LINKING CLIMATE CHANGE TO IMPACT AND ADAPTATION STUDIES: MODELING OF EXTREME RAINFALL PROCESSES OVER A WIDE RANGE OF SPACE AND TIME SCALES

2019 ◽  
Author(s):  
VAN-THANH VAN NGUYEN
Keyword(s):  
Climate Change ◽  
Time Scales ◽  
Extreme Rainfall ◽  
Adaptation Studies ◽  
Space And Time ◽  
Wide Range

scholarly journals Scale-Invariance Generalized Logistic (GLO) Model for Estimating Extreme Design Rainfalls in the Context of Climate Change

10.29007/5xqt ◽  
2018 ◽  
Author(s):  
Truong-Huy Nguyen ◽  
Van-Thanh-Van Nguyen
Keyword(s):  
Climate Change ◽  
Time Scales ◽  
Scale Invariance ◽  
Regional Climate ◽  
Climate Change Impacts ◽  
Extreme Rainfall ◽  
Logistic Distribution ◽  
Generalized Logistic Distribution ◽  
Climate Simulations ◽  
Wide Range

Statistical models based on the scale-invariance (or scaling) concept has increasingly become an essential tool for modeling extreme rainfall processes over a wide range of time scales. In particular, in the context of climate change these scaling models can be used to describe the linkages between the distributions of sub-daily extreme rainfalls (ERs) and the distribution of daily ERs that is commonly provided by global or regional climate simulations. Furthermore, the Generalized Logistic distribution (GLO) has been recommended in UK for modeling of extreme hydrologic variables. Therefore, the main objective of the present study is to propose a scaling GLO model for modeling ER processes over different time scales. The feasibility and accuracy of this model were assessed using ER data from a network of 21 raingages located in Ontario, Canada. Results of this assessment based on different statistical criteria have indicated the comparable performance of the proposed scaling GLO model as compared to other popular models in practice. Furthermore, an illustrative application of the proposed model for evaluating the climate change impacts on the ERs in Ontario using the available NASA downscaled regional climate simulations has demonstrated the accuracy and robustness of the GLO model.

scholarly journals The role of glacier dynamics and threshold definition in the characterisation of future streamflow droughts in glacierised catchments

2017 ◽  
Author(s):  
Marit Van Tiel ◽  
Adriaan J. Teuling ◽  
Niko Wanders ◽  
Marc J. P. Vis ◽  
Kerstin Stahl ◽  
...  
Keyword(s):  
Climate Change ◽  
Time Scales ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Glacier Area ◽  
Short Term ◽  
Drought Characteristics ◽  
Wide Range ◽  
Glacier Dynamics ◽  
The Future

Abstract. Glaciers are essential hydrological reservoirs, storing and releasing water at various time scales. Short-term variability in glacier melt is one of the causes of streamflow droughts, defined as below normal water availabilities. Streamflow droughts in glacierised catchments have a wide range of interlinked causing factors related to precipitation and temperature on short and long time scales. Climate change affects glacier storage capacity, with resulting consequences for discharge regimes and drought. Future projections of streamflow drought in glacierised basins can, however, strongly depend on the modelling strategies and analysis approaches applied. Here, we examine the effect of different approaches, concerning the glacier modelling and the drought threshold, on the characterisation of streamflow droughts in glacierised catchments. Streamflow is simulated with the HBV-light model for two case study catchments, the Nigardsbreen catchment in Norway and the Wolverine catchment in Alaska, and two future climate change scenarios (RCP4.5 and RCP8.5). Two types of glacier modelling are applied, a constant and dynamical glacier area conceptualisation. Streamflow droughts are identified with the variable threshold level method and their characteristics are compared between two periods, a historical (1975–2004) and future (2071–2100) period. Two existing threshold approaches to define future droughts are employed, (1) the threshold from the historical period and (2) a transient threshold approach, whereby the threshold adapts every year in the future to the changing regimes. Results show that drought characteristics differ among the combinations of glacier area modelling and thresholds. The historical threshold combined with a dynamical glacier area projects extreme increases in drought severity in the future, caused by the regime shift due to a reduction in glacier area. The historical threshold combined with a constant glacier area results in a drastic decrease of the number of droughts. The drought characteristics between future and historic periods are more similar when the transient threshold is used, for both glacier dynamics conceptualisations. With the transient threshold causing factors of future droughts, can be analysed. This study revealed the different effects of methodological choices on future streamflow drought projections and it highlights how the options can be used to analyse different aspects of future droughts: the transient threshold for analysing future drought processes, the historical threshold to assess changes between periods, the constant glacier area to analyse the effect of short term climate variability on droughts and the dynamical glacier area to model realistic future discharges under climate change.

On Statistical Modeling of Extreme Rainfall Processes for Urban Water Infrastructure Design in the Context of Climate Change

2020 ◽  
Author(s):  
Van-Thanh-Van Nguyen
Keyword(s):  
Climate Change ◽  
Spatial Scales ◽  
Extreme Rainfall ◽  
Engineering Practice ◽  
Climate Projections ◽  
Urban Water ◽  
Water Infrastructure ◽  
Changing Climate ◽  
Main Challenge ◽  
Wide Range

<p><span>There exists an urgent need to assess the possible impacts of climate change on the Intensity-Duration-Frequency (IDF) relations in general and on the design storm in particular for improving the design of urban water infrastructure in the context of a changing climate. At present, the derivation of IDF relations in the context of climate change at a location of interest has been recognized as one of the most challenging tasks in current engineering practices. The main challenge is how to establish the linkages between the climate projections given by Global Climate Models (GCMs) at the global scale and the observed extreme rainfalls at a given local site. If these linkages could be established, then the projected climate change conditions given by GCMs could be used to predict the resulting changes of local extreme rainfalls and related runoff characteristics.  Consequently, innovative downscaling approaches are needed in the modeling extreme rainfall (ER) processes over a wide range of temporal and spatial scales for climate change impact and adaptation studies in urban areas. Therefore, the overall objective of the present paper is to provide an overview of some recent progress in the modeling of extreme rainfall processes in a changing climate from both theoretical and practical viewpoints. In particular, the main focus of this paper is on recently developed statistical downscaling (SD) methods for linking GCM climate predictors to the observed daily and sub-daily rainfall extremes at a single site as well as at many sites concurrently. In addition, new SD procedures are presented for describing the linkages between GCM outputs and rainfall characteristics at a given location where the rainfall data are limited or unavailable, a common and crucial challenge in engineering practice.</span></p>

Scaling the Necropolitical Anthropocene

2020 ◽  
Vol 9 (4) ◽  
pp. 77-91
Author(s):  
Tyler S. Rife
Keyword(s):  
Climate Change ◽  
Theoretical Concepts ◽  
Ecological Concept ◽  
Space And Time ◽  
Desert Landscape ◽  
Ecological Potential

In this essay, I demonstrate how the ecological concept of “scaling” carries potential to animate critical logics in the Anthropocene. I argue that scaling can expose unexpected linkages across space and time that help to denaturalize particular ecological formations as entangled, rather than separate. I demonstrate the critical ecological potential of scaling by performing it rhizomatically, weaving across scales of space and time while juxtaposing theoretical concepts with my experiences of life as a resident in the urban desert landscape of Phoenix, AZ. This ecology ultimately reveals how climate change acts as a complex necropolitic of the Anthropocene.

A MODELING SYSTEM FOR CLIMATE CHANGE RISK ASSESSMENT, MANAGEMENT AND HEDGING IN COASTAL AREAS

2017 ◽  
Author(s):  
Sergei Soldatenko ◽  
Sergei Soldatenko ◽  
Genrikh Alekseev ◽  
Genrikh Alekseev ◽  
Alexander Danilov ◽  
...  
Keyword(s):  
Climate Change ◽  
Risk Assessment ◽  
Coastal Areas ◽  
Mitigation Strategies ◽  
System Structure ◽  
The Arctic ◽  
Risk Modeling ◽  
Wide Range ◽  
Adverse Weather ◽  
The Impact

Every aspect of human operations faces a wide range of risks, some of which can cause serious consequences. By the start of 21st century, mankind has recognized a new class of risks posed by climate change. It is obvious, that the global climate is changing, and will continue to change, in ways that affect the planning and day to day operations of businesses, government agencies and other organizations and institutions. The manifestations of climate change include but not limited to rising sea levels, increasing temperature, flooding, melting polar sea ice, adverse weather events (e.g. heatwaves, drought, and storms) and a rise in related problems (e.g. health and environmental). Assessing and managing climate risks represent one of the most challenging issues of today and for the future. The purpose of the risk modeling system discussed in this paper is to provide a framework and methodology to quantify risks caused by climate change, to facilitate estimates of the impact of climate change on various spheres of human activities and to compare eventual adaptation and risk mitigation strategies. The system integrates both physical climate system and economic models together with knowledge-based subsystem, which can help support proactive risk management. System structure and its main components are considered. Special attention is paid to climate risk assessment, management and hedging in the Arctic coastal areas.

Understanding Distressed Residential Transaction Discounts Across Price Segments and Market Conditions

2020 ◽  
Vol 42 (1) ◽  
pp. 151-182
Author(s):  
Ramya Rajajagadeesan Aroul ◽  
J. Andrew Hansz ◽  
Mauricio Rodriguez
Keyword(s):  
Transaction Costs ◽  
Time Varying ◽  
Market Segment ◽  
Market Conditions ◽  
Large Market ◽  
Space And Time ◽  
Wide Range ◽  
Time Periods ◽  
Market Areas

In the literature, there is a wide range of discounts associated with foreclosures. Comparisons across studies are difficult as they use different methodologies across large areas over different time periods. We employ a consistent methodology across space and time. We find modest discounts, within the range of typical transaction costs, in all but the highest priced market segment. Higher priced segments could explain prior findings of substantial discounts. We find that discounts are time-varying, with discounts increasing with market distress. A one-size-fits-all approach is not appropriate when estimating distressed transaction discounts across large market areas or under changing market conditions.

The Biology of Mediterranean-Type Ecosystems

2018 ◽  
Author(s):  
Karen J. Esler ◽  
Anna L. Jacobsen ◽  
R. Brandon Pratt
Keyword(s):  
Climate Change ◽  
South Africa ◽  
Invasive Species ◽  
Habitat Loss ◽  
Endemic Species ◽  
Geographic Area ◽  
Cutting Edge ◽  
Wide Range ◽  
The Mediterranean ◽  
Mediterranean Type Ecosystems

The world’s mediterranean-type climate regions (including areas within the Mediterranean, South Africa, Australia, California, and Chile) have long been of interest to biologists by virtue of their extraordinary biodiversity and the appearance of evolutionary convergence between these disparate regions. Comparisons between mediterranean-type climate regions have provided important insights into questions at the cutting edge of ecological, ecophysiological and evolutionary research. These regions, dominated by evergreen shrubland communities, contain many rare and endemic species. Their mild climate makes them appealing places to live and visit and this has resulted in numerous threats to the species and communities that occupy them. Threats include a wide range of factors such as habitat loss due to development and agriculture, disturbance, invasive species, and climate change. As a result, they continue to attract far more attention than their limited geographic area might suggest. This book provides a concise but comprehensive introduction to mediterranean-type ecosystems. As with other books in the Biology of Habitats Series, the emphasis in this book is on the organisms that dominate these regions although their management, conservation, and restoration are also considered.

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