scholarly journals The implications of disconnectivity for the study of contemporary geomorphic processes

2017 ◽  
Vol 19 (1) ◽  
pp. 5-15
Author(s):  
SLAYMAKER Olav
Keyword(s):  
Human Activities ◽  
Spatial Scales ◽  
Scale Problem ◽  
Conservation Of Mass ◽  
Natural Processes ◽  
The Past ◽  
Temporal And Spatial ◽  
Spatio Temporal ◽  
Geomorphic Processes

The emphasis on the understanding of contemporary geomorphic processes that has dominated Anglophone geomorphological literature over the past 50 years has seen huge progress but also some set-backs. We now have reliable measurements of mean rates of operation of all subaerial processes responsible for modification of landforms and landscapes and have made good progress in estimating the role of human activities as compared with “natural” processes. Some limited progress has been achieved in understanding the scale problem but problems remain. Perhaps the single most surprising development has been the recognition of the ubiquity of disconnectivity in geomorphic systems, the need to calculate virtual velocities of whole geomorphic systems and the relevance of this understanding to the general spatio-temporal scale problem. We have always known that most geomorphic processes operate intermittently but we have continued to depend on models that imply that mass and energy move freely through geomorphic systems and that conservation of mass and energy occurrs uninterruptedly at all temporal and spatial scales.

scholarly journals The Value of Citizen Science in Increasing Our Knowledge of Under-Sampled Biodiversity: An Overview of Public Documentation of Auchenorrhyncha and the Hoppers of North Carolina

2021 ◽  
Vol 9 ◽  
Author(s):  
Kyle D. Kittelberger ◽  
Solomon V. Hendrix ◽  
Çağan Hakkı Şekercioğlu
Keyword(s):  
North Carolina ◽  
Citizen Science ◽  
Spatial Scales ◽  
The United States ◽  
Undescribed Species ◽  
The Past ◽  
Global Biodiversity ◽  
Temporal And Spatial

Due to the increasing popularity of websites specializing in nature documentation, there has been a surge in the number of people enthusiastic about observing and documenting nature over the past 2 decades. These citizen scientists are recording biodiversity on unprecedented temporal and spatial scales, rendering data of tremendous value to the scientific community. In this study, we investigate the role of citizen science in increasing knowledge of global biodiversity through the examination of notable contributions to the understanding of the insect suborder Auchenorrhyncha, also known as true hoppers, in North America. We have compiled a comprehensive summary of citizen science contributions—published and unpublished—to the understanding of hopper diversity, finding over fifty previously unpublished country and state records as well as dozens of undescribed and potentially undescribed species. We compare citizen science contributions to those published in the literature as well as specimen records in collections in the United States and Canada, illuminating the fact that the copious data afforded by citizen science contributions are underutilized. We also introduce the website Hoppers of North Carolina, a revolutionary new benchmark for tracking hopper diversity, disseminating knowledge from the literature, and incorporating citizen science. Finally, we provide a series of recommendations for both the entomological community and citizen science platforms on how best to approach, utilize, and increase the quality of sightings from the general public.

scholarly journals Re-Arranging Space, Time and Scales in GIS: Alternative Models for Multi-Scale Spatio-Temporal Modeling and Analyses

2019 ◽  
Vol 8 (2) ◽  
pp. 72 ◽  
Author(s):  
Yi Qiang ◽  
Nico Van de Weghe
Keyword(s):  
Spatial Data ◽  
Spatial Scales ◽  
Space Time ◽  
Unified Framework ◽  
Temporal Modeling ◽  
Multi Scale ◽  
Space And Time ◽  
Pyramid Model ◽  
Temporal And Spatial ◽  
Spatio Temporal

The representations of space and time are fundamental issues in GIScience. In prevalent GIS and analytical systems, time is modeled as a linear stream of real numbers and space is represented as flat layers with timestamps. Despite their dominance in GIS and information visualization, these representations are inefficient for visualizing data with complex temporal and spatial extents and the variation of data at multiple temporal and spatial scales. This article presents alternative representations that incorporate the scale dimension into time and space. The article first reviews a series of work about the triangular model (TM), which is a multi-scale temporal model. Then, it introduces the pyramid model (PM), which is the extension of the TM for spatial data, and demonstrates the utility of the PM in visualizing multi-scale spatial patterns of land cover data. Finally, it discusses the potential of integrating the TM and the PM into a unified framework for multi-scale spatio-temporal modeling. This article systematically documents the models with alternative arrangements of space and time and their applications in analyzing different types of data. Additionally, this article aims to inspire the re-thinking of organizations of space, time, and scales in the future development of GIS and analytical tools to handle the increasing quantity and complexity of spatio-temporal data.

Arctic systems in the Quaternary: ecological collision, faunal mosaics and the consequences of a wobbling climate

2017 ◽  
Vol 91 (4) ◽  
pp. 409-421 ◽  
Author(s):  
E.P. Hoberg ◽  
J.A. Cook ◽  
S.J. Agosta ◽  
W. Boeger ◽  
K.E. Galbreath ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Pathogen Transmission ◽  
Tipping Points ◽  
Climate Oscillations ◽  
The Past ◽  
Ecological Barriers ◽  
History Of ◽  
Temporal And Spatial ◽  
Time Frames ◽  
Faunal Assembly

AbstractClimate oscillations and episodic processes interact with evolution, ecology and biogeography to determine the structure and complex mosaic that is the biosphere. Parasites and parasite–host assemblages are key components in a general explanatory paradigm for global biodiversity. We explore faunal assembly in the context of Quaternary time frames of the past 2.6 million years, a period dominated by episodic shifts in climate. Climate drivers cross a continuum from geological to contemporary timescales and serve to determine the structure and distribution of complex biotas. Cycles within cycles are apparent, with drivers that are layered, multifactorial and complex. These cycles influence the dynamics and duration of shifts in environmental structure on varying temporal and spatial scales. An understanding of the dynamics of high-latitude systems, the history of the Beringian nexus (the intermittent land connection linking Eurasia and North America) and downstream patterns of diversity depend on teasing apart the complexity of biotic assembly and persistence. Although climate oscillations have dominated the Quaternary, contemporary dynamics are driven by tipping points and shifting balances emerging from anthropogenic forces that are disrupting ecological structure. Climate change driven by anthropogenic forcing has supplanted a history of episodic variation and is eliminating ecological barriers and constraints on development and distribution for pathogen transmission. A framework to explore interactions of episodic processes on faunal structure and assembly is the Stockholm Paradigm, which appropriately shifts the focus from cospeciation to complexity and contingency in explanations of diversity.

scholarly journals Detecting the Quantitative Hydrological Response to Changes in Climate and Human Activities at Temporal and Spatial Scales in a Typical Gully Region of the Loess Plateau, China

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 257
Author(s):  
Peng Guo ◽  
Jiqiang Lyu ◽  
Weining Yuan ◽  
Xiawan Zhou ◽  
Shuhong Mo ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Water Conservation ◽  
Human Activities ◽  
Water Resource Management ◽  
Vegetation Index ◽  
Spatial Scales ◽  
Shaanxi Province ◽  
Hydrological Response ◽  
The Loess Plateau ◽  
Temporal And Spatial

This study examined the Chabagou River watershed in the gully region of the Loess Plateau in China’s Shaanxi Province, and was based on measured precipitation and runoff data in the basin over a 52-year period (1959–2010), land-use types, normalized difference vegetation index (NDVI), and other data. Statistical models and distributed hydrological models were used to explore the influences of climate change and human activity on the hydrological response and on the temporal and spatial evolution of the basin. It was found that precipitation and runoff in the gully region presented a downward trend during the 52-year period. Since the 1970s, the hydrological response to human activities has become the main source of regional hydrological evolution. Evapotranspiration from the large silt dam in the study area has increased. The depth of soil water decreased at first, then it increased by amount that exceeded the evaporation increase observed in the second and third change periods. The water and soil conservation measures had a beneficial effect on the ecology of the watershed. These results provide a reference for water resource management and soil and water conservation in the study area.

Using Earth Observations to engender a social-ecological systems perspective on rural livelihoods and wellbeing.

2020 ◽  
Author(s):  
Peter Hargreaves ◽  
Gary Watmough
Keyword(s):  
Sustainable Development ◽  
Sustainable Development Goals ◽  
Spatial Scales ◽  
Earth Observation ◽  
Ecological Systems ◽  
Social Ecological Systems ◽  
Social Ecological ◽  
Development Goals ◽  
Temporal And Spatial ◽  
Spatio Temporal

<p>An estimated 70% of the world’s poorest people live in rural spaces. There is a consistent differentiation between rural and urban contexts, where the former are typically characterised by weak infrastructure, limited services and social marginalisation. At the same time, the world’s poorest people are most vulnerable to global change impacts. Historic pathways to measuring and achieving poverty reduction must be adapted for an era of increasingly dynamic change, where spatio-temporal blind spots preclude a comprehensive understanding of poverty and its manifestation in rural developing contexts. To catalyse an effective poverty eradication narrative, we require a characterisation of the spatio-temporal anatomy of poverty metrics. To achieve this, researchers and practitioners must develop tools and mobilise data sources that enable the detection and visualisation of economic and social dimensions of rural spaces at finer temporal and spatial scales than is currently practised. This can only be realised by integrating new technologies and non-traditional sources of data alongside conventional data to engender a novel policy landscape.</p><p>Cue Earth Observation: the only medium through which data can be gathered that is global in its coverage but also available across multiple temporal and spatial scales. Earth Observation (EO) data (collected from satellite, airborne and in-situ remote sensors) have a demonstrable capacity to inform, update, situate and provide the necessary context to design evidence-based policy for sustainable development. This is particularly important for the Sustainable Development Goals (SDGs) because the nested indicators are based on data that can be visualised, and many have a definitive geospatial component, which can improve national statistics reporting.</p><p>In this review, we present a rubric for integrating EO and geospatial data into rural poverty analysis. This aims to provide a foundation from which researchers at the interface of social-ecological systems can unlock new capabilities for measuring economic, environmental and social conditions at the requisite scales and frequency for poverty reporting and also for broader livelihoods and development research.  We review satellite applications and explore the development of EO methodologies for investigating social-ecological conditions as indirect proxies of rural wellbeing. This is nested within the broader sustainable development agenda (in particular the SDGs) and aims to set out what our capabilities are and where research should be focused in the near-term. In short, elucidating to a broad audience what the integration of EO can achieve and how developing social-ecological metrics from EO data can improve evidence-based policymaking.</p><p><strong>Key words:</strong> Earth Observation; Poverty; Livelihoods; Sustainable Development Goals; Remote Sensing</p>

Biogeomorphological research frontiers: from ant mounds to Mars

2020 ◽  
Author(s):  
Heather Viles
Keyword(s):  
High Risk ◽  
Spatial Scales ◽  
The Past ◽  
Scientific Controversies ◽  
Wide Range ◽  
Geomorphological Processes ◽  
Temporal And Spatial ◽  
Ecological Dimension ◽  
Research Frontiers ◽  
Ant Mounds

<p>Biogeomorphology is a vibrant area of scientific research which focuses on the two-way interrelationships between ecological and geomorphological processes across a wide range of temporal and spatial scales. Whilst ecological influences on geomorphology were often perceived in the past as a rather niche topic, most geomorphologists now  consider the ecological dimension as being crucial to the evolution and behaviour of geomorphological systems. However, there is still much to be done to explore the intersections between ecology and geomorphology. It is now timely to investigate what frontier research in biogeomorphology might look like over the coming years. This paper explores some characteristics of frontier research (addressing scientific controversies, focusing on hard-to-answer questions, employing atypical methods and concepts, being paradigm-challenging, and having a high risk of failure) in the context of tomorrow’s biogeomorphology. As examples, the paper addresses current progress in research on the geomorphological contributions of ants on Earth, and microbial biosignatures on Mars.</p>

The role of precipitation in hydrological model uncertainty

2020 ◽  
Author(s):  
András Bárdossy ◽  
Chris Kilsby ◽  
Faizan Anwar ◽  
Ning Wang
Keyword(s):  
Conceptual Models ◽  
Spatial Scales ◽  
State Variables ◽  
Rainfall Runoff ◽  
Physically Based ◽  
Spatially Distributed ◽  
Spatio Temporal ◽  
Step Care ◽  
Model Approach

<p>Rainfall-runoff models produce outputs which differ from observations due to uncertainties in process description, process parametrization, uncertainties in observations and changing spatio-temporal variability of input and state variables. Traditionally, attention has been focused mostly on process parameters to quantify runoff uncertainty using e.g. GLUE.</p><p>Here we have focused on the role of precipitation uncertainty relating to discharge. For this purpose, we used an inverse model approach. We generated time series of daily precipitation with high spatial resolution  using a modified version of Random Mixing and the Shannon-Whittaker interpolation to improve simulated runoff using the SHETRAN (physically-based) and HBV (conceptual) models, both spatially distributed for various sub-catchments of the Neckar River in Germany.  HBV was initially calibrated using interpolated precipitation, while SHETRAN uses pre-defined parameters. The modelling goal was to find a spatio-temporal series of precipitation which improved the predicted runoff,  under the constraints that the precipitation values be the same at the measurement locations and share their spatial variability with the observations at a given step. Care was taken to select subsequent days for improvement such that the previously improved step considered the effect of the previous steps.</p><p>We asked the questions: i) does improving precipitation inputs for one sub-catchment bring runoff improvement for the others? ii) Can the improved precipitation using SHETRAN be used for HBV and still get runoff improvements as compared to the interpolated precipitation and vice versa?</p><p>Results showed that overall runoff errors were reduced by 40 to 50% for all sub-catchments. For the peaks, a reduction of 70 to 90% was observed. As compared with the interpolated fields, new fields showed similar overall distribution but different details at finer spatial scales. Swapping improved precipitations between SHETRAN and HBV showed improvement as compared with the discharge from interpolated precipitation.</p>

scholarly journals SPATIO-TEMPORAL VARIATION OF PM<sub>2.5</sub> CONCENTRATION IN CHINA FROM 1998 TO 2016 AND ITS RESPONSE TO ECONOMIC DEVELOPMENT

2020 ◽  
Vol XLII-3/W10 ◽  
pp. 49-55
Author(s):  
H. Z. Zhang ◽  
J. J. Chen ◽  
X. N. Zhao ◽  
J. Liu
Keyword(s):  
Economic Development ◽  
Inner Mongolia ◽  
Rapid Development ◽  
The West ◽  
The Past ◽  
Spatial Distribution Characteristics ◽  
Temporal And Spatial ◽  
Spatio Temporal ◽  
Pm2.5 Concentration ◽  
China’S Economy

Abstract. China's economy has experienced rapid development in the past few decades, and economic development has also brought serious pollution problems, which has attracted wide attention of scholars at home and abroad. Based on the data of global PM2.5 remote sensing products and China's economic development from 1998 to 2016, the temporal and spatial variations of PM2.5 concentration in China from 1998 to 2016 were analyzed, and the response of PM2.5 concentration in China to economic development was studied. The results showed that the average annual PM2.5 concentration in 1998–2016 showed the spatial distribution characteristics of high in the East and low in the west; during 1998–2016, PM2.5 increased significantly in most regions, but decreased significantly in Inner Mongolia, Shaanxi, Ningxia and Gansu, while PM2.5 did not change significantly in some parts of the central region; during 1998–2007, PM2.5 concentration in most regions of China experienced rapid economic development. The concentration of PM2.5 in a few areas such as Inner Mongolia decreased significantly, while that in Yunnan, Sichuan and Inner Mongolia did not change significantly. During the 10 years of economic slowdown in China (2008–2016), the downward trend of PM2.5 concentration in China was expanding. The concentration of PM2.5 in the central and southern regions decreased or did not change significantly, except in the northwest and a few northeast regions. The change of PM2.5 concentration responds obviously to economic development, but the response of different regional economic development to the change of PM2.5 concentration is different.

Temporal and spatial variation of catastrophic river floodings in the Lower Yellow River from AD 960 to 1938

The Holocene ◽  
2017 ◽  
Vol 27 (9) ◽  
pp. 1359-1369 ◽  
Author(s):  
Xiangping Zhang ◽  
Xiuqi Fang
Keyword(s):  
Yellow River ◽  
Spatial Scales ◽  
Alluvial Fan ◽  
Lower Yellow River ◽  
The Lower Yellow River ◽  
Spatial Changes ◽  
Temporal And Spatial ◽  
Spatio Temporal ◽  
Downstream Movement ◽  
Past 1000 Years

This study is intended to investigate the patterns for the temporal and spatial changes of catastrophic river floodings which took place in the Lower Yellow River, based on the available records collected from historical documents, and rearranged in a GIS database. A series of catastrophic river floodings from AD 960 to 1938 was reconstructed, and their temporal and spatial variations were analyzed, which leads to the conclusions, among others. (1) The increasing trend of frequency of catastrophic river floodings in the Lower Yellow River is not so significant in the past 1000 years. (2) Most dike breachings and overtoppings occurred near the apex of the Yellow River Alluvial Fan, and the number of dike breaching and overtopping was gradually reduced as the elevation decreased. (3) Under different spatio-temporal backgrounds, dike breaching and overtopping developed either downstream or upstream, which is evidenced by both the downstream movement for large temporal and spatial scales in dike breaching and overtopping places in AD 1128–1344 and 1391–1447 and the upstream movement for small temporal and spatial scales in AD 960–969, 1730–1761, and 1807–1819.

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