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Earth surface systems - Complexity, order and scale
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This book provides a theory to overcome the problem of identifying the principles behind the interdependence of different aspects of nature. Climate, vegetation, geology, landforms, soils, hydrology, and other environmental factors are all linked. Many scientists agree that there must be some general principles about the way in which earth surface systems operate, and about the ways in which the interactions of the biosphere, lithosphere, hydrosphere, and atmosphere manifest themselves. Yet there may be inherent limits on our ability to understand and isolate these interactions using traditional reductionist science. The argument of this book is that the simultaneous presence of order and chaos reflects fundamental, common properties of earth surface processes and systems. It shows how and why this is the case, with examples ranging from evolutionary and geological times scales to microscale examinations of process mechanics.
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... This matrix describes vectors of delay space coordinates that estimate the original phase space generating the dynamics of X [40,41]. The eigenvalues that can be calculated from the Jacobian matrix are local Lyapunov exponents, used in diagnostic analysis of chaotic systems [64], including in geomorphology [65] and ecology [51]. ...
... This matrix describes vectors of delay space coordinates that estimate the original phase space generating the dynamics of [40,41]. The eigenvalues that can be calculated from the Jacobian matrix are local Lyapunov exponents, used in diagnostic analysis of chaotic systems [64], including in geomorphology [65] and ecology [51]. ...
Dynamics of arable and pastoral farming systems in Scotland over the period 1867–2020 are documented using time series analysis methods, including for nonlinear dynamical systems. Results show arable and pastoral farming, at a national scale, are dynamic over a range of timescales, with medium- and short-term dynamics associated with endogenous system forces and exogenous factors, respectively. Medium-term dynamics provide evidence of endogenous systems-level feedbacks between farming sectors responding to change in world and national cereal prices as an economic driver, and act to dampen impacts of exogenous shocks and events (weather, disease). Regime shifts are identified in national cereal prices. Results show change and dynamics as emergent properties of system interactions. Changes in dynamics and strength of endogenous dampening over the duration of the study are associated with dynamical changes from major governmental policy decisions that altered the boundary conditions for interdependencies of arable and pastoral farming.
... Na verdade, os temas apresentados acima (na intenção de ilustrar cada uma das cinco estratégias abarcadas pelo modelo FLICC) já indicam bastante bem a competência da Geografia para fornecer seus/suas profissionais à causa de debelar desinformações. O leitor possivelmente tenha notado que alguns temas se inscrevem dentro do âmbito tradicional de pelo menos quatro campos que nos são familiares: o dos estudos geofísicos em que as formas, as propriedades e as dinâmicas da Terra são explicadas segundo demonstrações experimentais ou modelagens (BOKULICH; ORESKES, 2017); o dos estudos geoecológicosem que a exploração antrópica dos recursos é tratada mediante a consideração de redes complexas de interatividade, das quais derivam, por exemplo, perturbações junto aos ciclos naturais biogeoquímicos(PHILLIPS, 1999); o da geografia médicaem que os princípios da epidemiologia são conjugados aos fatores de ordem socioeconômica, a fim de dar ênfase à natureza espacial da difusão de doenças (CARREL; EMCH, 2013); e o da geografia agrícolaem que as transformações regionais da produção econômica são examinadas em função do aporte trazido pelos avanços técnicos e biotecnológicos (DIBDEN; GIBBS; COCKLIN, 2013).Em se tratando da questão do aquecimento global seria importante verificar se os "cientistas" aludidos como contestadores do fenômeno (ou de sua causalidade antrópica) são realmente climatologistas. Porque poderíamos lançar a hipótese de que, por exemplo, esses especialistas eminentes, que dariam suporte à negação, embora possam ser diplomados em ciências físicas ou engenharias, não possuem pesquisa sobre o tema, que seja reconhecida por pares.Referente a uma discussão socioambientaltão cara ao pensamento geográfico -, poderiam ser estabelecidas análises objetivas acerca da representatividade dos problemas eventualmente identificados com respeito a agentes que fomentam a produção agrícola. ...
Em um contexto de amplificação do acesso a plataformas e mídias digitais, se é certo dizer que, por um lado, ele tende a beneficiar iniciativas de popularização de conhecimentos, não se deve, por outro, menosprezar os riscos também aumentados de uma difusão preocupante de notícias falsas. Este artigo resulta de um estudo preliminar a respeito de um dos problemas relacionados a essa situação ambivalente: a disseminação de ideias que desacatam a autoridade da ciência em produzir conhecimento confiável. Demonstramos a vulnerabilidade da opinião pública diante de uma relação pouco formalizada entre comunicadores sociais e profissionais da ciência. E sugerimos que se essa relação puder ser aperfeiçoada, um campo disciplinar que sem dúvida cumpriria um papel especial na instrução pública é o das ciências da Terra – em que a Geografia seria um caso bastante singular.
... Currently, there seems to be a refinement of research in relation to roads such as water repellency (Papierowska et al. 2020), shear strength (Ubido, Ogbonnaya & Ukah 2020), and air pollution through traffic (Wawer et al. 2020), among other studies, which describe roads as an element of the landscape. Currently, roads are analyzed holistically and they are part of an integrated landscape system, characterized as an open system, with continuous material and energy exchanges with the environment (Phillips 1999). ...
Over time, roads have become an important study object. Several studies were carried out to understand the importance of roads on the hydrogeomorphological dynamics on hillslopes and watershed. Nonetheless, new gaps and new research methods emerged as research progressed on this subject. Therefore, to understand the evolution and new challenges of research on roads, a bibliographic review was prepared based on 300 articles searched in the Scopus platform considering the last two decades (2001–2010 and 2011–2020). We use keywords that refer to roads in the search field, e.g., soil erosion on roads, delivery rate, bank, rails, highways, abandoned roads, and road rehabilitation. The data were tabulated and separated according to the following themes: data collection method, study purposes, road types, and geographic location. Our main conclusions were a) in the 2000s, around 60% of surveys were carried out on unpaved roads and rural roads, mainly in roadbed features; b) In the 2010, occurred a decentralization on the research on rural roads from mainstream countries as US and Australia to Latin American countries e.g., Brazil and Middle East e.g., Iran; c) the studies in emerging countries, mostly tested known research methods in different landscapes of tropical climate; d) a new research perspective in recent decades have emerged, focusing on the influence of roads on the landscape’s dynamics. Finally, roads are recognized as a humanmade landscape signature and studies about nature and biodiversity conservation, particularly at watershed scale, must considered this anthropogenic feature.
... Little work has been done on how chaos applies to within channel phenomena; Nikora (1991) has examined the fractal structure of river planforms but arguably the most important contribution to this Held has been the connection made by Phillips (1990Phillips ( : 1995Phillips ( : 1999 between hydrauhc geometry and chaos and PhiUips' approach to this problem is considered in some detail below. ...
p>This thesis is concerned with the indeterminacy of morphology in alluvial river channel cross-section and river channel planform. Indeterminacy herein, is defined as the inability to determine the individual case at a given scale of measurement. In order to assess current theoretical approaches in geomorphology to fluvial indeterminacy and to provide a framework for future investigations, an original historical review of the aims of geomorphology is presented. It is concluded that geomorphology has always considered itself as scientific, and in particular, that many geomorphologists view the discipline as a physical science. Given that geomorphology wants to produce scientific knowledge, and this is the framework within which indeterminacy is to be investigated, an original review of what characteristics scientific knowledge is presented. The primary conclusion of this review is that science is explanation by laws, of which there are three types: causal, aleatory statistical and chaos. Furthermore, it is concluded that a hallmark of scientific knowledge is its predictive capability, although the relationship between knowledge and prediction is problematic. In light of this conceptual framework, fluvial indeterminacy in geomorphology is approached by testing the three forms of law and their associated predictive statements.
The predictions that the three types of scientific law make are tested in experimental conditions using a flume, where the relationship between controls and morphology can be regulated. Causal laws which operate at the scale of the individual measurement fail predictive tests. It is not possible to predict the morphology of a specified point on a sediment surface, given values of controls, primarily because internal processes (which are as yet unknown) in the fluid-sediment system, obscure any relationship. The addition of variables does not make the system determinate. The proactive identification of chaos laws (which operate at the scale of the attractor and for which a new hypothesis is proposed in geomorphology, based on the chaos nature of turbulence) via fractal analysis also fails predictive tests.</p
... Even so, in geomorphology it is often easiest to identify the prevalent processes at one or various scales (since most processes and forms within geomorphology are scale independent, cf., Phillips, 2001Phillips, , 1999. For example, we are taught early on that in geomorphic systems there occurs a correspondence between the scales of process and forms. ...
Dr. Anthony Orme was a well-rounded geomorphologist, but he may be most distinguished as a coastal field geomorphologist. This passion for the field tradition was passed onto many of his students who, in turn, have continued to pass along such traditions to their students. In the spirit of Tony Orme, we present this short examination of two types of relict coastal landforms, selected regionally due to our current research foci and sites that highlight our modern field research in the US and Caribbean, and especially in areas and of topics that would have intrigued our academic grandfather.
In Northern California, we addressed the ubiquitous yet often overlooked marine terrace staircases that flank the shore along the Coast. Ascending from the sea, four to five relict terraces have been identified that can reach 600m across and as high as 300m above the shoreline. As a product of early sea level fluctuation, and tectonic uplift and flexing, the terraces have captivated geomorphologists, ecologists, coastal management specialists, and land developers for centuries. However, it was only in the 1960s that their peculiar morphologies were identified and analyzed first based on their unique subsurface composition (dunal ridges 300-800’ asl) and vicariant patches of stunted trees (Cupressus pigmaea). In this study we examine the influences, morphology, and relict nature of two terrace complexes in Mendocino and Santa Cruz Counties.
On the tropical island of Barbados, the occurrences of intriguing mushroom-shaped rocks are prevalent at the shoreline, yet vicariant and relict mushroom rocks have been identified 40m above, and 500m from the sea. Previous research has identified diverse factors influencing the development of these notched rock pedestals as salt weathering, erosional wave-action, bioerosion, and wetting/drying cycles. However – like in Mendocino – was it sea level fluctuation and/or tectonic uplift that was responsible for their occurrence now 500m from, and 40m above the current shoreline where similar mushroom rocks are presently undergoing change, development, and morphogenesis?
In Northern California and Barbados, it is this unexpected occurrences and origins of these relict landforms that continue to fuel the spirit of the field experience in geomorphology, geography, geology, and the earth sciences, predominantly driven from the early passions, lessons, wisdom, and spirit of our life and academic mentors like Antony ‘Tony’ Orme.
... Considering only cases where a 11 , a 22 < 0, if a 12 , a 21 have opposite signs the system is stable, and development is convergent (see (Logofet, 1994;Phillips, 1999;Puccia and Levins, 1985) for details on qualitative stability analysis). For instance, weathering at the bedrock interface positively influences regolith thickness, while in some situations thicker regolith cover may reduce the weathering rate. ...
Thresholds are ubiquitous in Earth surface systems and fundamental to landscape evolution. They occur at the level of process mechanics, and at the broader level of landscape system states, and may be fuzzy or crisp in their occurrence and/or the ability to measure or define them. Five main types of thresholds occur: force vs. resistance, storage capacities, relative rates of linked processes, saturation and depletion effects, and limiting factors. Tipping points and regime shifts are types of thresholds that occur at the landscape level (or broader) and are abrupt. As virtually all landscape systems are strongly influenced by thresholds, and many are threshold-dominated, landscapes and ESS are nonlinear, opening up possibilities for complex phenomena that do not occur in linear systems. One of these is dynamical instability, which can be both a consequence (via nonlinearity) and a cause of thresholds. Instability is a cause of thresholds in the case of system-level meta-thresholds. These are shifts in the positive or negative effects, or in the relative magnitudes, of interactions within the system. They can result in switches between dynamically stable and unstable modes, often manifested as convergent or divergent evolution.
... These include storms, floods, fires, and human agency ( Fig. 9.7). There exist numerous examples of divergent geomorphic, pedologic, and hydrologic evolution because of the persistence and/or growth of local disturbances (see Phillips, 1999Phillips, , 2006bBrunsden, 2001 for syntheses and overviews; Toomanian et al., 2006;Pawlik and Samonil, 2018;and Samonil et al., 2018 for soil geomorphology examples;and Fryirs, 2017 for fluvial examples). Some of these features that are new on a local scale may also be novel in general. ...
The Perfect Landscape is a broad, but formally expressed, conceptual model incorporating the law-place-history explanatory triad, explicitly dealing with contingency, and recognizing the interplay of individuality and idiosyncrasies in Earth surface system with shared characteristics and regularities. It holds that individual landscapes reflect a combination of general laws and geographically and historically contingent controls that are highly improbable in terms of duplication elsewhere. The Perfect Landscape concept also indicates that landscape individuality and idiosyncrasy can only increase as more variables are considered. An approach to analyzing and understanding perfect landscapes is based on nine axioms for landscape interpretation. The evolution of perfect landscapes requires creativity in the form of the appearance of new features that are selected for. Several lines of evidence that such creativity occurs in abiotic as well as biotic aspects of landscapes are presented.
... Similarly, multiple trajectories can occur in successional responses of vegetation to geomorphic disturbances [298,299]. Given the possibility of nonlinear system behavior, reach-scale biogeomorphic knowledge cannot be readily scaled up without accounting for emergent dynamics that can arise at a broader spatial scale due to, for example, hillslope-channel connectivity or storage within the sediment routing system [206,300]. As noted above, these geomorphic sources of complexity in the overall, basin-scale behavior of the mountain fluvial systems can be further complicated by biogeomorphic interactions. ...
Rivers are complex biophysical systems, constantly adjusting to a suite of changing governing conditions, including vegetation cover within their basins. This review seeks to: (i) highlight the crucial role that vegetation’s influence on the efficiency of clastic material fluxes (geomorphic connectivity) plays in defining mountain fluvial landscape’s behavior; and (ii) identify key challenges which hinder progress in the understanding of this subject. To this end, a selective literature review is carried out to illustrate the pervasiveness of the plants’ effects on geomorphic fluxes within channel networks (longitudinal connectivity), as well as between channels and the broader landscape (lateral connectivity). Taken together, the reviewed evidence lends support to the thesis that vegetation-connectivity linkages play a central role in regulating geomorphic behavior of mountain fluvial systems. The manuscript is concluded by a brief discussion of the need for the integration of mechanistic research into the local feedbacks between plants and sediment fluxes with basin-scale research that considers emergent phenomena.
As propriedades dos sistemas complexos são presentes no dinamismo e evolução do relevo terrestre. Na Geomorfologia os entendimentos e ferramentas ligados à Ciência e Teoria da Complexidade já são bem conhecidos. Porém, ainda é pouco discutida e difundida em âmbito nacional. Pretende-se neste artigo apresentar uma revisão teórica contextual sobre algumas das considerações já realizadas na relação entre Geomorfologia e Complexidade. Discorreu-se sobre a incorporação de noções como desequilíbrio, instabilidades, incertezas, auto-organização e foram refletidas algumas repercussões ontológicas, como o reconhecimento das não-linearidades e caráter singular-histórico do fenômeno geomorfológico, e epistemológicas como o diálogo entre métodos tradicionalmente tratados unilateralmente. Torna-se necessário construir essa relação a partir do diálogo com os autores e abordagens já praticadas, refletindo as novas ideias, noções e técnicas em confronto com a tradição.
Biogeoscience is a rapidly growing interdisciplinary field that aims to bring together biological and geophysical processes. This book builds an enhanced understanding of ecosystems by focusing on the integrative connections between ecological processes and the geosphere, hydrosphere and atmosphere. Each chapter provides studies by researchers who have contributed to the biogeoscience synthesis, presenting the latest research on the relationships between ecological processes, such as conservation laws and heat and transport processes, and geophysical processes, such as hillslope, fluvial and aeolian geomorphology, and hydrology. Highlighting the value of biogeoscience as an approach to understand ecosystems, this is an ideal resource for researchers and students in both ecology and the physical sciences.
Evaluation of the impacts of artificial drainage systems on wetlands requires an assessment of the hydrologic equilibrium status of the surface hydrologic system. Hydrologic equilibrium is characterised by a high correlation between surplus moisture (as calculated by Thornthwaite's methodology) and stream discharge. A qualitative stability analysis shows that deterioration of artificial drainage channels is the process allowing the surface hydrologic system to adjust to the disturbances. The model is tested by examining the correlation between surplus and discharge for a small watershed altered by forestry drainage which is periodically rehabilitated. With hydrologic equilibeium arbitrarily defined as a surplus-discharge correlation coefficient {succeeds or equal to} 0.8, it is shown that the original, largely undisturbed watershed was in hydrologic equilibrium. Disequilibrium was induced by artificial drainage-ways, with a return to equilibrium over time. Subsequent renovations of ditches and canals were associated with a recurrence of disequilibrium. The surface hydrologic system is metastable, and cannot be expected to return to previously-existing states following a disturbance. Consistently maintained artificial drainage system appears to preclude any return to any type of hydrologic equilibrium.
Sand bars having spacing equal to half the surface wavelength may be formed by the action of partially-standing waves on an erodible bed. Here the stages of development of a patch of bars has been investigated in a wave tank, using rapid, accurate, ultra-sonic detection systems to monitor both the changing bed profile and the evolving surface wavefield. Initially, small-scale ripples formed on a (flattened) bed surface. These ripples varied in size according to position in the wave envelope, and had asymmetrical profiles due to asymmetry in the near-bed oscillatory motion. Vortex shedding from the ripples gave rise to regions of net sediment accumulation (bar crests) and erosion (troughs) linked to position in the wave envelops. The bars formed with wavelength satisfying the Bragg condition and with bar crests positioned down-wave of the antinodes of elevation. As expected, this produced an increase in the overall reflection coefficient of the bar patch as the bars grew in height. The present observations of the resonant interaction between surface waves and an erodible bed are believed to be the most detailed and accurate to have been reported to date. -from Authors
The relationship between erosion and shoreline configuration was investigated along the New Jersey shore of Delaware Bay. During a period of intense erosion and shoreline retreat the irregularity and complexity of the shoreline configuration, as measured by the fractal dimension, increased significantly. -from Author
Landscapes are the instantaneous result of concurrently active uplift (endogenic process) and degradation (exogenic process), which view has been taken as the result of a fundamental 'principle of antagonism' of landscape evolution. It turns out that the endogenically caused features are statistically systematic, the exogenically caused features statistically random. A further principle active in landscape evolution is that of instability: deviations from uniformity generally tend to increase. This fact is expressed eg in the growth of meander loops, erosion cirques, karst holes, etc. -from Author
We suggest that the atmosphere–ocean–earth system is unlikely to be intransitive, i.e. to admit two or more possible climates, any one of which, once established, will persist forever. Our reasoning is that even if the system would be intransitive if the external heating could be held fixed, say as in summer, the new heating patterns that actually accompany the advance of the seasons will break up any established summer circulation, and an alternative circulation may develop during the following summer, particularly if chaos has prevailed during the intervening winter. We introduce a very-low-order geostrophic baroclinic “general circulation” model, which may be run with or without seasonal variations of heating. Under perpetual summer conditions the model is intransitive, admitting either weakly oscillating or strongly oscillating westerly flow, while under perpetual winter conditions it is chaotic. When seasonal variations of heating are introduced, weak oscillations prevail through some summers and strong oscillations prevail through others, thus lending support to our original suggestion. We develop some additional properties of the model as a dynamical system, and we speculate as to whether its behaviour has a counterpart in the real world. DOI: 10.1034/j.1600-0870.1990.t01-2-00005.x