Physical-mechanical behavior of fresh and completely altered rocks as an important factor of slope instability in the El Rosario Monarch Butterfly Sanctuary, Michoacán, Mexico

Slope instability in the Butterfly Biosphere Reserve (RBMM) Michoacán, Mexico, is a widespread phenomenon that results from the complex interaction among different factors such as climate, slope, and the spatial distribution of different rock units. The climate is temperate subhumid, with rains in summer and an annual average rainfall of 700 to 1250 mm. The main physiographic units of the area are volcanic mountains, with slopes greater than 30 degrees. The main scope of this study is to characterize the physical-mechanical properties of fresh and completely altered lower Miocene andesitic lavas of the Sierra de Angangueo (Cerro El Campanario, province of El Rosario, Michoacán) by implementing laboratory tests (bulk density, permeability, porosity, uniaxial compressive strength). The fresh rock sample presents total porosity, permeability, and UCS values of 0.262 mD, 17.1 %, and 63.5 MPa, respectively. Instead, the altered rock display values of 393.71 mD, 60.9 %, and 0.26 MPa. Our results suggest that the slope and the degradation of the rock properties induced by alteration are the conditioning factors of instability in the region. Atypical rainfalls may act as triggering mechanism for slope failure.

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Grupo México: Epítome de la deshumanización y la barbarie del extractivismo

Ecología Política. Cuadernos de debate internacional ◽

10.53368/ep60macep02 ◽

2020 ◽

pp. 24-32

Author(s):

Sol Pérez Jiménez

Keyword(s):

Biosphere Reserve ◽

Monarch Butterfly ◽

Power Elite ◽

Development Discourse ◽

Considerable Evidence ◽

The North ◽

Mexican State ◽

Sea Of Cortes ◽

Mining Projects ◽

The Power Elite

The hegemonic development discourse continues to promote mining as an activity that generates progress despite the considerable evidence to the contrary. The article analyzes Grupo Mexico’s history, the largest mining consortium in the country, as part of the power elite. It shows how it achieved a monopoly of the leading copper deposits in the north of the country thanks to its alliances with the Mexican State. Later on, we present the cartography of the expansion of its operations in the north of the country, including the opening of controversial mining projects in strategic areas for biodiversity conservation such as the Sea of Cortés, the Baja California peninsula and, the Monarch Butterfly Biosphere Reserve in Michoacán. Therefore, it is argued that it is important to consider companies’ environmental and social records when evaluating mining concessions’ renewal or revocation.

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The importance of the traditional fire knowledge system in a subtropical montane socio-ecosystem in a protected natural area

International Journal of Wildland Fire ◽

10.1071/wf15181 ◽

2016 ◽

Vol 25 (9) ◽

pp. 911 ◽

Cited By ~ 9

Author(s):

H. Leonardo Martínez-Torres ◽

Alicia Castillo ◽

M. Isabel Ramírez ◽

Diego R. Pérez-Salicrup

Keyword(s):

Forest Fires ◽

Participant Observation ◽

Ecological Factors ◽

Biosphere Reserve ◽

Animal Husbandry ◽

Monarch Butterfly ◽

Knowledge System ◽

Structured Interviews ◽

Social Rules ◽

Protected Natural Area

The use of fire for traditional agriculture, animal husbandry and forestry is highly important to farmers in developing countries where this practice is continuously blamed as being the main cause of forest fires. That is the case in the Monarch Butterfly Biosphere Reserve (MBBR), Mexico, where paradoxically, little is known about the inhabitants’ traditional uses of fire. In this study we characterise fire users, describe traditional fire uses and identify the ecological and social rules involved in the use of fire in the MBBR. Through participant observation and semi-structured interviews we found a robust body of knowledge among local people regarding the geophysical and ecological factors determining fire behaviour. This information is transferred orally and through everyday practices from parents to children. We identified nine types of fire uses. The most common is ‘mound burns’, which entails a process of extraction-piling-drying-burning of weeds from agricultural fields. Social rules are aimed at decreasing the risk of forest fires. Our results suggest there is a traditional fire knowledge system in the MBBR that has undergone changes and has adapted to the ecological and social reality of the region during the past few decades.

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Flora y Vegetación de las zonas núcleo de la Reserva de la Biosfera Mariposa Monarca, México

Botanical Sciences ◽

10.17129/botsci.1678 ◽

2017 ◽

pp. 43

Author(s):

Guadalupe Cornejo-Tenorio ◽

Alejandro Casas ◽

Berenice Farfán ◽

José Luis Villaseñor ◽

Guillermo Ibarra-Manríquez

Keyword(s):

Cloud Forest ◽

Vascular Plant ◽

Coniferous Forest ◽

Biosphere Reserve ◽

Field Work ◽

Monarch Butterfly ◽

Oak Forests ◽

Vegetation Types ◽

Voucher Specimens ◽

One Year

A study of the flora and vegetation physiognomy was conducted at the core zones of the Monarch Butterfly Biosphere Reserve, in the states of México and Michoacán. Collection of plant specimens was carried out du ring one year of field work and this activity was supplemented by a review of voucher specimens previously collected in the area and deposited at the Mexican herbaria IEB, EBUM, and MEXU. A total of 423 vascular plant species including 32 infraespecific taxa and grouped in 86 families and 244 genera were identified, Families with the largest species richness were Asteraceae (103), Lamiaceae (21), Fabaceae (17), and Scrophulariaceae (17).The most speciose genera were Salvia (13), Stevia (8), and Ageratina (7). Mexican endemic species comprised 135 (31.9%) species, which included 13 infrae spec ific taxa; 40 of these species belong to Asteraceae. Herbs were represented by 326 species, followed by shrubs (5 1) and trees (33). The main vegetation types recognized were coniferous forest (including combinations of fir, pine, and oak forests), cloud forest, anthropogenic grass land, and Quercus forest.

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Numerical Analysis of Soil Slope Stabilization by Soil Nailing Technique

Engineering, Technology & Applied Science Research ◽

10.48084/etasr.2859 ◽

2019 ◽

Vol 9 (4) ◽

pp. 4469-4473

Author(s):

D. A. Mangnejo ◽

S. J. Oad ◽

S. A. Kalhoro ◽

S. Ahmed ◽

F. H. Laghari ◽

...

Keyword(s):

Factor Of Safety ◽

Slope Failure ◽

Limit Equilibrium ◽

Slope Instability ◽

Soil Nailing ◽

Soil Slope ◽

Prevention Measures ◽

Soil Nail ◽

Soil Shear Strength ◽

Nail Diameter

Slope instability may be a result of change in stress conditions, rise in groundwater table and rainfall. Similarly, many slopes that have been stable for several years can abruptly fail due to changes in geometry, weak soil shear strength or as the effect of an external force. Debris flows (i.e. slope failures) take place without any warning and can have devastating results. So, it is vital to understand the slope failure mechanism and adopt safety prevention measures. Soil nailing is one of the widely used stabilization techniques for soil slopes. In this study, soil nail technique is proposed to upgrade the existing slope in clay. A parametric study was conducted to understand the effects of different nail diameter (i.e. 25mm and 40mm) and nail inclination (i.e. 200, 250, 300, 350 and 400) on slope stability. Morgenstern-Price (i.e. limit equilibrium) method was used to determine the factor of safety of the slope. It was found that the factor of safety of the existing slope improved significantly with three rows of 40mm diameter nail at an inclination of 400.

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Characteristics of ground motion and threshold values for colluvium slope displacement induced by heavy rainfall: a case study in northern Taiwan

Natural Hazards and Earth System Science ◽

10.5194/nhess-16-1309-2016 ◽

2016 ◽

Vol 16 (6) ◽

pp. 1309-1321 ◽

Cited By ~ 5

Author(s):

Ching-Jiang Jeng ◽

Dar-Zen Sue

Keyword(s):

Slope Stability ◽

Heavy Rainfall ◽

Slope Failure ◽

Drainage System ◽

Threshold Value ◽

Slope Instability ◽

Disaster Prevention ◽

Strain Gages ◽

Slope Displacement ◽

Northern Taiwan

Abstract. The Huafan University campus is located in the Ta-lun Shan area in northern Taiwan, which is characterized by a dip slope covered by colluvium soil of various depths. For slope disaster prevention, a monitoring system was constructed that consisted of inclinometers, tiltmeters, crack gages, groundwater level observation wells, settlement and displacement observation marks, rebar strain gages, concrete strain gages, and rain gages. The monitoring data derived from hundreds of settlement and displacement observation marks were analyzed and compared with the displacement recorded by inclinometers. The analysis results revealed that the maximum settlement and displacement were concentrated on the areas around the Hui-Tsui, Zhi-An, and Wu-Ming buildings and coincided with periods of heavy rainfall. The computer program STABL was applied for slope stability analysis and modeling of slope failure. For prevention of slope instability, a drainage system and tieback anchors with additional stability measures were proposed to discharge excess groundwater following rainfall. Finally, threshold value curves of rainfall based on slope displacement were proposed. The curves can be applied for predicting slope stability when typhoons are expected to bring heavy rainfall and should be significant in slope disaster prevention.

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The Role of Cover Thickness in the Rainfall-Induced Landslides of Nocera Inferiore 2005

Geosciences ◽

10.3390/geosciences10060228 ◽

2020 ◽

Vol 10 (6) ◽

pp. 228 ◽

Cited By ~ 2

Author(s):

Lucia Coppola ◽

Alfredo Reder ◽

Guido Rianna ◽

Luca Pagano

Keyword(s):

Boundary Condition ◽

Slope Failure ◽

Slope Instability ◽

Critical Duration ◽

Numerical Analyses ◽

Critical Event ◽

Test Case ◽

Soil Suction ◽

Main Function ◽

Cover Thickness

In the context of rainfall-induced landslides involving pyroclastic soils, the present work analyzes the influence of cover thickness on slope stability conditions. To this aim, the slope failure that occurred in Nocera Inferiore (4th March 2005) is selected as a reference test case, providing the actual weather forcing history that preceded the event, the hydraulic characterization of the soil involved, and the lowermost boundary condition (variously fractured calcareous bedrock underlying the cover). By maintaining unchanged soil hydraulic properties, the relationship between domain thickness, initial soil suction distribution, and slope instability induced by critical rainfall is investigated by numerical analyses. These refer to a rigid unsaturated domain subject to one dimensional flow conditions under the effects of incoming (precipitation) and outcoming (evaporation) fluxes applied at the uppermost boundary. The main outcomes indicate that critical event duration increases significantly with increasing the domain thickness. This relationship is strongly influenced by initial suction distribution. A linear relationship results for soil suction that is assumed to be constant at the beginning of the critical event. However, this relationship is quadratic if, by simulating the actual antecedent meteorological conditions, suction at the beginning of the critical event is the main function of the domain thickness. Additional numerical analyses were carried out to characterize the influence of a different lowermost boundary condition. Outcomes indicate that, for the same thickness, critical duration is substantially longer if the cover contact is with the same material as that of the cover.

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