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European Journal of Applied Sciences – Vol. 12, No. 5

Publication Date: October 25, 2024

DOI:10.14738/aivp.125.17718.

Azizi, S. (2024). Drought and Environmental Transformations of Lake Urmia: An Integrated Analysis Using Machine Learning and

GIS. European Journal of Applied Sciences, Vol - 12(5). 290-315.

Services for Science and Education – United Kingdom

Drought and Environmental Transformations of Lake Urmia: An

Integrated Analysis Using Machine Learning and GIS

Sepideh Azizi

Department of Urban and Regional Planning,

University of Illinois Urbana-Champaign

ABSTRACT

In the late 1990s, Lake Urmia, located in northwestern Iran, was the largest

saltwater lake in the Middle East. However, it has experienced severe shrinkage

over the years, culminating in its division into two separate sections by 2008, with

long-term consequences still uncertain. This study examines the changes in Lake

Urmia from 2010 to 2020, focusing on various drought indicators such as

Temperature Condition Index (TCI), Normalized Difference Vegetation Index

(NDVI), Vegetation Condition Index (VCI), Palmer Drought Severity Index (PDSI),

and Standardized Precipitation Index (SPI). We monitored evolving drought

patterns in the lake's watershed and applied machine learning techniques to

classify agricultural lands within the basin, assessing their transformations over

time. Additionally, we analyzed the distribution of the UV Aerosol Index to

understand dust storm occurrences caused by the exposed lakebed due to

prolonged droughts. Our study presents statistical findings from modeling the

interactions among these indicators, aiming to deepen our understanding of the

drought impacts on Lake Urmia and its surrounding area. The research highlights

the urgent need for measures to preserve the region’s ecological balance. Given

Lake Urmia’s significance to neighboring countries and its historical and

ecological value, international cooperation is essential. We employed Geographic

Information Systems (GIS) and Google Earth Engine to enhance the clarity of our

findings, providing a comprehensive view of the environmental changes. Our

analysis of key indicators—VCI, PDSI, TCI, and SPI—reveals significant

relationships that offer insights into the interplay between vegetation health and

climatic conditions, which are crucial for effective resource management.

Keywords: Urmia Lake, Watershed, Drought, Climate changes, Remote Sensing,

Agriculture.

INTRODUCTION

In recent decades, studying lake changes has found a special status among countries and even

at the international levels [1]. There are several reasons associated with the declining of lakes.

One of the most notable reasons for such incidents has been severe climate changes. Besides

that, anthropogenic effects such as over exploitation of water resources, over cultivating and

building dams across the rivers or streams to hold back water from entering the lakes could

result in droughts. Drought is defined as a lack of moisture which negatively affects the

environmental, economic and social aspects of life on this planet [2]. Droughts occur in both

arid and wet regions, leading to water supply deficits [3]. However, the characteristics of

drought, including frequency, severity, and duration, vary across different locations [4]. To

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Azizi, S. (2024). Drought and Environmental Transformations of Lake Urmia: An Integrated Analysis Using Machine Learning and GIS. European

Journal of Applied Sciences, Vol - 12(5). 290-315.

URL: http://dx.doi.org/10.14738/aivp.125.17718

capture the complexity of drought, scientists have established four classifications:

meteorological drought, agricultural drought, hydrological drought, and socio-economic

drought [5].

Drought’s contribution in reducing precipitation and causing limitation of water sources

made people manage water usage for agricultural, urban and industrial functions.

Constructing dams across a stream or a river is an example of these efforts to store water for

producing electricity and other human needs. Today, studying the changes in the lake water

level is needed to protect them for their importance in survival and conservation of natural

heritage [6]. The sustainable management of water resources in the face of a growing

population is a pressing global issue, as highlighted by the phenomenon known as the Aral

Sea syndrome. The diversion of rivers feeding the Aral Sea for irrigation purposes has

resulted in its continuous shrinkage, leading to significant ecological and biological

consequences. These include the destruction of local species, disruption of local communities

through dust and salt storms, and even alterations in the climate of the surrounding regions

[7,8,9]. This is what we are experiencing about Urmia Lake in northwest of Iran.

From 1995 onwards, Lake Urmia underwent a substantial decline in its water level. Over the

course of 18 years, between 1995 and 2013, the lake witnessed a staggering reduction of

approximately 60% in its surface area. The decline was even more severe in terms of volume,

with the lake losing over 90% of its total volume during the same period [10,11,12,13].

Although fluctuations in the lake level from year to year were always significant, the drastic

decline experienced in the 1990s stands out as a remarkable event, at least within the past

century [14,15]. The decrease in volume had detrimental effects on the lake's ecosystem. The

aquatic habitat suffered a substantial reduction due to the declining water levels. In addition,

the lake's salinity levels surged to over 300 gL−1, further exacerbating the situation [16]. This

increase in salinity adversely impacted the reproduction rate of Artemia Urmiana, a key

species inhabiting the lake, leading to a severe decline in their population [17]. Furthermore,

numerous islands that existed within the lake disappeared, and the dried-up lakebed became

covered with layers of sand dunes and evaporites, transforming it into an expansive salty

desert [18]. The prospects for Urmia Lake bear resemblance to the plight of the Aral Sea,

which has experienced severe drying and inflicted windblown salt storms on the surrounding

communities [19]. Unlike the Aral Sea, the densely populated vicinity of Urmia Lake puts a

significantly larger number of people at risk [20], leading to reports of thousands already

abandoning the area [21]. With an estimated risk reaching people within a 500 km radius of

the lake [19], the situation could exacerbate existing economic, political, and ethnic tensions

in this volatile region [22].

Additionally, the Urmia Lake drought has led to widespread salt land formation, reducing

farmland fertility. The affected land area with soil salinity has risen from 2.86% in 1990 to

16.68% in 2020. Using the combined spectral response index, Feizizadeh et al. identified a

high or very high risk of soil degradation in 38.45% of the study area, posing a significant

threat to food production [23]. Feizizadeh et al. also revealed the profound consequences of

the Lake Urmia drought on food production, indicating a significant decline over the past 30

years. By employing a combination of cellular automaton and Markov modeling, future

projections anticipate further reductions in food production over the next three decades.

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European Journal of Applied Sciences (EJAS) Vol. 12, Issue 5, October-2024

These findings emphasize the critical environmental impact of the Urmia Lake drought on

regional food security [24]. The public had a strong notion that the drying up of Lake Urmia

posed health risks [25]. Feizizadeh et al. found a direct link between the drought of Lake

Urmia, the expansion of salt diffusion centers, and an increased risk of hypertension in

Shabestar County. The presence of salt diffusion centers, along with specific environmental

factors, significantly contributes to hypertension prevalence in the entire Lake Urmia basin.

These findings highlight the ongoing impact of the lake drought on the health of residents in

the surrounding areas [26]. This basin is home to approximately 6 million people and

considered a significant agricultural region [27]. Within Lake Urmia’s basin, there are

approximately 510,000 hectares of irrigated lands, served by 33 modern and traditional

irrigation networks. However, the reported irrigation efficiency is relatively low, with farming

achieving 37% efficiency and gardening reaching 45% efficiency, according to the Iran

Ministry of Energy [28]. Over the past four decades, the agricultural land area in the Urmia

basin has expanded more than threefold, facilitated by numerous reservoirs and an extensive

irrigation network [29].

The basin has seen the construction of 41 small and large reservoirs since 1970, which store a

significant amount of water (approximately 2000×106m3) and support these 510,000

hectares of irrigated land served by 33 irrigation networks. Concurrently, there has been a

notable decrease in precipitation and an upward trend in average maximum temperature,

resulting in a transition from a semi-arid to an arid climate classification for the basin

[30,12,31]. The combination of scarce water resources, population growth, and the pressing

demand for food has created challenging conditions for water resources. Factors such as

unregulated and inefficient utilization of water and soil resources, inadequate water demand

management (particularly in agriculture), and a lack of timely and suitable policies for water

resource management in both supply and demand sectors have contributed to the current

unfavorable state. Consequently, the impact on water resource security and economic

indicators has reached an inevitable stage in this area [32]. The environmental challenges

faced by Lake Urmia are attributed to a combination of natural and human factors.

Construction projects like the Shahid Kalantari Highway, along with the building of numerous

dams and intensive agricultural practices, have contributed to the reduction of the lake area

and water level. These factors have also resulted in the production of harmful dust storms in

the region [33].

However, Determining the exact causes behind the significant decline in water levels during

the past two decades remains a subject of controversy. Several recent papers have discussed

reasons for the shrinkage of Urmia Lake and the possible environmental consequences. Ülke

Keskin et al. analyzed the drought in the Lake Urmia basin using different time scales and

precipitation data. Short-term scales respond quickly to rainfall changes, while long-term

scales exhibit prolonged drought. Additionally, the comparison of time scales reveals the

coexistence of wet and dry conditions in different scales simultaneously [4]. Moreover, using

the Variable Infiltration Capacity (VIC) hydrological model, a study by Shadkam investigated

the causes behind the reduced inflow to Lake Urmia. It found that climate change was

primarily responsible for this decline, but water resources development, particularly

irrigation, also made a significant contribution to the problem [34]. According to Delju et al.,

the most severe drought in the past four decades has been attributed to a reduction in