scholarly journals Risk assessment of a water supply system under climate variability: a stochastic approach

2011 ◽  
Vol 38 (3) ◽  
pp. 252-262 ◽  
Author(s):  
Beatrice B. Yung ◽  
Bryan A. Tolson ◽  
Donald H. Burn

A model is developed to assess risk to a municipal water supply system under the influence of population growth and climate variability. To incorporate the uncertainty in water use, a model that combines time series Monte Carlo simulations and a deterministic artificial neural network (ANN) is developed to simulate the daily water demand under climate variation. The model is first applied to assess how climate change alters the risk of a current water supply system and is then used to estimate the effects of demand management programs and system expansion. The model quantifies water supply system risk in terms of reliability, resiliency, and vulnerability (RRV). The model evaluates 11 scenarios defined by combining various population growth forecasts, demand management programs, system expansions, and global climate model (GCM) scenarios. The simulation results suggest that a rise in temperature and a change in precipitation magnitude will negatively impact the performance of the case study system.

2020 ◽  
Author(s):  
Raphael Hébert ◽  
Ulrike herzschuh ◽  
Thomas Laepple

<p>Multidecadal to millenial timescale climate variability has been investigated over the ocean</p><p>using extensive proxy data and it was found to yield coherent interproxy estimates of global and regional sea-surface temperature (SST) climate variability (Laepple and Huybers, 2014). Global Climate Model (GCM) simulations on the other hand, were found to exhibit an increasingly large deficit of regional SST climate variability for increasingly longer timescales.</p><p>Further investigation is needed to better quantify terrestrial climate variability for long</p><p>timescales and validate climate models.</p><p>Vegetation related proxies such as tree rings and pollen records are the most widespread</p><p>types of archives available to investigate terrestrial climate variability. Tree ring records are</p><p>particularly useful for short time scales estimates due to their annual resolution, while pollen-based reconstructions are necessary to cover the longer timescales. In the present work, we use a large database of 1873 pollen records covering the northern hemisphere in order to quantify Holocene vegetation and climate variability for the first time at centennial to multi-millenial timescales.</p><p>To ensure the robustness of our results, we are particularly interested in the spatio-temporal representativity of the archived signal in pollen records after taking into account the effective spatial scale, the intermittent and irregular sampling, the age-uncertainty and the sediment mixing effect. A careful treatment of the proxy formation allows us to investigate the spatial correlation structure of the pollen-based climate reconstructions as a function of timescales. The pollen data results are then contrasted with the analysis replicated using transient Holocene simulations produced with state-of-the-art climate models as well as stochastic climate model simulations.Our results indicate a substantial gap in terrestrial climate variability between the climate model simulations and the pollen reconstructions at centennial to multi-millenial timescales, mirroring the variability gap found in the marine domain. Finally, we investigate how future climate model projections with greater internal variability would be affected, and how this increases the uncertainty of regional land temperature projections.</p>


2017 ◽  
Vol 38 (4) ◽  
pp. 400-407 ◽  
Author(s):  
LT Wong ◽  
KW Mui ◽  
Y Zhou

High-rise housing, a trend in densely populated cities around the world, increases energy use for water supply and corresponding greenhouse gas emissions. With emphasis on improving the energy efficiency in the water supply systems, this paper proposes an energy efficiency evaluation measure for the water supply system designs and demonstrates its potential applications in a typical high-rise water supply system. In the proposed measure, the energy efficiency in a water supply system is defined as the potential energy required at the demand locations divided by the pumping energy of the supply system. The outcome of this paper provides useful benchmark references not only for the water supply system designs but also for the water demand management programmes in buildings. Practical application: An energy efficiency evaluation measure for the water supply system designs is used to establish benchmark references for not only the water supply system designs but also for the water demand management programmes in buildings.


2021 ◽  
Vol 6 (1) ◽  
pp. 34
Author(s):  
Ikhwansyah Isranuri ◽  
Nur Asnah Sitohang

Planning for a clean water supply system is a community service program carried out by USU in collaboration with the Dinas Pemberdayaan Masyarakat dan Desa(PMD) of the Pemko Tebing Tinggi. The problem encountered is the unavailability of clean water. This condition can interfere with people's daily activities such as the need for households. The clean water supply system that is implemented is the application of appropriate technology in the sense that it is easy to operate and all components are easy to care for by the public. The purpose of this activity is to provide clean water that meets health requirements, namely colorless, tasteless and odorless. This system is also planned to provide clean water for the next few years. The projection of population growth is also a consideration, which is calculated based on the average population growth data. Based on the Indonesian National Standard (SNI), the need for clean water for a population with a population of 300 households with the household category is 120 liters per person per day, so the water requirement is 1.67 liters/second. The source of water is obtained by digging 15 meters deep by installing 15 concrete rings with a diameter of 80 cm and a height of 100 cm. Then a pump is installed to suck water and then it is pumped into a poly tank (capacity 2100 liters) storage tank which is located at a height of 5-6 meters. Before flowing from the tank  to the pipe, the water is filtered using a filter. For this purpose, a piping installation complete with a valve and a float is designed to automatically close the pipe when the tank is full. The result of water from this system is clean water and suitable for consumption by residents.


2017 ◽  
Vol 31 (9) ◽  
pp. 2885-2898 ◽  
Author(s):  
Pradeep Amarasinghe ◽  
An Liu ◽  
Prasanna Egodawatta ◽  
Paul Barnes ◽  
James McGree ◽  
...  

2018 ◽  
Vol 96 (4) ◽  
pp. 391-403
Author(s):  
Hongli WANG ◽  
Linjing QIU ◽  
Xiaoning XIE ◽  
Zhiyuan WANG ◽  
Xiaodong LIU

1998 ◽  
Vol 27 ◽  
pp. 617-622 ◽  
Author(s):  
Ian Simmonds ◽  
David A. Jones ◽  
David J. Walland

The characteristics of, and the mechanisms causing, multi-decadal variability are currently receiving much attention. This undertaking is particularly challenging in the sub-Antarctic region because of the paucity of data, and the complexity of the governing physical processes. In this paper we report on aspects of high-southern-latitude variability which appear in the European Centre for Medium-range Weather Forecasts twice-daily analyses for the period 1 January 1980 to 31 August 1996 and in the results of global climate model experiments. We show that the number of cyclone positions in the 50-70°S latitude band exhibits considerable interannual variability, as well as changes on longer time-scales. The seasonal distribution of cyclones is linked with the “semi-annual oscillation". We show that the variability of this phenomenon in a 1000 year run of the GFDL coupled model shows “red” characteristics fand on decadal time-scales is similar to that displayed in the available observationsi. The interaction with the ocean and sea ice is siressed as an important factor in determining the nature of climate variability in sub-Antarctic latitudes.


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