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21.
Curtis D. Holder 《水文研究》2003,17(10):2001-2010
Fog precipitation occurs when fog droplets are filtered by the forest canopy and coalesce on the vegetative surfaces to form larger water droplets that drip to the forest floor. This study examines the quantity of throughfall compared with incident precipitation produced by the canopy of a lower montane rain forest (2100 m) and an upper montane cloud forest (2550 m) in the Sierra de las Minas Biosphere Reserve, Guatemala. Fog precipitation was measured with throughfall and precipitation gauges from 23 July 1995 to 7 June 1996. Fog precipitation occurred during sampling periods when throughfall exceeded incident precipitation. Fog precipitation contributed <1% of total water inputs in the cloud forest at 2100 m during the 44‐week period, whereas fog precipitation contributed 7·4% at 2550 m during the same period. The depth equivalent of fog precipitation was greater at 2550 m (203·4 mm) than at 2100 m (23·4 mm). The calculation of fog precipitation in this study is underestimated. The degree of underestimation may be evident in the difference in apparent rainfall interception between 2100 m (35%) and 2550 m (4%). Because the apparent interception rate at 2550 m is significantly lower than 2100 m, the canopy probably is saturated for longer periods as a result of cloud water contributions. Data show a seasonal pattern of fog precipitation most evident at the 2550 m site. Fog precipitation represented a larger proportion of total water inputs during the dry season (November to May). Because cloud forests generate greater than 1 mm day?1 of fog precipitation in higher elevations of the Sierra de las Minas, the conservation of the cloud forest may be important to meet the water demands of a growing population in the surrounding arid lowlands. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
22.
SONIA I. ARBONA 《Geographical review》1998,88(1):47-63
ABSTRACT. Large amounts of synthetic pesticides are used in Guatemala to increase the production of nontraditional crops. Almolonga, a township in the western highlands, produces vegetables for markets in Mexico and Central America. Almolongueños make intensive use of limited cultivable land and abundant water resources, as well as sizable amounts of synthetic pesticides. Among Almolongueños, congenital malformations, cancer, anemia, and respiratory infections await substantiated links to exposure to pesticides. The prevalence of infectious and parasitic diseases and nutritional deficiencies—the dominant health concerns—may be heightened by excessive use of pesticides. Public-health initiatives involve the rational use of pesticides or their elimination. 相似文献
23.
Holocene vegetation change in the northern Peten and its implications for Maya prehistory 总被引:1,自引:0,他引:1
An 8400 cal yr record of vegetation change from the northern Peten, Guatemala, provides new insights into the environmental history of the archaeological area known as the Mirador Basin. Pollen, loss on ignition, and magnetic susceptibility analyses indicate warm and humid conditions in the early to mid-Holocene. Evidence for a decrease in forest cover around 4600 cal yr B.P. coincides with the first appearance of Zea mays pollen, suggesting that human activity was responsible. The period between 3450 cal yr B.P. and 1000 cal yr B.P. is characterized by a further decline in forest pollen types, includes an abrupt increase in weedy taxa, and exhibits the highest magnetic susceptibility values since the early Holocene, all of which suggest further agricultural disturbance in the watershed. A brief drop in disturbance indicators around 1800 cal yr B.P. may represent the Preclassic abandonment of the area. Changing pollen frequencies around 1000 cal yr B.P. indicate a cessation of human disturbance, which represents the Late Classic collapse of the southern Maya lowlands. 相似文献
24.
Rebecca Clouser 《Geographical review》2019,109(3):382-398
This paper investigates the long‐term ties between security, development, and fear in Guatemala. I argue that as the development apparatus in Guatemala has long been structured around violence and security concerns, development encounters in the contemporary era continue to be shaped by fear. The confluence of multiple mechanisms of fear, including the legacies of violence, surveillance, and coercion, structure development encounters in profound ways. Drawing on semistructured interviews with development practitioners, I examine their perceptions of fear's impact on development encounters at the local level to highlight the problematic culture of fear rhetoric, which serves to obscure practices through which lived experiences of fear are reproduced. Emphases on social cohesion, solidarity, and behaviors which “better contribute” to development work to mask the racialized elements of these discourses and ultimately serve to silence and delegitimize indigenous demands for structural change and justice in the country 相似文献
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26.
S. ENDO S. R. WALLIS M. TSUBOI R. TORRES DE LEÓN L. A. SOLARI 《Journal of Metamorphic Geology》2012,30(2):143-164
Lawsonite eclogite (metabasalt and metadolerite) and associated metasedimentary rocks in a serpentinite mélange from an area just south of the Motagua fault zone (SMFZ), Guatemala, represent excellent natural records of the forearc slab–mantle interface. Pseudosection modelling of pristine lawsonite eclogite reproduces the observed predominant mineral assemblages, and garnet compositional isopleths intersect within the phase fields, yielding a prograde P–T path that evolves from 20 kbar, 470 °C (M1) to 25 kbar, 520 °C (M2). The dominant penetrative foliation within the eclogite blocks is defined by minerals developed during the prograde evolution, and the associated deformation, therefore, took place during subduction. Thermometry using Raman spectra of carbonaceous material in metasedimentary rocks associated with the SMFZ eclogites gives estimates of peak‐T of ~520 °C. Barometry using Raman spectroscopy shows unfractured quartz inclusions in garnet rims retain overpressures of up to ~10 kbar, implying these inclusions were trapped at conditions just below the quartz/coesite transition, in agreement with the results of phase equilibrium analysis. Additional growth of Ca‐rich garnet indicates initial isothermal decompression to 20 kbar (M3) followed by hydration and substantial cooling to the lawsonite–blueschist facies (M4). Further decompression of the hydrated eclogite blocks to the pumpellyite–actinolite facies (3–5 kbar, 230–250 °C) is associated with dehydration and veining (M5). The presence of eclogite as m‐ to 10 m‐sized blocks in a serpentinite matrix, lack of widespread deformation developed during exhumation and derived prograde P–T path associated with substantial dehydration of metabasites within the antigorite stability field suggest that the SMFZ eclogites represent the uppermost part of the forearc slab crust sampled by an ascending serpentinite diapir in an active, moderate‐T subduction zone. 相似文献
27.
J. P. Laplante 《社会与自然资源》2014,27(3):231-248
Since 2005, more than 78 Maya communities representing approximately one million Guatemalans have held referendums called consultas comunitarias, which ask the community whether they are in agreement with mineral, hydroelectric, and/or other megaprojects in their traditional territory. Participation in the consultas is a form of resistance to the granting of mineral rights to corporate interests. In Canada, where much of the Guatemalan mining investment is based, “socially responsible investment firms” (SRIs) promote corporate respect for Indigenous rights. Based on interviews and participant observation, we highlight the perspectives of Maya consulta organizers in three communities that have undertaken consultas to resist the mining licenses of the Canadian mining company Goldcorp, Inc. We argue that a strict policy of corporate respect for the right to free, prior, and informed consent of affected communities is a minimum requirement for Maya acceptance of SRI legitimacy. 相似文献
28.
W. GEORGE LOVELL 《Geographical review》2013,103(2):199-209
Between 1961 and 1996, more than 200,000 people in Guatemala lost their lives as a result of state‐orchestrated acts of terror denied still by the national security forces who committed them. A U.N. Truth Commission was repeatedly obstructed by army and police personnel from gaining access to official records, being told that no documentation of the type sought existed. Bureaucracies do not work that way, even ones with good reason to destroy or conceal evidence of an incriminating nature. It was nonetheless of startling import when an attorney working for Guatemala's Human Rights Office stumbled upon an archive recording the deeds of the National Police. Known now to contain an estimated 80 million documents, the Archivo Histórico de la Policía Nacional is a cabinet of atrocities that reveals conspiracy and complicity on the part of police officers engaged in a ghoulish network of surveillance, intimidation, abduction, torture, and murder. 相似文献
29.
ABSTRACTField and petrologic characteristics of two new eclogite localities within the Guatemala Suture Complex (GSC) north of the Motagua Fault are presented. The Tuncaj Hill locality exposes a coherent body of retrogressed eclogite hundreds of metres long that is associated with serpentinite of the North Motagua Unit. The Tanilar River locality exposes numerous bands and lenses of eclogite hosted in sialic gneisses of the Chuacús Complex. The Tuncaj eclogite has a two-stage prograde evolution containing the peak assemblage Grt + Omp + Ttn + Czo + Zo ± Am, formed at temperatures <720°C. In contrast, eclogites of the Tanilar unit are characterized by the paragenesis Omp + Grt + Rt ± Phg ± Qtz ± Ep giving higher peak conditions of T = 720–830°C and P = 2.1–2.7 GPa, near the stability field of coesite. Previously obtained data and our thermobaric calculations suggest distinct petrotectonic evolutions for the various types of eclogites within the suture. The lawsonite eclogites south of the Motagua Fault were probably produced in a mature Farallon subduction zone during the Early Cretaceous. The northern high-pressure (HP) blocks in serpentinite mélange and coherent amphibolite bodies with eclogite relics were generated by the Early Cretaceous subduction of the proto-Caribbean lithosphere under the Great Caribbean Arc. A continental block, the North American passive margin, reached the arc’s trench in the Campanian and was subducted to ca. 80 km depth, producing the eclogites of the Chuacús Complex. As the slab was delaminated and partially exhumed, the continental Chuacús became tectonically juxtaposed with HP blocks of the proto-Caribbean that had been accreted to the Caribbean plate forming the North Motagua Unit. The juxtaposed group migrated to mid-crustal level and was contemporaneously retrogressed under epidote-amphibolite facies conditions. 相似文献
30.
Matthew John Taylor 《GeoJournal》2007,69(3):181-198
This paper examines how civil war in Guatemala created and destroyed community cohesion, which, in turn, influences land use
practices in the frontier region of Ixcán today. The impact of civil war on the environment and land use in this region takes
many forms. Some communities took refuge in Mexico. Other communities refused to take refuge in Mexico and also refused to
submit to military rule. These communities of “people in resistance” formed highly cohesive units in order to evade military
detection. The lessons of cooperation and the high levels of cohesion they developed during their years in hiding have carried
over to their successful management of natural resources in post-conflict Guatemala. Return refugees accumulated higher levels
of cohesion while in refuge because they often participated in workshops organized and funded by outside relief agencies.
Higher levels of community cohesion have allowed return refugee communities to better organize and use their land in more
sustainable ways. Other communities did not flee and thus endured military rule. They were forced out of their dispersed land
parcels into concentrated model villages. Concentration of community members forced intensive use of the environment in the
zone immediately surrounding the new settlement. Often, distrust permeated these occupied communities and community cohesion
dipped. Today, these low levels of community cohesion lead to a lack of consensus on how to use land and resources in the
community. The overall goal of the paper is to point out the community level variation in the relationship between military
actions, community cohesion, and the environment.
相似文献
Matthew John TaylorEmail: |