125 resultados para landform


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Camera Botanica 1 - testing a design process (unrealised buildings). ---------- Sited in a highly biodiverse and bushfire prone heathlands on the South-east coast of Western Australia, Camera Botanica 1 is a test of a new design methodology for achieving ecologically sustainable architecture in biodiverse, bushfire prone landscapes. ---------- The design methods were intensively site-based with the author-designer conducting his own site surveys using high-end professional grade surveying equipment such as: Real Time Kinematic GPS (landform survey); Terrestrial laser scanning (vegetation survey); laser levelling and Total Station surveys (erection of scaffolds and contour lines). ---------- This was the first time, internationally, that terrestrial laser scanning was used to measure vegetation. These precise surveys enabled the construction of highly detailed models and drawings - a facility that has not been available prior to this technology. ---------- Designed for a real client and a real site - Camera Botanica 1 is a hypothetical design outcome which demonstrates the efficacy of a new design methodology and thus expands on knowledge of the applicability of new surveying technologies to the design of ecologically sustainable architecture in biodiverse landscapes.

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Camera Botanica 2 - testing a design process (unrealised building). Sited in a highly biodiverse and bushfire prone heathlands on the South-east coast of Western Australia, Camera Botanica 2 is a test of a new design methodology for achieving ecologically sustainable architecture in biodiverse, bushfire prone landscapes. ---------- The design method was intensively site-based with the author-designer conducting his own site surveys using high-end professional grade surveying equipment such as: Real Time Kinematic GPS (landform survey); Terrestrial laser scanning (vegetation survey); laser levelling and Total Station surveys (erection of scaffolds and contour lines). ---------- This was the first time, internationally, that terrestrial laser scanning was used to measure vegetation. These precise surveys enabled the construction of highly detailed models and drawings - a facility that has not been available prior to this technology. ---------- Designed for a real client and a real site - Camera Botanica 2 is a hypothetical design outcome which demonstrates the efficacy of a new design methodology and thus expands on knowledge of the applicability of new surveying technologies to the design of ecologically sustainable architecture in biodiverse landscapes.

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It is a matter of public record that the former Prime Minister of Australia, the Honourable Paul Keating, upset certain Australian architects with his intervention into the redevelopment of the 22-hectare “Barangaroo” site on Sydney Harbour. While Keating’s intervention continues to provide engaging theatre for Sydney residents the debate is also an interesting expression of the narrative of contestation that has been played out historically about the waters of Sydney Harbour. From a cultural studies perspective, the Harbour, and the Sydney Harbour Bridge, has been for many years a political and imaginative space that captures a diversity of local and national preoccupations. Keating’s announcement that planners have a “once-in-200-year opportunity to call a halt to the kind of encroachments we have seen in the past” is in fact another moment in the long history of disputation over the impact of the man-made environment on the natural landform in this area. This paper addresses the spaces of Sydney Harbour as represented in recent debates and in writing and film from previous decades. The argument suggests that the Harbour is a complex site of public and private enactment that is played out in a diverse range of cultural representations. In particular, the paper notes the work of Michel de Certeau on the mythic qualities of certain spaces in relation to the space of the Harbour. ‘The Greatest Harbour in the World’ argues that the Harbour, and the Bridge, fulfils a particular historical and cultural function that gives this space a set of meanings that are well beyond the typical parameters of urban development.

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Determination of the environmental factors controlling earth surface processes and landform patterns is one of the central themes in physical geography. However, the identification of the main drivers of the geomorphological phenomena is often challenging. Novel spatial analysis and modelling methods could provide new insights into the process-environment relationships. The objective of this research was to map and quantitatively analyse the occurrence of cryogenic phenomena in subarctic Finland. More precisely, utilising a grid-based approach the distribution and abundance of periglacial landforms were modelled to identify important landscape scale environmental factors. The study was performed using a comprehensive empirical data set of periglacial landforms from an area of 600 km2 at a 25-ha resolution. The utilised statistical methods were generalized linear modelling (GLM) and hierarchical partitioning (HP). GLMs were used to produce distribution and abundance models and HP to reveal independently the most likely causal variables. The GLM models were assessed utilising statistical evaluation measures, prediction maps, field observations and the results of HP analyses. A total of 40 different landform types and subtypes were identified. Topographical, soil property and vegetation variables were the primary correlates for the occurrence and cover of active periglacial landforms on the landscape scale. In the model evaluation, most of the GLMs were shown to be robust although the explanation power, prediction ability as well as the selected explanatory variables varied between the models. The great potential of the combination of a spatial grid system, terrain data and novel statistical techniques to map the occurrence of periglacial landforms was demonstrated in this study. GLM proved to be a useful modelling framework for testing the shapes of the response functions and significances of the environmental variables and the HP method helped to make better deductions of the important factors of earth surface processes. Hence, the numerical approach presented in this study can be a useful addition to the current range of techniques available to researchers to map and monitor different geographical phenomena.

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The water content distribution in the surface layer of Maoping slope has been studied by testing the water content at 31 control sites. The water content profiles at these sites have also been determined. The water content distributions at different segments have been obtained by using the Kriging method of geostatistics. By comparing the water content distributions with the landform of the slope, it was shown that the water content is closely dependent on the landform of the slope. The water content distribution in the surface layer provided a fundamental basis for landslide predication and treatment.

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Based on the fact that the concentration flowlines of overland flow depend on the surface landform of hillslope, a kinematic wave model was developed for simulating runoff generation and flow concentration caused by rainfall on hillslopes. The model-simulated results agree well with experimental observations. Applying the model to the practical case of Maoping slope, we obtained the characteristics of runoff generation and infiltration on the slope. Especially, the simulated results adequately reflected the confluent pattern of surface runoff, which offers a scientific foundation for designing the drainage engineering on the Maoping slope.

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本文主要通过大量的植物群落学调查和植被、环境状况的数量分析,分别从植物区系、森林群落及其主要木本物种、干扰和物种多样性五个方面分析了三峡大老岭地区山地植被景观的空间格局及其与环境因子的关系,结果表明: 1) 植物区系:科的分布区类型以热带性质为主;属一级温带性质明显,北温带、东亚和泛热带诸分布类型突出;区系上属于华中植物区系地区的东部。 2) 在垂直梯度上:种子植物属热带分布诸类的比例自海拔400至800米(~1100米)之间呈上升趋势,然后下降;温带分布的第8、9、10、11类随海拔而上升;地中海-中亚中心分布的第12、13类只见于比较干热的河谷地带;东亚分布和中国特有属在海拔900~1100m和1600~1800m段取得小的峰值;世界分布属的比例随海拔而上升,蕨类植物属则相反。 分别用种子植物属的分布型比列构成,和全部521个属的种类数量,对15个海拔段作聚类分析:前者首先反应了海拔1100~1200m处的划分,与植被干扰状况的垂直分布差异一致;后者强调了海拔900/1000m和1800/1900m 处的分异,可能反映了地带性常绿阔叶林基带/常绿落叶阔叶混交林带,和常绿落叶阔叶林带/落叶阔叶林带的分异。 3) 对本地区森林植被的数量分类结果表明:基本上可以分为中低海拔次生落叶 针阔混交林和中高海拔山地常绿落叶阔混交林两大群。第一群主要包括栓皮栎林-杉木林-马尾松林组(低海拔段)和短柄抱栎林-锥栗林组(中低海拔段)。第二群包括中低海拔沟谷常绿阔叶林组、中海拔段常绿落叶阔叶混交林组和高海拔段米心水青冈林-茅栗林组。 DCCA排序区分了11个群落类型或群落组。采用的7个地貌因子变量中效果显著的可归纳为三组:①海拔,主要反映热量和降水梯度;②坡度和坡位,可能主要反映土壤厚度及其水分和养分状况;③坡向及坡位,反映光照条件。其中植被格局的海拔梯度效应最显著。沿海拔梯度分段分析上述诸因子对植被格局差异影响的垂直分布,表明海拔因子的局部效应在海拔600-800m和1500-1700m段最显著;坡向的效应在海拔1600m以上最突出;坡面、坡位、坡形、坡度等因子的作用在海拔中部最大。对植被格局影响因子的贡献进行定量分离,表明地形对对大老岭森林格局具有强烈的控制作用。 4) 对大老岭森林植被275个主要的木本种类进行TWINSPAN分类,得到16个种组;DCCA排序结果将上述16组合并为8群,两方面都主要反映了沿海拔和坡位+坡向的分化;海拔中部的局部地形差异导致物种组的分化比两端更细致和强烈。 根据物种生活型及其在植物群落中的地位,分6个种组进行排序和环境解释,表明:①尽管低海拔地段受到强烈人为干扰,常绿种类仍显示了数量和性质沿海拔梯度的变化;②珍稀物种在海拔梯度上形成两个相对集中的区段,大致对应于山地常绿落叶阔叶混交林带的上下边缘;③先锋树种在中低海拔的中上坡位富集;④在中、高海拔的中低坡位,落叶的乔木伴生种显示了极大的多样性;⑤为数不多的针叶树种在海拔和局部地形梯度上也有明确分异;⑥它们和落叶的栎(Quercus)、栗(Castanea)、水青冈(Fagus)、鹅耳枥(Carpinus)属物种在大老岭地区不同地形部位的植被中起着主要的建群作用。 具体统计海拔梯度上,常绿和落叶的乔、灌木4类物种分布的种数变化表明:海拔1100m以下人为活动干扰与木本物种多样性呈一致的负相关;海拔1100m以上常绿种减少与与落叶种的增加形成对照;1100~1700m之间是落叶乔木种最丰富的地段,海拔1700m以上四类物种数量急剧下降,与山顶脊附近生境多样性降低、植物群落类型趋同有关。另外,典型亚热带的棕榈和蕉只见于海拔1000m以下;针叶树种以海拔1150m左右为界分成两组。前述4类物种的分布边界在海拔850~1050m和海拔1650~1750m之间形成比较明显的峰值,基本对应着山地常绿落叶阔叶混交林带的上下边缘。 根据海拔分布范围,将样方中出现的558种木本植物按常绿乔/灌种和落叶乔/灌种分别分成5个热量生态类群。统计各自的面分比表明:a. 落叶灌木种的多样性分布重心在海拔梯度上的位置比落叶乔木种高,常绿种则相反,因此灌木和类的分布特征能更好的反映次生环境中的植被-气候关系;b. 在海拔850~1850m的木本物种形成巨大的多样性,仅出现于这一段的物种也很可观;亲缘物种的分化和替代突出,反映其对生物多样性发生和维持的意义重大;c. 亚热带中山地带对落叶种生物多样性的意义远大于常绿种。 5)统计全部群落样方内枯立木、倒伏木、断头木和伐桩四类受干扰木的大小、数量、物种以反映地形对干扰的影响:①枯立木以2~15cm径级个体为主,小径级的树种选择性不强,主要分布在山南坡口上坡位,海拔1800m以上尤多,在陡峭的坡地中部减少;其大径级个体的物种构成和分布格局反映了与生境干旱有关干扰的存在。②倒伏木主要分布在海拔1200~1800m之间坡面中部和顶脊两侧,发生频率与坡度成正比;坡地中部以中、小径级阳性树种为主,山坡顶脊两侧的倒伏木则多为大径级的群落优势种。③断头木主要分布在海拔1200~1700m,和海拔1900m以上。小径级的断头木分布格局接近于枯立木,较大径级的断头木则多与倒伏木的分布相关,断头木中少有典型的阳性树种,主要由林下荫耐种构成。④人为砍伐的伐桩主要为中大径级的植被建群种或优势种个体,在海拔1000m以下,1100-1200m和1600-1800m形成三个峰值,其分布主要与人口密度、生产方式、林木种类以及交通运输便捷程度有关,通常沟谷和山脊线上的伐桩密度较大。大老岭地区人为干扰主要反映在海拔1100m以下,自然干扰的格局在海拔1100m以上才得到反映。 6)在不同取样尺度上,对大老岭地区森林群落各层次α多样性和β多样性的空间格局分析表明:i. 乔木层α多样性在海拔1200-1800m之间取值较高,灌木、草本层α多样性的垂直梯度不显著,但在海拔1200-1800m之间的波动变化较为剧烈,南坡面有最丰富的灌木层多样性而西坡乔木层的物种最丰;从植被整体上,海拔1000m以下物种丰富度较低,1000-1700m之间变化剧烈,1700m以上丰富度水平较高。ii. 海拔1000-2000m之间94个样方中,乔、灌、草三层多种生物多样性指数变化影响因子的大小顺序是:坡位>海拔>坡向>坡面>坡度>坡形。乔、灌、草各层几种多样性指数在多维的地形因子梯度上形成各异的分布格局,反映了山地物种多样性格局控制因子的多样性和多尺度,及局部地形因子对景观尺度上生物多样性空间格局的强烈影响。iii.对海拔1050m和1670m处植被α多样性的变尺度分析表明:随取样尺度增大,低海拔乔木、灌木层α多样性增长速率比高海拔大;后者草本层的多样性增长比较快。海拔1050m处群落各层的α多样性在800m~2尺度上渐近稳定;海拔1670m处,400m~2尺度上各层α多样性指数已基本稳定。 南、北、西坡面β多样性沿海拔梯度大致减少,在海拔1600m以上更明显,在海拔梯度中部变化剧烈。反映不同坡面上群落间异质性水平是:西坡>北坡>南坡。 在对植被、环境上述各个方面的格局特征分析基础上,对三峡地区侵入岩山地类型建立了一个综合的植被景观格局模式。 文章最后就两个景观尺度植被-环境的综合性问题进行了讨论:1)气候、植物区系、植被和物种分布等对老岭以至于三峡地区和亚热带山地常绿落叶阔叶混交林带的位置、宽度的反映;和气候、地形、干扰等因子对这一生态过渡带格局和动态的影响;2)三峡地区生物多样性垂直分布的特征、维持和变化的现代机制,以及保护的重点和策略

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During 28-29, September 2005, water was drawn from Hanjiang River and Houguan Lake to the Yangzi River via Sanjiao Lake and Nantaizi Lake in Wuhan in order to provide favorable conditions for ecosystem restoration. To evaluate the feasibility and validity of drawing water as a means of ecosystem restoration, zooplankton populations were studied 3 times (before, immediately after finishing and a month after drawing water) at seven locations from 27 Sept. 2005 to 2 Nov. 2005. Water quality in the lakes was mostly improved and zooplankton species richness decreased as soon as drawing water had finished but increased a month after drawing water. Zooplankton density and biomass was reduced in the lakes by drawing water but was increased at the entrance to Sanjiao Lake because of landform geometry change. Before drawing water, most species in Sanjiao Lake e.g., Brachionus sp. and Keratella sp. were tolerant of contamination. After drawing water oligotrophic-prone species such as Lecane ludwigii and Gastropus stylifer emerged. We conclude that drawing water could be important for improving water quality and favour ecosystem restoration. Dilution of nutrient concentrations may be an important role in the effect.

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研究了黄土沟壑区小流域塬面、坡地、梯田和沟道土壤微量元素的剖面分布特征,以揭示不同地形条件下微量元素的有效性及地球化学特性.结果表明,不同土层土壤全量微量元素的变异系数均小于15%,为小变异土壤性质,有效态和吸附态铁和锰的变异系数均高于36%,为高度变异土壤性质;有效态和吸附态锌和铜属于中到高度变异.全量铁、锰和铜以沟道土壤较高,全锌、有效态和吸附态微量元素含量以塬面土壤较高.不同形态微量元素的剖面分布趋势取决于地形条件.不同地形下成土过程及不同地形条件所对应的土地利用方式造成了全量微量元素的差异,而土壤有机质含量的差异是不同地形条件下有效态和吸附态微量元素剖面分布特征不同的主要原因.

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植被生态序列是小地形对植被空间分布影响的反映。采用样线法,对安塞纸坊沟支沟拐沟中南北向短坡面深沟谷和长坡面浅沟谷断面进行植被调查,分析其植被生态序列特征、物种组成及物种多样性。结果表明:短坡面深沟谷序列主要以灌乔木等演替后期物种为主,而长坡面浅沟谷序列则主要为草本物种;同一序列中,阴坡、沟谷地具有比阳坡、沟间地复杂的演替后期群落;序列中物种主要由菊科(Compositae)、豆科(Leguminoseae)和禾本科(Gramineae)构成,生活型主要为多年生草本,生态型以旱生、中旱生为主。α多样性指数在阴坡和短坡面深沟谷序列较高,β多样性指数在地形变化活跃的沟缘线区较高。研究结果可为黄土丘陵沟壑区植被建设人工调节提供参考依据。

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     Over the past two decades, magnetoclimatological studies of loess-paleosol sequences in the Chinese Loess Plateau (CLP) have made outstanding achievements, which greatly promote the understanding of East Asian paleomonsoon evolution, inland aridification of Asia, and past global climate changes. Loess magnetic properties of the CLP have been well studied. In contrast, loess magnetic properties from outside the CLP in China have not been fully understood. We have little knowledge about the magnetic properties of loess in the Ili Basin, an intermontane depression of the Tianshan (or Tien Shan) Mountains. Here, we present the results of rock magnetic measurements of the Ili loess including mass magnetic susceptibility (χ) and anhysteretic remanent magnetization (ARM), high/low temperature dependence of susceptibility (TDS) and hysteresis, as well as X-ray diffraction (XRD) for mineral analysis. Based on the comparison with loess-paleosol sequences in the CLP (hereafter referred to as the Chinese loess), we discuss the possible magnetic susceptibility enhancement mechanism of the Ili loess. The results show that 1) the total magnetic mineral concentration of the Ili loess is far lower than that of the Chinese loess, though they have similar magnetic mineral compositions. The ferrimagnetic minerals in the Ili loess are magnetite and maghemite, and the antiferromagnetic mineral is hematite; XRD analysis also identifies the presence of ilmenite. The ratio of maghemite is lower in the Ili loess than in the Chinese loess, but the ratios of magnetite and hematite are higher in the Ili loess than in the Chinese loess. 2) The granularity of magnetic minerals in the Ili loess, dominated by pseudo-single domain (PSD) and multi-domain (MD) grains, is generally much coarser than that of the Chinese loess. Ultrafine pedogenically-produced magnetic grains have a very limited contribution to the susceptibility enhancement. Rather, PSD and MD particles of magnetite and maghemite are the main contributors to the enhancement of susceptibility in the Ili loess. 3) The susceptibility enhancement mechanism for the Ili loess is complicated and superimposes both a wind velocity/vigor model (Alaskan or Siberian model) and the in situ ultrafine grain pedogenic model; the former might play an important role in the Ili loess. 4) Magnetic susceptibility enhancements of the Ili loess are related not only to the eolian input of the source area, but also to the local climate, landform, and geological background. Therefore, great care should be taken when reconstructing paleoclimate using magnetic susceptibility data from the Ili loess.

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Landscape agriculture is the combination of landscape ecology and agriculture. Its basic idea is from the system theory and landscape ecology. Now landscape agriculture is getting more and more attention because of its multi-functional roles. For example, it can exploit the agricultural ecosystem more rationally, make full use of the self-adjustment function of the natural patches and corridors in the field, as well as the effects from landform types and topological components. It uses regenerative biological energy to a large extent, constitutes beautiful scenic view and protects the diversity of genetics, species, ecosystems and landscapes. Landscape agriculture emphasizes environment improvement, bio-diversity protection and tourism development, thus provides new possibility for the increase of economical benefits and gets the positive feedback loop started. An example from the former Soviet Union is presented as well in this paper

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地形条件是影响黄土高原地区土壤性质分布的主要因素,研究不同地形条件下土壤性质的分布是合理评价黄土区土壤质量状况的重要前提。论文研究了黄土高原沟壑区小流域地形条件对土壤性质剖面分布的影响,结果表明土壤硝态氮、速效磷、碱性磷酸酶和蔗糖酶为高度变异的土壤性质;pH值和过氧化氢酶为小变异土壤性质。塬面和沟道土壤pH值和过氧化氢酶活性较低,阳离子交换量较高。土壤有机质、全氮、全磷、速效磷、碱性磷酸酶和蔗糖酶活性在土壤剖面随土层深度的增加逐渐降低,且均表现为塬面>梯田>坡地>沟道的趋势。不同地形条件下土壤pH值的变化由地形条件引起的土壤过程及硝态氮在土壤中的累积引起;阳离子交换量的变化由成土过程、pH值和有机质的差异引起;土壤有机质及氮、磷养分的差异由与地形条件对应的土地利用方式引起;土壤酶活性的差异则是有机质的差异引起的。

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以土壤水分条件及地形等因素为依据 ,进行了立地条件类型的划分 ,共划分了 3个类型组和 9个类型 ,并提出了小流域林草布局的典型模式。根据立地条件类型划分和小流域布局模式可以看出 ,延安研究区有条件发展乔木林 ,但并不是到处都可发展乔木林 ,因此 ,依据立地条件类型进行造林种草的合理布局进行植被建设是取得成功的必要措施。