Changing the Hydrological Cycle in US Midwest

© 2003 Eugene S. Takle

The landscape of north central Iowa before the European settlement of the mid to late 1800s consisted on prairie pot holes with seasonal standing water. Iowa has almost 12,000,000 acres (4,500,000 hectares) of poorly drained soil. This soil provides rich and productive farm land and has been drained by the use of agricultural drainage tile installed at 100 ft intervals across fields. Therefore, approximately 1 million miles of drainage tile underlies Iowa's poorly drained soils. By adding to this the length of tile underlying soils that are marginally drained, I estimate that there are about 1.3 million miles of drainage tile in the state. Northern Illinois has similar poor drainage, as do parts of Indiana, Ohio, southern Minnesota, and northern Missouri. Adding contributions from these states, we likely have over 3 million miles of drainage tile underlying the Midwest. Laid end to end, this tile would stretch from the Earth to the Moon and back 6 times. This massive tile system eliminates, or reduces the time period for, standing water on the surface over large regions, which, in turn leads to less surface evaporation and higher daytime surface temperatures. It might be argued that this hydrological change to the landscape rivals the Three Gorges Dam in China for the scale of impact.

For more information refer to:

http://ohioline.osu.edu/aex-fact/0320.html