Transcript Ppt - WMO
Integrating climate and weather products in Water Resources Management by Francis Mutua University of Nairobi Climate and Water Resources The climate of the Earth is controlled mainly by the energy from the sun • Atmosphere • Hydrosphere • Lithosphere • Biosphere Anthropogenic forces change the equilibrium SUN’S ENERGY THE CLIMATE SYSTEM ATMOSPHERE + STRATOSPHERE Moisture Pressure Temperature Energy/dynamics G.H. gases Etc LAND Terrestrial water resources Topography Glaciers + Ice-caps Bio-systems Etc OCEANS Temperature Salinity Energy/dynamics Glaciers + icecaps Bio-systems Etc Climate variability • Climate variability is strongly linked to variations in the the solar output – variability with time-scales > 1 yr. etc. Examples: ENSO (3-6 yrs), sunspot activity (11 yrs), QBO (2 yrs), • The oscillation of the earth around the sun (Time-scale = seasons): Seasonality: notably in precipitation, temperature humidity and evaporation • The combination yields seasons NORMALABN in precipitation : BNNEAR- • Climate variability introduces a corresponding variability in the hydrological cycle Climate Variability and Water Resources • Hence climate variations have significant consequences on the quality and quantity of water in all hydrological regimes. • Climate variability is the major cause of the extremes which are observed in hydrological systems: floods and droughts • Thus floods (quick onset) and droughts (slow onset) hazards are part of the climate systems and therefore unavoidable • However, they need not become disasters because it is possible to to be prepared for them (especially drought hazards) • Often, they turn into disasters – Famine and crop failure – Deaths (humans and livestock) – Adverse economic impacts and impoverishment – Conflicts • All because climate and weather information and products are not adequately factored into national disaster management. Climate Change • Climate change – The IPCC projections of air temperature change over the next century, following 2xCO2 is an increase of 1o to 3.5oC, with a "best estimate" of 2oC Ppt, Temp, winds, Press., Evp, etc. – The manifestation of climate change would imply that the water resources would respond with the corresponding irreversible trend (and perhaps higher variability) as with the climate. • Other forcings which exacerbate the impacts of climate change on water resources – population pressure – land use and land management Ordinarily exacerbate – agricultural and industrial developments water related disaster risks (floods+droughts) – domestic attitudes Now add climate change! – recreation demands, etc Scenarios for Assessing Impacts of climate change on Water Resources • Uncertainties – Future emissions (SRES story-lines) – Future concentrations (climate CO2 cycle chemistry physics) – Response of climate (Time lags) – Natural variability? – GCMs GCM/RCM Synthetic/Incremental Analoque Downscaling GCMRegional EMISSIONS Scenarios frompopulation, energy, economic models CONCENTRATIONS CO2, methane, sulphates, etc Carbon cycle and chemistry models Synthetic Climate Change Scenarios (Thresholds) GLOBAL CLIMATE CHANGE Global Climate Models (GCMs) Statistical Downscaling of GCMoutputs to Regional outputs Regional Climate Models (RCMs) (MM5, PRECIS, etc. Regional Climate Change Scenarios IMPACTS Analogue Climate Change Scenarios Integrating climate-change in water resources management CALIBRATION OF THE HYDROLOGIC SYSTEM MANAGEMENT Climate Input (Historical Data) Baseline characteristics Soils Geology Topography Vegetation Land-use etc Water Resources Characteristics (Historical Data) (Calibration and Verification of the Water Resources Model) (Use of the Calibrated Model to Assess Impacts of Climate Change on Water Resources) FACTORING CLIMATE CHANGE IN WATER RESOURCES SYSTEM MANAGEMENT Climate Change Scenarios as Input Basin scenarios Soils Geology Topography Vegetation Land-use etc Assessment of Impacts of Climate and Basin Change on Water Resources characteristic s Improved water resources management Plans for ground and surface water developments Coastal waters Hazards Integrating Climate and weather in Water Resources Management CLIMATE AND WEATHER PRODUCTS AND INFORMATION Climate variability (ENSO, Sunspot activity, SEASONAL Synoptics, QBOs, etc) OUTLOOKS Climate-Change (Scenarios) HYDROLOGY and/or Hydraulics (Modeling) Physical basin characteristics and scenarios Soils Land-use Vegetation and land cover etc Socio-economic factors +scenarios Hydrologic outlooks: Surface and groundwater deficit/excess (flood & drought hazards) Warnings, awareness and preparedness Early warning systems Climate integrated and improved water resources management with disaster risk mitigation strategies