Programme  OS3c Climate change: detecting trends, projecting future  abstract 80

Comparative Study Climatic Changes with Contemporary Basin River Changes in Iran

Author(s): Manijeh Ghohroudi Tali, Mahnaz Khademi
Dr. Manijeh Ghohroudi Tali Assistant of professor Tarbiat Moallem University , Mahnaz Khademi Architect student, Azad Eslami University, Tehran, Iran

Keyword(s): Climatic changes, River basins, Mann-Kendall, Urmia Lake, Iran

Article: abs80_article.pdf
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Session: OS3c Climate change: detecting trends, projecting future
AbstractUnderstanding climatic changes by

means of trend determination and study of major climatic parameters, particularly rainfall and temperature, and their

comparison with records of climatic changes in the past can reveal patterns of changes. The present study

investigates changes in climatic elements such as precipitation, maximum temperature and minimum temperature by

Mann-Kendall model in Iran .
Spatial comparison tables were prepared and the changeability of climatic

elements were modeled on the basis of the region of highest changes in climatic elements and the zoning of climatic

elements by geostatistic methods. Taking into account the significance of seasonal changes in Iran and the effect of

the two seasons of spring and winter on the water resources of the country, changes arising from these two seasons

were investigated. Then, using the Cokriging method, the relationship between these changing variables were defined

on the basis of the regression model, and the relevant tests were conducted. The models obtained show that Iran

should expect a climate which has not been experienced by her at least during the past 50,000 years, and that its

changes are not separate from global climatic changes.

Y = -0.59-0.01X (Precipitation

changes in spring)
Y = -0.382-0.02X (Precipitation changes in winter)
Y = -0.797-0.007X

(Minimum temperature changes in spring)
Y = -0.607+0.019X (Minimum

temperature changes in winter)
Y = -0.782-0.016X (Maximum temperature changes in spring)

Y = -0.479-0.04X (Maximum temperature changes in winter)

As northwest Iran experiences

higher climatic changes, Urmia Lake basin was investigated as the sample basin. ETM satellite images were used for

reconnaissance of surfaces of changes and SRTM satellite images for determining the height of surfaces of changes

arising from climatic change. The supervised classification was conducted on the basis of the sampling of lakeside

surfaces, which clearly reveald the existence of four surfaces in the lake. Based on the studies conducted on these

surfaces and the climatic changes concerned, it was concluded that each surface of the lake is proof of long-term

climatic changes. Smaller and waterside surfaces indicate short-term climatic mutations and variations. Given the

results of the study, it can be predicted that water resources in Iran will face more serious problems in a way that the

natural strength of Iran to preserve and provide water resources will gradually subside. In other words, water

resources in Iran will encounter waste through increase of floods and evaporations.

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