Environmental Water Demand Research Articles

Erratum for “The Role of Reservoir Reoperation to Mitigate Climate Change Impacts on Hydropower and Environmental Water Demands”

Erratum for “The Role of Reservoir Reoperation to Mitigate Climate Change Impacts on Hydropower and Environmental Water Demands”

Estimating the riverine environmental water demand under climate change with data mining models

Estimating the riverine environmental water demand under climate change with data mining models

Sustainable Adaptation Plan in Response to Climate Change and Population Growth in the Iraqi Part of Tigris River Basin

Climate change and population growth play crucial roles in the planning of future water resources management strategies. In this paper, a balancing between projected water resources and water demands in the Iraqi Part of the Tigris River Basin (TRB) was evaluated till the year 2080 based on RCPs 2.6, 4.5 and 8.5 and population growth. This paper examined a sustainable adaptation plan of water resources in the TRB considering three scenarios; (S1) as no change in the current strategy, (S2) as improved irrigation efficiency and (S3) as improved irrigation and municipal water use efficiency. The results showed a decline in streamflow will occur in the range from 5 to 18.4% under RCP 2.6 and RCP 8.5, respectively. The minimum increase in water demand is expected for RCP 2.6 (maximum increase for RCP 8.5) by 51.8 (208.2), 9.9 (42) and 1.2 (7)% for the municipal–industrial, irrigation and environmental water demands, respectively, compared with the RP. The main finding indicated that S1 is the worst scenario, with water stress in four provinces, especially on the warmest RCP. Whereas, under S2 and S3 conditions, water stress can be eliminated. Increasing ambition towards adaptation becomes obligatory for developing sustainable water sources, supporting water food securities and increasing resilience towards climate change.

Analyzing hydrological alteration and environmental flows in a highly anthropized agricultural river basin system using SWAT+, WEAP and IAHRIS

Study regionZarineh River Basin, a significant contributor to Urmia Lake inflow, Iran. Study focusEmploying SWAT+, WEAP, and IAHRIS, we assess environmental flow impacts on the Zarineh River Basin through two key aspects. Firstly, we evaluate the dam-induced alteration of the hydrological regime. Secondly, we explore future implications by prioritizing water allocation for environmental flows. Our approach involves developing, calibrating, and validating a SWAT+ hydrological model, analyzing hydrological alteration indicators using IAHRIS, and calculating environmental flows using the basic flow method in the SWAT+ post-processing tool. Using the WEAP water allocation model, three scenarios are assessed: 1) status quo, prioritizing drinking water and industry over agriculture; 2) environmental flows, prioritizing regulation compliance; 3) improved irrigation efficiency, facilitating a 10% increase while maintaining environmental flow prioritization.New hydrological insights for the region: The study reveals the altered flow regime’s failure to capture seasonal variations during dry years, particularly in winter and spring. Environmental and agricultural water demands compete, posing challenges to water management in the basin. Prioritizing environmental requirements increases reliability by 56% for environmental flows but decreases it by 11% for agriculture. Balancing environmental flows and agricultural water demands is crucial. A third scenario considers increased irrigation efficiency, requiring both decreased water allocation and enhanced efficiency. This research offers policymakers insights into formulating balanced environmental flow strategies, considering water demand reliability and basin hydrology.

A comparative study of different optimization algorithms for the optimum operation of the Mahabad dam reservoir

In this study, the performance of the Differential Evolution (DE) Algorithm, the Genetic Algorithm (GA) and Teaching-Learning Based Optimization (TLBO) Algorithm are compared for the optimum operation of the Mahabad dam reservoir. The Reservoir supplies agricultural, environmental, municipal and industrial water demands of the area. The desktop reserve model is used for estimating the minimum environmental demand. Six alternative agricultural water management scenarios are proposed and a sensitivity analysis is performed on the agricultural demands under different scenarios. The results of the study indicate that both DE and GA algorithms performed nearly equally; however, the DE Algorithm reached its result more quickly with the reliability of 74.19 % compared to the results of the GA and TLBO. A 30 % decrease in agricultural demand in the fifth scenario with 87.56 % reliability provides the best results.

Dynamic Adaptive Environmental Flows (DAE‐Flows) to Reconcile Long‐Term Ecosystem Demands With Hydropower Objectives

AbstractThis study investigates how environmental flows (e‐flows) can be designed as dynamic operating policies to optimize long‐term economic and ecosystem performance in reservoir systems. The main goal is to provide e‐flow solutions that contribute to better preparedness and flexibility of hydro‐systems to face multiyear stress periods, reducing the impact of water crises. The methodology framework combines a fish‐flow model with a multi‐objective evolutionary algorithm to construct multiple environmental water demand curves and capture the opportunity cost of different levels of ecosystem preservation. The water demand curves applied to a stochastic dynamic hydro‐economic model then derive dynamic e‐flow policies that balance immediate and future water use tradeoffs. The approach, termed dynamically adaptive environmental flows (DAE‐flows), is demonstrated on the Paraná River Basin, Brazil, a large‐scale hydropower system. Results show that the approach can adjust e‐flows (coordinated with other hydro‐system releases) over the time horizon, sacrificing them at certain times at the expense of some ecosystem loss, but improving long‐term ecosystem functioning. A long‐term approach to adaptation also yields better results for the environment without imposing a hard constraint to hydropower during droughts. Even under a drier climate change scenario, this allowed maintenance and improvement of environmental performance in most years, so during severe droughts the water could still be reallocated to hydropower but at a lesser cost to the environment.

The Role of Reservoir Reoperation to Mitigate Climate Change Impacts on Hydropower and Environmental Water Demands

Adapting reservoir operation to a changing climate is important to improve water system performance toward benefits including water security, and energy production. However, managers still need to know if and how reoperation can also assist long-term mitigation of climate change impacts on aquatic ecosystems, creating, for example, opportunities to revert fish migration and recruitment losses. This paper investigates the operational adaptive capacity of water systems to mitigate climate change impacts on both hydropower and aquatic ecosystems, with a detailed representation of fish species recruitment response to flow regime changes. The methodology framework combines hydroclimatic modeling, explicit stochastic reservoir operation modeling, and predictive modeling of migratory fish recruitment abundance, illustrated using the large-scale hydropower system of the Paraná River Basin in Brazil. Results identified that operating policies can be adapted to improve hydropower production under a changing climate with drier conditions by 2% to 8% compared with current operating policies. Although insufficient to eliminate all energy losses that climate change may cause, the optimized operation provided flexibility to adjust flow releases and reduce the likelihood of future severe multiyear deficits, which are very harmful to fish populations. Adapting operation to climate change sacrificed fish recruitment performance over a few years of the time horizon to maintain an overall higher storage, but it also improved the chances of producing flow releases in magnitude, timing, and duration during long drier periods that prevented more severe impacts of climate change on fish recruitment and population. This indicates that it might be possible to have synergies in adapting reservoir operation to not only prevent energy losses, but also to improve fish recruitment under climate change. The ecosystem resiliency under adapted operation increased up to 2 times compared with the isolated climate change effect.

Analyzing Water Conservation Techniques and Sustainable Irrigation Practices to Ensure the Availability of Clean Water for Future Generations

To keep ecosystems functioning, keep people alive, and propel social and economic progress, there must be access to clean water. The quantity and quality of freshwater resources are under jeopardy due to growing water scarcity, pollution, and climate change. In light of these issues, one of the most important things we can do to protect the supply of potable water for generations to come is to implement sustainable irrigation practices and water conservation measures. In light of the impending water crisis, this introduction lays the groundwork for an in-depth examination of sustainable irrigation practices and water conservation methods, discussing their significance, obstacles, and consequences. In light of increasing environmental challenges and water demands, it is critical to take immediate and decisive action to safeguard and responsibly manage water supplies. In light of changing environmental, social, and economic dynamics, this analysis aims to shed light on how to achieve water security and resilience by examining the concepts, innovations, and practical implementations of sustainable irrigation and water conservation. The main aim of this study is to analyze water conservation techniques & strategies of sustainable irrigation practices to provide insight for ensuring availability of clean water for future generations.

Hydro-Economic Modeling of Water Resources Management Challenges: Current Applications and Future Directions

Hydro-economic modeling (HEM) addresses research and policy questions from socioeconomic and biophysical perspectives under a broad range of water-related topics. Applications of HEM include economic evaluations of existing and new water projects, alternative water management actions or policies, risk assessments from hydro-climatic uncertainty (e.g., climate change), and the costs and benefits of mitigation and/or adaptation to such events. This paper reviews applications of HEM in five different categories: (1) climate change impacts and adaptation, (2) water–food–energy–ecosystems nexus management, (3) capability to link to other models, (4) innovative water management options, and (5) the ability to address and integrate uncertainty. We find that (i) the increasing complexity and heterogeneity of water resource management problems due to the growing demand and competition for water across economic sectors, (ii) limited availability and high costs of developing additional supplies, and (iii) emerging recognition and consideration of environmental water demands and value, have inspired new integrated hydro-economic problems and models to address issues of water–food–energy nexus sustainability, resilience, reliability through water (re)allocation based on the relative “value” of water uses. In the past decade, the field of HEM has improved the integration of ecosystem needs, but their representation is still insufficient and mostly ineffective. HEM studies address how to sustainably manage water resources, including groundwater which has become an area of particular interest in climate change adaptation. The current most used spatial and temporal resolutions (basin-scale and yearly time-step) are appropriate for planning but not for operational decisions and could be underestimating impacts from extreme events (e.g., flood risk) captured only by sub-monthly time scales. In addition, HEM primarily focuses on biophysical and economic indicators but often overlooks preferences and perspectives of stakeholders. Lastly, HEM has been widely used to analyze transboundary cooperation, showing benefits for increasing water security and economic development, particularly as climate change develops. We conclude that the field of HEM would benefit from developing more operational models and enhancing the integration of commonly neglected variables, such as social equity components, ecosystem requirements, and water quality.

THE ENVIRONMENTAL FLOW METHOD FOR SUPPLEMENTING THE WATER NEEDED FOR THE MANAGEMENT OF SELANGOR RIVER, MALAYSIA

The shortage of water resources is one of the main problems in the world today, and water pollution and under-utilization of water resources are two factors contributing to this shortage. Appropriate supplement environmental flow can have a positive impact on dilution of pollutants, and consequently on fish habitats and the characteristics of the river channels. The purpose of this study is to determine the environmental water demand of the lower Selangor River, known as Sungai Selangor, through the Tennant Method, and then compare the data with the findings in available documents in order to ascertain the most economical and favorable supplement environmental flow method. The results of this study show that the months of November and December between the years 2009 and 2018 were the peak periods of discharge, with it being important for the discharge of these two months to meet 200% of the average annual flow needed to maintain fish habitats and channels in downstream Sungai Selangor. To meet the requirements of supplement environmental flow and improvement of water quality, it is recommended that the spillway working gate of the Sungai Kerling hydropower plant be modified so that the flow can be discharged downstream to supplement the environmental flow. Providing environmental flows for downstream would generate economic benefits and allow upstream and downstream regions to share resources.

An Ecological Expert System Optimization for Assessing Environmental Water Requirements of Hypersaline Lakes

The present study proposes an applicable methodology to optimize environmental water requirement of hypersaline lakes with a focus on Urmia lake as the case study in which remote sensing analysis, machine learning model and fuzzy expert system are linked. A machine learning model was developed to simulate effective abiotic parameters in which bands of operational land imager (Landsat 8) were inputs and depth and total dissolved solids were the outputs of the model. Moreover, an ecological expert system using Mamadani fuzzy inference system was developed to generate the habitat suitability map for the selected target species. Then, a multivariate linear model was developed to assess unit habitat suitability in which water level and total inflow of the lake were the variables of the model. An optimization model was developed to assess environmental water requirement in which habitat suitability between natural and regulated flows and water supply loss was minimized. The multivariate linear model was applied to assess habitat suitability in the optimization model. Based on the results in the case study, the proposed combined model is able to balance the ecological requirements and water demand by allocating 60% and 40% of total inflow to environmental water requirement and water demand respectively. Average habitat loss proposed by the optimal environmental water requirement was less than 20% which implies the robustness of the model. Generating habitat suitability maps of the lake by a reliable method which is used in the environmental flow optimization might be the significance of the proposed method.

Reservoir optimal operation with an integrated approach for managing floods and droughts using NSGA-III and prospect behavioral theory

• An integrated management of floods and droughts is examined. • Optimal operation of a reservoir using a novel NSGA-III algorithm. • Prospect theory is utilized to simulate farmers' heterogeneous behavior. • The standardized runoff index (SRI) is used to define hydrological conditions. Establishing a holistic approach to manage floods and droughts is essential considering the different hydrological conditions. This work aimed to demonstrate how the integrated management of floods and droughts (IMFD) can increase sustainability and decrease the vulnerability of reservoirs against water-related disasters. To do so, a non-integrated management of floods and droughts (NMFD) is compared to an IMFD approach for the optimal operation of a reservoir (Doroudzan dam) to evaluate the sustainability of each scenario, especially the environmental water demand for Bakhtegan lake. Doroudzan dam provides water for different users, especially the environmental water demand. The IMFD and NMFD are differentiated through the development of industrial activities and the construction of a new regulatory dam, respectively. Each management scenario is tested under three hydrological conditions, i.e., dry, normal, and wet, which are determined by the standardized runoff index (SRI). Additionally, in the IMFD scenario, optimal cropping patterns are proposed to farmers by policymakers to increase water use efficiency. The heterogeneity in farmers’ response to adopting these cropping patterns is simulated through a well-known behavioral theory, prospect theory (PT). A novel optimization algorithm, NSGA-III, is utilized to determine the optimal operation of the reservoir and a bankruptcy scenario is utilized to share released water from the reservoir between the involved stakeholders. Results show the superiority of the IMFD scenario against the NMFD scenario in terms of decreasing water shortage as well as agricultural and environmental vulnerability, especially in dry conditions due to implementing more sustainable solutions. The average annual financial wealth generated by the IMFD scenario is greater than that of the NMFD scenario by about 68% through development in the industrial activities as a more profitable sector. Also, the utilization of PT shows how downstream and upstream farmers behave distinctly towards policymakers’ recommendations because they have different viewpoints about the amount of available water.

Post-Treatment of Reclaimed Municipal Wastewater through Unsaturated and Saturated Porous Media in a Large-Scale Experimental Model

In recent decades, groundwater overexploitation has caused an important aquifer level decline in arid zones each year. In addition to this issue, large volumes of effluent are produced each year in metropolitan areas of these regions. In this situation, an aquifer storage and recovery system (ASR) using the reclaimed domestic wastewater can be a local solution to these two challenges. In this research, a post-treatment of reclaimed municipal wastewater has been investigated through unsaturated–saturated porous media. A large-scale, L-shaped experimental model was set up near the second-stage wastewater treatment plant (WWTP) in the west of greater Tehran. The water, soil, and treated wastewater of the experimental model were supplied from the aquifer, site, and WWTP, respectively. The 13 physicochemical parameters, temperature and fecal coliform were analyzed every 10 days in seven points for a period of four months (two active periods of 40 days with a 12-h on–off rate (wet cycles) and a rest period of 40 days (dry cycle) between the two wet cycles). The results showed that the effects of the saturated zone were twice as great as those of the unsaturated zone and two-thirds of the total treatment efficiency. Furthermore, a discontinuous wet–dry–wet cycle had a significant effect on effluent treatment efficiency and contaminants’ reduction. In conclusion, an aquifer storage and recovery system using treated wastewater through the unsaturated–saturated zones is a sustainable water resource that can be used for agriculture, environmental and non-potable water demands.

An ecological interval two-stage fuzzy shadow price model for environmental flow allocation in the Shaying River Basin

Abstract In recent years, social water is pressurizing ecological water, causing the environmental flow to not be guaranteed and destroying the ecological environment. This research aims to coordinate social and natural water use to bring about optimal economic benefits, while ensuring environmental flow requirements. In this study, an interval two-stage fuzzy shadow price model (ITS-SPM) has been developed, which combines two-stage programming (TSP) and system of water value to optimize environmental flow. The ITS-SPM is mainly characterized as system benefits constituted by expected water resource benefits and water shortage penalty. This model has removed the uncertainties of economic data and environmental water demand (expressed fuzzy and interval). It has been found that adjusting the social water structure can effectively solve the problem of insufficient ecological flow. The ITS-SPM can make the adjustment of social water use more reasonable, which will produce benefits, unlike the current agricultural water reduction policy. Under the premise of guaranteeing optimal economic benefits, the added value of environmental water use in different scenarios is (social water structure adjustment) as follows: in 2020, it was expected that Shaying River water would increase by at least 13.49%; in 2025, it is expected to increase by at least 33.35%; in 2030, the increase will be by at least 57.54%; and in 2035, it will be by at least 77.50%.

Water Management Balance as a Tool for Analysis of a River Basin with Conflicting Environmental and Navigational Water Demands: An Example of the Warta Mouth National Park, Poland

Allocating finite water resources between different water uses is always a challenging task. Searching for a solution which satisfies the water needs (requirements) of all water users without compromising the water requirements of river ecosystems calls for analyzing different water management options and their expected consequences. Water management balances are usually used for comparison of water resources with the needs of water users. When aquatic and water dependent ecosystems are considered in a similar manner as other users, searching for the optimum water resources allocation, without neglecting requirements of the natural environment, is possible. This paper describes basic modeling assumptions and methodological solutions, which allow for taking into account some tasks related to the protection of aquatic and water dependent ecosystems. The water balance model, developed for a catchment comprising the Warta Mouth National Park, was applied to find out whether supplying adequate amounts of water for conservation (or restoration) of wet meadows and wetland habitats in the area is possible, while still satisfying the demands of other water users.

Method for monitoring environmental flows with high spatial and temporal resolution satellite data.

Monitoring environmental flows is crucial to maintaining the function and stability of river and lake ecosystems. However, current methods for monitoring environmental flows are expensive and ground based, and the accuracy of the results needs to be verified to evaluate the environmental flows. This evaluation is hampered by the problem of data shortages, such as hydrological and ecological data. In this study, a method for monitoring environmental flows is proposed using multisource high spatial and temporal resolution satellite data. A case study in the Yongding River Basin demonstrates that the method is feasible for monitoring the environmental flows of rivers in semiarid and arid areas. The results show that the environmental flows and months with large water discharges and shortages in the three control sections of the Yongding River Basin were different. Moreover, the downstream river width rarely met the environmental water demand, achieving this only for one period from 2017 to 2019 according to the three typical types of years (an average water year, a dry year, and an extremely dry year). This method and the results have applications in planning environmental flows and could improve the comprehensive management of the ecological environment in river basins.

Evaluating integrated water management strategies to inform hydrological drought mitigation

Abstract. Managing water–human systems during water shortages or droughts is key to avoid the overexploitation of water resources and, in particular, groundwater. Groundwater is a crucial water resource during droughts as it sustains both environmental and anthropogenic water demand. Drought management is often guided by drought policies, to avoid crisis management, and actively introduced management strategies. However, the impact of drought management strategies on hydrological droughts is rarely assessed. In this study, we present a newly developed socio-hydrological model, simulating the relation between water availability and managed water use over 3 decades. Thereby, we aim to assess the impact of drought policies on both baseflow and groundwater droughts. We tested this model in an idealised virtual catchment based on climate data, water resource management practices and drought policies in England. The model includes surface water storage (reservoir), groundwater storage for a range of hydrogeological conditions and optional imported surface water or groundwater. These modelled water sources can all be used to satisfy anthropogenic and environmental water demand. We tested the following four aspects of drought management strategies: (1) increased water supply, (2) restricted water demand, (3) conjunctive water use and (4) maintained environmental flow requirements by restricting groundwater abstractions. These four strategies were evaluated in separate and combined scenarios. Results show mitigated droughts for both baseflow and groundwater droughts in scenarios applying conjunctive use, particularly in systems with small groundwater storage. In systems with large groundwater storage, maintaining environmental flows reduces hydrological droughts most. Scenarios increasing water supply or restricting water demand have an opposing effect on hydrological droughts, although these scenarios are in balance when combined at the same time. Most combined scenarios reduce the severity and occurrence of hydrological droughts, given an incremental dependency on imported water that satisfies up to a third of the total anthropogenic water demand. The necessity for importing water shows the considerable pressure on water resources, and the delicate balance of water–human systems during droughts calls for short-term and long-term sustainability targets within drought policies.

Assessing the Impact of Management Options on Water Allocation in River Mubuku-Sebwe Sub-Catchments of Lake Edward-George Basin, Western Uganda

Limited studies in East Africa and particularly in Uganda have been carried out to determine and map water use and demands. This study aimed at assessing the impact of management options on sustainable water allocation in environmentally sensitive catchments of Mubuku and Sebwe of Lake Edward-George basin in Western Uganda. We used hydro-meteorological data analysis techniques to quantify the available water. We applied Mike Hydro model to allocate water to the different ongoing developments in the catchment based on 2015 and 2040 water demand management scenarios. We used the Nile Basin Decision Support System to assess the sustainability of the different water management scenarios for sustainable water resources use. Reliability computation did not consider hydropower in this study. Results show that water available in 2015 was 60 MCM/YR and 365 MCM/YR for Sebwe and Mubuku, respectively and is projected to decrease by 15% and 11% by the year 2040 under climate scenario RCP8.5. We project water demand to rise by 64% for domestic, 44% for livestock, 400% for industry, 45% for hydro power and 66% for irrigation by 2040. Mubuku water demand is projected to increase from 5.2 MCM in 2015 to 10.7 MCM in 2040. Mubuku available water is projected to fall from 364.8 to 329.8 MCM per annum. Sebwe water demand is projected to increase from 9.7 MCM in 2015 to 22.2 MCM in 2040 and its available water is projected to fall from 60 to 52 MCM per annum by the year 2040 from 2015. Water managers ought to allocate water based on the reliable water allocation which prioritizes domestic and environmental water demands, allocates 90% of industrial demand, 70% of irrigation and 60% of livestock demand. We recommend institutionalizing this model to guide water allocation in the Mubuku-Sebwe sub catchments. Water users should employ more efficient water use techniques to achieve high reliability and sustainable water resources management.

Impact of Pumping Rate on Contaminant Transport in Groundwater—A Numerical Study

Public supply wells are commonly considered one of the most significant sources of freshwater on Earth. Therefore, potential well water contamination can conceivably be regarded as a crucial issue that is closely correlated with both environmental protection and water demand. In the present study, a three-dimensional numerical model is developed to simulate unsteady and spatially varying groundwater flow, along with contaminant migration. Besides, the proposed model is capable of investigating well water quality by the change of the wells’ pumping rates. The developed model uses a finite-volume time splitting numerical technique to solve governing groundwater flow and soluble contaminant transport equations. Comparison of the numerical simulation results with analytical solutions, as well as experimental and field data, clearly demonstrates the satisfactory performance of the present model. The fundamental aim of the study is to evaluate the effect of pumping rate and its variations on pollution migration through saturated porous media. To meet this purpose, contaminant concentrations and contaminants’ travel time were studied under different pump flow rate conditions. The modeling results revealed that choosing an optimum range for the pumping rate increases contaminant travel time and reduces aquifer vulnerability.

Climate variables on the hydrographic basin of Uruçuí Preto River – Piauí, Brazil subsidies for the management of water and agricultural resources

The knowledge of the climatic characteristics of the hydrographic basins, especially regarding the temporal and spatial distribution of rainfall, the relative humidity of the air and the maximum, minimum and average temperatures of the air, which offer important subsidies to the management of water resources and agriculture. The irregular distribution of rainfall indicates instability in the entry of water into the hydrological system, exercising control over water availability in time and space, the relative humidity of the air influences animal and plant behaviors and the amount of water available in the atmosphere. The temperature, on the other hand, influences the evapotranspiration rates, indicating the energy availability of the environment and, consequently, the environmental water demand. The work presents characteristics of the hydrographic basin of the Uruçuí Preto River (BHRUP), in terms of rainfall, relative humidity, temperature, climatological water balance and climatic regimes. The graphs of annual behavior and seasonal regimes elaborated for 25 pluviometric stations distributed in the interior and around the basin, most of them in operation since the 1960s, followed by the elaboration of average isoietas charts and the one of the rainiest semester, relative humidity of the air, isotherms of the maximum, minimum and average temperatures, and of the letters of potential evapotranspiration, real evaporation and water deficit. The climatic types were appreciated due to the influence of the habitual behavior of the atmosphere on the potential and real environmental demand for water and also on the anthropic demand. The Thornthwaite (1948, 1953) climate system was used, based on the comparison between potential evapotranspiration and rainfall.