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Evaluation of the effects of climate change on meteorological and hydrological parameters using climatic models and Mann – Kendall test (case study: Urmia Lake)

Abstract Climate change and increase of global temperature are important environmental issues on which various studies have been conducted in recent years. This issue has a high importance due to environmental, economic and social impacts because, human activities are based on climate stability. In this article, effects of climate change on meteorological and hydrological parameters of Urmia Lake watershed have been investigated and forecasted for period 2010-2100. In order to forecast meteorological parameters, Atmosphere General Circulation Model was used. Temperature, precipitation and evaporation data were downscaled and calibrated using LARS software by SDSM model and observed data. In continue, Artificial Neural Network (ANN) was used to simulate model of precipitation to runoff. The models outputs mostly showed increase of temperature and evaporation and decrease of precipitation in future periods. Also, the results of Mann-Kendall indicated that, climate change and global warming is not significant on long-term trend of hydrological factors affecting Urmia Lake. Therefore, the factors of rapid reduction of the lake water level in recent years should be explored among climatic fluctuations such as wet and drought, and human factors such as dam constructing, uncontrolled extraction of groundwater and unsuitable irrigation methods.

Abstract
Climate change and increase of global temperature are important environmental issues on which various studies have been conducted in recent years. This issue has a high importance due to environmental, economic and social impacts because, human activities are based on climate stability. In this article, effects of climate change on meteorological and hydrological parameters of Urmia Lake watershed have been investigated and forecasted for period 2010-2100. In order to forecast meteorological parameters, Atmosphere General Circulation Model was used. Temperature, precipitation and evaporation data were downscaled and calibrated using LARS software by SDSM model and observed data. In continue, Artificial Neural Network (ANN) was used to simulate model of precipitation to runoff. The models outputs mostly showed increase of temperature and evaporation and decrease of precipitation in future periods. Also, the results of Mann-Kendall indicated that, climate change and global warming is not significant on long-term trend of hydrological factors affecting Urmia Lake. Therefore, the factors of rapid reduction of the lake water level in recent years should be explored among climatic fluctuations such as wet and drought, and human factors such as dam constructing, uncontrolled extraction of groundwater and unsuitable irrigation methods.

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J. Bio. & Env. Sci. 2014<br />

40 years statistics <str<strong>on</strong>g>of</str<strong>on</strong>g> precipitati<strong>on</strong> <strong>and</strong> temperature.<br />

The results <str<strong>on</strong>g>of</str<strong>on</strong>g> this research showed that, <str<strong>on</strong>g>climate</str<strong>on</strong>g><br />

<str<strong>on</strong>g>change</str<strong>on</strong>g> in this regi<strong>on</strong> has not had tangible effect <strong>on</strong><br />

temperature but, it has caused to decrease<br />

precipitati<strong>on</strong>. Taghavi (2005) studied <str<strong>on</strong>g>the</str<strong>on</strong>g> trend <str<strong>on</strong>g>of</str<strong>on</strong>g><br />

temperature <strong>and</strong> precipitati<strong>on</strong> indices in 16 synoptic<br />

stati<strong>on</strong>s in order to detect <str<strong>on</strong>g>climate</str<strong>on</strong>g> <str<strong>on</strong>g>change</str<strong>on</strong>g> in various<br />

regi<strong>on</strong>s. Then it was c<strong>on</strong>cluded that, most <str<strong>on</strong>g>of</str<strong>on</strong>g> warm<br />

indices have increasing trend as well as decreasing<br />

trend for cold indices. Azizi et al., (2008) used<br />

multivariate statistical analysis <strong>and</strong> Box-Jenkins<br />

model in order to investigate <str<strong>on</strong>g>the</str<strong>on</strong>g> existence <str<strong>on</strong>g>of</str<strong>on</strong>g><br />

significant trend in temperature <strong>and</strong> humidity<br />

variables <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> western half <str<strong>on</strong>g>of</str<strong>on</strong>g> Iran. Seyf et al. (2009)<br />

in <str<strong>on</strong>g>the</str<strong>on</strong>g> <strong>study</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>climate</str<strong>on</strong>g> <str<strong>on</strong>g>change</str<strong>on</strong>g> <str<strong>on</strong>g>of</str<strong>on</strong>g> Sabzevar city in a 50<br />

year statistical period c<strong>on</strong>cluded that, mean annual<br />

precipitati<strong>on</strong> does not show a significant trend but,<br />

<str<strong>on</strong>g>the</str<strong>on</strong>g> data <str<strong>on</strong>g>of</str<strong>on</strong>g> mean annual temperature has a rising<br />

trend. Khosravi et al. (2010) investigated <str<strong>on</strong>g>the</str<strong>on</strong>g> effect <str<strong>on</strong>g>of</str<strong>on</strong>g><br />

<str<strong>on</strong>g>climate</str<strong>on</strong>g> <str<strong>on</strong>g>change</str<strong>on</strong>g> <strong>on</strong> water resources <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> Middle East<br />

<strong>using</strong> World Bank <strong>and</strong> IPCC. The results <str<strong>on</strong>g>of</str<strong>on</strong>g> this<br />

research explain that, according to IPCC <str<strong>on</strong>g>climate</str<strong>on</strong>g><br />

<str<strong>on</strong>g>change</str<strong>on</strong>g> scenario, <str<strong>on</strong>g>the</str<strong>on</strong>g>re will increase by 1 to 2 ⁰C <strong>and</strong><br />

precipitati<strong>on</strong> will decrease by 20%.<br />

Change in water level in <str<strong>on</strong>g>the</str<strong>on</strong>g> lakes is mostly due to<br />

<str<strong>on</strong>g>change</str<strong>on</strong>g> in river flows <strong>and</strong> <str<strong>on</strong>g>change</str<strong>on</strong>g> in precipitati<strong>on</strong> <strong>on</strong><br />

<str<strong>on</strong>g>the</str<strong>on</strong>g> lakes <strong>and</strong> evaporati<strong>on</strong> from <str<strong>on</strong>g>the</str<strong>on</strong>g>ir surface. Water<br />

level <str<strong>on</strong>g>of</str<strong>on</strong>g> a number <str<strong>on</strong>g>of</str<strong>on</strong>g> lakes has been dropped<br />

throughout <str<strong>on</strong>g>the</str<strong>on</strong>g> world during <str<strong>on</strong>g>the</str<strong>on</strong>g> past decades because<br />

<str<strong>on</strong>g>of</str<strong>on</strong>g> human activities (Khosravi et al., 2010).<br />

Atmosphere General Circulati<strong>on</strong> Models are threedimensi<strong>on</strong><br />

<strong>models</strong> which have been developed based<br />

<strong>on</strong> various <strong>climatic</strong> scenarios in order to simulate <str<strong>on</strong>g>the</str<strong>on</strong>g><br />

effect <str<strong>on</strong>g>of</str<strong>on</strong>g> greenhouse impact <strong>on</strong> current <str<strong>on</strong>g>climate</str<strong>on</strong>g> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g><br />

earth, those are able to forecast future <str<strong>on</strong>g>climate</str<strong>on</strong>g> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g><br />

earth (IPCC, 2007). One <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> main limitati<strong>on</strong>s in <str<strong>on</strong>g>the</str<strong>on</strong>g><br />

use <str<strong>on</strong>g>of</str<strong>on</strong>g> <strong>climatic</strong> outputs <str<strong>on</strong>g>of</str<strong>on</strong>g> general circulati<strong>on</strong> <strong>models</strong><br />

is that, <str<strong>on</strong>g>the</str<strong>on</strong>g> accuracy <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g>se <strong>models</strong> is about 200 km<br />

which is inappropriate for investigati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g><br />

mountainous regi<strong>on</strong>s <strong>and</strong> <strong>climatic</strong> <strong>parameters</strong> such as<br />

precipitati<strong>on</strong> <strong>and</strong> temperature. SDSM is <strong>on</strong>e <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g><br />

most famous generating <strong>models</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> r<strong>and</strong>om data <strong>on</strong><br />

wea<str<strong>on</strong>g>the</str<strong>on</strong>g>r, <strong>and</strong> is used to produce daily precipitati<strong>on</strong>,<br />

radiati<strong>on</strong>, minimum <strong>and</strong> maximum daily temperature<br />

in a stati<strong>on</strong> under current <strong>and</strong> future <strong>climatic</strong><br />

c<strong>on</strong>diti<strong>on</strong>s (Dehghanipoor et al., 2012). Downscaling<br />

algorithm <str<strong>on</strong>g>of</str<strong>on</strong>g> SDSM model has been used with much<br />

appropriate results in many <strong>meteorological</strong>,<br />

<strong>hydrological</strong> <strong>and</strong> envir<strong>on</strong>mental branches in<br />

geographical ranges from Europe, Nor<str<strong>on</strong>g>the</str<strong>on</strong>g>rn America<br />

<strong>and</strong> Sou<str<strong>on</strong>g>the</str<strong>on</strong>g>astern <str<strong>on</strong>g>of</str<strong>on</strong>g> Asia (Willy et al., 2002). The<br />

purpose <str<strong>on</strong>g>of</str<strong>on</strong>g> this <strong>study</strong> is to investigate <str<strong>on</strong>g>the</str<strong>on</strong>g> effect <str<strong>on</strong>g>of</str<strong>on</strong>g><br />

<str<strong>on</strong>g>climate</str<strong>on</strong>g> <str<strong>on</strong>g>change</str<strong>on</strong>g> <strong>on</strong> variati<strong>on</strong> trend <str<strong>on</strong>g>of</str<strong>on</strong>g> <strong>meteorological</strong><br />

<strong>and</strong> <strong>hydrological</strong> <strong>parameters</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> some stati<strong>on</strong>s located<br />

in <str<strong>on</strong>g>the</str<strong>on</strong>g> watershed <str<strong>on</strong>g>of</str<strong>on</strong>g> <strong>Urmia</strong> <strong>Lake</strong> <strong>using</strong> <strong>climatic</strong> <strong>models</strong><br />

<strong>and</strong> <strong>Mann</strong> <strong>Kendall</strong> <strong>test</strong>.<br />

Materials <strong>and</strong> methods<br />

Study area<br />

<strong>Urmia</strong> <strong>Lake</strong> is located in <str<strong>on</strong>g>the</str<strong>on</strong>g> northwest <str<strong>on</strong>g>of</str<strong>on</strong>g> Iran <strong>and</strong><br />

between Western <strong>and</strong> Eastern Azerbaijan provinces.<br />

This lake is <str<strong>on</strong>g>the</str<strong>on</strong>g> sec<strong>on</strong>d most saline lake <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> world<br />

after Bahrolmeyet in Palestine. Length <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> lake is<br />

13 to 140 km <strong>and</strong> its width is 15 to 85 km, its mean<br />

depth is 6 m <strong>and</strong> <str<strong>on</strong>g>the</str<strong>on</strong>g> height is 1274 m from sea level.<br />

Area <str<strong>on</strong>g>of</str<strong>on</strong>g> <strong>Urmia</strong> <strong>Lake</strong> has been reported by 5000 to<br />

5500 km 2 . <strong>Urmia</strong> <strong>Lake</strong> watershed has been placed<br />

between nor<str<strong>on</strong>g>the</str<strong>on</strong>g>rn latitude 35⁰ 29ʹ to 38⁰ 40ʹ <strong>and</strong><br />

eastern l<strong>on</strong>gitude 44⁰ 13ʹ <strong>and</strong> 47⁰ 53ʹ. The highest<br />

point <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>the</str<strong>on</strong>g> watershed is close to Sabalan<br />

mountaintop by 3850 m. Therefore, existing elevati<strong>on</strong><br />

difference in <str<strong>on</strong>g>the</str<strong>on</strong>g> watershed is estimated by 2576 m.<br />

C<strong>on</strong>sidering that <str<strong>on</strong>g>the</str<strong>on</strong>g> province has been located <strong>on</strong> <str<strong>on</strong>g>the</str<strong>on</strong>g><br />

path <str<strong>on</strong>g>of</str<strong>on</strong>g> air masses entrance from <str<strong>on</strong>g>the</str<strong>on</strong>g> west <strong>and</strong><br />

northwest, <strong>and</strong> existence <str<strong>on</strong>g>of</str<strong>on</strong>g> Zagros mountains in <str<strong>on</strong>g>the</str<strong>on</strong>g><br />

south <strong>and</strong> southwest, heights in <str<strong>on</strong>g>the</str<strong>on</strong>g> west <strong>and</strong> Ararat<br />

in <str<strong>on</strong>g>the</str<strong>on</strong>g> north, <str<strong>on</strong>g>the</str<strong>on</strong>g> maximum amount <str<strong>on</strong>g>of</str<strong>on</strong>g> precipitati<strong>on</strong><br />

has been occurred in this regi<strong>on</strong> <strong>and</strong> it has generated<br />

high flow rivers.<br />

The purpose <str<strong>on</strong>g>of</str<strong>on</strong>g> this research is to investigate <str<strong>on</strong>g>the</str<strong>on</strong>g><br />

effect <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>climate</str<strong>on</strong>g> <str<strong>on</strong>g>change</str<strong>on</strong>g> <strong>on</strong> <strong>meteorological</strong> <strong>and</strong><br />

<strong>hydrological</strong> <strong>parameters</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <strong>Urmia</strong> <strong>Lake</strong> watershed.<br />

With regard to <str<strong>on</strong>g>the</str<strong>on</strong>g> importance <str<strong>on</strong>g>of</str<strong>on</strong>g> temperature,<br />

precipitati<strong>on</strong> <strong>and</strong> evaporati<strong>on</strong> <strong>parameters</strong> in<br />

investigating <str<strong>on</strong>g>the</str<strong>on</strong>g> <str<strong>on</strong>g>effects</str<strong>on</strong>g> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>climate</str<strong>on</strong>g> <str<strong>on</strong>g>change</str<strong>on</strong>g>, <str<strong>on</strong>g>the</str<strong>on</strong>g>se<br />

<strong>meteorological</strong> <strong>parameters</strong> were used in this research.<br />

114 | Khaneshan et al

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