scholarly journals Multiple drivers and extreme events collapse social-ecological systems sooner

2021 ◽  
Author(s):  
Simon Willcock ◽  
Gregory Cooper ◽  
John Addy ◽  
John Dearing
Keyword(s):  
Extreme Events ◽  
Chilika Lagoon ◽  
Tipping Points ◽  
Lake Water Quality ◽  
Natural Systems ◽  
Forest Dieback ◽  
Social Ecological Systems ◽  
Primary Stress ◽  
Island Community ◽  
The Impact

Abstract The world’s ecosystems are undergoing unprecedented changes due to the impact of climate change and local human activities. A major concern is the possibility of tipping points where ecosystems and landscapes change abruptly to undesirable states. We consider what happens to the timing of tipping points when current stresses strengthen whilst systems experience additional stresses and/or extreme events. We run experiments on four mathematical models that simulate tipping points in lake water quality, the Easter Island community, the Chilika lagoon fishery, and forest dieback. We show that the strongest impacts occur under increasing levels of primary stress, but additional and more extreme stresses in all four models bring the tipping points significantly closer to today. Translating the results to the real world underlines the need for humanity to reduce damaging disturbances and global warming, and to be vigilant for signs that natural systems are degrading more rapidly than previously thought.

scholarly journals Does agricultural intensification cause tipping points in ecosystem services?

2021 ◽  
Author(s):  
Stephen C. L. Watson ◽  
Adrian C. Newton ◽  
Lucy E. Ridding ◽  
Paul M. Evans ◽  
Steven Brand ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Agricultural Intensification ◽  
Spatial Dynamics ◽  
Policy Option ◽  
List Type ◽  
Tipping Points ◽  
Software Models ◽  
Non Linear ◽  
Study Interval ◽  
The Impact

Abstract Context Agricultural intensification is being widely pursued as a policy option to improve food security and human development. Yet, there is a need to understand the impact of agricultural intensification on the provision of multiple ecosystem services, and to evaluate the possible occurrence of tipping points. Objectives To quantify and assess the long-term spatial dynamics of ecosystem service (ES) provision in a landscape undergoing agricultural intensification at four time points 1930, 1950, 1980 and 2015. Determine if thresholds or tipping points in ES provision may have occurred and if there are any detectable impacts on economic development and employment. Methods We used the InVEST suite of software models together with a time series of historical land cover maps and an Input–Output model to evaluate these dynamics over an 85-year period in the county of Dorset, southern England. Results Results indicated that trends in ES were often non-linear, highlighting the potential for abrupt changes in ES provision to occur in response to slight changes in underlying drivers. Despite the fluctuations in provision of different ES, overall economic activity increased almost linearly during the study interval, in line with the increase in agricultural productivity. Conclusions Such non-linear thresholds in ES will need to be avoided in the future by approaches aiming to deliver sustainable agricultural intensification. A number of positive feedback mechanisms are identified that suggest these thresholds could be considered as tipping points. However, further research into these feedbacks is required to fully determine the occurrence of tipping points in agricultural systems.

scholarly journals Shift Detection in Hydrological Regimes and Pluriannual Low-Frequency Streamflow Forecasting Using the Hidden Markov Model

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2058 ◽  
Author(s):  
Larissa Rolim ◽  
Francisco de Souza Filho
Keyword(s):  
Time Series ◽  
Markov Model ◽  
Hidden Markov Model ◽  
Extreme Events ◽  
Hidden Markov ◽  
Low Frequency ◽  
Streamflow Forecasting ◽  
Hydrologic Time Series ◽  
Low Frequency Variability ◽  
The Impact

Improved water resource management relies on accurate analyses of the past dynamics of hydrological variables. The presence of low-frequency structures in hydrologic time series is an important feature. It can modify the probability of extreme events occurring in different time scales, which makes the risk associated with extreme events dynamic, changing from one decade to another. This article proposes a methodology capable of dynamically detecting and predicting low-frequency streamflow (16–32 years), which presented significance in the wavelet power spectrum. The Standardized Runoff Index (SRI), the Pruned Exact Linear Time (PELT) algorithm, the breaks for additive seasonal and trend (BFAST) method, and the hidden Markov model (HMM) were used to identify the shifts in low frequency. The HMM was also used to forecast the low frequency. As part of the results, the regime shifts detected by the BFAST approach are not entirely consistent with results from the other methods. A common shift occurs in the mid-1980s and can be attributed to the construction of the reservoir. Climate variability modulates the streamflow low-frequency variability, and anthropogenic activities and climate change can modify this modulation. The identification of shifts reveals the impact of low frequency in the streamflow time series, showing that the low-frequency variability conditions the flows of a given year.

The impact of extreme events on energy price risk

2021 ◽  
pp. 105308
Author(s):  
Jun Wen ◽  
Xin-Xin Zhao ◽  
Chun-Ping Chang
Keyword(s):  
Extreme Events ◽  
Price Risk ◽  
Energy Price ◽  
The Impact

scholarly journals Citizen Science Tools Reveal Changes in Estuarine Water Quality Following Demolition of Buildings

2021 ◽  
Vol 13 (9) ◽  
pp. 1683
Author(s):  
Nandini Menon ◽  
Grinson George ◽  
Rajamohananpillai Ranith ◽  
Velakandy Sajin ◽  
Shreya Murali ◽  
...  
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Citizen Science ◽  
Secchi Depth ◽  
Lake Water Quality ◽  
Demolition Waste ◽  
Water Colour ◽  
Water Quality Variables ◽  
The Impact

Turbidity and water colour are two easily measurable properties used to monitor pollution. Here, we highlight the utility of a low-cost device—3D printed, hand-held Mini Secchi disk (3DMSD) with Forel-Ule (FU) colour scale sticker on its outer casing—in combination with a mobile phone application (‘TurbAqua’) that was provided to laymen for assessing the water quality of a shallow lake region after demolition of four high-rise buildings on the shores of the lake. The demolition of the buildings in January 2020 on the banks of a tropical estuary—Vembanad Lake (a Ramsar site) in southern India—for violation of Indian Coastal Regulation Zone norms created public uproar, owing to the consequences of subsequent air and water pollution. Measurements of Secchi depth and water colour using the 3DMSD along with measurements of other important water quality variables such as temperature, salinity, pH, and dissolved oxygen (DO) using portable instruments were taken for a duration of five weeks after the demolition to assess the changes in water quality. Paired t-test analyses of variations in water quality variables between the second week of demolition and consecutive weeks up to the fifth week showed that there were significant increases in pH, dissolved oxygen, and Secchi depth over time, i.e., the impact of demolition waste on the Vembanad Lake water quality was found to be relatively short-lived, with water clarity, colour, and DO returning to levels typical of that period of year within 4–5 weeks. With increasing duration after demolition, there was a general decrease in the FU colour index to 17 at most stations, but it did not drop to 15 or below, i.e., towards green or blue colour indicating clearer waters, during the sampling period. There was no significant change in salinity from the second week to the fifth week after demolition, suggesting little influence of other factors (e.g., precipitation or changes in tidal currents) on the inferred impact of demolition waste. Comparison with pre-demolition conditions in the previous year (2019) showed that the relative changes in DO, Secchi depth, and pH were very high in 2020, clearly depicting the impact of demolition waste on the water quality of the lake. Match-ups of the turbidity of the water column immediately before and after the demolition using Sentinel 2 data were in good agreement with the in situ data collected. Our study highlights the power of citizen science tools in monitoring lakes and managing water resources and articulates how these activities provide support to Sustainable Development Goal (SDG) targets on Health (Goal 3), Water quality (Goal 6), and Life under the water (Goal 14).

THE IMPACT OF RECASTS ON THE DEVELOPMENT OF PRIMARY STRESS IN A SYNCHRONOUS COMPUTER-MEDIATED ENVIRONMENT

2016 ◽  
Vol 39 (2) ◽  
pp. 257-285 ◽  
Author(s):  
Özgür Parlak ◽  
Nicole Ziegler
Keyword(s):  
Information Exchange ◽  
Computer Mediated Communication ◽  
Lexical Stress ◽  
Phonological Development ◽  
Mediated Communication ◽  
Primary Stress ◽  
Acoustic Correlates ◽  
Sentence Reading ◽  
Computer Mediated ◽  
The Impact

Although previous research has demonstrated the efficacy of recasts on second language (L2) morphology and lexis (e.g., Li, 2010; Mackey & Goo, 2007), few studies have examined their effect on learners’ phonological development (although see Saito, 2015; Saito & Lyster, 2012). The current study investigates the impact of recasts on the development of lexical stress, defined as the placement of emphasis on a particular syllable within a word by making it louder and longer, in oral synchronous computer-mediated communication (SCMC) and face-to-face (FTF) interaction. Using a pretest-posttest design, intermediate learners of English were randomly assigned to one of four groups: FTF recast, SCMC recast, FTF control, or SCMC control. Pre- and posttests consisted of sentence-reading and information-exchange tasks, while the treatment was an interactive role-play task. Syllable duration, intensity, and pitch were used to analyze learners’ development of stress placement. The statistical analyses of the acoustic correlates did not yield significant differences. However, the observed patterns suggest that there is need for further investigation to understand the relationship between recasts and development of lexical stress.

scholarly journals Emergent properties in microbiome networks reveal the anthropogenic disturbance of farming practices in vineyard soil fungal communities

2020 ◽  
Author(s):  
Rüdiger Ortiz-Álvarez ◽  
Hector Ortega-Arranz ◽  
Vicente J. Ontiveros ◽  
Charles Ravarani ◽  
Alberto Acedo ◽  
...  
Keyword(s):  
Small World ◽  
Fungal Communities ◽  
Local Network ◽  
Emergent Properties ◽  
Farming Practices ◽  
Natural Systems ◽  
Vineyard Soil ◽  
Global Agriculture ◽  
Network Properties ◽  
The Impact

AbstractAgro-ecosystems are human-managed natural systems, and therefore are subject to generalized ecological rules. A deeper understanding of the factors impacting on the biotic component of ecosystem stability is needed for promoting the sustainability and productivity of global agriculture. Here we propose a method to determine ecological emergent properties through the inference of network properties in local microbial communities, and to use them as biomarkers of the anthropogenic impact of different farming practices on vineyard soil ecosystem functioning. In a dataset of 350 vineyard soil samples from USA and Spain we observed that fungal communities ranged from random to small-world network arrangements with differential levels of niche specialization. Some of the network properties studied were strongly correlated, defining patterns of ecological emergent properties that are influenced by the intensification level of the crop management. Low-intervention practices (from organic to biodynamic approaches) promoted densely clustered networks, describing an equilibrium state based on mixed (generalist-collaborative) communities. Contrary, in conventionally managed vineyards, we observed highly modular (niche-specialized) low clustered communities, supported by a higher degree of selection (more co-exclusion proportion). We also found that, although geographic factors can explain the different fungal community arrangements in both countries, the relationship between network properties in local fungal communities better capture the impact of farming practices regardless of the location. Thus, we hypothesize that local network properties can be globally used to evaluate the effect of ecosystem disturbances in crops, but also in when evaluating the effect of clinical interventions or to compare microbiomes of healthy vs. disturbed conditions.

Characterizing hydro-meteorological extremes from a societal perspective

2021 ◽  
Author(s):  
Ekaterina Bogdanovich ◽  
Lars Guenther ◽  
Markus Reichstein ◽  
Georg Ruhrmann ◽  
René Orth
Keyword(s):  
Extreme Events ◽  
Goodness Of Fit ◽  
Heat Waves ◽  
Explanatory Power ◽  
Potential Temperature ◽  
Well Being ◽  
Apparent Temperature ◽  
Temperature Threshold ◽  
Temperature Thresholds ◽  
The Impact

<p>Extreme hydro-meteorological events often affect the economy, social life, health, and well-being. One indicator for the impact of extreme events on society is the concurrently increased societal attention. Such increases can help to measure and understand the vulnerability of the society to extreme events, and to evaluate the relevance of an event, which is important for disaster research and risk management. In this study, we analyzed and characterized hydro-meteorological extreme events from a societal impact perspective. In particular, we investigated the impact of heat waves on societal attention in European countries with contrasting climate (Germany, Spain, and Sweden) using Google trends data during 2010–2019. Thus, we seek to answer two general research questions: (i) how and when do extreme events trigger societal attention, (ii) are there temperature thresholds at which societal attention increases? </p><p>To describe heat waves, we used maximum, minimum, average, and apparent temperature, aggregated to a weekly time scale. We analyzed the relationship between temperature and societal attention using piecewise regression to identify potential temperature-related thresholds in societal attention. The threshold is determined as the breaking point between two linear models fitted to data. We determined the corresponding goodness of fit by computing R<sup>2</sup> for each temperature variable. The variable with the highest R<sup>2</sup> is considered as the most influential one.</p><p>The overall relationship between temperature and Google attention to heat waves is significant in all countries and reveals clear temperature thresholds. The variable with the highest explanatory power is the weekly average of the daily maximum temperatures, which accounts for 71% of google attention in Germany, 51 % in Sweden, and 38 % in Spain. For Germany, similar results are found with media attention. In Sweden, with its colder climate, a lower temperature threshold is identified, indicating higher heat vulnerability. No significant impact of temperatures from the previous weeks is found. While further work is needed to improve the understanding of the attention-heat coupling, the demonstrated significant societal attention response to heat waves offers the opportunity to characterize heat waves from an impact perspective using the identified temperature variables, time scales, and thresholds.</p>

Mitigating the Impact of Extreme Events

2015 ◽  
pp. 32-53
Author(s):  
Doaa Taha
Keyword(s):  
Emergency Management ◽  
Extreme Events ◽  
September 11 ◽  
Lessons Learned ◽  
Economic Environment ◽  
Public Private Partnerships ◽  
Original Research ◽  
Effective Response ◽  
September 11 Attacks ◽  
The Impact

Years have gone by since 9/11/2001. Still, it seems as though it were only yesterday: the shock, the tragedy, the heartbreak. Of all the questions, one keeps coming back, “Have we learned what we need to know to mitigate the impact of such events in the future?” The answer is a hesitant “Perhaps.” Today, still dealing with an economic disaster the magnitude of which has not been experienced in decades, there is great concern that any gains made from lessons learned by 9/11 will be further eroded. In this chapter, original research considering four corporations directly involved in the September 11 attacks is revisited in view of today's emphasis on public private partnerships and economic environment. In reexamining the original research, this chapter considers the value of public private partnerships as part of the emergency management community, and as part of an effective response to future incidents.

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