1 / 36

Meteorology Precipitation Evaporation Transpiration Evapotranspiration

Meteorology Precipitation Evaporation Transpiration Evapotranspiration. Systems science An approach to hydrological studies in this unit. Evapotranspiration. Precipitation. Interception. Pond Storage. Throughfall. Interception Storage. Overland Flow. Infiltration.

mmike
Télécharger la présentation

Meteorology Precipitation Evaporation Transpiration Evapotranspiration

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Meteorology Precipitation Evaporation Transpiration Evapotranspiration

  2. Systems science An approach to hydrological studies in this unit

  3. Evapotranspiration Precipitation Interception Pond Storage Throughfall Interception Storage Overland Flow Infiltration Soil moisture storage Interflow Channel storage Runoff Throughflow Groundwater recharge Groundwater discharge Return flow Groundwater storage Baseflow

  4. Koeppen classification BoM => Climate Services => Climate data online => Climate maps

  5. Precipitation • Definition: • All forms of moisture being released from the atmosphere • Snow, hail, sleet, drizzle, rainfall • Rainfall primary mechanism for Australia/Jordan

  6. Precipitation BoM => Satellite => Full disk Satellite images

  7. Precipitation 3 40 /m 3 30 20 Saturation level Amount of water vapour cm 10 10 20 0 30 o Air Temperature C

  8. Cloud formation Precipitation Convection Warm air rises from warm land mass Frontal Warm air rises over cold front Orographic Warm air rises over topographic high

  9. What controls where rain falls? • Highly variable distribution • At all scales – country to backyard variation • Altitude, aspect, slope, ocean temperature Cooler air Weather direction Measurement, angle of rain

  10. About Units... Some hydrologic processes are measured by depth and others by volume. Rainfall and evaporation are measured by depth (usually millimetres) One cubic metre (m3) = 1000 litres One millimetre depth over one hectare = 10m3 10cm depth over one hectare = 1000m3 = 1Megalitre (ML) Rainfall and evaporation are also by rate (mm/hour, mm/day, mm/year)

  11. Measuring precipitation

  12. Measuring precipitation World Meteorological Organisation (WMO) Standard rain gauge Pluviometer

  13. Tipping Bucket Rain Gauge

  14. Data logger connects to computer and www or phone line or telemetry Automated temporal measurement

  15. Automated recording of several measurements Phone or telemetry reading

  16. Optical rain gauge Measures intensity by rainfall passing through a light beam

  17. Radar • Temporal distribution • - Intensity • Duration • Spatial distribution • Aerial • Virga? or fall? • Fire? Insects?

  18. Evaporation Pan

  19. Pan Evaporation conversion to Evapotranspiration Pan reading over 24 hours (minus rainfall input) ET = Pan reading x Pan factor Pan factor ~ 0.5 to 0.8 usually ~ 0.75

  20. Transpiration • Type and age of plant: • Leaf area • Leaf orientation • Leaf surface • Stomata • Environment: • Humidity • Temperature • Light intensity • Wind • Soil moisture

  21. Measuring eddies Porometer Sap flow Ventilated chamber

  22. Porometer Portable, widely used in horticultural industry and reasonably easily calibrated

  23. Sap flow measurement Uses thermocouple device Measures sap flow in both directions Xylem (flows up) Phloem (flows down) Widely used in forestry industry

  24. Interception, Interception storage, Stem flow, Throughfall (the hard ones to accurately measure)

  25. Stem flow is measured using interceptor drains around the trunk, Throughfall is measured using rain gauges under the tree canopy

  26. Lysimeters

  27. Direct measurements Weight changes Deep drainage

  28. ET = Si + PR + IR –Sf - DE ET = Evapotranspiration in a given time period Si = Initial soil water volume Sf = Final soil water volume PR = Precipitation into lysimeter IR = Irrigation water into lysimeter DE = Drainage of water from lysimeter Hydrologic equation I – O = ΔS

More Related