Al Busayta

Photo Credit: Google EartH

Al Busayta Agriculture Fields: Central Pivot Irrigation Saudi Arabia Lulu Almana | Landscape Analysis | Spring 2011 | Columbia University

Location://

Photo Credit: Google EartH

Background:// Global land under irrigation increased from 131 million acres in 1901 to 704 million acres in 2002. (Puma, 2010)

Significant temperature repression in heavily irrigated regions in India “cooled by as much as 5 degrees.� (Puma, 2010)

My studied landscape consists of ir-rigated agriculture that depends ex-clusively on ground water. It consumes about 80-90% of the total water con-sumption in Saudi Arabia.

In 2004 research, it was expected that there will be 25% depletion of ground water resources by 2010 in the country because of irrigated agriculture.

Crops? Alfalfa, Potato, Tomato, Wheat.

Background:// The fields are able to flourish in the arid region due to center-pivot irrigation, also called circle irrigation, a method of crop irrigation in which equipment rotates around a pivot.

Central pivot irrigation is a form of overhead (sprinkler) irrigation consisting of several segments of pipe (usually galvanized steel or aluminium) joined togeth-er and supported by trusses, mounted on wheeled towers with sprinklers positioned along its length. The machine moves in a circular pattern and is fed with water from the piv-ot point at the center of the circle. Fossil water is mined from depths as great as 3,000 • and pumped to the surface, and distributed through these pivot points.

Photo Credit: Google Earth user monzir84

Photo Credit: NASA

Question://

What changes occurred during the last 20 years in the size and density of the irrigated agricultural fields?

Data:// - Idrisi Native File (.rst) - True Composite (.rst) - ascii (.asc)

GeoTIFF Landsat ETM+

2000

1990 Landsat TM GeoTIFF

- Idrisi Native File (.rst) - True Composite (.rst) - ascii (.asc)

2006 Landsat ETM+ GeoTIFF - Idrisi Native File (.rst) - True Composite (.rst) - ascii (.asc)

Data://

1990 Landsat TM GeoTIFF

- Idrisi Native File (.rst) - True Composite (.rst) - ascii (.asc)

Data://

2000 Landsat ETM+ GeoTIFF

- Idrisi Native File (.rst) - True Composite (.rst) - ascii (.asc)

Data://

2006 Landsat ETM+ GeoTIFF

- Idrisi Native File (.rst) - True Composite (.rst) - ascii (.asc)

Analysis:/visual/supervised classifications/ 1990

Legend: Agriculture Desert

Analysis:/visual/supervised classifications/ 2000

Legend: Agriculture Desert

Analysis:/visual/supervised classifications/ 2006

Legend: Agriculture Desert

Analysis:/quantitative/fragstats metrics/

Percentage of Land: 8.478%

Number of Patches: 225

METRICS

Total Area: 866923.62

2000

1990 METRICS

2006 Number of Patches: 32 Total Area: 75118.4233

Percentage of Land: 0.9661%

??

Limitations://

Some Fragstats results don’t sound correct (contagion can’t be 100 for all).

Couldn’t get ascii file for 2006 (maybe because of rel-atively big number of rows & columns?)

In supervised classification, high moisture desert got picked up as crops.

In 2006, classification of agriculture class became less defined because the fields increased in density (not as clear as 1990 & 2000).

Conclusion://

The increase is clear from 1990 to 2006 Concerns of fossil water depletion.

There is a significant need to revise these irrigation patterns with irrigation manage-ment strategies and assessing water conser-vation programs in the area.

Photo Credit: World Bulletin

If irrigation has to be reduced in these areas, temperatures could jump, the scientists say, and downwind rain-fall might decline. How serious those problems would seem in comparison to the accompanying food shortages?

Photo Credit: Google EartH

Thank you!

Lulu Almana | Landscape Analysis | Spring 2011 | Columbia University