of 21/21
AGRON / MTEOR 404 Global Change Changes to Water Resources Raymond Arritt Department of Agronomy

AGRON / MTEOR 404 Global Change

  • View

  • Download

Embed Size (px)


AGRON / MTEOR 404 Global Change. Changes to Water Resources Raymond Arritt Department of Agronomy. Effects of water resources. erosion Timing in crop growth cycle Runoff – wastewater treatment, pollution Groundwater depletion, subsidence Distribution of rainfall, shifting patterns - PowerPoint PPT Presentation

Text of AGRON / MTEOR 404 Global Change

  • AGRON / MTEOR 404Global ChangeChanges to Water ResourcesRaymond ArrittDepartment of Agronomy

  • Effects of water resourceserosionTiming in crop growth cycleRunoff wastewater treatment, pollutionGroundwater depletion, subsidenceDistribution of rainfall, shifting patternsHydropower (energy)Distribution of ecosystems; desertification

  • Effect on flood plainsWater ownership who gets to use it?Ecology and biodiversity new species introduced, take over and lose diversityShift in rainfall patterns (wet and dry regions)Sustainable development building

  • Irrigation systems change in demandEnergy production cooling water for powerplants and industryWater conservation awarenessSnowmaking for ski areasDams and storageGlaciersHow do we get people to understand?

  • IPCC Fourth Assessment Report Summary for Policy Makers

  • A simple surface water budgetPrecipitation Evaporation = Runoff + D Storagestorage includes lots of things:soil moisture, aquifers, reservoirs, withdrawals for irrigation, glaciers, snowpack, etc.

  • IPCC Fourth Assessment Report Summary for Policy Makers

  • Change in annual runoff2041-2060 compared to 1900-1970Where do we see increases in runoff?Where do we see decreases?

  • Predicted changes in groundwater recharge

  • Some observed effects on water resources

  • Predicted effects of climate change on water resources

  • Fastest growing states

  • Water resource stress without climate changeCurrent2055 (IPCC A2 scenario)

  • Change in water resource stress with climate changereduced water stress in tropical regionsincreased water stress outside the tropicsresults from two different climate models

  • What is drought?One definition:

    Elements of the definition:deficiency of precipitationextended period (how long is "extended"?)water shortage for some user ("group or activity") A deficiency of precipitation over an extended period that causes water shortage for some group or activity.

  • Drought depends on the user

    Crops rely on stored soil water. Soil water can be rapidly depleted, so that monthly droughts may affect crops.

  • Drought depends on the user

    Rivers and streams may dry out during seasonal droughts.

  • Drought depends on the user

    Multi-year droughts may deplete ground water that supports communities.

  • Drought, more preciselyMust define the time period over which precipitation is below normal.Must define what is a water shortage that affects a particular activity.

  • Iowa corn yields1988 drought1993 flood

  • RememberChanges to water resources depend on more than just the change in rainfall.Whether a change is good, bad, or neutral depends on who we are and what were interested in.