The use of long-term rainfall records for augmenting historic flood series: a case study on the upper Dee, Aberdeenshire, Scotland

1987 ◽  
Vol 78 (4) ◽  
pp. 275-285 ◽  
Author(s):  
L. J. McEwen
Keyword(s):  
Extreme Value Analysis ◽  
Short Term ◽  
Historical Sources ◽  
Climatic Fluctuations ◽  
Value Analysis ◽  
Rainfall Events ◽  
General Terms ◽  
Recurrence Intervals

ABSTRACTEstablishing the magnitude and frequency of floods within upland catchments on the basis of short-term gauged runoff records is crucially dependent upon the extent to which the record is truly representative. In the case of the River Dee, upstream of Crathie in Aberdeenshire, gauged discharge records are limited in length. Although the middle Dee has been gauged since 1929, the gauge within the upper catchment has only ten years of record. Thus, reliable estimates of the return intervals of extreme floods for this part of the Dee can only be obtained by using a variety of historical sources to extend the flood series.Long-term rainfall records, where available, provide a valuable independent check on the reconstructed flood series. Such rainfall records, when analysed in terms of the magnitude, frequency and duration of major events, should, in general terms, correspond with the flood series. In this paper, the recurrence interval of extreme rainfalls of varying magnitude and duration in upper Deeside is estimated by extreme value analysis of the annual maximum series. The frequency of rainfall events above varying thresholds is also assessed. The existence of climatic fluctuations giving highly variable recurrence intervals for rainfall events of the same magnitude is demonstrated. Finally, the seasonality of frequent flood-producing storms is analysed. Patterns observed within the rainfall record are compared with those previously established within the historic flood series to substantiate and augment the flood record.

Pesticide Runoff Simulations: Long-Term Annual Means vs. Event Extremes?

1992 ◽  
Vol 6 (3) ◽  
pp. 725-730 ◽  
Author(s):  
Ralph A. Leonard ◽  
Clint C. Truman ◽  
Walt G. Knisel ◽  
Frank M. Davis
Keyword(s):  
Event Analysis ◽  
Short Term ◽  
Rainfall Events ◽  
Loading Effects ◽  
Limited Application ◽  
Annual Total ◽  
Recurrence Intervals ◽  
Annual Means ◽  
Pesticide Runoff

The GLEAMS model (Groundwater Loading Effects of Agricultural Management Systems) is used to illustrate model application in evaluating potential pesticide runoff of two similar pesticides from one soil. This limited application was chosen for simplicity in illustrating relationships between annual means and single events. When using annual totals of simulated pesticide runoff for comparing two pesticides or assessing risks, long-term 50-yr simulations are preferable to short 10-yr simulations. When short-term simulations are performed, care must be exercised in selecting representative climatic periods. For short half-life pesticides, as demonstrated in this study, initial rainfall events on or near the day of application will often contribute most to annual pesticide lost. In these cases, single event analysis may be required. Procedures are demonstrated for expressing annual total pesticide losses and single rainfall event losses probabilistically in terms of expected recurrence intervals.

A Comparison of Methods for Assessing the Lifetime Reliability of a Moored FPSO

2004 ◽  
Author(s):  
Andrew J. Grime ◽  
R. S. Langley
Keyword(s):  
Reliability Analysis ◽  
Offshore Structures ◽  
Extreme Value Analysis ◽  
Design Codes ◽  
Short Term ◽  
Safety Level ◽  
Value Analysis ◽  
Design Storm ◽  
Current Design

Current design codes for floating offshore structures are based on measures of short-term reliability. That is, a design storm is selected via an extreme value analysis of the environmental conditions and the reliability of the vessel in that design storm is computed. Although this approach yields valuable information on the vessel motions, it does not produce a statistically rigorous assessment of the lifetime probability of failure. An alternative approach is to perform a long-term reliability analysis in which consideration is taken of all sea states potentially encountered by the vessel during the design life. Although permitted as a design approach in current design codes, the associated computational expense generally prevents its use in practice. A new efficient approach to long-term reliability analysis is presented here, the results of which are compared with a traditional short-term analysis for the surge motion of a representative moored FPSO in head seas. This serves to illustrate the failure probabilities actually embedded within current design code methods, and the way in which design methods might be adapted to achieve a specified target safety level.

scholarly journals Typology of historical sources and the reconstruction of long‐term historical changes of riverine fish: a case study of the A ustrian D anube and northern R ussian rivers

2013 ◽  
Vol 23 (4) ◽  
pp. 498-515 ◽  
Author(s):  
Gertrud Haidvogl ◽  
Dmitry Lajus ◽  
Didier Pont ◽  
Martin Schmid ◽  
Mathias Jungwirth ◽  
...  
Keyword(s):  
Historical Sources ◽  
Historical Changes ◽  
Riverine Fish

scholarly journals Long-Term and Seasonal Trends in Global Wave Height Extremes Derived from ERA-5 Reanalysis Data

2020 ◽  
Vol 8 (12) ◽  
pp. 1015
Author(s):  
Alicia Takbash ◽  
Ian R. Young
Keyword(s):  
Southern Hemisphere ◽  
Wave Height ◽  
Significant Wave Height ◽  
Reanalysis Data ◽  
Extreme Value Analysis ◽  
Winter Storms ◽  
Value Analysis ◽  
Weather Forecasts ◽  
Significant Wave

A non-stationary extreme value analysis of 41 years (1979–2019) of global ERA5 (European Centre for Medium-Range Weather Forecasts Reanalysis) significant wave height data is undertaken to investigate trends in the values of 100-year significant wave height, Hs100. The analysis shows that there has been a statistically significant increase in the value of Hs100 over large regions of the Southern Hemisphere. There have also been smaller decreases in Hs100 in the Northern Hemisphere, although the related trends are generally not statistically significant. The increases in the Southern Hemisphere are a result of an increase in either the frequency or intensity of winter storms, particularly in the Southern Ocean.

Cordaid’s Post-Disaster Shelter Strategy in Haiti: Linking Relief and Development

2014 ◽  
Vol 39 (3) ◽  
pp. 77-85
Author(s):  
Harmen Janse ◽  
Kees van der Flier
Keyword(s):  
Urban Area ◽  
Urban Areas ◽  
Life Support ◽  
Comparative Case Study ◽  
Urban Context ◽  
Short Term ◽  
Stage Of Development ◽  
Post Disaster

Haiti was struck by a heavy earthquake in 2010 and international aid poured into the country. News reports in 2011 were not very positive about the results of post-disaster reconstruction: “The relief efforts are only putting Haiti on life-support instead of evolving into the next stage of development”. One of the non-governmental organisations (NGOs) involved in Haiti was Cordaid, implementing a ‘transitional shelter strategy’ to support the transformation of neigh-bourhoods from a state of life-support into a state of self-sustaining development. The strategy was implemented in both a rural and an urban area. The main feature of the strategy was the provision of structures that could be adapted from simple shelters to permanent houses. Since the results of the strategy were mixed and ambiguous, a comparative case study was conducted to evaluate the shelter strategy in both areas. The objective was to draw lessons about what has to be taken into account when formulating future urban shelter strategies. The case study is discussed in this article. The main finding from the case study is that producing the intended number of shelters within the financial and time budgets that were set (efficiency), was more difficult in the urban area than in the rural area. But the conditions for linking relief and development (effectiveness) are more favourable in the urban context. NGOs may achieve long-term (effective) results in the urban context when a lower efficiency can be justified. That is why NGOs need to engage in a debate about the extent to which they are able to focus on long-term shelter or housing strategies. The important element in the debate is communication with the donors who are often focused on short-term relief measures. However urban areas cannot be rebuilt with only short-term interventions. The link between relief and development has to be made by a process-orientated approach focusing on capacities of local participants.

Disaster Management and Continuity Planning in Libraries

2016 ◽  
Vol 5 (1) ◽  
pp. 26-41 ◽  
Author(s):  
Rebecca Hamilton ◽  
Diane Brown
Keyword(s):  
Success Factor ◽  
Short Term ◽  
Continuity Planning ◽  
Critical Success ◽  
Business Operations ◽  
Asset Recovery ◽  
Disaster Preparation

Libraries are taking on new roles in a disaster and with that comes strategic responsibilities beyond traditional asset recovery activities. In the past, library disaster plans have emphasized recovery of materials. Here, the emphasis is on continuing business operations. Libraries have become the centers of communication for their communities in a crisis. This article will demonstrate the essential role of libraries before, during and after a disaster, both short term and long term and how to get a seat at the table with community planners by demonstrating the functions that are critical to recovery. A literature review and case study are used to develop these recommendations. A critical success factor is to use a disaster preparation methodology that includes a business continuity plan.

scholarly journals Challenges in modelling isoprene and monoterpene emission dynamics of Arctic plants: a case study from a subarctic tundra heath

2016 ◽  
Vol 13 (24) ◽  
pp. 6651-6667 ◽  
Author(s):  
Jing Tang ◽  
Guy Schurgers ◽  
Hanna Valolahti ◽  
Patrick Faubert ◽  
Päivi Tiiva ◽  
...  
Keyword(s):  
Response Curve ◽  
Large Scale ◽  
Ecosystem Model ◽  
The Arctic ◽  
Short Term ◽  
Response Curves ◽  
Arctic Plants ◽  
Scale Modelling

Abstract. The Arctic is warming at twice the global average speed, and the warming-induced increases in biogenic volatile organic compounds (BVOCs) emissions from Arctic plants are expected to be drastic. The current global models' estimations of minimal BVOC emissions from the Arctic are based on very few observations and have been challenged increasingly by field data. This study applied a dynamic ecosystem model, LPJ-GUESS, as a platform to investigate short-term and long-term BVOC emission responses to Arctic climate warming. Field observations in a subarctic tundra heath with long-term (13-year) warming treatments were extensively used for parameterizing and evaluating BVOC-related processes (photosynthesis, emission responses to temperature and vegetation composition). We propose an adjusted temperature (T) response curve for Arctic plants with much stronger T sensitivity than the commonly used algorithms for large-scale modelling. The simulated emission responses to 2 °C warming between the adjusted and original T response curves were evaluated against the observed warming responses (WRs) at short-term scales. Moreover, the model responses to warming by 4 and 8 °C were also investigated as a sensitivity test. The model showed reasonable agreement to the observed vegetation CO2 fluxes in the main growing season as well as day-to-day variability of isoprene and monoterpene emissions. The observed relatively high WRs were better captured by the adjusted T response curve than by the common one. During 1999–2012, the modelled annual mean isoprene and monoterpene emissions were 20 and 8 mg C m−2 yr−1, with an increase by 55 and 57 % for 2 °C summertime warming, respectively. Warming by 4 and 8 °C for the same period further elevated isoprene emission for all years, but the impacts on monoterpene emissions levelled off during the last few years. At hour-day scale, the WRs seem to be strongly impacted by canopy air T, while at the day–year scale, the WRs are a combined effect of plant functional type (PFT) dynamics and instantaneous BVOC responses to warming. The identified challenges in estimating Arctic BVOC emissions are (1) correct leaf T estimation, (2) PFT parameterization accounting for plant emission features as well as physiological responses to warming, and (3) representation of long-term vegetation changes in the past and the future.

scholarly journals Alternatives to groundwater abstraction as a measure to stop land subsidence: a case study of Semarang, Indonesia

2019 ◽  
Vol 125 ◽  
pp. 01003 ◽  
Author(s):  
Wesley Beek ◽  
Bart Letitre ◽  
H. Hadiyanto ◽  
S. Sudarno
Keyword(s):  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Drinking Water Treatment ◽  
Decision Makers ◽  
Groundwater Abstraction ◽  
Short Term ◽  
Treatment Services

The Water as Leverage project aims to lay a blueprint for urban coastal areas around the world that are facing a variety of water-related issues. The blueprint is based upon three real case studies in Bangladesh, India and Indonesia. The case of Indonesia focuses on Semarang, a city that faces issues like flooding, increased water demand, and a lack of wastewater treatment. In this report I summarise the different techniques available to tackling these issues. Along with this I provide a cost-benefit analysis to support decision makers. For a short term it is recommended to produce industrial water from (polluted) surface water as a means to offer an alternative to groundwater abstraction. On a long term it is recommended to install additional wastewater and drinking water treatment services to facilitate better hygiene and a higher quality of life.

Time Series Forecasting in Retail Sales Using LSTM and Prophet

2021 ◽  
pp. 241-262
Author(s):  
Clony Junior ◽  
Pedro Gusmão ◽  
José Moreira ◽  
Ana Maria M. Tome
Keyword(s):  
Time Series ◽  
Data Science ◽  
Short Term Memory ◽  
Special Kind ◽  
Time Series Forecasting ◽  
Short Term ◽  
Term Memory ◽  
Use Of Time

Data science highlights fields of study and research such as time series, which, although widely explored in the past, gain new perspectives in the context of this discipline. This chapter presents two approaches to time series forecasting, long short-term memory (LSTM), a special kind of recurrent neural network (RNN), and Prophet, an open-source library developed by Facebook for time series forecasting. With a focus on developing forecasting processes by data mining or machine learning experts, LSTM uses gating mechanisms to deal with long-term dependencies, reducing the short-term memory effect inherent to the traditional RNN. On the other hand, Prophet encapsulates statistical and computational complexity to allow broad use of time series forecasting, prioritizing the expert's business knowledge through exploration and experimentation. Both approaches were applied to a retail time series. This case study comprises daily and half-hourly forecasts, and the performance of both methods was measured using the standard metrics.

Comparison of the Long-Term Trends of the Largest Waves in the Ice-Free Arctic Waters From Different Reanalysis Products

2018 ◽  
Author(s):  
Takuji Waseda ◽  
Takehiko Nose ◽  
Adrean Webb
Keyword(s):  
Arctic Ocean ◽  
The Arctic ◽  
Extreme Value Analysis ◽  
Positive Trend ◽  
Value Analysis ◽  
The Arctic Ocean ◽  
Ship Route ◽  
Long Term Trends ◽  
Horizontal Grid

The long-term trends of the expected largest waves in the ice-free Arctic waters from Laptev to Beaufort Seas was studied analyzing the ERA-interim reanalysis from 1979 to 2016. The analysis showed that the positive trend is largest in October and increased almost 70 cm in 38 years. For ships navigating the Northern Ship Route, it is important to know what the possible largest waves to expect during its cruise. In view of conducting the extreme value analysis, the uncertainty of the largest wave needs to be validated. However, the observation in the Arctic Ocean is limited. We, therefore, rely on the reanalysis wave products in the Arctic Ocean, whose uncertainty is yet to be determined. ERA-Interim and ERA-5 are compared in the Laptev, the East Siberian, Chukchi and Beaufort Seas. The comparison is relevant as the two products differ in its horizontal grid resolution and availability of the satellite altimeter significant wave height data assimilation. During 2010–2016 when the ERA5 is available, only a small difference from ERA-Interim was detected in the mean. However, the expected largest waves in the domain tended to be large for the ERA-5, 8% normalized bias. The tendency was quite similar with a high correlation of 0.98.

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