Risk Of Water Shortage Research Articles

Evaluation of U.S. Manufacturing Subsectors at Risk of Physical Water Shortages.

The potential impact of water shortages on U.S. manufacturing is unknown. While water for manufacturing constitutes an estimated 6% of U.S. water intake, the data (i.e., location, quantity, and purpose of water intake) needed to determine this impact does not exist. This paper will identify manufacturing subsectors at risk of physical water shortages by applying a method for estimating U.S. manufacturing water intake at the necessary spatial and sectoral resolutions. First, the data requirements to quantify a manufacturing facility's water footprint within the context of the watershed are developed. Second, using international data, water intake at the national, state, and county-levels by each U.S. manufacturing subsector is estimated. Third, manufacturing subsectors that are most vulnerable to risks of physical water shortages are identified. Based on the results, the Paper, Primary Metals, Chemical, Petroleum and Coal Products, and Food subsectors have the largest intake, respectively. However, the Primary Metals, Fabricated Metals, Transportation Equipment, Petroleum and CoalProducts, and Plastics and Rubber subsectors are at the greatest risk of physical water shortages based on concentrations of water intake in water-stressed regions. The results can be used to develop strategies to mitigate the risks of water shortages on the U.S. manufacturing sector.

Managing risks and future options from new lakes in the deglaciating Andes of Peru: The example of the Vilcanota-Urubamba basin

Rapidly growing lakes in deglaciating mountain regions represent both: emerging risks and options for human livelihoods. In the Andes of Peru, seasonal water scarcity and Glacial Lake Outburst Floods (GLOF) pose a serious threat for highly exposed and vulnerable people. In addition, water demand is growing due to increasing irrigated agriculture, population and hydropower production. In this context, we assess current and future water risks and management options for the Vilcanota-Urubamba basin, Southern Peru. Therefore, the GLOF susceptibility of glacier lakes and the potential maximum reach of damaging flow were analysed. Eighteen out of 134 current and another six out of 20 future glacier lakes were identified as potentially highly susceptible to GLOF. A total of eight existing and one possible future lakes indicate very high risk potentials. Furthermore, a comprehensive surface water balance scheme for five selected subcatchments reveals that future river discharge could be reduced by some 2–11% (7–14%) until 2050 (2100). Particularly in headwaters and during dry seasons, glacier contribution representing roughly 15–25% to total streamflow is crucial and would substantially decrease to below 4–22% (1–3%) until 2050 (2100) with strong glacier shrinkage under intense warming (scenario RCP8.5). In the middle and lower basin, long-term water availability could be jeopardized by growing irrigated agriculture and hydropower capacity. Combining a GLOF and water shortage risk assessment, three key hotspots of current and future water risks were identified. In the context of the identified risks and complex intertwining of water users involving conflict potentials, robust adaptation planning is necessary within an integrative water and risk management framework. Therefore, it is crucial to incorporate ancestral and local knowledge for long-term management planning and implementation. This process should take place beyond temporarily limited governmental and project agency and strengthen broad acceptance of corresponding measures for adapting to hydroclimatic and socioeconomic changes.

Water shortage risk transferred through interprovincial trade in Northeast China

With active interprovincial economic trade, water resources embodied in economic goods and services are also transferred. In China, water resources are uneven spatial distributed and many regions are facing serious water shortage. As the spatial mismatch of water resources and water consumers, provincial water shortage risk are changing by transferring in or out water resources in wetter regions or drier regions. In this study, we constructed a water shortage risk trade model to assess one region’s (sector’s) potential economic output reduction induced by its economic trade partners’ water shortage. Take Northeast China (including Heilongjiang, Jilin and Liaoning province, namely HJL region) as a case study, we figured out the provinces that have larger risk on HJL region’s sectoral economic output and the main provinces influenced by HJL region’s water shortage. Finally, we analyzed the water shortage risk transfer among sectors in HJL region. The results show that risk from HJL region is mainly transferred to coastal regions and a large quantity of virtual water shortage risk (VWSR) are transferred among sectors in this region due to the intensive trade activities within this region. Water shortage in Heilongjiang transferred larger risk to other provinces than Jilin and Liaoning, while vulnerability index of Liaoning is higher than Heilongjiang, Jilin, which is vulnerable to water shortage in Heilongjiang, Jilin and Beijing. This study can provide insights for local water security management through identifying the key provinces and trade pathways to reduce water risk and avoid water risk transferring to improve the intersectoral and interprovincial water coordinated management for achieving national water sustainable supplying.

Complex interactions between climate change, sanitation, and groundwater quality: a case study from Ramotswa, Botswana

Groundwater quantity and quality may be affected by climate change through intricate direct and indirect mechanisms. At the same time, population growth and rapid urbanization have made groundwater an increasingly important source of water for multiple uses around the world, including southern Africa. The present study investigates the coupled human and natural system (CHANS) linking climate, sanitation, and groundwater quality in Ramotswa, a rapidly growing peri-urban area in the semi-arid southeastern Botswana, which relies on the transboundary Ramotswa aquifer for water supply. Analysis of long-term rainfall records indicated that droughts like the one in 2013–2016 are increasing in likelihood in the area due to climate change. Key informant interviews showed that due to the drought, people increasingly used pit latrines rather than flush toilets. Nitrate, fecal coliforms, and caffeine analyses of Ramotswa groundwater revealed that human waste leaching from pit latrines is the likely source of nitrate pollution. The results in conjunction indicate critical indirect linkages between climate change, sanitation, groundwater quality, and water security in the area. Improved sanitation, groundwater protection and remediation, and local water treatment would enhance reliable access to water, de-couple the community from reliance on surface water and associated water shortage risks, and help prevent transboundary tension over the shared aquifer.

Evaluation of the spatial distribution of submarine groundwater discharge in a small island scale using the 222Rn tracer method and comparative modeling

Submarine groundwater discharge (SGD) is an important source of freshwater, nutrients, and other chemicals to the coastal water, and has significant impacts and implications for the coastal environment and ecology. Here, we combined geochemical tracers and hydrologic modeling to investigate the spatial patterns and quantities of SGD and submarine fresh groundwater discharge (SFGD) at a small island of western Japan. The results reveal large spatial variability in SGD and SFGD, significant discharge in areas with steep topography, and much lower discharge from low-lying areas. Topographic influences are likely to be a major driver of spatial variability in SFGD. The 222Rn mass balance model and two-end-member mixing model were used to estimate the SGD and SFGD rates. The values were ranged from 5.43 to 25.4 cm·d−1 with an average value of 16.2 cm·d−1, and 0.39 to 1.98 cm·d−1 with a mean value of 1.17 cm·d−1, for SGD and SFGD, respectively. The total flux of SFGD was calculated to be 8.49 × 106 m3·yr−1, with 4.37 × 106 and 4.12 × 106 m3·yr−1 in the northern and southern regions of the island, respectively. The results were consistent with the values estimated by the topographic-based model. The ratio of the average annual SFGD to average annual precipitation (3.69 × 107 m3) reached up to 23%, and the magnitude of annual SFGD was found to be similar to the total discharge from nine large rivers. Since the island faces a risk of water shortage, the results of the study can provide a useful insight into developing appropriate groundwater management strategies in this island's habitats.

Water resources planning in bioethanol production from sugarcane

The biofuels industry has grown and has positioned itself in Colombia for national purposes, these come from biomass sources such as agricultural crops. Bioethanol is the most used in Colombia and is obtained from sugarcane. One of the main concerns of the sector and society, is the high water consumption associated with agricultural crops (9,000 m3 / ha-year), there are currently 232,000 hectares of sugarcane for the production of sugar and bioethanol. Given the aforementioned, the need arises to carry out a planning of industrial increase of the sector taking into account as a main base the demand and availability of water resources for different activities in the Cauca river basin and the demand for sugarcane crops. In this document it is presented a mathematical model and the evaluation of different scenarios of the estimation of the trend of water consumption in the bioethanol production process in Colombia and in this way to establish scenarios of high risk of water shortage both for the population, interested parties and cane cultivation.

Optimal Allocation of Water Resources from the “Wide-Mild Water Shortage” Perspective

A major objective of the optimization of water resources allocation is to ensure the supply an adequate amount of water to users at the right time and maximize the utilization of water resources. However, in case of insufficient water supply, water shortage is likely to occur intensively for specific water users or in specific periods, referred to as a “concentrated water shortage”. The risk of a concentrated water shortage should be shared across a wider range of users and periods, so that it would have a less severe impact on each calculation unit in each period, which we refer to as the “wide-mild water shortage”. In this study, the nonlinear weight of the water supply objective function can be converted into a piecewise linear weight based on the law of diminishing marginal utility, making it possible to reduce or even eliminate the concentrated water shortage and thus making the allocation of water resources more reasonable. The case study in the Nen River basin in northeast China shows that the improved method results in a significant increase in water shortage units but a significant reduction in water shortage range. As a consequence, water shortage is more uniformly distributed from April to June, which contributes to solving the concentrated water shortage problem in May. However, it should be noted that to what extent the wide-mild water shortage can be realized depends not only on the marginal utility of water demand, but also on the available water supply and the regulative capacity of water supply projects. In spite of this, the improved method enables water to be supplied more suitably for users at the appropriate time, which contributes to improving the utilization of water resources and helping decision-makers better address the problem of concentrated water shortage.

A multi-stage fuzzy stochastic programming method for water resources management with the consideration of ecological water demand

In this paper, a multi-stage fuzzy stochastic programming (MFSP) method is introduced to deal with uncertainties presented as fuzzy sets and probability distributions. Moreover, it is able to reflect dynamics of uncertainties and the related decision processes through constructing a series of representative scenarios within a multi-stage context under a set of fuzzy α-cut levels. A management problem about long-term planning of water resources system has been studied to illustrate applicability of the proposed approach. With ecological water demand being considered, the framework solves the complex problems that can hardly be solved in previous individual model research and promotes sustainable development. The results indicate that the dynamic and complexity of water resources allocation can be reflected through the multilayer discrete context tree. Moreover, real-time correction for reducing the risk of water shortage and low economic penalty can be presented. They can also help identify satisfaction degree of the goal and feasibility degree of constraints in an interactive way, enabling decision makers to generate a series of alternatives under various system conditions. Overall, it can not only contribute to decision makers for in-depth analysis, but also for sustainable development of ecosystem.

Agricultural Water Allocation under Uncertainty: Redistribution of Water Shortage Risk

AbstractThis article develops an economic model to analyze how the risk of water shortages affects farmers’ land irrigation decision and how the priority‐based water sharing arrangement redistributes such a risk among farms with different water rights priorities. The analysis brings together an array of comprehensive data files on irrigation rights, water supplies, and agricultural land use from eastern Idaho. Results indicate that a more left‐skewed distribution of streamflow significantly discourages land irrigation among farmers except the most senior rights holders. The priority‐based water sharing arrangement redistributes the macroscale risk of water shortages and thus exposes farmers of different water rights priorities to heterogeneous levels of risk: senior water rights holders are affected the least and such a risk is instead passed mostly on to junior water rights holders. The role of water rights in risk redistribution is more significant when the probability distribution of water shortage risk is asymmetric rather than symmetric. The historical development pattern of water rights influences how the priority of water rights takes effect on land irrigation decision.

Copula-based joint probability distribution of water supply and demand in Luhun irrigation district

Abstract The potential of the copula method to construct the joint probability distribution of three hydrological variables characterizing water supply and demand (WSD) is explored for the Luhun irrigation district of China. The marginal distributions of rainfall, reference crop evapotranspiration (ET0) and irrigation water are simulated by the corresponding best-fitting cumulative distribution functions. Furthermore, the correlations between every pair of variables are quantified. On this basis, the two-dimensional joint distributions of rainfall and (ET0) (representing natural WSD), and irrigation water and (ET0) (representing man-made WSD), and the three-dimensional joint distribution of rainfall, irrigation water, and (ET0) (representing natural–man-made WSD) are established. The results reveal that the best-fitting marginal distributions for rainfall and (ET0) and irrigation water are the normal distribution and the Weibull distribution. Moreover, for rainfall and (ET0), the Student's t copula is applied to obtain the joint distribution, while the corresponding copula for (ET0) and irrigation water is the Clayton copula. Finally, the three-dimensional Student's t copula is selected to explore the dependence structure among rainfall, irrigation water, and (ET0). Therefore, these joint distributions provide an efficient approach to assess water shortage risks in the irrigation district.

Assumption-Simulation-Feedback-Adjustment (ASFA) Framework for Real-Time Correction of Water Resources Allocation: a Case Study of Longgang River Basin in Southern China

Water resources allocation is subject to uncertain future conditions and therefore needs real-time correction. This study develops a framework of “assumption-simulation-feedback-adjustment” (ASFA) for real-time correction of water resources allocation. The assumption component constructs a water resources allocation model and generates initial allocation solution (IAS); the simulation component applies IAS in a real-time hydrological scenario; the performance information is input into the feedback component. Three feedback functions, including gain function, correlation function, and least square function, are employed to deal with the information, and the value of output gain is determined for the adjustment component. The result then is a feedback allocation solution (FAS). This study applied ASFA to Longgang River basin, China, as a case study, compared FASs generated by three different feedback functions as well as IAS. Results showed that FAS generated by the gain function (FAS_GF) performed better with a higher assurance rate and less risk of continuous water shortage. Results also showed that to achieve the same management requirement, FAS_GF had a lower requirement of the amount of diverted water, indicating that the ASFA framework can make better use of water resources and reduce the pressure of diverted water. The ASFA framework builds a feedback mechanism for real-time correction of water resources allocation, provides a novel perspective for addressing the challenge of future uncertainty, which significantly improves the solutions of water allocation.

Water shortage risk assessment considering large-scale regional transfers: a copula-based uncertainty case study in Lunan, China

The risk of water shortage caused by uncertainties, such as frequent drought, varied precipitation, multiple water resources, and different water demands, brings new challenges to the water transfer projects. Uncertainties exist for transferring water and local surface water; therefore, the relationship between them should be thoroughly studied to prevent water shortage. For more effective water management, an uncertainty-based water shortage risk assessment model (UWSRAM) is developed to study the combined effect of multiple water resources and analyze the shortage degree under uncertainty. The UWSRAM combines copula-based Monte Carlo stochastic simulation and the chance-constrained programming-stochastic multiobjective optimization model, using the Lunan water-receiving area in China as an example. Statistical copula functions are employed to estimate the joint probability of available transferring water and local surface water and sampling from the multivariate probability distribution, which are used as inputs for the optimization model. The approach reveals the distribution of water shortage and is able to emphasize the importance of improving and updating transferring water and local surface water management, and examine their combined influence on water shortage risk assessment. The possible available water and shortages can be calculated applying the UWSRAM, also with the corresponding allocation measures under different water availability levels and violating probabilities. The UWSRAM is valuable for mastering the overall multi-water resource and water shortage degree, adapting to the uncertainty surrounding water resources, establishing effective water resource planning policies for managers and achieving sustainable development.

Strategic optimization of water reuse in wafer fabs via multi-constraint linear programming technique

The risk of water shortage has been posing as a threat to water demanding industries in Taiwan, including the high-tech industries where ultrapure water is needed for the production of microchips. Such risks are especially unpredictable in the age of climate change, where more frequent extreme climate events such as prolonged droughts have sent these industries scrambling for securing water supply at a very high cost. The national policy also mandates strict water recycling standards for these high-tech plants, while the risk of water supply shortage also forces the industry to be water-conscious. However, most plants set their water recycling strategies based on experience or “rules of thumb” practices, without implementing optimization tools that can help making decisions in a more scientific approach. In this study we applied linear programming technique to optimize the water recovery path for a microchip assembly plant. A water balance diagram was formulated and completed to determine the existing water recycling performance, and the data was converted to a water flow network. The water flow network was then derived with a mathematical model to formulate a linear optimization problem. The proposed linear programming model is composed of mass balance constraints, unit specification constraints, capacity constraints as well as water quality constraints (discharge limits). The linear programming method was effectively appplied to improve the efficiency of water reuse. With the installation of the regeneration units, an increase of ∼40.1% in the volume of reused water was predicted. The results from water cost structure also indicated that, at higher water tariff, water reuses through reclaiming and generating spent effluents can alleviate the overall water consumption costs.

Towards adaptive governance for urban drought resilience: the case of Da Nang, Vietnam

To address drought risks and risks of water shortages in cities it is essential to build resilience. Acknowledging that this is a process initiated by actors and institutions, this article presents a framework to analyze dynamics in the governance system for urban water services. The framework is applied to Da Nang, a drought-prone city in central Vietnam, to explore the elements and factors in the urban water sector that enhance or inhibit resilience to drought and find potential strategies to build resilience. The study finds that the framework has been helpful in identifying where changes and systematic interventions are needed to enhance resilience.

Optimization of Water Resource Management Using Chooser Option Contracts under Uncertainty

Optimization of water resource management is very important to reduce water shortage risk and increase economic benefit. Water option can be used as a flexible instrument in water resource management. In this study, chooser options are designed for water managers to buy additional water in drought periods and sell redundant water in wet periods. To make optimal decisions under uncertainties including probability distributions and intervals, an inexact two-stage mixed-integer programming (ITSMIP) model is applied. To illustrate the role of chooser options in water resource management, a case study is presented. Factors which influence the willingness of buying the chooser options are analyzed and the optimal water allocation plans are also provided. The results demonstrate that chooser options can help water managers mitigate the impact of water shortage and increase utilization efficiency of water resource greatly.

Study on the Climate Adaption Planning for an Industrial Company with Regional Risk of the Water Supply System—A Case in Taiwan

Extreme uneven spatial and temporal distributions of rainfall pose the risk of water shortage to the industries in Taiwan, particularly during dry seasons, which may be worsen under climate change. This study aims to develop adaptation actions for an industrial company to reduce the risk of droughts. The Formosa Plastics Corporation (FPC) in Chuoshui River watershed is selected as a study case and an integrated risk assessment tool of water resources TaiWAP is used. The water shortage of FPC is mainly in the dry seasons because the water rights of public and agricultural uses are prioritized over industrial use. The considered adaptation options including water reuse, a desalination plant, smart agricultural water management, and rainwater harvesting. The results show that the waste-water reuse and sea-water desalination are the most effective adaptation options, which reduces the water shortage risks 33–44% per day in the return period of ten years. The results are generalized for the reference of other studies. The risk assessment and adaptation measure identification of the company require regional information. Moreover, some adaptation measures that the company implements help reduce the water shortage of the region and are consequently beneficial to the company, e.g., smart agricultural water management.

Joint risk of interbasin water transfer and impact of the window size of sampling low flows under environmental change

Constructing a joint distribution of low flows between the donor and recipient basins and analyzing their joint risk are commonly required for implementing interbasin water transfer. In this study, daily streamflow data of bi-basin low flows were sampled at window sizes from 3 to183days by using the annual minimum method. The stationarity of low flows was tested by a change point analysis and non-stationary low flows were reconstructed by using the moving mean method. Three bivariate Archimedean copulas and five common univariate distributions were applied to fit the joint and marginal distributions of bi-basin low flows. Then, by considering the window size of sampling low flows under environmental change, the change in the joint risk of interbasin water transfer was investigated. Results showed that the non-stationarity of low flows in the recipient basin at all window sizes was significant due to the regulation of water reservoirs. The general extreme value distribution was found to fit the marginal distributions of bi-basin low flows. Three Archimedean copulas satisfactorily fitted the joint distribution of bi-basin low flows and then the Frank copula was found to be the comparatively better. The moving mean method differentiated the location parameter of the GEV distribution, but did not differentiate the scale and shape parameters, and the copula parameters. Due to environmental change, in particular the regulation of water reservoirs in the recipient basin, the decrease of the joint synchronous risk of bi-basin water shortage was slight, but those of the synchronous assurance of water transfer from the donor were remarkable. With the enlargement of window size of sampling low flows, both the joint synchronous risk of bi-basin water shortage, and the joint synchronous assurance of water transfer from the donor basin when there was a water shortage in the recipient basin exhibited a decreasing trend, but their changes were with a slight fluctuation, in particular at shorter window sizes. The decreasing magnitude of individual water shortage risk in the recipient basin was significantly greater than that of joint bi-basin water shortage risk at all window sizes. Although the donor basin had much rich water, but its individual risk accounted for more than 25.3% within a window size of 30days provided that its instream flow was maintained. In practical design and management of interbasin water transfer, impacts of the window size of sampling low flows under environmental change on the joint distribution of bi-basin low flows and the individual risk of water shortage in the donor basin should be paid more attention.

The joint distribution of reference crop evapotranspiration and irrigation water in the irrigation district

Abstract For the irrigation district, irrigation water is the manual water supply for the farmland while reference crop evapotranspiration (ET0) reflects water demand. Thus, the joint distribution of irrigation water and ET0 can reveal water shortage risk under the condition of the manual water supply. In order to understand their relationships and overcome the drawbacks of different marginal distributions of hydrological variables, Archimedean copulas are introduced. Based on the data series of ET0 and irrigation water in the Luhun irrigation district of China, the univariate marginal distributions of ET0 and irrigation water are first selected. Then, with the Gumbel–Hougaard copula in the Archimedean copulas, the joint distribution of ET0 and irrigation water is proposed. The results show that the best-fitting marginal distributions of ET0 and irrigation water are generalized extreme values and normal distributions, respectively, but for their joint distribution, the Gumbel–Hougaard copula is the best-fitting one. The water shortage risks with different encounter situations of ET0 and irrigation water are better revealed using the proposed copula-based joint distribution.

Encounter risk analysis of rainfall and reference crop evapotranspiration in the irrigation district

Rainfall and reference crop evapotranspiration are random but mutually affected variables in the irrigation district, and their encounter situation can determine water shortage risks under the contexts of natural water supply and demand. However, in reality, the rainfall and reference crop evapotranspiration may have different marginal distributions and their relations are nonlinear. In this study, based on the annual rainfall and reference crop evapotranspiration data series from 1970 to 2013 in the Luhun irrigation district of China, the joint probability distribution of rainfall and reference crop evapotranspiration are developed with the Frank copula function. Using the joint probability distribution, the synchronous-asynchronous encounter risk, conditional joint probability, and conditional return period of different combinations of rainfall and reference crop evapotranspiration are analyzed. The results show that the copula-based joint probability distributions of rainfall and reference crop evapotranspiration are reasonable. The asynchronous encounter probability of rainfall and reference crop evapotranspiration is greater than their synchronous encounter probability, and the water shortage risk associated with meteorological drought (i.e. rainfall variability) is more prone to appear. Compared with other states, there are higher conditional joint probability and lower conditional return period in either low rainfall or high reference crop evapotranspiration. For a specifically high reference crop evapotranspiration with a certain frequency, the encounter risk of low rainfall and high reference crop evapotranspiration is increased with the decrease in frequency. For a specifically low rainfall with a certain frequency, the encounter risk of low rainfall and high reference crop evapotranspiration is decreased with the decrease in frequency. When either the high reference crop evapotranspiration exceeds a certain frequency or low rainfall does not exceed a certain frequency, the higher conditional joint probability and lower conditional return period of various combinations likely cause a water shortage, but the water shortage is not severe.

Risk Analysis of Reservoir Operations Considering Short-Term Flood Control and Long-Term Water Supply: A Case Study for the Da-Han Creek Basin in Taiwan

This study applies an integrated methodology to assess short-term over-levee risk and long-term water shortage risk in the Da-Han Creek basin, which is the most important flood control and water storage system in northern Taiwan. An optimization model for reservoir flood control and water supply is adopted, to determine reservoir releases based on synthetic inflow hydrographs during typhoons, which are generated by Monte Carlo simulations. The release is then used to calculate the water level at a downstream control point using a novel developed back-propagation neural network-based model, to reduce computational complexity and achieve automatic-efficient risk evaluation. The calculated downstream water levels and final reservoir water levels after a typhoon event are used to evaluate the mapped over-levee risk and water shortage risk, respectively. The results showed that the different upper limit settings for the reservoir have a significant influence on the variation of 1.19 × 10−5% to 75.6% of the water shortage risk. This occurs because of the insufficient inflow and narrow storage capacity of the Shih-Men Reservoir during drought periods. However, the upper limit settings have a minor influence (with a variation of only 0.149% to 0.157%) on the over-levee risk in typhoon periods, because of the high protection standards for the downstream embankment.