Integrating a Climate Change Assessment Tool into Stakeholder-Driven Water Management Decision-Making Processes in California

There is an emerging consensus in the scientific community that climate change has the potential to significantly alter prevailing hydrologic patterns in California over the course of the 21st Century. This is of profound importance for a system where large investments have been made in hydraulic infrastructure that has been designed and is operated to harmonize dramatic temporal and spatial water supply and water demand variability. Recent work by the authors led to the creation of an integrated hydrology/water management climate change impact assessment framework that can be used to identify tradeoffs between important ecosystem services provided by the California water system associated with future climate change and to evaluate possible adaptation strategies. In spite of the potential impact of climate change, and the availability of a tool for investigating its dimensions, actual water management decision-making processes in California have yet to fully integrate climate change analysis into their planning dialogues. This paper presents an overview of decision-making processes ranked based on the application of a 3S: Sensitivity, Significance, and Stakeholder support, standard, which demonstrates that while climate change is a crucial factor in virtually all water-related decision making in California, it has not typically been considered, at least in any analytical sense. The three highest ranked processes are described in more detail, in particular the role that the new analytical framework could play in arriving at more resilient water management decisions. The authors will engage with stakeholders in these three processes, in hope of moving climate change research from the academic to the policy making arena.     

Methodology to Evaluate Aquifers Water Budget Alteration Due to Climate Change Impact on the Snow Fraction

This paper aims to propose a methodology to evaluate and quantify perturbed groundwater budgets considering the projected reduction of Average Snow Fraction of Surface Runoff (ASFSR). Future groundwater budgets are generated considering different CC temporal Scenarios, RCMs, as well as the status of each Groundwater Body (GwB). The proposed methodology is applied to the Central Mountain Range of Iberian Peninsula (Avila Province). Existing studies show a drastic Reduction on Snow Melting (RSM) and on Cumulative Snow Volume (CSV). This leads to a huge reduction of Average Snow Fraction of Surface Runoff (ASFSR) and on groundwater availability calculated through the indicator Perturbed Exploitation Index (PEI). There are important differences depending on the RCM used, on the temporal CC Scenario and on the GwB considered. Main difficulties and challenges comprise the lack of field data and rigorous studies on modelling of groundwater hydrodynamic modelling. Despite of that, research results show a robust and generalized increase in all Exploitation Indexes (EI). EI increase is of 4.17?% for IP1 (Short Term) RCP 4.5, 14.94?% for IP2 (Medium Term) RCP 4.5, 17.65?% for IP3 (Long Term) RCP 4.5. On the other hand, there is an increase of 9.89?% for IP1 RCP 8.5, 19.05?% for IP2 RCP 8.5 and 35.14?% for IP3 RCP 8.5. Thus, there is a generalised and very important decrease of recharge (PARR) of 59.03?% for IP1 RCP 4.5, 88.97?% for IP2 RCP 4.5, 90.02?% for IP3. Likewise, for RCP 8.5, there is a decrease of 72.69?% for IP1 RCP 8.5, 88.97?% for IP2 RCP 8.5 and 97.90?% for IP3.

     

水资源承载力多属性决策评价研究

提出了水资源承载能力评价的多属性决策方法,给出了用多属性决策理论计算水资源承载力的数学模型.以ELECTRE法为对象,详细说明了多属性决策的计算步骤与方法,并用于计算疏勒河水资源承载力.结果表明:采用多属性决策建立的模型能够很好地对水资源承载力进行评价,在水资源承载力评价中,具有良好的应用前景.     

Adaptation of Water Resources System to Water Scarcity and Climate Change in the Suburb Area of Megacities

Water Resources Management - The projection of climate change impacts can be very crucial for water resources planning and management. Hashtgerd plain is an immigrant destination due to...     

The Role of Regulation in Meeting Water Demands under Climate Change

The satisfaction of water demands in semi-arid regions could be affected as a consequence of climate change. In this study, the impact due to future climate scenarios in the Chira and Piura basins located in northern Peru was evaluated. Two indicators, the demand satisfaction index (I₁) and the demand reliability index (I_2p), were used to analyze water scarcity problems. An analysis of the basins by region highlighted the importance of regulation infrastructure in minimizing the effects of climate change to meet water demands.     

Changes in Irrigation Planning and Development Parameters Due to Climate Change

Considering changes in irrigation planning and development due to climate change is necessary to avoid system failure. This study demonstrated that changes in dependable flow and diversion water requirements in the future due to climate change will reduce potential irrigable areas. Climate change were based on the published projected climate in the study area. The dependable flow derived from successfully calibrated and validated Soil and Water Assessment Tool (SWAT) model streamflow simulations and the diversion water requirements based on the CROPWAT estimations of irrigation scheme were used to assess the potential irrigable areas. Substantial reductions in potential rice production areas (-4% to – 39%) were largely due to dwindled dependable flow (-1% to -25%) and an increase in diversion water requirement (+?7% to?+?26%). Reduction in potential irrigable area was projected during dry and normal years and may worsen towards the late twenty-first century under the worst-case climate scenario. Swelling of rivers during wet years will increase stream flows and potential irrigable areas but may also pose a danger of flooding. The development of water storage structures is necessary to reduce the adverse impacts of too much water during the wet years. Crop calendars should also be retrofitted to optimize the use of available rainfall during dry and normal years and climate-proof future irrigation systems. The results showed that it is necessary to incorporate climate change in irrigation planning and development. The methodologies described here could be used to climate-proof future irrigation systems in other areas in the Philippines and other countries.

     

Water Structures and Climate Change Impact: a Review

Climate change impact started to play significant role since the last three decades almost in every aspects of life especially on meteorological and climatological events and their impacts on water resources, which are managed by engineering structures. Its effects on hydro-meteorological data are assessed by means of available methodologies, but the climate change impact of engineering water structures (dams, culverts, channels, wells, highways and their side drainages, levees, etc.) are not treated equally. This paper provides the review of the necessary adaptation, combat and mitigation activities against the climate change for protection, construction or augmentation of the engineering water structures design capacity. Additionally, land use practices and geomorphological changes also trigger the climate changes on the engineering water structures. The main aim of this paper is to present the impact of such changes on the engineering water structure capacity, operation and maintenance.

     

Optimization of Run-of-River Hydropower Plant Design under Climate Change Conditions

The assessment of climate change and its impacts on hydropower generation is a complex issue. This paper evaluates the application of representative concentration pathways (RCPs, 2.6, 4.5, and 8.5) with the change factor (CF) method and the statistical downscaling method (SDSM) to generate six climatic scenarios of monthly temperature and rainfall over the period 2020–2049 in the Karkheh basin, Iran. The identification of unit hydrographs and component flows from rainfall, evaporation and streamflow data (IHACRES) model was employed to simulate runoff for the purpose of designing a run-of-river hydropower plant in the Karkheh basin. The non-dominated sorting genetic algorithm (NSGA)-II was employed to maximize yearly energy generation and the plant factor, simultaneously. Results indicate the runoff scenarios associated with the SDSM lead to higher run-of-river hydropower generation in 2020–2049 compared to the CF results.     

Assessment of Water Resources Vulnerability and Adaptation to Climate Change

This paper provides an overview of the 'standard' methodology developed for the United States Country Studies Program on the Assessment of Water Resources Vulnerability and Adaptation to Clim ate Change. The methodology is described in more detail in accompanying articles in this issue. A standard methodology was developed for two reasons. First, for countries with little or no experience in hydrologic and water resources modelling, it provided a simple, yet appropriate set of modelling tools that could be quickly learned and applied with a limited data set. Second, it provided a consistent methodology for synthesizing results for regional and global assessments as well as cross-country and cross-regional comparisons.     

Optimal Hydropower Generation Under Climate Change Conditions for a Northern Water Resources System

This paper examines climate change impacts on the water resources system of the Manicouagan River (Québec, Canada). The objective is to evaluate the performance of existing infrastructures under future climate projections and the associated uncertainties. The main purpose of the water resources system is hydropower production. A reservoir optimization algorithm, Sampling Stochastic Dynamic Programming (SSDP), was used to derive weekly operating decisions for the existing system subject to reservoir inflows reflecting future climate, for optimum hydropower production. These projections are simulations from the SWAT hydrologic model for climate change scenarios for the period from 2010 to 2099. Results show that the climate change will alter the hydrological regime of the study area: earlier timing of the spring flood, reduced spring peak flow, and increased annual inflows volume in the future compared to the historical climate. The SSDP optimization algorithm adapted the operating policy to the future hydrological regime by adjusting water reservoir levels in the winter and spring, and increasing the release through turbines, which in the end increased power generation. However, there could be more unproductive spills for some power plants, which would decrease the overall efficiency of the existing water resources system.     

A Hybrid Model-Based Adaptive Framework for the Analysis of Climate Change Impact on Reservoir Performance

Water Resources Management - Climate change and population growth have influenced social and physical water scarcity in many regions. Accordingly, the future performance of water storage...     

Water Balance,Climate Change and Land-use Planning in the Pearl Harbor Basin,Hawai'i

The Pearl Harbor basin on the tropical oceanic island of O'ahu, Hawaii, exhibits extreme climatic gradients, rapid land-use change and groundwater use near sustainable yield. The basin's water usage and groundwater recharge, and hence water yield, are strongly influenced by the spatial distribution of land use. Current recharge is expected to drop by about one-eighth with the demise of the remaining sugar-cane and pineapple. Evidence suggests that lower rainfall and increased evaporation may well accompany warmer periods in Hawaii, and water-balance simulations indicate many scenarios having a significant decrease in available water. Land-use planners can use such results in tandem with multiobjective optimization models to generate alternative land-use plans and show trade-offs among objectives.     

Water Resource Availability in Three Catchments of Swaziland under Expected Climate Change

Abstract

The greenhouse gases (CO₂, CH₄, N₂O, HFCs, PFCs, and SF₆) concentrations in the atmosphere have increased very much since the industrial revolution. The greenhouse gas effect has been projected to cause a global average temperature increase on the order of 1.4 to 5.8°C over the period of 1990 to 2100. The global average annual precipitation is projected to increase during the 21^st century due to the greenhouse effect. The impact of climate change on hydrology and water resources in the three catchments of Swaziland (Komati, Mbuluzi and Ngwavuma) has been evaluated using General Circulation Model results (rainfall, potential evapotranspiration, air temperature etc.) as inputs to a rainfall runoff model. Three General Circulation Models (GCMs) namely: Canadian Climate Change Equilibrium (CCC-EQ); Geophysical Fluid Dynamics Laboratory (GFDL) and United Kingdom Transient Resilient (UKTR) were found appropriate for use to project the temperature and precipitation changes for Swaziland for year 2075. This information was used to generate the temperature, precipitation and potential evapotranspiration values for the three catchments for year 2075 which was input into a calibrated WatBall rainfall runoff model. Simulation results without taking into consideration of water use projections show that there will be high flows during the summer months but low flows during the winter months. Simulation results after taking into consideration of water use projections show a water deficit from June to September in both the Komati, and Ngwavuma catchments and a water deficit from May to September in the Mbuluzi catchment. This means that the environmental water needs and Swaziland's water release obligation in the three catchments to South Africa and Mozambique will not be met during the winter months under expected climate change conditions.     

Performance Indexes Analysis of the Reservoir-Hydropower Plant System Affected by Climate Change

Assessing the effects of climate change phenomenon on the natural resources, especially available water resources, considering the existing constraints and planning to reduce its adverse effects, requires continuous monitoring and quantification of the adverse effects, so that policymakers can analyze the performance of any system in different conditions clearly and explicitly. The most important objectives of the present research including: (1) calculating the sustainability index for each demand node based on the characteristics of its water supply individually and also calculating the sustainability index of the whole water supply system, (2) investigation the compatible of changes trend among various reservoir performance indexes and (3) evaluation the changes in performance reservoir indexes in the future time period compared to the baseline tie period under three Concentration Pathway (RCP) RCP2.6, RCP4.5 and RCP8.5 scenarios for all water demand nodes and the entire water supply system. To this end, first, climatic parameters data affecting on the water resources such as temperature and precipitation were gathered in the baseline period (1977–2001) and the climatic scenarios were generated for the future period (2016–2040) using the Fifth Assessment Report (AR5) of the International Panel on Climate Change (IPCC). Then, the irrigation demand changes of the agricultural products with the Cropwat model and the value of inflow to the reservoir with the Artificial Neural Network (ANN) model were calculated under the climate change effects. In the next step, the climate change effects on the water supply and demand were simulated using Water Evaluation and Planning model (WEAP), and its results were extracted so as the water management indexes. The results show that the temperature will increase in the future period under all three RCP scenarios (RCP2.6, RCP4.5 and RCP8.5) compared to the baseline period, while precipitation will decrease under the RCP2.6 scenario but will increases under RCP4.5 and RCP8.5 scenarios. Under the trend of changing in temperature and rainfall, the irrigation demand in the agricultural sector in all scenarios will increase compared to the baseline period. However, the inflow of reservoir will decrease under the RCP2.6 and RCP4.5 scenarios and will increases under RCP8.5 scenario. Evaluation of WEAP modeling results shows that the sustainability index of the entire Marun water-energy system will decrease in the future period compared to the baseline period under the RCP2.6, RCP4.5 and RCP8.5 scenarios by 13, 10 and 8%, respectively. The decrease in the system sustainability index shows that in the absence of early planning, the Marun water-energy supply system will face several challenges for meeting the increasing demand of water in different consumer sectors in the coming years.

     

On the Barriers to Adaption to Less Water under Climate Change: Policy Choices in Mediterranean Countries

Barriers and constraints to adapting water resources management to climate change in the Mediterranean region are analysed in this paper. First, we analysed the risks to the water resources sector derived from climate change. We then identified the main objective of water adaptation measures: ensuring there is enough water for food, for people, and for ecosystems. This implies visions about availability - being sufficient water -, accessibility - both physical and economic access -, and adequacy - being safe for ecosystems and human consumption. A portfolio of local and collective actions to adapt water management for agriculture to climate change in Mediterranean countries is presented. Adaptation strategies included improved efficiency, optimisation of governance, enhancement of participation, development of risk-based choices, and economic instruments. Finally, the paper categorised the constraints to implement the measures, give specific examples about these issues and also quantify their impact. When considering constraints and opportunities to implement these water management practices, any environmental policy regulating their adoption should be based on recommending the use of extension and training to local actors on the application of the practices.     

Water Law and Planning Frameworks Under Climate Change Variability: Systemic and Adaptive Management of Flood Risk

Climate change is predicted to bring more extreme climatic variability to Australia. Yet recent reforms to Australian water law and governance have typically focused on water scarcity, not floods. In the summer of 2010/2011, devastating floods in a major urban centre and in regional areas were powerful reminders of the need for more systemic and adaptive responses for water resources management. Using Queensland and Victoria as case studies, the article demonstrates how the water law frameworks in both states assume ‘stationarity’ through the adoption of standards such as the 1:100 year flood event probability—an assumption that climate change has rendered unreliable. The article then examines the consequences of reliance on these past modes, particularly in respect of land use planning measures for flood risk adaptation. Finally, this article considers systemic responses for improved flood management focussing on strategic government planning, driven in part by potential litigation in the courts, as well as more local ‘autonomous’ adaptation in community-based initiatives.     

气候变化下水资源适应性对策的定量评估方法

论述了气候变化背景下水资源管理所面临的主要问题和适应性管理的基本内涵,介绍了应对气候变化影响的水资源适应性管理的国内外研究进展,梳理归纳了目前分析评价适应性管理对策的几种不同方法,认为定量分析适应性对策的经济效益至为关键,成本效益分析的步骤主要包括:①点绘实物量基线曲线;②点绘经济量基线曲线;③点绘过去适应性管理变化曲线;④分析气候变化引发的变化;⑤适应性管理获得的效益变化。     

中国东部季风区水资源脆弱性评价

以中国东部季风区的八大流域为例,从水资源供需安全的角度,对2000年水资源状况和未来气候变化情景下的水资源脆弱性进行了评价。结果表明:海河流域是中国水资源的严重脆弱区,黄河和淮河均处于高度脆弱状态,辽河流域、松花江流域、长江流域、东南诸河和珠江流域绝大部分地区处于中度脆弱状态;未来气候变化使得中国东部季风区八大流域的水资源脆弱性均明显加重,黄淮海流域均上升到严重脆弱状态,对气候变化极度敏感,必须采取相应措施来积极应对气候变化对流域水资源的不利影响。     

Characterisation of the Sensitivity of Water Resources Systems to Climate Change

This paper offers a methodology that enables characterisation of the behaviour of water resources systems under the impact of climate change through assessment of sensitivity patterns in a wide range of hydrologic variations produced by such change. Analysis is based on the application of two indicators that, in turn, draw on the results of a system optimisation model. Under this methodology the potential sensitivity of water resources systems in the cases of different climate projections are visualised, allowing those systems that require special attention in their adaptation to climate change to be identified. The methodology is applied to three basins located in Spain: Guadalquivir, Ebro and the Spanish part of the international basin Duero.     

Water Conflict Management between Agriculture and Wetland under Climate Change: Application of Economic-Hydrological-Behavioral Modelling

Water Resources Management - Water resources at the basin level are affected by climate change in the form of available water scarcity and multiple droughts leading to conflicts among different...