landslide event. The spatial representativeness of the reference rain gauge is evaluated and the rainfall thresholds are assessed and calibrated using the receiver operating characteristic (ROC) metrics. Results show that landslide events located up to 10 km from the rain gauge can be used to calculate the rainfall thresholds in the study area; however, these thresholds may be used with acceptable confidence up to 50 km from the rain gauge. The rainfall thresholds obtained using linear and potential regression perform well in ROC metrics. However, the intermediate thresholds based on the probability of landslide events established in the zone between the lower-limit threshold and the upper-limit threshold are much more informative as they indicate the probability of landslide event occurrence given rainfall exceeding the threshold. This information can be easily included in landslide early warning systems, especially when combined with the probability of rainfall above each threshold.info:eu-repo/semantics/publishedVersio

Damaging flood risk in the Portuguese municipalities

Modeling and understanding the impact of climate change on flooding processes in Mediterranean climate areas, namely in southern Europe, is a complex endeavor, which must also consider exposure and vulnerability patterns. Assuming that vulnerability plays a relevant role in explaining the degree of loss due to natural hazards, the present research compares a flood-susceptibility index with a social-vulnerability index and a historical record of flood losses, both aggregated at the municipal level. The purpose of this research is to define municipal flood risk profiles that would rank the 278 municipalities and contribute to the strategic allocation of resources and flood risk management [...]info:eu-repo/semantics/publishedVersio

Aplicação exploratória de análise multicritério para representação municipal da susceptibilidade a cheias rápidas em Portugal continental

[...] Este estudo descreve uma metodologia exploratória de avaliação de susceptibilidade a cheias rápidas para Portugal Continental, adotando uma abordagem multicritério, a partir de um conjunto de 9 fatores condicionantes, definidos ao município: escoamento acumulado, hierarquia fluvial de Strahler, rugosidade, declive, depósitos aluvionares, grau de impermeabilização, litologia de elevada permeabilidade, Landform Classification e escoamento anual. A atribuição do peso de cada fator baseou-se em Análise Hierárquica de Processos (AHP) [...]info:eu-repo/semantics/publishedVersio

Multi-hazard Susceptibility Assessment for Land Use Planning in the Lisbon Metropolitan Area

The Lisbon Metropolitan Area is a risk hotspot in Portugal due to excessive exposure to natural and environmental hazards. In this work, a multi-hazard susceptibility assessment is performed for the 118 parishes that constitute the study area, considering the spatial incidence of seven hazardous processes: earthquakes, tsunami, beach erosion and coastal flooding, coastal erosion and cliff retreat, landslides, floods, and forest fires. The relative importance of hazardous processes was established through the Analytic Hierarchy Process (AHP), based on the frequency-magnitude relationship of each process and its damage capacity. All the parishes exhibiting very high multi-hazard susceptibility have high earthquake susceptibility and most are located in riverine or coastal zones, thus subjected to floods and/or coastal erosion (affecting beaches and/or cliffs).info:eu-repo/semantics/publishedVersio

Can Baited Pitfall Traps for Sampling Dung Beetles Replace Conventional Traps for Sampling Ants?

Ants  and  dung  beetles  are  widely  used  in  monitoring  biodiversity  and  are  considered  excellent  environmental  indicators.  Although  the pitfall trap is the most commonly used method to sample dung beetles and ants in ecological studies, beetles are usually sampled using dung‐baited pitfall traps while ants are sampled using un‐baited pitfalls. In the protocol for collecting the beetles it is necessary to have attractive baits in pitfalls. In order to minimize collection effort and costs and to facilitate logistics, it is necessary to determine if there is an effect of the baits on the biodiversity of ants collected in the same traps. Therefore, the objective of this work was to find out whether baited pitfalls could replace conventional pitfalls for the capture of ants. In a total of 42 areas of native habitat, three baited pitfall traps and three without bait were installed, all in the same transect, equidistant ten meters and in activity for 48 hours. In total, 150 species were collected, of which 131 were recorded in non‐baited pitfalls and 107 in baited pitfalls. Traps without bait contributed to 28% of the total number of species captured in this study, whereas pitfalls with bait contributed only to 12% of the total species caught. However, 60% of the total species were captured regardless of the method. In addition to the loss of species among the types of traps, the effect of the method modifies the species composition. We concluded that depending on the type of study, a small decrease in the number of species and change in the composition can influence the results. Thus, we recommend that baited pitfalls should not replace conventional pitfalls.Palavras-chave: Método de coleta; Protocolo de coleta; Desenho da amostra; Esforço de amostragem