Ecosystem Service Impacts of Urban Water Supply and Demand Management

Utilities face the challenge of enhancing long-term water security while minimising undesirable economic, social and environmental impacts of supply and demand management options. This paper provides an example of how the ecosystem services concept can be used to enumerate and organise broad impacts of water supply options. A case study of Adelaide, South Australia, is used to examine costs and benefits associated with different sources of water and source-water mix scenarios. Ecosystem service impacts are estimated using estimates from the literature. Seven water supply and demand management options are considered for Adelaide: 1) the River Murray, 2) Mt. Lofty Ranges catchments, 3) wastewater reuse, 4) desalination, 5) stormwater harvesting, 6) groundwater and 7) water conservation. The largest costs are associated with sourcing water from conservation measures such as water restrictions on outdoor watering estimated at $1.87/kL. Salinity damage costs associated with residential uses are estimated at up to $1.54/kL. Salinity damage costs of wastewater reuse were estimated at $1.16/kL. The largest benefit is coastal amenity services associated with stormwater harvesting and treatment estimated at $1.03/kL. Results show that there is a trade-off between financial costs and ecosystem services impacts with source-water mix scenarios with the highest ecosystem services cost having the lowest financial O&M cost and vice versa. This highlights the importance of taking ecosystem services into account when evaluating water supply options.     

Assessment of Future Water Scarcity at Different Spatial and Temporal Scales of the Brahmaputra River Basin

Climate change is one of the main driving forces that affect both the temporal and spatial variability of water availability. Besides climatic change, current demographic trends, economic development and related land use changes have direct impact on increasing demand for freshwater resources. Taken together, the net effect of these supply and demand changes has led to a growing water scarcity in major international river basins. The Brahmaputra River Basin is one of the most vulnerable areas in the world, as it is subject to combined effect of climate change and development pressures. A robust assessment of water scarcity considering both climatic and socio-economic changes is therefore vital for policy makers of the basin. In this study, we analyze future water scarcity of the Brahmaputra Basin in a geographically and temporally detailed manner, incorporating several novel approaches: (i) the application of consistent set of scenarios to estimate future water scarcity; (ii) estimation of water demand in terms of both water withdrawals and consumptive water use; (iii) comparison of water demand and availability on different temporal scales i.e., yearly, seasonal and monthly rather than only annual basis. (iv) assessment of groundwater recharge affected by climate change together with future demands for groundwater abstraction. Although the Brahmaputra Basin is one of the water abundant regions of the world, our analysis illustrates that during dry season water scarcity for the Basin will become more severe in the coming decades, which requires special attention to the decision makers of the authority.     

A Comprehensive Approach for Spatial and Temporal Water Demand Profiling to Improve Management in Network Areas

The aim of this paper is to present a comprehensive approach for spatial and temporal demand profiling in water distribution systems. Multiple linear regression models for estimating network design parameters and decision trees for predicting daily demand patterns are presented. Proposed approach is a four-step procedure: data collection, data processing, data characterization, and spatial and temporal demand profiling. Continuous flow measurements and infrastructure and billing data were collected from a large set of water network areas and combined with census data. Main results indicate that family structures (i.e., families with elderly or adolescents), individuals’ mobility (i.e., people employed in the tertiary sector and university graduates) and public consumption (i.e., public spaces’ irrigation) are key-variables to profile water demand. Profiling models are of the utmost importance to describe water demand in areas with no monitoring but with similar socio-demographic characteristics to the ones analyzed, to improve network operation and to support network planning and design in new areas. Obtained models have been tested for new areas, showing good prediction performances.     

Sustainable Water Supply and Demand Management in Semi-arid Regions: Optimizing Water Resources Allocation Based on RCPs Scenarios

Climate as one of the key factors in water resources management affects the amount of water in the hydrological cycle, which subsequently impacts the level of water availability. Considering the challenges that the South Alborz Region, Iran is currently facing in supplying water for various consumers; in this study, the climate change adaptation scenarios are investigated for sustainable water supply and demand. This study uses a procedure in which five different adaptation approaches, under RCPs scenarios, were established using the WEAP model to assess the impacts of various adaptation strategies on increasing the balance between water supply and demand over current and 2020s accounts. The findings suggest an imbalance between supply and demand in the current situation with the greatest imbalance in domestic use while the minimum in the industrial sector. The results of assessing adaptive scenarios show that various scenarios have different effects on balancing the water supply and demand by different consumers; on the other hand, the scenarios that directly affect domestic water demand have the greatest effect on minimizing the gap between supply and demand in the region; therefore, the options for decreasing the population demand along with diminishing the losses in the domestic water distribution network are the most effective alternatives for balancing supply and demand under all of the climate scenarios. The findings of this research indicate that adaptive management with the focus on restricting demand helps actively management of water resources in the regions with scarce water resources.

     

Spatiotemporal Assessment of Water Conservation Function for Ecosystem Service Management Using a GIS-Based Data-Fusion Analysis Framework

Water Resources Management - In order to improve water ecological service and ensure water resource protection, it is imperative to develop an effective evaluation method to identify the...     

水资源需求侧管理中的激励机制研究

对水资源需求侧管理中的激励机制进行了探讨,建立了基于峰谷分时水价和节水奖励的激励机制模型。结果表明：用水高峰期各主体的最优取水量随着系统高阈值的增大而增大;低谷期各主体的最优取水量随着系统低阈值的增大而增大;正常期各主体的最优取水量随着系统低阈值的增大而增大。在用水高峰期,可通过设定较低的系统高阈值来降低高峰期的取水量;在用水低谷期,可通过设定较高的系统低阈值来提高低谷期的取水量。高低阈值区间越小,越有利于削峰填谷。     

Future Water Supply and Demand Management Options in the Athabasca Oil Sands

The Athabasca River Basin, home to Canada's growing oil sands mining industry, faces challenging trade‐offs between energy production and water security. Water demand from the oil sands mining industry is projected to increase as climate change is projected to alter the seasonal freshwater supply. In this study, a range of water management options are developed to investigate the potential trade‐offs between the scale of bitumen production and industry growth, water storage requirements, and environmental protection for the aquatic ecosystems, under projections of mid‐century climate change. It is projected that water storage will be required to supplement river withdrawals to maintain continuous bitumen production under the impacts of future climate warming. If high growth in future bitumen production and water demand is the priority, then building sufficient water storage capacity to meet industry demand will be comparable to a week of lost revenue because of interrupted production. If environmental protection is prioritized instead, it will require over nine times the water storage costs to maintain water demand under a high industry growth trajectory. Future water use decisions will need to first, determine the scale of industry and environmental protection, and second, balance the costs of water storage against lost revenue because of water shortages that limit bitumen production. This physically based assessment of future water trade‐offs can inform water policy, water management decisions, and climate change adaptation plans, with applicability to other regions facing trade‐offs between industrial development and ecosystem water needs. Copyright © 2016 John Wiley & Sons, Ltd.     

Optimization Approach to Designing Water Supply Systems in Non-Coastal Areas Suffering from Water Scarcity

This article presents a novel optimization approach to designing water supply systems in non-coastal areas with water scarcity. In such areas, high water demand caused by population increases and economic development can only be satisfied with seawater supply. Furthermore, most of the non-coastal users are located at long distances and sometimes at altitudes very diverse from the coastline, meaning long pipelines and several pumping stations will be required to effectively supply water. The proposed optimization approach based on a mixed integer nonlinear programming model offers optimal designs of water supply systems from an economic and technical perspective. It determines the location and size of desalination plants and the design of the water transport network including pipelines of specified length and diameter and pumping stations that minimize capital and operational costs of the whole system. A case study in a hyper-arid region of Chile was used to validate the applicability of the proposed model and the results show its aptitude for determining global optimal solutions to real-scale problems.     

Spatial and Temporal Analysis of Hydrological Provision Ecosystem Services for Watershed Conservation Planning of Water Resources

Spatial planning for sustainable water resources development requires precise information on the local potential for providing water yield in a watershed. For water resource conservation, we analyzed spatial and temporal patterns of hydrological provision ecosystem services in the upper Teshio watershed of northernmost Japan. The Soil and Water Assessment Tool (SWAT) was applied to simulate hydrologic processes and determine parameters affecting the water cycle. The spatial increase of water yield at flat area near river channel in winter was explained by low field capacity of soil water, absence of water uptake by crops and gentle topography. The spatial patterns of snowmelt and rainfall were important drivers of the spatial pattern in water yield during other periods. The zonation model was applied to investigate dynamic changes in spatial conservation prioritization of hydrological provision ecosystem services, according to simulated water yields in February, April and October. The results showed that the conservation priority ranking dynamically changed spatially and temporally. Our economic assessment of hydrological provisioning services (irrigation, electricity production and household usage) indicated that the spatial pattern of the priority for water resources was different from that of economic value of the provisioning services. Our results indicated that a combination of hydrologic and cost zonation models would improve sustainable management planning of water resources and their hydrological ecosystem services have great spatiotemporal fluctuation.     

大沙河灌区节水工程项目水资源评价及供需平衡分析

对开平市大沙河灌区农业综合开发节水工程项目水资源进行水量平衡供需计算分析,计算结果分析表明,灌区节水工程项目实施改造和调整农业结构后,除可满足城镇供水要求及农业灌溉保证率达到90%外,还有盈余水量,达到节水增效的目的,项目综合效益显著。     

Estimated Per Capita Water Usage Associated with Different Levels of Water Scarcity Risk in Arid and Semiarid Regions

Water scarcity in arid and semi-arid regions is a great economic, environmental and social problem, where the people living in these regions have to use technologies, such as cistern, to ensure water for their survival. Given the difficulties in these regions, this paper aims to propose a methodology to estimate per capita water use for different levels of water shortage risk, ensuring water supply under the conditions of arid and semi-arid regions; and present a case study for the Brazilian semi-arid region. The methodology is based on analysis of spatial and temporal risks of water shortage in the cisterns. Analysis of the temporal risk of water shortage is based on the premise that the cistern is without water for 3 consecutive days with return periods of 5, 10 and 20 years. To ascertain the spatial risk of per capita water use associated with these return periods in hydrologically homogeneous regions, we evaluate the confidence interval associated with the average monthly water use. Thus, the proposed methodology allows to determine the potential water use in each homogeneous region. For the Brazilian semiarid region it is possible to identify the areas where local population has a greater restriction on the access to water (central semiarid region) and areas where there is greater water availability (north and south of the semi-arid). This variation of water availability allows to adapt management measures accounting for the ground conditions of each location, in order to meet the water needs of the local population.     

Hotspots Assessment of Spatial Water Losses in the Off-Farm Open Channels Irrigation Supply System

Open channels are the dominant off-farm systems employed to supply irrigation water in both developed and developing countries. However, a majority of these systems are often criticised for their low conveyance efficiencies. Under the water scarce environment, improving the conveyance efficiency provides an opportunity to realise basin level water savings. To define the quantum of such opportunities, there is a need to identify the location, nature and amount of water losses (hotspots) in the off-farm open channels irrigation supply system that can be saved, in a cost-effective manner, through investments in the conveyance infrastructures. This paper presents the hotspots assessment of the off-farm open channels irrigation supply system located in New South Wales, Australia. Hotspots assessment is primarily drawn upon the public domain datasets and information available in the published literature or anecdotal evidences. The study area has a 296 km long network of open channels spanning over 96,000 ha. The results indicate that almost 50% of the water losses due to channel seepage occur at specific hotspots that cover only 1.7% of the length of the total channel network. The presented approach has a potential to help make consistent and transparent decisions for allocating irrigation infrastructure investments across different stakeholders.     

Optimal Water Quality Management Considering Spatial and Temporal Variations in a Tidal River

There is an increasing need to establish wastewater treatment facilities for improving water quality of heavily polluted rivers in rapidly urbanizing areas. Optimization models are widely used to determine the pollutant removal levels at different pollution sources, with the aim of minimizing the wastewater treatment cost and satisfying certain water quality criteria. Water quality is usually evaluated in a prescribed space or time point. Thus it cannot reflect the overall status of a tidal river that has significant spatio-temporal variations. In this paper, new spatio-temporal water quality criteria, which consider the water quality violation against specified water quality standards during the whole simulation period of time for the entire river simulated, are proposed and then applied to optimization of a wastewater treatment system in Shenzhen, China. The results indicate that the optimization based on the proposed criteria facilitates an improved performance of wastewater treatment systems in terms of water quality along the whole river during a long time period, instead of just in a prescribed space or time point. Furthermore, use of the new criteria derives a better Pareto front of cost and water quality in terms of convergence and coverage compared with the conventional criteria and thus they are recommended as the water quality criteria to measure spatial and temporal variation in a tidal river for wastewater treatment system planning.     

基于Logistic回归模型的张掖市水资源供需风险研究

为缓解张掖市水资源供需矛盾,并为水资源科学管理提供决策依据,收集张掖市2006—2015年水资源相关数据,并选取张掖市供水量、需水量和缺水量3个变量,运用Logistic回归模型,得出张掖市水资源供需风险率及其影响程度;使用谱系聚类法评价其风险率并确定风险等级,最后得出张掖市在2种水平年可能存在的供需风险程度。结果表明:近10 a来,张掖市水资源均存在供需不平衡、供需矛盾的问题;张掖市未来经济发展与当地水资源供需状况有关,而供需风险的高低与供水保证率有直接关系。建议张掖市政府实行多措并举来保证水资源供应量充足,使得供需风险处于低风险。     

Temporal Stability Analysis for the Evaluation of Spatial and Temporal Patterns of Surface Water Quality

Water Resources Management - Better characterizing the spatio-temporal pattern of water quality would increase the ability to effectively manage water resources. This study applied the...     

辽宁省水资源需水预测及供需分析

对辽宁省各行业的需水进行了全面预测，并结合水利工程计划，对不同水平年的水资源可利用量进行了分析，为合理开发水资源量提供了科学依据。     

基于溶解氧平衡法的南四湖生态需水量研究

提出一种基于水体溶解氧平衡法的湖泊生态需水量计算方法。首先计算大气复氧量和水生植物光合作用产氧量,然后计算水生生物呼吸耗氧量和底泥中有机污染物降解耗氧量,根据湖泊产氧量与耗氧量的平衡方程,确定不同水质条件下逐月水生生物需水量。以南四湖为例,计算了大气复氧量和水生植物光合作用的产氧量以及水生生物呼吸耗氧量和底泥中有机污染物降解耗氧量,在综合考虑逐月蒸发、渗漏需水量的基础上,依据溶解氧平衡方程,确定了湖泊逐月基本生态需水量。     

北京市水资源供需分析

北京是一个水资源紧缺的特大型城市,随着首都经济和社会的快速发展,水资源供需矛盾越来越突出.根据"北京城市总体规划",从北京市水资源开发利用、需水量预测分析等方面,对北京市的水资源供需平衡情况进行了分析,并提出了解决或缓解北京市水资源供需矛盾的建议.