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    CTL and Drought - Part 2
The Hydrograph Story

The water level in rivers and streams is a good recorder of current weather events like a sudden thunderstorm to long term drought conditions due to lack of precipitation. A hydrograph [see right image], a graph that represents streamflow or averaged flow rates over a period of time, may provide a visual clue to the climate patterns around us. Explore the hydrograph page in the Climate Science for 1 Year section.

Some inquiry questions to ponder when viewing the hydrograph page are:

  • What patterns do you find in all of the hydrographs represented?
  • What weather, climate and seasonal patterns are represented by the streamflow patterns?

Water Deficits

When a geographical location has a means to record levels of precipitation and evapotranspiration, one can devise a "budget" to determine water surpluses or deficits on a monthly and annual basis. CTL offers a water budget study in the Boulder Watershed in Colorado, USA. The Water Budget Page compares two areas separated by 25 miles and differing by almost 5,000 feet in elevation. Inquiry exercises make use of water budget graphs and tables to assess when water shortfalls occurs.

Comparing Different Decades

The hydrographs on the Comparing Different Decades page show streamflow data from five different decades beginning with the 1920's.

This longer time-frame of water data offers an opportunity to examine "outside" influences such as ENSO that periodically inflicts drought conditions on large geographical regions. For more about ENSO, view the Climate Science for 10 Years and Climate Resource for 10 Years pages.


Drought History
Explore Climate Summary pages to find out about significant drought events or periods. In particular, viewsummary pages from the 10, 100, 1000 and 10,000 year sections. For inquiry purposes, when did these droughts occur and what impact did they have on human civilization?

The Climate History for 100 Years has a special section on drought. Here, you will find a reconstruction of precipitation of Northwest New Mexico that compares more recent drought periods to ones occuring over the past 2,000 years. Additionally, visit NOAA's Paleo Perspective: North American Drought page for more information about how paleoclimatic data gives clues to dry periods of the past and why we should care about droughts.

The Climate History for 1000 Years has a special focus on the Climate and Culture of the American Southwest. The main question addressed in this section is whether extended drought was really severe enough to force the cliff dwellers [the Anasazi, the Ancient Ones] away from the region? You will find an interesting discussion pertaining to the question of drought and how it can impact human culture.

Lastly, you can scan the Climate History Timeline for all drought events and periods.

Click the Drought Button to Continue

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