Water Allocation Scenarios Research Articles

Evaluation of Water Allocation Scenarios in the Seomjin River Watershed Based on CMIP6 Scenarios

This study evaluated the impact of climate change and water allocation scenarios on water security in the Seomjin River Basin using K-WEAP (Korea-Water Evaluation and Planning System). The findings indicated that domestic water and instream flow are vulnerable to climate change, while industrial water supply may fail to meet future demand in certain regions. Moreover, prioritizing instream flow was found to compromise the stability of the domestic water, and equal allocation adversely affected both domestic and industrial water security. Consequently, maintaining the current system appears to be the most effective approach; however, future studies should focus on developing flexible strategies that consider the effects of climate change and regional characteristics in a more detailed manner.

Assessment of Future Water Security under Climate Change: Practical Water Allocation Scenarios in a Drought-Prone Watershed in South Korea

Seomijn River Basin has numerous hydraulic structures designed to satisfy water demands and mitigate future droughts. However, the increasing water demand and export to neighboring areas cause water deficits and conflicts between water users. Therefore, practical strategies to mitigate the potential damage from climate change are essential. In this study, we aimed to propose practical strategies under climate change by examining the future water security of the Seomjin River Basin under five different water allocation scenarios referenced from the practical policies of various countries. Future climate models determined based on extreme precipitation indices of the ETCCDI were used to investigate their impact on water security, which was evaluated using unmet demand; demand coverage; reliability, resilience, and vulnerability; and aggregation index metrics. We found that prioritizing domestic and industrial water use is the optimal water security strategy, and unconditional allocation of instream flow can cause a significant water deficit for other water uses. However, prioritizing all water uses equally also proved effective under some conditions. Thus, our study highlights the importance of adaptive management and suggests that the optimal water allocation strategy lies in its flexibility in response to varying circumstances.

Trends in the future evolution of rural settlements in oasis-desert areas under water use simulation scenarios: Take the Hexi Corridor region of China as an example

The uncontrolled expansion of rural settlements caused by the imbalance in the matching of land and water resources has hindered the realization of the goal of sustainable rural development in the oasis-desert area. In this study, “water resources-land resources-oasis rural settlements” are integrated into the same framework of symbiosis development, and the evolution of rural settlements in the context of water and land resources constraints is predicted. We used the coupled “SD-SOS-FLUS” (“system dynamics-suitable oasis structure-future land use simulation”) model to predict the differences in rural settlement sizes and their spatial distribution under the inertial development water use scenario (ID) and sustainable development water use scenario (SD) in the northeast part of the Hexi Corridor in China. In addition, we explored differences in oasis circle structure and land use structure under different water allocation scenarios. Compared with a single model, the coupled model “SD-SOS-FLUS” can better simulate the symbiosis relationship between “water resources-land resources- oasis rural settlements”. Through the prediction, the proportion of water used for production in the ID scenario is still as high as 86.30 %, while the proportion of ecological water use is only 11.50 %, and the continuous imbalance of the water use structure results in the area of arable land and rural settlements will be increased to 7,473.21 km2 and 487.16 km2. It increased by 115.63 km2 and 41.28 km2 respectively compared to 2020, which in turn made the oasis area expanding outward, and the radius R of the oasis also increased from 53.65 km in 2020 to 54.79 km in 2030. The area of arable land and rural settlements under water and land resource constraints in the SD scenario decreased to 5223.56 km2 and 105.04 km2. The contraction of the oasis increases the transition zone circle width B2 from 19.88 km in 2020 to 24.58 km in 2030, an increase of 5 km compared to the ID scenario. As a result of the spatial reconfiguration, the number of rural settlement patches decreased from 1.04 × 104 to 0.15 × 104 in 2020, saving 3.41 × 104 ha of land after optimization.

An ordered multi-objective fuzzy stochastic approach to sustainable water resources management: a case study from Taiyuan City, China

Abstract The uncertainty of socioeconomic development and climate change poses challenges to the sustainable management of water resources in Taiyuan, China. The study proposes a type-2 fuzzy chance-constrained ordered multi-objective fractional programming (T2FCC-ORMOFP) model to address the allocation of water under uncertainties. The model incorporates type-2 fuzzy programming and chance-constrained programming into an overall framework to handle multiple uncertainties under multi-level and multi-objective conflicts, while using fractional programming to reflect the marginal benefits of the system. It prioritizes the principles of optimal, fair, and stable distribution by the upper-level governing authorities, while considering the social and economic environmental benefits of lower-level decision-making. The optimal water allocation scenarios were obtained under different hydrological guarantee rates, violation levels of water supply constraints, and net economic benefits of type-2 fuzzy numbers for 2030. Additionally, groundwater is replaced by reclaimed water in varying proportions for flexible water supply. The results show that the water demand in Taiyuan cannot be ignored, and the risk of water shortage is more sensitive for the agricultural and industrial sectors. The recycled water substitution strategy can optimize the water supply structure and improve social and economic benefits (9–12%). Also T2FCC-ORMOFP can improve overall efficiency (20%) compared with a single-level model.

Long-term natural streamflow forecasting under drought scenarios using data-intelligence modeling

Long-term river streamflow prediction and modeling are essential for water resource management and decision-making related to water resources. This research paper considers the importance of these predictions and proposes a model to address scarcity scenarios to support decision-making in water allocation, flood management, and drought prediction scenarios. Machine learning (ML) techniques offer promising alternatives for improving long-term streamflow prediction. However, most existing studies on ML models for streamflow prediction have focused on shorter time horizons, limiting their broader applicability. Consequently, there is a need for dedicated research that addresses the use of ML models in long-term streamflow prediction. Considering this research gap, this paper presents an ML-based approach that learns and replicates the natural flow dynamics of a river, allowing for the simulation of reduced flow scenarios (25 % and 50 % reduction). This capability allows for simulating drought scenarios of varying severity, providing valuable insights for water service managers. This study significantly contributes to the progress of predicting long-term river streamflow through the application of machine learning models. Moreover, this study offers valuable insights and recommendations for hydrologists to improve future research efforts.

An integrated water resources management model considering carbon source and sink under uncertainty: A case study of agricultural water-dominated basin

The global drive for carbon neutrality promotion through integrated water resource management (IWRM) in the face of burgeoning water demand is of great importance. This study developed an interval fuzzy-credibility chance-constrained multi-objective programming (IFCMP) model for water resources-carbon system (WCS) planning, which not only accounts for multiple uncertainties within system parameters, such as interval, fuzzy, and stochastic, but also effectively balances the conflicting objectives of water scarcity, benefits, emissions, and carbon sinks. The IFCMP-WCS model was applied to an agricultural water-dominated zone in the Tarim River Basin, China. Multiple water-allocation scenarios were examined, encompassing five prefecture-level cities, five departments, and three planning years. The results indicated that: (1) the water deficit was increasing over time, limited by water supply capacity, reaching 0–3.49 × 109 m3 in 2035; (2) as water allocation rises, system benefits and pollutant emissions increase, with the agricultural sector contributing the most economic benefits and pollutant emission; (3) the Tarim River Basin is an important carbon sink area, with the net carbon sink increasing from 8781.7–10,771.1 × 103 to 8851.1–10,937.9 × 103 tonnes during the planning horizon; (4) compared to single-objective models, the IFCMP-WCS model can offer more applicable water resource management options. These findings provide useful information for decision-making regarding IWRM and enhancing the net carbon sink in the Tarim River Basin.

Water allocation scenarios for public supply and irrigated agriculture in the São Francisco River integration project

To mitigate the problems derived from the water shortage in the semi-arid northeastern region, the São Francisco River Integration Project (PISF) is being developed, transferring waters from the São Francisco River to other watersheds in the states of Pernambuco, Ceará, Rio Grande do Norte, and Paraíba. The sustainable management of these flows will be vital to guarantee their uses. This research aimed to evaluate scenarios of water allocation for public supply and irrigated agriculture, in order to assist in the management of water resources and the maintenance of these uses in the upper course of the Paraíba River (PB), East Axis of the PISF. The evaluation of multiple uses was carried out through the analysis of the permits issued for the Poções and Epitácio Pessoa reservoirs in 2019. Water allocation scenarios were undertaken considering the presence and absence of the PISF waters, based on the application of the AcquaNet model. The most significant water demands identified were, in Poções reservoir, public supply (1), and in Epitácio Pessoa reservoir, public supply (1) and irrigation (583). The water allocation scenarios showed deficits in meeting public supply and for irrigation in the simulations with and without PISF waters; however, in the scenarios involving PISF or when it provided a greater flow, these deficits were reduced. The results of this research provide information that contributes to decision-making for sustainable water management and to ensure the multiple uses of water, contributing to the improvement of the quality of life of the beneficiary population.

An Optimization Scheme of Water Resources Allocation Based on the Particle Swarm Algorithm

Climate change will exacerbate water scarcity, as warmer temperatures will increase evaporation from soil and water surfaces, raising crop water requirements, and consumers’ demand for energy will increase at higher temperatures, with a concomitant increase in demand for cooling water. Therefore, water scarcity has evolved into a global issue, most notably in the Colorado Basin. As the climate changes, the future of the Colorado River becomes even more tragic. The river’s water levels are dropping year after year, while the water needs of the surrounding urban development are increasing, in what seems to be an endless cycle. At the same time, the entire southwestern United States may be in an unprecedented resource crisis as a result. Therefore, we have modeled water supply, demand, and allocation scenarios and constructed a water allocation model using the Colorado Basin water allocation as an example, combining Lake Mead, Lake Powell, and the agricultural, industrial, and residential demand for water and electricity in five states. To better achieve the optimal balance between the economy and the environment, we set three objectives: economic efficiency, regional surplus water, and total regional electricity generation, and solved the problem using a particle swarm algorithm. By solving the Colorado Basin water allocation problem, we explore a feasible solution with high generalization capability that can be applied in the future to scenarios of rational water allocation in multiple regions around the world.

Conjunctive Operation of Sand Dam and Groundwater Well for Reliable Water Supply during Drought Conditions

Some mountainous regions without water service facilities are among the areas most vulnerable to drought. In these locations, it is particularly essential to establish practical alternatives to cope with the increase in the intensity and duration of droughts caused by climate change. This study proposes a methodology for the conjunctive use of a sand dam and groundwater well under various drought conditions. The method has been applied to a small mountainous area in South Korea. Owing to the scarcity of observational data, it is crucial to properly estimate the hydrological components necessary for judging the feasibility and reliability of conjunctive operations. The step-by-step procedures for performing the tasks are presented in this study. For the inflow of the sand dam, which is a portion of the basin runoff, two different approaches were employed and compared: the Kajiyama formula and a simple two-parameter monthly water balance model (TPM). Water budget analysis allowed for the determination of whether the current and increased water demand could be met under various drought conditions. Preliminary analysis revealed that a sand dam alone could not reliably meet the demand for 10-year or more severe drought conditions. Various water allocation scenarios between surface water (i.e., sand dam) and groundwater were tested. Conjunctive use of a sand dam and groundwater well turned out to increase the reliability of the water supply. As water demand increases and droughts become more severe, the role of groundwater increases. With appropriate resource allocation, 100% water supply reliability could be achieved, even for one year-lasting 50-year drought. We demonstrated how a system could be flexibly operated to meet the target demands monthly, given the system reliability level.

Reallocation of water resources according to social, economic, and environmental parameters

Population growth, urbanization, and industrial development have significantly increased water demands in many countries, raising the concerns about water resources sustainability to meet the needs of humans and the environment. Furthermore, the economy-oriented allocation of water resources has caused many socio-environmental problems. The main goal of this study is to develop a system dynamics modeling framework that integrates economic, social, and environmental dimensions for the decision of water resources allocation. The Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) is used to rank modeling scenarios and identify the best strategy for water allocation. In the application to East Azerbaijan province of Iran, six industry groups (including chemical, food and beverage, non-metal, machinery and equipment, metal, and textile), thirteen water allocation scenarios, and five criteria (including profit index, employment index, return of surface water, groundwater sustainability index, and total allocated water) were considered. The TOPSIS results showed that in the best scenario most water was allocated to the non-metal industry with a relative distance of 0.63 to the ideal solution. On the other hand, the current water allocation scenario ranked seventh, indicating that significant improvements are required to take into account the social, economic, and environmental factors for optimal reallocation of water resources among different industry users.

Adaptation of a compromise programming approach for evaluating the localized impacts of water allocation

ABSTRACT Evaluating localized impacts of water allocation scenarios (WASs) is an important multi-attribute water decision problem. The impacts of WASs are not the same across a basin, and may have their own spatial variations. Conventional multi-attribute decision-making (MADM) is not capable of capturing and implementing the spatial variations. Using these methods often results in simplification or even oversimplification. Herein a new framework is developed involving a compromise programming approach (CP), fuzzy analytical hierarchy process (FAHP) and distributed indicators. The framework is applied to the Aras basin, Iran. Adaptation of the proposed framework leads to an evaluation of WASs based on their integrated localized impacts and spatial trade-offs. Results show that using lumped indicators rather than distributed indicators imposes significant uncertainties in the evaluation process. Applying CP, distributed indicators and fuzzy weights simultaneously extended the interval with stable ranking and allowed the determination of regional overall priorities and optimal spatial water allocation.

Identification of water scarce regions of kunthipuzha river basin using water allocation tool

Water scarcity and consequent droughts are of serious concern for almost all countries around the world. Since climate change is expected to exacerbate the already existing water stresses, the improvement of water efficiency against water scarcity and drought is very much important. The study aims at pin pointing the water stressed areas in Kunthipuzha River basin so that management practices can be suggested for the identified areas to minimize the water scarcity problems. To contribute towards this goal, Water Evaluation and Planning (WEAP) model is used, which is a Decision Support System (DSS) to assess water availability and investigate the impacts of different water allocation scenarios (water demand management strategies) aimed at meeting various sectorial water demands. The results from the study revealed that out of 13 sub basins of Kunthipuzha, 2 comes under severely stressed, 2 under moderately stressed and 3 under lowly stressed regions. The results derived can be used in future to work out feasible management practices for mitigating the water scarcity problems.

Minimization of Water Use Conflicts in Kunthipuzha River Basin by Use of Water Allocation Tool

Water scarcity and consequent droughts are of serious concern for almost all countries around the world. Since climate change is expected to exacerbate the already existing water stresses, the improvement of water efficiency against water scarcity and drought is very much important. The water stressed areas within the Kunthipuzha river basin were identified by allocating the available water for various demands using the WEAP model. This study aims at suggesting some Best Management Practices (BMPs) for those water stressed areas so as to minimize the water scarcity problems. To contribute towards this goal, Water Evaluation and Planning (WEAP) model is used, which is a decision support system (DSS) to assess water availability and investigate the impacts of different water allocation scenarios (water demand management strategies) aimed at meeting various sectorial water demands. The results from the study revealed that the implementation of BMP’s like improving the irrigation efficiency, changing of planting date, changing of crops etc. could bring in significant reduction in water scarcity problems in the identified hotspots. Moreover, in certain sub basins it was found that it would be possible to completely eliminate water scarcity by implementing combinations of BMPs. Thus, such studies done in an extensive manner will help in finding a balance between what is needed and what is available within the environment which in turn serves as an important step in achieving water resource sustainability.

Mitigate water shortage by improving hydropower generation strategy of the cascade reservoir system in the Be River Basin, Vietnam

Abstract To meet increasing water consumption with limited water resources, management approaches that transfer water between purposes must be improved for sustainable development. This entails an urgent requirement for appropriate water resources management within water–energy interaction if severe water shortage occurs occasionally. This study evaluates hydropower generation policies of a cascade reservoir system in the Be River Basin in terms of security of water supply and energy production. The Generalized Water Allocation Simulation Model (GWASIM) was applied to simulate the water use of a complex system of hydropower generation and water supply. Two water allocation scenarios and six alternatives defined by varying monthly generating hours were modeled and compared. The results demonstrate that a compromise between hydropower generation and water supply can be negotiated to reduce the severity of water shortages. Different monthly hours of hydropower generation among alternatives show an effect on improving power production and reliable water supply. This study provides overall insight into the performance of a multi-purpose cascade reservoir system. It will provide a foundation for improving future study of reservoir operations in meeting the increasing demands of water and energy in Vietnam.

Can Managed Aquifer Recharge Mitigate the Groundwater Overdraft in California's Central Valley?

AbstractGroundwater plays a critical role in sustaining agriculture in California's Central Valley (CV). However, groundwater storage in the CV has been declining by around 3 km3/year over the last several decades, with much larger declines during the 2007–2009 and 2012–2015 droughts. Managed Aquifer Recharge (MAR) can potentially mitigate existing overdraft by recharging excess streamflows (during flood periods) to the aquifers. However, the degree to which the existing CV groundwater overdraft might be mitigated by MAR is unknown. We applied a coupled surface water‐groundwater simulation model to quantify the potential for groundwater overdraft recovery via MAR. To quantify the potential benefit of MAR, we used the coupled surface water‐groundwater model to simulate water allocation scenarios where streamflow above the 90th or 80th percentiles was reallocated to aquifers, subject to constraints on the maximum depth of applied water (0.61 and 3.05 m). Our results show that MAR could recover 9–22% of the existing groundwater overdraft CV‐wide based on a 56‐year simulation (1960–2015). However, the impact of MAR varies strongly among regions. In the southern CV where groundwater depletion is most serious, the contribution of MAR to the overdraft recovery would be small, only 2.7–3.2% in the Tulare basin and 3.2–7.8% in the San Joaquin basin. However, transferring excess winter flow from the northern to the southern CV for MAR would increase the overdraft recovery to 30% in San Joaquin and 62% in Tulare. Our results also indicate that MAR has the potential to supplement summer low flows (52–73%, CV‐wide) and reduce flood peaks.

Water and treated wastewater allocation in urban areas considering social attachments

Although economic and environmental considerations have been well integrated into water resources management, the social aspects have been usually neglected. Quantifying and embedding social attachments in the water resource management models are so challenging. In this paper, a novel approach is proposed to quantify and consider social attachments for water and wastewater allocation in urban areas. In the management of shared resources, one of the main issues is the level of cooperation among agents. In a multi-agent environment, stakeholders can decide non-aligned or depending on their interests and social attachment, have some cooperation and coordination in the decision making process. In the proposed approach, an effort has been made to take into account the effects of social attachments on agents' decisions. In this paper, social network analysis is applied to evaluate the coordination level between agents in the use of shared water resources. A paired physical and behavioral simulation model is developed to assess water and wastewater allocation scenarios. A reinforcement learning approach, namely Q-learning is used to develop the behavioral model, which is linked with social attachments. To evaluate the applicability of the proposed approach, the Kan River Basin in the western part of the Tehran metropolitan area is studied. By using the proposed approach for a 25-year simulation horizon and 63 water and treated wastewater allocation scenarios, it is shown that it has merits to find the best scenarios in different conditions and can enhance the sustainability of the water resources in the study area. According to the results, improving the social attachments in the study area can reduce the over exploitation of groundwater and improve the groundwater quality.

Assessment of Surface Water Resources in Great Ruaha River Sub-Basin Tanzania: Application of WEAP Model for Water Allocation and Utilization Impacts Analysis

The Great Ruaha River (GRR) sub-basin is one of the most important waterways in Tanzania as it supports important economic activities. The sub-basin is progressively faced with an inevitable situation of increasing water demand among competing users while the quantity and quality of water is diminishing. The focus of this study was to assess allocation of existing (2012) and future (up to 2025) quantities of surface water in the GRR sub-basin with consideration of priorities given in the Tanzania Water Resources Management Act, 2009 in the order: domestic, environment, agriculture, livestock and non-domestic. Simulation of water allocation scenarios of irrigation expansion (IE) and implementation of environmental flow requirements (EWD) and their impacts on met demands was done by using WEAP model. Results showed that under current and future conditions, available streamflows are sufficient for the first two water use priorities. Implementation of EWD and IE scenarios will change demands in comparison with reference scenario by 80%, -38% and 45% and shortages by 147%, 123% and 13% in Little Ruaha, Ndembera and Kisigo catchments respectively. To eliminate water shortages, construction of reservoirs, use of alternative supply sources (especially in agriculture) and water demand management measures are recommended.

Towards a Healthy Ganga—Improving River Flows Through Understanding Trade Offs

WWF-India along with its partners is working towards the conservation of Ganga since last decade. During 2015-16, along with partners, WWF-India conducted an action research study in over 2 million hectare of culturable command area of two irrigation systems taking off from River Ganga, to understand the barriers to implementation of Environmental Flows (E-Flows) in the Ganga. Under this initiative, the team tried to bridge the knowledge gap about potential trade-offs for implementation of E-Flows in a critical stretch of Ganga. The team made an attempt to understand the surface water allocation and water use scenario in western and central part of the state of Uttar Pradesh, where the Ganga water is used for agriculture purpose through major irrigation infrastructure. The E-Flows recommendations for critical locations downstream of two barrages, i.e. head-works of two major irrigation schemes, were developed. A framework was developed to assess the costs and benefits of various flow regimes. Such a framework helps discuss the trade-offs emerging from E-Flows releases onto other committed allocations across various users. This paper discusses approaches for management of trade-offs to restore E-Flows in this stretch of Ganga, and include various management options – like (i) promotion of irrigation water use efficiency, (ii) gradual and marginal shift in land towards less-water intensive crops and (iii) institutional aspects. The paper argues that, whilst there is a widespread apprehension that, any curtailment in the allocation quota for irrigation would lead to adverse impact onto the farming community; but actually after assessing the trade-offs, it can be inferred that, the E-Flows implementation in this stretch of Ganga would require enhancement of water in the river, but that requirement is not substantial. Towards the end of the paper, challenges and opportunities for E-Flows implementation in the Upper Ganga are discussed. This paper attempts to discuss one of the newer approach in which, economic analysis has been used to articulate the rational for implementation of E-Flows regime.

Farm level decision support for sugarcane irrigation management during drought

A large portion of global sugarcane is produced under irrigation, and this often occurs in areas where water supply is not abundant or reliable. Crop management decisions during limited water supply are complex and require information on the impacts of irrigation strategies on crops and profitability. This paper describes the development of a computerized system to support farm level management of limited irrigation water for sugarcane production. The system comprises a daily crop and water balance model, an irrigation module and a gross margin calculator. The model calculates crop yield and survival for the current (Y1) and the next season (Y2), for multiple fields on a farm, for a given irrigation strategy and water supply/climate scenario. Irrigation strategies that can be explored include: (1) scheduling irrigation using growth phase specific soil water thresholds (SWT), and (2) postponing replanting and/or abandoning low potential fields. Farm gross margin is calculated from simulated yields and production costs at field level and takes into account re-establishment costs when crops fail. The system was applied in a case study for a hypothetical farm of 18 fields near Komatipoort, South Africa.. Four possible restricted water allocation scenarios were investigated, namely, a mildly and severely restricted allocation (˜50% and 25% of the full allocation) over a 24 month and 12 month period. Results from the case study show that under most circumstances a SWT of 60% of plant available soil water capacity applied during the germination and stalk growth phases produced the best outcome. Reducing SWT to 30% during the tillering phase makes more water available for use on other fields, resulting in higher crop survival under severe restrictions. Abandoning low potential fields under severe water restriction limited financial loss in Y2, but reduced future productive capacity thereafter.Results suggest that the system produces realistic responses to irrigation applied and drought. It has the potential to aid strategic decision-making for irrigated sugarcane production during drought.

Resolving water allocation conflicts using WEAP simulation model and non-cooperative game theory

Disparity in water supply and demand often leads to conflicts among users over water resources in basins. Game theory is a new tool recently employed for resolving such conflicts. The present study uses non-cooperative games to resolve the conflicts in the Zayandehroud basin. The games are simulated between two stakeholders by the graph model conflict resolution (GMCR) method as one of the non-cooperative methods. The stakeholders are Isfahan Regional Water Company (IRWC) and Agriculture-Jahad Organization (AJO). Stakeholders can execute some strategies competitively, which include A: developing farming lands, B: improving irrigation efficiency, C: controlling withdrawals from aquifers, and D: selling water to the industrial sector. A and B are executed by AJO and C and D are executed by IRWC. The sustainable water allocation scenarios are obtained by GMCR and employed in a water evaluation and planning simulation model to supply consumers’ water demand. The best sustainable scenario selected based on GMCR concepts requires irrigation efficiency of agricultural lands to be improved in order to achieve a demand meeting index of 90% and, in contrast, there will be not control on water withdrawal from aquifers.