607 resultados para STEEP


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Toledo, una ciudad laberíntica, de calles estrechas, empinadas y oscuras, en el siglo XV se convirtió en un escenario idóneo para la delincuencia. En tal situación, los regidores, llevados por el ansia de mantener el orden público, dispusieron toda clase de medidas, muchas de las cuales, aunque buscaban reprimir el delito, perseguían fines que iban más allá del resarcimiento de las víctimas del malhechor. A menudo la defensa de la paz pública se priorizó frente a la búsqueda objetiva de los culpables del delito, con el deseo de establecer una imagen poderosa de la justicia.

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Increased occurrence of drought and dry spells during the growing season have resulted in increased interest in protection of tropical water catchment areas. In Mgeta, a water catchment area in the Uluguru Mountains in Tanzania, water used for vegetable and fruit production is provided through canals from the Uluguru South Forest Reserve. The clearing of forest land for cultivation in the steep slopes in the area is causing severe land degradation, which is threatening the water catchment area, livelihoods, and food security of the local communities, as well as the major population centers in the lowlands. In this paper, the economic performance of a traditional cropping-livestock system with East African (EA)-goats and pigs and extensive vegetable production is compared with a more sustainable and environmentally friendly crop-dairy goat production system. A linear programming (LP) crop-livestock model, maximizing farm income considering the environmental constraints in the area was applied for studying the economic performance of dairy goats in the production system. The model was worked out for the rainy and dry seasons and the analysis was conducted for a basic scenario representing the current situation, based on the variability in the 30 years period from 1982-2012, and in a scenario of both lower crop yields and increased crop variability due to climate change. Data obtained from a sample of 60 farmers that were interviewed using a questionnaire was used to develop and parameterize the model. The study found that in the steep slopes of the area, a crop-dairy goat system with extensive use of grass and multipurpose trees (MPTs) would do better than the traditional vegetable gardening with the EA goat production system. The crop-dairy goat system was superior both in the basic and in a climate change scenario since the yield variation of the grass and MPTs system was less affected compared to vegetable crops due to more tree cover and the use of perennial grasses. However, the goat milk production in the area was constrained by inadequate feeding and lack of an appropriate breeding program. Hence, farmers should enhance goat milk production by supplementing with more concentrate feed and by implementing goat-breeding principles. Moreover, policy measures to promote such a development are briefly discussed.

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The Mount Meager Volcanic Complex (MMVC) in south-western British Columbia is a potentially active, hydrothermally altered massif comprising a series of steep, glaciated peaks. Climatic conditions and glacial retreat has led to the further weathering, exposure and de-buttressing of steep slopes composed of weak, unconsolidated material. This has resulted in an increased frequency of landslide events over the past few decades, many of which have dammed the rivers bordering the Complex. The breach of these debris dams presents a risk of flooding to the downstream communities. Preliminary mapping showed there are numerous sites around the Complex where future failure could occur. Some of these areas are currently undergoing progressive slope movement and display features to support this such as anti-scarps and tension cracks. The effect of water infiltration on stability was modelled using the Rocscience program Slide 6.0. The main site of focus was Mount Meager in the south- east of the Complex where the most recent landslide took place. Two profiles through Mount Meager were analysed along with one other location in the northern section of the MMVC, where instability had been detected. The lowest Factor of Safety (FOS) for each profile was displayed and an estimate of the volume which could be generated was deduced. A hazard map showing the inundation zones for various volumes of debris flows was created from simulations using LAHARZ. Results showed the massif is unstable, even before infiltration. Varying the amount of infiltration appears to have no significant impact on the FOS annually implying that small changes of any kind could also trigger failure. Further modelling could be done to assess the impact of infiltration over shorter time scales. The Slide models show the volume of material that could be delivered to the Lillooet River Valley to be of the order of 109 m3 which, based on the LAHARZ simulations, would completely inundate the valley and communities downstream. A major hazard of this is that the removal of such a large amount of material has the potential to trigger an explosive eruption of the geothermal system and renew volcanic activity. Although events of this size are infrequent, there is a significant risk to the communities downstream of the complex.

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Recently, water was observed flowing from a section of steep slope along US-2 near St. Ignace, Michigan in addition to soil sloughing in the area where the water is flowing from the slope. An inspection of the area also showed the presence of sinkholes. The original construction drawing for US-2 also indicated that sinkholes were present in this area prior to road construction in 1948. An investigation was conducted to determine the overall stability of the slope. The slope consists primarily of aeolian sand deposits. Laboratory testing determined the shear strength of the slope material to have a friction angle around 30°, which is also the slope angle. Thus, the slope is at its maximum angle for stability—however, the slope is also heavily wooded which provides additional support to the slope. Although the area surrounding the water flow has been sloughing, the remaining slope remains intact.

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We quantified the ecosystem effects of small-scale gears operating in southern European waters (Portugal, Spain, Greece), based on a widely accepted ecosystem measure and indicator, the trophic level (TL). We used data from experimental fishing trials during 1997 to 2000. We studied a wide range of gear types and sizes: (1) gill nets of 8 mesh sizes, ranging from 44 to 80 mm; (2) trammel nets of 9 inner panel mesh sizes, ranging from 40 to 140 mm; and (3) longlines of 8 hook sizes, ranging from Nos. 15 (small) to 5 (large). We used the number of species caught per TL class for constructing trophic signatures (i.e. cumulative TL distributions), and estimated the TL at 25, 50 and 75% cumulative frequency (TL25, TL50, TL75) and the slopes using the logistic function. We also estimated the mean weighted TL of the catches (TLW). Our analyses showed that the TL characteristics of longlines varied much more than those of gill and trammel nets. The longlines of large hooks (Nos. 10, 9, 7, 5) were very TL selective, and their trophic signatures had very steep slopes, the highest mean TL50 values, very narrow mean TL25 to TL75 ranges and mean TLW > 4. In addition, the mean number of TL classes exploited was smaller and the mean TL50 and TLW were larger for the longlines of small hooks (Nos. 15, 13, 12, 11) in Greek than in Portuguese waters. Trammel and gill nets caught more TL classes, and the mean slopes of their trophic signatures were significantly smaller than those of longlines as a group. In addition, the mean number of TL classes exploited, the mean TL50 and the TLW of gill nets were significantly smaller than those of trammel nets. We attribute the differences between longlines of small hooks to bait type, and the differences between all gear types to their characteristic species and size-selectivity patterns. Finally, we showed how the slope and the TL50 Of the trophic signatures can be used to characterise different gears along the ecologically 'unsustainable-sustainable' continuum.

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O trabalho apresenta a organização espacial do uso da terra no município de Agudo-RS. Pode-se ver que a ocupação tem uma forte relação com relevo. A atividade de cultivo de arroz está em áreas de baixa declividade(menos de 5%), constituído por rampas, cultivo de tabaco realiza-se em porções de declividades intermediárias(menos de 15 %), as colinas,e a presença de árvores é concentrada em áreas de encostas (mais de 30%), morros e associações de colina. Proposta para ocupação do atual município, envolvem estudos de características físicas e ambientais.This paper presents the spatial organization of the land use in the county of Agudo-RS.  One can see that the occupation has a strong relationship with relief, thus, the activity of rice cultivation in areas consisting of low slope, the ramps (less than 5%), tabacco farming in portions of intermediate slopes, the hills (less than 15%) and the presence of trees is concentrated in areas of steep slopes, associations of hills and hillock (more than 30%). Proposition to occupation of the current council, involve studies of  physical and environmental characteristics.

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Purpose Inadequate soil use and management practices promote commonly negative impacts on the soil constituents and their properties, with consequences to ecosystems. As the soil mineralogy can be permanently altered due to soil use, this approach can be used as a tool to monitor the anthropogenic pressure. The objective of the present study was to assess the mineralogical alterations of a Brazilian regosol used for grape production for 40 years in comparison with a soil under natural vegetation (forest), aiming to discuss anthropogenic pressure on soils. Material and methods Soil samples were collected at depths of 0?0.20 and 0.20?0.40 m from vineyard production and natural vegetation sites. Physical and chemical parameters were analysed by classic approaches. Mineralogical analyses were carried out on <2 mm, silt and clay fractions. Clay minerals were estimated by the relative percentage of peak surface area of the X-ray patterns. Results and discussion Grape production reduced the organic matter content by 28% and the clay content by 23% resulting in a decreasing cation exchange capacity. A similar clay fraction was observed in both soils, containing kaolinite, illite/mica and vermiculite with hydroxy-Al polymers interlayered. Neither gibbsite nor chlorite was found. However, in the soil under native vegetation, the proportion of illite (79 %) was higher than vermiculite (21 %). Whereas, in the soil used for grape production during 40 years, the formation of vermiculite was promoted. Conclusions Grape production alters the proportions of soil constituents of the regosol, reducing clay fraction and organic matter contents, as well as promoting changes in the soil clay minerals with the formation of vermiculite to the detriment of illite, which suggests weathering acceleration and susceptibility to anthropogenic pressure. Recommendations and perspectives Ecosystems in tropical and subtropical climates can be more easily and permanently altered due to anthropogenic pressure, mainly as a consequence of a great magnitude of phenomena such as temperature amplitude and rainfall that occurs in these regions. This is more worrying when soils are located on steep grades with a high anthropogenic pressure, like regosols in Southern Brazil. Thus, this study suggests that changes in soil mineralogy can be used as an important tool to assess anthropogenic pressure in ecosystems and that soil quality maintenance should be a priority in sensible landscapes to maintain the ecosystem quality.