scholarly journals Sustainability Considerations in Water–Energy–Food Nexus Research in Irrigated Agriculture

2020 ◽  
Vol 12 (15) ◽  
pp. 6274
Author(s):  
Ahmad Hamidov ◽  
Katharina Helming
Keyword(s):  
Spatial Scales ◽  
Evidence Base ◽  
Irrigated Agriculture ◽  
Sustainable Food ◽  
Sustainable Solutions ◽  
Trade Offs ◽  
Temporal And Spatial ◽  
Increasing Demand ◽  
Water Scarce ◽  
Important Evidence

Irrigated agriculture is essential to satisfying the globally increasing demand for food and bio-based products. Yet, in water scarce regions, water-use for irrigation aggravates the competition for the use of water for other purposes, such as energy production, drinking water and sanitation. Solutions for sustainable food production through irrigated agriculture require a systemic approach to assess benefits and trade-offs across sectors. Here, the water–energy–food (WEF) nexus has become an important concept in natural resource management. It has been conceptualized to analyze linkages and trade-offs between the three sectors, across temporal and spatial scales. However, the concept has so far mainly been conceptual, with little empirical evidence or proof of concept in real world cases. The objective of this paper was to take stock of the rapidly advancing literature on the WEF nexus in irrigated agriculture, and to analyze how the concept was actually implemented in research studies, and how the nexus between water, food and energy was actually dealt with. The study period ranges from 2011 to 2019, and includes 194 articles. Results showed that the WEF nexus is indeed very relevant in irrigated agriculture, and the respective literature makes up one third of all WEF nexus papers. Modeling and empirical research have caught up with conceptual synthesis studies during the last four years, thereby indicating that the WEF nexus concept is indeed increasingly operationalized. However, most studies addressed the WEF nexus from a perspective of either socioeconomic, technological or environmental categories, and they place one of the dimensions of water, food or energy into the foreground. To address sustainable development, there is a need to fully integrate across research disciplines and thematic dimensions. Such studies are only starting to emerge. These findings are an important evidence-base for future WEF nexus research on irrigated agriculture, in support of sustainable solutions for water scarce regions, especially in settings undergoing transformations.

Habitat selection by roe deer and sheep: does habitat ranking reflect resource availability?

1999 ◽  
Vol 77 (5) ◽  
pp. 776-783 ◽  
Author(s):  
Atle Mysterud ◽  
Per Kristian Larsen ◽  
Rolf Anker Ims ◽  
Eivind Østbye
Keyword(s):  
Habitat Selection ◽  
Food Availability ◽  
Resource Availability ◽  
Roe Deer ◽  
Antipredator Behavior ◽  
Spatial Scales ◽  
Ovis Aries ◽  
Domestic Sheep ◽  
Trade Offs ◽  
Temporal And Spatial

Habitat ranking is often assumed to reflect food availability, but habitat selection may involve trade-offs, for example, between selecting for food or cover. We tested whether the habitat selection of 27 radio-collared European roe deer (Capreolus capreolus) and 10 free-ranging domestic sheep (Ovis aries) on a forest range in southern Norway reflected resource availability. We predicted that ruminants of different feeding types would use habitats according to the main forage class, but that antipredator behavior might remove the correlation between habitat selection and food availability, thus making temporal and spatial scaling crucial. As predicted, habitat selection by sheep was highly correlated with grass availability on both the home-range and study-area scales. The habitat ranking of roe deer habitat selection did not correlate with the availability of herbs on either scale, but rather was correlated with the availability of canopy cover. We found a clear effect of temporal scale on habitat selection by roe deer. During summer, roe deer used forest habitats with more forage to a greater extent when they were active than when they were inactive, and tended to use habitats with greater availability of herbs at night. We conclude that scale-dependent trade-offs in habitat selection may cause inconsistent habitat rankings when pooled across temporal and spatial scales.

scholarly journals Mainstreaming natural flood management: A proposed research framework derived from a critical evaluation of current knowledge

2021 ◽  
pp. 030913332199729
Author(s):  
Nicola Ellis ◽  
Karen Anderson ◽  
Richard Brazier
Keyword(s):  
Flood Risk ◽  
Current Knowledge ◽  
Spatial Scales ◽  
Critical Evaluation ◽  
Flood Management ◽  
Evidence Base ◽  
New Approach ◽  
Trade Offs ◽  
Management Method ◽  
The Uk

Natural flood management (NFM), or working with natural processes, is a growing flood risk management method in the UK, Europe and worldwide. However, unlike the current dominant technical flood management, it lacks an established evidence base of flood risk parameters. This lack of evidence base can limit the uptake of NFM as a flood management method. This paper critically evaluates examples of NFM and wider relevant literature in order to identify NFM knowledge gaps and suggest how to overcome these. The UK is used as a microcosm of different environments for diverse examples. The sections include: land cover, land management, landscape interactions and trade-offs, evaluating the wider benefits of NFM and, finally, scaling from plot to catchment. This concludes in a suggested framework for a new approach to NFM research, which encompasses spatial scales, interactions and trade-offs of NFM and consistency of reporting results. Widening the NFM empirical evidence base should be seen as an opportunity for a new approach to flood research through exploring new habitats and new flood resilience methods.

Larval Feeding: Mechanisms, Rates, and Performance in Nature

2018 ◽  
Keyword(s):  
Marine Invertebrates ◽  
Spatial Scales ◽  
Size Spectrum ◽  
Larval Feeding ◽  
Natural Habitats ◽  
Feeding Mechanism ◽  
Temporal And Spatial ◽  
And Performance ◽  
Bioenergetics Models ◽  
Many Particles

Larvae of many marine invertebrates must capture and ingest particulate food in order to develop to metamorphosis. These larvae use only a few physical processes to capture particles, but implement these processes using diverse morphologies and behaviors. Detailed understanding of larval feeding mechanism permits investigators to make predictions about feeding performance, including the size spectrum of particles larvae can capture and the rates at which they can capture them. In nature, larvae are immersed in complex mixtures of edible particles of varying size, density, flavor, and nutritional quality, as well as many particles that are too large to ingest. Concentrations of all of these components vary on fine temporal and spatial scales. Mechanistic models linking larval feeding mechanism to performance can be combined with data on food availability in nature and integrated into broader bioenergetics models to yield increased understanding of the biology of larvae in complex natural habitats.

Humans and the Environment

2013 ◽  
Keyword(s):  
Spatial Scales ◽  
Empirical Studies ◽  
Human Action ◽  
Cultural Practice ◽  
Environmental Archaeology ◽  
Archaeological Data ◽  
Temporal And Spatial ◽  
Global And Local ◽  
The Relationship ◽  
The Way

The environment has always been a central concept for archaeologists and, although it has been conceived in many ways, its role in archaeological explanation has fluctuated from a mere backdrop to human action, to a primary factor in the understanding of society and social change. Archaeology also has a unique position as its base of interest places it temporally between geological and ethnographic timescales, spatially between global and local dimensions, and epistemologically between empirical studies of environmental change and more heuristic studies of cultural practice. Drawing on data from across the globe at a variety of temporal and spatial scales, this volume resituates the way in which archaeologists use and apply the concept of the environment. Each chapter critically explores the potential for archaeological data and practice to contribute to modern environmental issues, including problems of climate change and environmental degradation. Overall the volume covers four basic themes: archaeological approaches to the way in which both scientists and locals conceive of the relationship between humans and their environment, applied environmental archaeology, the archaeology of disaster, and new interdisciplinary directions.The volume will be of interest to students and established archaeologists, as well as practitioners from a range of applied disciplines.

scholarly journals 8-Day and Daily Maximum and Minimum Air Temperature Estimation via Machine Learning Method on a Climate Zone to Global Scale

2021 ◽  
Vol 13 (12) ◽  
pp. 2355
Author(s):  
Linglin Zeng ◽  
Yuchao Hu ◽  
Rui Wang ◽  
Xiang Zhang ◽  
Guozhang Peng ◽  
...  
Keyword(s):  
Spatial Scale ◽  
Air Temperature ◽  
Spatial Scales ◽  
Model Performance ◽  
Global Scale ◽  
Scale Model ◽  
Validation Dataset ◽  
Daily Maximum ◽  
Climate Zone ◽  
Temporal And Spatial

Air temperature (Ta) is a required input in a wide range of applications, e.g., agriculture. Land Surface Temperature (LST) products from Moderate Resolution Imaging Spectroradiometer (MODIS) are widely used to estimate Ta. Previous studies of these products in Ta estimation, however, were generally applied in small areas and with a small number of meteorological stations. This study designed both temporal and spatial experiments to estimate 8-day and daily maximum and minimum Ta (Tmax and Tmin) on three spatial scales: climate zone, continental and global scales from 2009 to 2018, using the Random Forest (RF) method based on MODIS LST products and other auxiliary data. Factors contributing to the relation between LST and Ta were determined based on physical models and equations. Temporal and spatial experiments were defined by the rules of dividing the training and validation datasets for the RF method, in which the stations selected in the training dataset were all included or not in the validation dataset. The RF model was first trained and validated on each spatial scale, respectively. On a global scale, model accuracy with a determination coefficient (R2) > 0.96 and root mean square error (RMSE) < 1.96 °C and R2 > 0.95 and RMSE < 2.55 °C was achieved for 8-day and daily Ta estimations, respectively, in both temporal and spatial experiments. Then the model was trained and cross-validated on each spatial scale. The results showed that the data size and station distribution of the study area were the main factors influencing the model performance at different spatial scales. Finally, the spatial patterns of the model performance and variable importance were analyzed. Both daytime and nighttime LST had a significant contribution in the 8-day Tmax estimation on all the three spatial scales; while their contribution in daily Tmax estimation varied over different continents or climate zones. This study was expected to improve our understanding of Ta estimation in terms of accuracy variations and influencing variables on different spatial and temporal scales. The future work mainly includes identifying underlying mechanisms of estimation errors and the uncertainty sources of Ta estimation from a local to a global scale.

scholarly journals Sequential modelling of the Earth’s core magnetic field

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Guillaume Ropp ◽  
Vincent Lesur ◽  
Julien Baerenzung ◽  
Matthias Holschneider
Keyword(s):  
Magnetic Field ◽  
Prior Information ◽  
Spatial Scales ◽  
Model Parameters ◽  
International Geomagnetic Reference Field ◽  
The Earth ◽  
Temporal And Spatial ◽  
Different Sources ◽  
Original Approach ◽  
Modelling Approach

Abstract We describe a new, original approach to the modelling of the Earth’s magnetic field. The overall objective of this study is to reliably render fast variations of the core field and its secular variation. This method combines a sequential modelling approach, a Kalman filter, and a correlation-based modelling step. Sources that most significantly contribute to the field measured at the surface of the Earth are modelled. Their separation is based on strong prior information on their spatial and temporal behaviours. We obtain a time series of model distributions which display behaviours similar to those of recent models based on more classic approaches, particularly at large temporal and spatial scales. Interesting new features and periodicities are visible in our models at smaller time and spatial scales. An important aspect of our method is to yield reliable error bars for all model parameters. These errors, however, are only as reliable as the description of the different sources and the prior information used are realistic. Finally, we used a slightly different version of our method to produce candidate models for the thirteenth edition of the International Geomagnetic Reference Field.

scholarly journals Dissecting the turbulent weather driven by mechanical AGN feedback

2020 ◽  
Vol 498 (4) ◽  
pp. 4983-5002
Author(s):  
D Wittor ◽  
M Gaspari
Keyword(s):  
Feedback Loop ◽  
Spatial Scales ◽  
Self Regulation ◽  
Cosmic Time ◽  
Massive Galaxies ◽  
Temporal And Spatial ◽  
Lagrangian Tracers ◽  
Field Unit ◽  
Integral Field ◽  
Gaseous Halo

ABSTRACT Turbulence in the intracluster, intragroup, and circumgalactic medium plays a crucial role in the self-regulated feeding and feedback loop of central supermassive black holes. We dissect the 3D turbulent ‘weather’ in a high-resolution Eulerian simulation of active galactic nucleus (AGN) feedback, shown to be consistent with multiple multiwavelength observables of massive galaxies. We carry out post-processing simulations of Lagrangian tracers to track the evolution of enstrophy, a proxy of turbulence, and its related sinks and sources. This allows us to isolate in depth the physical processes that determine the evolution of turbulence during the recurring strong and weak AGN feedback events, which repeat self-similarly over the Gyr evolution. We find that the evolution of enstrophy/turbulence in the gaseous halo is highly dynamic and variable over small temporal and spatial scales, similar to the chaotic weather processes on Earth. We observe major correlations between the enstrophy amplification and recurrent AGN activity, especially via its kinetic power. While advective and baroclinc motions are always subdominant, stretching motions are the key sources of the amplification of enstrophy, in particular along the jet/cocoon, while rarefactions decrease it throughout the bulk of the volume. This natural self-regulation is able to preserve, as ensemble, the typically observed subsonic turbulence during cosmic time, superposed by recurrent spikes via impulsive anisotropic AGN features (wide outflows, bubbles, cocoon shocks). This study facilitates the preparation and interpretation of the thermo-kinematical observations enabled by new revolutionary X-ray integral field unit telescopes, such as XRISM and Athena.

Effects of seed dispersal, adult tree and seedling density on the spatial genetic structure of regeneration at fine temporal and spatial scales

2010 ◽  
Vol 7 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Fabrice Sagnard ◽  
Sylvie Oddou-Muratorio ◽  
Christian Pichot ◽  
Giovanni G. Vendramin ◽  
Bruno Fady
Keyword(s):  
Genetic Structure ◽  
Seed Dispersal ◽  
Spatial Genetic Structure ◽  
Spatial Scales ◽  
Seedling Density ◽  
Adult Tree ◽  
Temporal And Spatial

Implications of temporal and spatial scale for Atlantic salmon (Salmo salar) research

1998 ◽  
Vol 55 (S1) ◽  
pp. 9-21 ◽  
Author(s):  
Carol L Folt ◽  
Keith H Nislow ◽  
Mary E Power
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Multiple Scales ◽  
Spatial Scales ◽  
Effective Means ◽  
Research Strategies ◽  
Atlantic Salmon Salmo Salar ◽  
Temporal And Spatial ◽  
And Migration ◽  
Dependent Processes

The Atlantic salmon (Salmo salar) is a model species for studying scale issues (i.e., the extent, duration, and resolution of a study or natural process) in ecology. Major shifts in behavior and habitat use over ontogeny, along with a relatively long life span and large dispersal and migration distances, make scale issues critical for effective conservation, management, and restoration of this species. The scale over which a process occurs must be linked to the research design and we illustrate this with a discussion of resource tracking by Atlantic salmon. Identifying scale inconsistencies (e.g., when a process is evident at one scale but not another) is shown to be an effective means by which some scale-dependent processes are understood. We review the literature to assess the temporal and spatial scales used in Atlantic salmon research and find most current studies appear to sacrifice spatial and temporal extent for increased resolution. Finally, we discuss research strategies for expanding the temporal and spatial scales in salmon research, such as conducting multiple scales studies to elucidate scale inconsistencies, identifying mechanisms, and using techniques and approaches to generalize across studies and over time and space.

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