The effect of climate change on stream-flow and groundwate

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TECHNOLOGY NEEDS ASSESSMENT

• ADAPTING TO CLIMATE CHANGEWATER RESOURCES
• Wednesday 29 June 2005

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IPCC TARPREDICTIONS

• The effect of climate change on stream-flow and
  groundwater recharge varies regionally and
  between scenarios, largely following projected
  changes in precipitation. In some parts of the
  world, the direction of change is consistent
  between scenarios, although the magnitude is not.
  In other parts of the world, the direction of
  change is uncertain.
• Water quality is likely generally to be degraded
  by higher water temperature, but this may be
  offset regionally by increased flows. Lower flows
  will enhance degradation of water quality.

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IPCC TARPREDICTIONS

• Flood magnitude and frequency are likely to
  increase in most regions, and low flows are
  likely to decrease in many regions.
• Demand for water generally is increasing as a
  result of population growth and economic
  development, but it is falling in some countries.
  Climate change is unlikely to have a large effect
  on municipal and industrial demands but may
  substantially affect irrigation withdrawals.

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IPCC TARPREDICTIONS

• The impact of climate change on water resources
  depends not only on changes in the volume,
  timing, and quality of streamflow and recharge
  but also on system characteristics, changing
  pressures on the system, how the management of
  the system evolves, and what adaptations to
  climate change are implemented.
• Non-climatic changes may have a greater impact on
  water resources than climate change.
• Unmanaged systems are likely to be most
  vulnerable to climate change.

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IPCC TARPREDICTIONS

• Climate change challenges existing water
  resources management practices by adding
  additional uncertainty. Integrated water
  resources management will enhance the potential
  for adaptation to change.
• Adaptive capacity (specifically, the ability to
  implement integrated water resources management),
  however, is distributed very unevenly across the
  world.

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IPCC TARPREDICTIONS

• Global average temperature increased by 0.6 C
  over the last century, while sea levels rose by 9
  to 20 cm.
• The IPCC projects increases in the global average
  surface temperature by between 1.4C and 5.8C
  and in sea level by between 9 and 88 cm.
• Sea level rise in combination with hurricane
  landfalls presents one of the greatest
  climate-related hazards in tropical Latin America

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STRESSES

• Changing land-use and land-management practices
  (such as the use of agrochemicals) are altering
  the hydrological system, often leading to
  deterioration in the resource baseline.
• Changing demands generally are increasing
  pressures on available resources, although per
  capita demand is falling in some countries.
• The objectives and procedures of water management
  are changing too In many countries, there is an
  increasing move toward sustainable water
  management and increasing concern for the needs
  of the water environment

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Guide for Assessing Vulnerability

• General tools
• IPCC Guidelines on the Use of Scenario Data for
  Climate Impact and Adaptation Assessment
• Improves the consistency in the selection,
  interpretation, and application of scenarios
  (climate, socioeconomic, and environmental) in
  climate impact and adaptation assessments.
• User support is provided by IPCC Data
  Distribution Centre, which was established to
  make freely available a number of global data
  sets of baseline and scenario information on
  climatic, environmental, and socioeconomic
  conditions.

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Guide for Assessing Vulnerability

• General tools
• IPCC Guidelines on the Use of Scenario Data for
  Climate Impact and Adaptation Assessment
• The guidelines have four main objectives
• introduce and describe the information and
  analytical tools being provided by the Data
  Distribution Center,
• offer guidance on how to interpret the baseline
  and scenario data held by the DDC and elsewhere,
• highlight and illustrate the key steps and
  procedures commonly required in applying a
  baseline and scenario data in impact and
  adaptation assessment, and
• suggest standards for reporting the results.

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Guide for Assessing Vulnerability

• Climate downscaling techniques
• Downscaling is a method for obtaining
  high-resolution climate or climate change
  information from relatively coarse-resolution
  global climate models (GCMs). Typically, GCMs
  have a resolution of 150-300 km by 150-300 km.
  Many impacts models require information at scales
  of 50 km or less, so some method is needed to
  estimate the smaller-scale information.
• Statistical Downscaling
• Statistical downscaling first derives statistical
  relationships between observed small -scale
  (often station level) variables and larger (GCM)
  scale variables, using either analogue methods
  (circulation typing), regression analysis, or
  neural network methods.

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Guide for Assessing Vulnerability

• Climate downscaling techniques
• Statistical DownScaling Model (SDSM)
• SDSM is a user-friendly software package designed
  to implement statistical downscaling methods to
  produce high-resolution monthly climate
  information from coarse-resolution climate model
  (GCM) data. The software also uses weather
  generator methods to produce multiple
  realizations (ensembles) of synthetic daily
  weather sequences.
• Dynamical Downscaling
• Dynamical downscaling uses a limited-area,
  high-resolution model (a regional climate model,
  or RCM) driven by boundary conditions from a GCM
  to derive smaller-scale information. RCMs
  generally have a domain area of 106 to 107 km2
  and a resolution of 20 to 60 km.

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Guide for Assessing Vulnerability

• MAGICC/SCENGEN
• MAGICC/SCENGEN is a user-friendly software
  package that takes emissions scenarios for
  greenhouse gases, reactive gases, and sulfur
  dioxide as input and gives global-mean
  temperature, sea level rise, and regional climate
  as output
• Weather generators
• Weather generators are statistical models used to
  generate realistic daily sequences of weather
  variables precipitation, maximum and minimum
  temperature, humidity, etc
• They are often used in conjunction with other
  techniques.

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Guide for Assessing Vulnerability

• Socioeconomic scenarios
• Developing Socioeconomic Scenarios Downscaling
  from the Special Report on Emissions Scenarios
  and Using Proxy Variables/Indicators
• Adoption of Existing Socioeconomic Scenarios
• Qualitative and Quantitative Scenarios
  Emphasizing Stakeholder Input

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Adaptation to Climate Change

• Water management is based on minimization of risk
  and adaptation to changing circumstances
  (usuallAy taking the form of altered demands). A
  wide range of adaptation techniques has been
  developed and applied in the water sector over
  decades.
• One widely used classification distinguishes
  between increasing capacity (e.g., building
  reservoirs or structural flood defenses),
  changing operating rules for existing structures
  and systems, managing demand, and changing
  institutional practices.

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Adaptation to Climate Change

• The first two often are termed supply-side
  strategies, whereas the latter two are
  demand-side. Over the past few years, there has
  been a considerable increase in interest in
  demand-side techniques.
• International agencies such as the World Bank
  (World Bank, 1993) and initiatives such as the
  Global Water Partnership are promoting new ways
  of managing and pricing water resources to manage
  resources more effectively (Kindler, 2000).

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Adaptation Tools

• Water Sector Tools for assessing water resource
  adaptations to climate change, focusing on
  regional water supply and demand analysis of
  managed water systems.
• WaterWare 
• This UNIX based software package is an advanced
  water resource simulation tool that incorporates
  numerous models and analyses for easy access to
  advanced tools of data analysis, simulation
  modeling, rule -based assessment, and
  multi-criteria decision support for a broad range
  of water resources management problems.

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Adaptation Tools

• Water Evaluation and Planning System (WEAP)
• Is a PC based surface and groundwater resource
  simulation tool, based on water balance
  accounting principles, which can test alternative
  sets of conditions of both supply and demand. The
  user can project changes in water demand, supply,
  and pollution over a long-term planning horizon
  to develop adaptive management strategies.
• RiverWare
• A general UNIX based river and reservoir modeling
  application with both operational and planning
  applications. This system offers multiple
  solution methodologies that include simulation,
  simulation with rules, and optimization.
  RiverWare can accommodate a variety of
  applications, including daily scheduling,
  operational forecasting, and long-range planning.

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Adaptation Tools

• Interactive River and Aquifer Simulation (IRAS)
• This tool is a PC based surface water resource
  simulation tool, based on water balance
  accounting principles that can test alternative
  sets of conditions of both supply and demand. The
  river system is represented by a network of nodes
  and links, with the nodes representing aquifers,
  gauges, consumption sites, lakes, reservoirs,
  wetlands, confluences, and diversions.
• Aquarius
• A computer model depicting the temporal and
  spatial allocation of water flows among competing
  traditional and nontraditional water uses in a
  river basin. The model focuses on optimization of
  a nonlinear system, where supplies and requested
  demands are prescribed on the system.

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Adaptation Tools

• RIBASIM
• RIBASIM is a generic model package for simulating
  the behavior of river basins under various
  hydrological conditions. The model package is a
  comprehensive and flexible tool that links the
  hydrological water inputs at various locations
  with the specific water users in the basin.
  RIBASIM enables the user to evaluate a variety of
  measures related to infrastructure and
  operational and demand management, and to see the
  results in terms of water quantity and flow
  composition.
• MIKE BASIN
• For addressing water allocation, conjunctive use,
  reservoir operation, or water quality issues,
  MIKE BASIN couples the power of ArcView GIS with
  comprehensive hydrologic modeling to provide
  basin -scale solutions. The MIKE BASIN philosophy
  is to keep modeling simple and intuitive, yet
  provide in-depth insight for planning and
  management.

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Adaptation Tools

• SPATIAL TOOLS FOR RIVER BASIN ENVIRONMENTAL
  ANALYSIS AND MANAGEMENT (STREAM)
• STREAM is a spatial hydrological model that
  allows for assessing hydrological impacts due to
  changes in climate and socio economic drivers.
• STREAM is set up according to a policy analytic
  framework and ensures a structured approach for
  an entire river basin including the coastal zone.
  
• STREAM uses hydrological input data, scenarios,
  adaptive strategies and provides output data on
  water availability and (salt water) quality.
• It integrates within this frame several types of
  interactions between effects of river management
  on the coastal zone, land and water uses such as
  short term deforestation and dam building, and
  long term impacts of climate change.

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LAST WORDS

• Scientists have documented climate-change induced
  changes in some 100 physical and 450 biological
  processes.
• In the Russian Arctic, higher temperatures are
  melting the permafrost, causing the foundations
  of five-story apartment buildings to slump.
• Worldwide, the rain, is often more intense.
  Floods and storms are more severe, and heat waves
  are becoming more extreme.
• Rivers freeze later in the winter and melt
  earlier. Trees flower earlier in spring, insects
  emerge faster and bird lay eggs sooner.
• Glaciers are melting. The global mean sea level
  is rising.The rate of climate change expected
  over the next 100 years is unprecedented in human
  history.
• http//www.unep.org/themes/climatechange/