Water Allocation Model Research Articles

Simulation-based multi-objective optimization framework for sustainable management of coastal aquifers in semi-arid regions

Groundwater is a strategic source of water supply, especially in arid and semi-arid coastal regions. Growing demand, along with scarce water sources, may impose intense pressure on this precious resource. This pressure will degrade water quality for future use and cause social inequality, despite supplying current needs. A novel sustainable management model for water allocation is developed to address these interconnected concerns in coastal aquifers. Three aspects of sustainable development are considered: groundwater quality with total dissolved solids (TDS) indicator for the environmental part, gross value added from water for the economic efficiency, and the Gini coefficient for social inclusion and equity. The problem is solved with a simulation-based multi-objective optimization framework using a numerical variable-density simulation code and three approved evolutionary algorithms, NSGA-II, NRGA, and MOPSO. The obtained solutions are integrated to enhance the solutions' quality by using each algorithm's strengths and dominated members' elimination. In addition, the optimization algorithms are compared. The results showed that NSGA-II is the best in terms of solutions quality, with the least number of total dominated members (20.43%) and a 95% success rate of obtained Pareto front. NRGA was supreme in finding extreme solutions, the least computational time, and diversity, with an 11.6% higher diversity value than the second competitive NSGA-II. MOPSO was the best in spacing quality indicator, followed by NSGA-II, showing their great arrangement and evenness in obtained solution space. MOPSO has the propensity for premature convergence and needs more stringent stopping criteria. The method is applied to a hypothetical aquifer. Still, the obtained Pareto fronts are determined to assist decision-makers in real-world coastal sustainable management problems by illustrating existing patterns among different objectives.

Optimization of economic return from water using water-energy-food nexus approach: A case of Karnafuli Basin, Bangladesh

This study evaluates the existing situation of the water energy and food resource interaction using an indicator-based approach and optimizes the resource use in the Karnafuli River Basin. A water allocation model based on an optimization tool, LINDO 6.1, with an objective function to maximize the economic return, is developed to allocate water to different water use sectors (domestic, agriculture, energy, industry, and environment) in the basin. It is observed that 14.58 m3 of water is required to generate 1 kWh of energy in Kaptai hydropower plant, while 4500 m3 of water is consumed to produce 1 ton of crops in the basin. Due to improper management, around 12,500 ha of land under the Karnafuli Irrigation Project remains un-irrigated, which can be cultivated with high-yield Boro crop. Results show that by prioritizing the agriculture sector, a maximum economic return of US$ 30.3 million can be obtained; however, with this only 55% of the satisfaction level is achieved for the environment sector. Systematic and integrated management of the resources is required in Karnafuli Basin for socioeconomic and sustainable development.

A Water Allocation Model for Multiple Uses Based on a Proposed Hydro-Economic Method

Water scarcity drives society to conflict over the allocation of water. Economical externalities based on the development of water production improve the decision-making process for planning water allocation and the operation of the water infrastructure. We present a proposed water allocation model using a priority-based and hydro-economic optimization kernel as a framework for improving the quality of information for the different user sectors, stakeholders, and institutions for the water allocation decision-making process. In addition, we propose a method for using hydro-economic optimization models without the marginal benefit curve of water demand. The proposed model, called AcquaNetGIS, was applied to the São Francisco Transboundary System, and the hydro-economic optimization was improved, allocating 7.0% more water for all users considered, including water supply, irrigation, and hydropower. Moreover, the minimum flow downstream from the Xingó hydropower station reached 98.5% (priority-based optimization) and 99.0% (hydro-economic optimization) during the optimization period. Depending on the rules and legislation, the sustainability of water allocation based on hydro-economic externalities may be a better solution for the planning and operation of complex water infrastructure systems. Multicriteria decision-making methods should consider the results of the proposed model in order to understand the stochastics of the hydrological regimes and economic production based on the availability of water.

Multicriteria land cover design via coupled hydrologic and multi-sector water management models

We investigate how hydrologic-land feedbacks and a hydrologic-water management linkage impact land cover arrangements optimized within a multiobjective land cover design framework. The framework integrates a spatially-distributed and physically-based hydrologic model, for simulating surface and subsurface flow and land processes, with a network-based multi-sector water resources management and allocation model. Both models used (Parflow, Pywr) are open-source. The framework is applied to a hillslope problem to identify land cover patterns that optimize trade-offs between water, food, energy and environment objectives. Results show trade-offs depend on land cover composition and the spatial arrangement of land covers within the catchment. Total runoff volume and peak flow of runoff was found to change 3 and 2-fold, respectively, between optimized solutions as land cover composition and spatial patterns were altered to satisfy different combinations of objectives. At the same time, up to a 15% reduction in the total runoff volume and an 8% reduction in the peak flow of runoff were observed within optimized land cover patterns having equal composition but different spatial arrangements. This emphasizes the impact on hydrologic behavior of the spatial location of land covers within a catchment. The emergence of patterns in land cover distribution for different trade-offs between objectives is driven by feedback mechanisms between subsurface hydrology and land processes, which are implicitly linked to the properties of each land cover and the interactions between neighboring land covers through lateral groundwater flow. The study demonstrates the added benefits of coupling distributed hydrologic models with water management simulation for multisector multicriteria land cover planning.

Assessment of vulnerability to water shortage in semi-arid river basins: The value of demand reduction and storage capacity

Interest in securing reliable water supplies has increased due to climate change and rapid population growth. This challenge is significant in growing areas with limited water supplies. To meet water demands, water managers are considering new storage infrastructure to increase the reliability of water supplies while also identifying opportunities to reduce water use per person. Although these strategies change water consumption patterns, their success at reducing shortages across space and time for different climate change scenarios remains unclear. In this paper, population- and climate-dependent future water supply and demand models are developed and integrated into a water allocation model calibrated for the South Platte River Basin of Colorado. Eight future climate scenarios are simulated using four statistically downscaled models from the Coupled Model Inter-Comparison Project Phase 5 (CMIP5) with two Representative Concentration Pathways (RCP). Lastly, findings from the water allocation model simulations are generalized beyond the study area using a novel approach by introducing dimensionless indices to characterize water shortage and basin conditions. Results reveal a threshold ratio of total storage capacity to mean water supply with a value of 0.64 above which additional storage has no effect on total water shortages. This threshold communicates the limitation of building storage infrastructure as a strategy to adapt to decreasing average water supplies for basins considering increasing storage capacity. However, basins with low current capacity are likely to fall below the threshold and could invest in reservoirs to mitigate future shortages.

Application of multi-agent decision-making methods in hydrological ecosystem services management

In this paper, a methodology is presented for managing hydrological ecosystem services by taking into account the hierarchy of stakeholders involved in the decision-making process. With this in mind, a water allocation model is first used for allocating water resources to demands. Then, several ecosystem services (ESs)-based criteria are defined to evaluate hydrological ESs of water resources management policies. A set of water and environmental resources management strategies (alternatives) are defined for decision-makers, and several drought management strategies are determined to decrease the area of key crops and water demands of agricultural nodes. To model a multi-agent multi-criteria decision-making problem for managing hydrological ESs, three main steps are considered as follows:•Different ES-based criteria (i.e., economic profit, NPP,11Net Primary Productivity and ecological index) are defined, and their grade-based values are estimated.•Several strategies are defined for stakeholders at different levels.•A recursive evidential reasoning (ER) approach, which considers a hierarchical structure for decision-makers and a leader-follower game, is used to select the best strategy for each decision-maker.The applicability and efficiency of the methodology are illustrated by applying it to a real-world case study. The methodology is general and can be easily applied to other study areas.

Assessment of Water Distribution for the Effectiveness of Water Allocation Modeling

This research intends to conduct the assessment of water distributing performance for supporting the performance index assessment of water allocation modeling. The main aim is intending to solve the conflict of water interest, so there is necessary to be carried out the water allocation so water user society will get the water regarding to their right fairly, efficiently, and sustainably. Along with the increasing of population number and the social and economy conditions of society, there will all be increasing water demand for various uses. However, the quality tends to decrease because it has potency to increase the local conflict becoming a conflict between the regency and city that is unwanted. The water preparation and allocation are activities in operating the water resource infrastructure, whose aim is to optimize the usage of water resource infrastructure. This research was conducted in the watersheds of Manjuto, Slagan, Dikit, Teraman, Muar, Padang Guci, Bangkenang, Manna, Kelam, Nasal, and Luas. The methodology consists of collecting data on each watershed that are water availability and water demand; then, water balance and distribution (allocation) are analyzed. The result of water allocation analysis shows the water availability due to the dependable discharge as the reference such as Q 80 or discharge with the probability of 80%; still several watersheds experience the water deficit in fulfilling the irrigation water requirement, household-city-industry (RKI), plantation, fishery, husbandry, and river flow maintenance needs. A new research is needed for the index assessment of water allocation in the watersheds that experience the water deficit to obtain the plan value of water demand fulfilling allocation in the water deficit condition, whether non-critical, lightly critical, moderately critical, and heavily critical. Keywords : water availability, water demand, water balance, water allocation. https://doi.org/10.55463/issn.1674-2974.50.3.7

Optimal Water Allocation Model of Inter-Basin Water Transfer Based on Option Contracts under Uncertainty

Optimal Water Allocation Model of Inter-Basin Water Transfer Based on Option Contracts under Uncertainty

Research on Optimal Allocation of Water Resources in Handan City Based on the Refined Water Resource Allocation Model

In order to realize the dynamic regulation and control of regional water resources and alleviate the imbalance between supply and demand of regional water resources, on the basis of the demand of refined management of water resources, the dynamic General Water Allocation and Simulation Model (GWAS) of Handan City was constructed. The research on the optimal allocation of water resources in different regions and counties under different normal and dry years in the planning years (2025 and 2035) was carried out. The results show that the allocated water volume in the normal and dry years of Handan in 2025 is 2.248 billion m3 and 2.150 billion m3, respectively, and the water shortage rate is 11.72% and 22.11%, respectively. The water shortage is mainly in agriculture. In 2035, the allocated water volumes in normal and dry years will be 2.504 billion m3 and 2.33 billion m3, respectively, and the water shortage rates will be 4.50% and 21.84%, respectively. After optimized allocation, the water supply structure was significantly improved. The proportion of groundwater supply will decrease at each planning level year, and the water supply of external water transfer and unconventional water will increase. This research can provide technical reference to the Handan development scheme depending on water resources in the future, as well as the optimal allocation of water resources in other cities in the Beijing–Tianjin–Hebei Region.

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.

Modified Multi–Source Water Supply Module of the SWAT–WARM Model to Simulate Water Resource Responses under Strong Human Activities in the Tang–Bai River Basin

In the past few decades, the water resources in the Tang–Bai River Basin showed a declining trend, due to the human–driven alteration of surface water and groundwater management. There are potential risks to the sustainable utilization of future water resources in response to agricultural, industrial, and domestic water supply. In this work, we used the water allocation and regulation model based on SWAT (SWAT–WARM model) to quantify the characteristics of water resources response under human activities in this basin. The multi–source water supply module was modified to improve the applicability of the SWAT–WARM model in this basin. We validated our simulations against observed runoff, water consumption, and supply. The main results were as follows: (a) We used the percent bias, the correlation coefficient, and the Nash–Sutcliffe efficiency coefficient to measure the model validity and found that the modified model did not show obvious advantages in runoff simulations, whereas it reproduced water consumption and supply better than the original model. The modified model had more advantages in reflecting the process of water resources transformation and utilization in the basin driven by strong human activities. (b) By comparing the variation of watershed water circulation fluxes under natural and human disturbance conditions in the Tang–Bai River Basin from 1995 to 2016, we found that human activities increased evapotranspiration by 6.8% and surface runoff increased by 10.0%, while groundwater resources decreased by 0.23 million m3/yr. (c) There was water shortage in the basin at different flow frequencies, among which agricultural water shortage accounted for the largest proportion, >70%. The basin should further strengthen agricultural and industrial water saving, reduce water consumption fundamentally, and ensure the sustainable development of economy and society.

Research and Application of the Mutual Feedback Mechanism of a Regional Natural-Social Dualistic Water Cycle: A Case Study in Beijing–Tianjin–Hebei, China

With the intensification of human activities, the natural water cycle has a significant nature-society dual feature, and identifying the mutual feedback mechanism between natural and social water cycles is an important basis for a more accurate simulation of the dualistic water cycle. In this study, two indexes of cumulative runoff change rate and social water cycle feedback rate are put forward, representing the degree of change in socio-hydrological unit runoff under the mutual feedback of the natural social water cycle in all upstream regions, and the degree influence of the water intake, consumption, and discharge process of the social water cycle on the natural water cycle in the socio-hydrological unit, respectively. Taking the Beijing–Tianjin–Hebei region, which is marked by strong human activities, as the study area, the 2035 natural-social dualistic water cycles were simulated by a water allocation and simulation (WAS) model. Different water supply types and use structures cause the social water cycle to increase or decrease local runoff in different areas. The social water cycle feedback rate is greater than 1 in Beijing and Tianjin, and less than 0.25 in the mountainous areas and the Hebei plain, indicating that the social water cycle of each unit in the Beijing–Tianjin–Hebei region increases or decreases local runoff due to different water supply types and use structures. The cumulative runoff change rate in this region was 0.66, indicating that the overall runoff was attenuated due to the social water cycle, and runoff attenuation was greater in the south than the north.

Modeling Probabilistic-Based Reliability Analysis for Irrigation Water Supply Due to Uncertainties in Hydrological and Irrigation Factors

This study aims to model a probabilistic-based reliability analysis, named the RA_IWS_Canal model, for calculating the probability of the irrigation water supply exceeding the water demand (i.e., reliability) within a multi-canal irrigation zone due to variations in hydrological and irrigation uncertainty factors. The proposed RA_IWS_Canal model is developed by coupling uncertainty and risk analysis with a logistic regression equation. The Zhudong irrigation zone, located within the Touqian River watershed in northern Taiwan, was selected as the study area, with the inflow from Shanping Weir, water supplies at 15 irrigation canals, and water intakes of two reservoirs (Baoshan and Baoshan II) and a water treatment plant (Yuandon); 1000 simulations of 10-day irrigation water allocations and resulting exceedance probabilities of the water supplies at the 15 canals were achieved using the multivariate Monte Carlo simulation and the uncertainty with the water allocation model (RIBASIM), and employed in the development of the proposed RA_IWS_Canal model. The model development and application results indicate that the uncertainty factors and the inflow from Shanping Weir markedly and positively influence the exceedance probability of the canal-based irrigation water supply to boost the corresponding reliability (about 0.8). The water intake of the Baoshan Reservoir has a lower relationship (by 0.19) than the Yuandon water treatment plant with the reliabilities of the irrigation water supplies at its downstream canals. As a result, the proposed RA_IWS_Canal model can evaluate the effect of not only the canal-based uncertainty factors, but also the regional features on the irrigation water supply reliability. In addition, using the proposed RA_IWS_Canal model, the planned irrigation water demands at various canals within a multi-canal irrigation zone could be accordingly formulated based on acceptable reliability.

Developing a Bi-level programming model for water allocation based on Nerlove’s supply response theory and water market

Developing a Bi-level programming model for water allocation based on Nerlove’s supply response theory and water market

Evaluation of farmers' participatory behavior and compensation policy for agricultural water-saving

Today, with the decreased available water resources and the intensification of the conflicts between users of water resources, the cooperation or non-cooperation of users in water protection programs, especially in the agricultural sector, is of crucial importance. Therefore, the present study is aimed to provide a framework to evaluate the participatory behavior of farmers with optimal patterns of water allocation and to estimate the necessary budget to compensate for the reduction of water consumption in agricultural areas. To achieve this aim, the integration of the economic-environmental programming model with a top-down analytical approach and the agent-based model with a bottom-up analytical approach has been applied in the present study. Thus, the irrigation network of Jiroft Plain was chosen as the study area and a sample of farmers in this irrigation network was extracted for the analysis of the agent-based model using simple random method. It was found that different forms of insistence on the individual behavior of farmers make it difficult to participate in optimal water allocation patterns with simultaneously providing economic and environmental goals. As the degree of participation with the optimal model of water allocation with equal weight to economic and environmental goals, despite the implementation of the policy of giving facilities with a very low interest rate for the installation of new irrigation technologies, is estimated about 20%. Finally, the necessary budget for compensation policy for agricultural water storage was calculated based on the proposed framework, which can be considered a useful tool for policy makers in water resources management.

Multi-objective water resources optimum allocation scheme based on an improved standard cuckoo search algorithm (ISCSA)

Abstract The standard cuckoo search algorithm (SCSA) is an intelligent population optimization algorithm, which is also a heuristic search algorithm. The advantages of the SCSA (such as its convenient operation, heuristic searching, etc.) make it easy to find an optimal solution and maintain a wide searching range. However, the SCSA also has some drawbacks, such as long searching time, and the ease of falling on a local optimum. In order to solve the problems existing with SCSA, in this paper, an improved standard cuckoo search algorithm (ISCSA) was studied, which includes chaotic initialization and a Gaussian disturbance algorithm. As a case study, taking economic, social and ecological benefits as the objective function, multi-objective water resources optimal allocation models were constructed in Xianxiang Region, China. The ISCSA was applied to solve the water allocation models and a multi-objective optimal water supply scheme for Xinxiang region was obtained. Water resources optimal allocation schemes for the planning level year (2025) for 12 water supply sub-regions were predicted. A desirable eco-environment and other benefits were achieved using the studied methods. The results show that the ISCSA has obvious advantages in the solution of water resources optimal allocation and planning.

Climate Adaptation Needs to Reduce Water Scarcity Vulnerability in the Tagus River Basin

In southern Europe, climate change is expected to aggravate water scarcity conditions and challenge current water management practices. The present paper evaluates the impacts of climate change in the highly regulated Tagus River basin and assesses various adaptation options, quantifying the effort needed to maintain the ability to sustain current water uses. A water management and allocation model covering surface and groundwater resources is used to evaluate available and renewable water resources for different climate scenarios. Additionally, the Water Exploitation Index Plus (WEI+) and water supply reliability criteria are used to quantify water scarcity and the ability to satisfy water demands, respectively. The results show that climate change will significantly change the stream flow regime and reduce water availability in the Tagus River basin, but the existing reservoir infrastructure will alleviate some of these impacts, especially in the dry half-year. Until the end of the century, water scarcity levels, measured by annual WEI+, are expected to increase in the Tagus River basin from 0.46 to 0.52 or 0.62, respectively under two Representative Concentration Pathways (RCP 4.5 or RCP 8.5). The benefits of streamflow regulation vary with the hydrological regimen, the current degree of water use and the role of groundwater resources to meet demand. The benefits of streamflow regulation are also dependent on the environmental flow requirements that will be adopted in the future. A reduction of water consumption for irrigation by 25% to 40% will significantly improve the Tagus River system performance and maintain the current scarcity situation in the future, under the expected scenarios of climate change.

Optimizing water allocation in an inter-basin water diversion project with equity-efficiency tradeoff: A bi-level multiobjective programming model under uncertainty

Achieving optimal water allocation in an inter-basin water diversion project is a challenge that involves multilevel stakeholders, and the uncertainty and disequilibrium of water allocation further intensify competition among different stakeholders. This study proposes a bi-level multiobjective programming model for water allocation in inter-basin water diversions that considers equilibrium sustainability. The model integrates interval parameter programming, fuzzy credibility-constrained programming, bi-level multiobjective programming, and the Gini coefficient into a general framework. The model not only balances the stakeholders at different levels to ensure water allocation equity but also comprehensively considers the fuzzy uncertainty of parameters and constraints to obtain the interrelationship among water diversion, water allocation satisfaction, and efficiency objectives. The developed model was applied to allocate water for the Hanjiang-to-Weihe Water Diversion Project in Shaanxi Province, China. The results showed that 1) the model derived a feasible tradeoff between upper basin manager and lower regional managers under different water diversion scenarios; 2) water allocations and objectives at each level are sensitive to changes in the credibility of water diversion; 3) the new model improves the equity of water allocation and ensures the efficient allocation to various stakeholders at each level based on a comparison of the proposed model with a model that does not consider equilibrium. The proposed model can help decision makers choose the optimal scheme based on their acceptable risk level to achieve a more efficient and sustainable water allocation for inter-basin water diversions.

Salt transport in a large agro-urban river basin: Modeling, controlling factors, and management strategies

Salinity poses a severe threat to urban and agricultural areas. Excess salt can accumulate in soils and groundwater, thereby impacting crop growth and productivity. In this study we quantify the influence of driving forces on salt transport in Colorado's South Platte River (drainage area of 62,937 km2) and investigate possible mediation strategies to reduce salinity levels in both urban and agricultural river reaches. A river salt transport model was developed that utilizes a water allocation model and accounts for multiple inputs and outputs of salt within the river network, including tributaries, wastewater treatment plants, road salt, return flows from rainfall and irrigation, and groundwater discharge. The flow and salt models are run on a monthly basis between 2002 and 2006 and tested against stream discharge and in-stream salinity concentration at multiple gage sites. A sensitivity analysis was implemented to determine the controlling factors behind salt transport in the river system by river reach and by season (spring, summer, fall, winter). SA results were used to guide selection of management practices (n = 256) that can control salinity in both urban and agricultural areas. For urban areas, during spring/summer and fall/winter, the most efficient management practice is to decrease WWTP effluent salinity concentration by 35% and to decrease applied road salt by 35%, respectively, resulting in decreases of 10–30% decrease in river salt concentration. For agricultural areas, the only management practices that achieve an in-river salinity concentration (1,000 mg/L) that prevents crop yield decrease during irrigation are aggressive practices that focus on WWTP effluent concentration, return flow salinity, and urban road salt. Results points to the extreme challenge of managing salinity in the South Platte River Basin and other similar basins and the aggressive urban approaches that must be implemented to sustain irrigation practices in the downstream regions of the basin.

Using the WEI+ index to evaluate water scarcity at highly regulated river basins with conjunctive uses of surface and groundwater resources.

This paper discusses the role and limitations of using WEI+ as a water resource management tool for highly regulated river basins, with a conjunctive use of surface and groundwater resources. By considering flow regulation by reservoirs and aquifer systems, seasonality of water availability and demand, returns from water uses and environmental flow requirements, WEI+ constitutes an improvement to existing quantitative water scarcity indexes. However, the computation of WEI+ in complex river basins systems requires detailed data on water availability and water allocation to various uses, which are hard to obtain from monitoring records. The paper describes how the combined use of hydrological and water allocation models can help to overcome data gaps in water accounting and contribute to an improved analysis of water scarcity in heterogeneous and intricate river basins. It also examines the information provided by WEI+ and by other widely used water scarcity indexes, such as the Water Stress Index and the Criticality Ratio, as well as discusses the ability of WEI+ to measure the performance of hydraulic systems, usually evaluated by parameters such as reliability, vulnerability, and resilience. The Tagus River transboundary basin was selected as case study due to massive flow regulation by multi-purpose reservoirs and significant seasonality of water availability and demand. Results show the benefits of using WEI+ to define levels of water scarcity, over other indexes. Within the Tagus River systems, high values of WEI+ are reached during the summer months in regions with intensive agriculture, denoting severe water stress conditions in most sub-basins. The analysis also reveals the strong dependence of Portugal, the downstream country, on flows from Spain, the upstream country.