Elsevier

Science of The Total Environment

Volume 559, 15 July 2016, Pages 317-325
Science of The Total Environment

Preserving the world second largest hypersaline lake under future irrigation and climate change

https://doi.org/10.1016/j.scitotenv.2016.03.190Get rights and content

Highlights

  • To restore drying Urmia Lake, the new official policy aims to increase inflow by cutting of irrigation water use substantially.

  • Inflow to the lake was projected under the different climate and anthropogenic scenarios.

  • Water availability in the basin will decrease under all climate change scenarios.

  • The new policy can help to preserve the lake only under a very limited future climate change.

  • To face all other climate and anthropogenic scenarios more drastic measures are needed.

Abstract

Iran Urmia Lake, the world second largest hypersaline lake, has been largely desiccated over the last two decades resulting in socio-environmental consequences similar or even larger than the Aral Sea disaster. To rescue the lake a new water management plan has been proposed, a rapid 40% decline in irrigation water use replacing a former plan which intended to develop reservoirs and irrigation. However, none of these water management plans, which have large socio-economic impacts, have been assessed under future changes in climate and water availability. By adapting a method of environmental flow requirements (EFRs) for hypersaline lakes, we estimated annually 3.7·109 m3 water is needed to preserve Urmia Lake. Then, the Variable Infiltration Capacity (VIC) hydrological model was forced with bias-corrected climate model outputs for both the lowest (RCP2.6) and highest (RCP8.5) greenhouse-gas concentration scenarios to estimate future water availability and impacts of water management strategies. Results showed a 10% decline in future water availability in the basin under RCP2.6 and 27% under RCP8.5. Our results showed that if future climate change is highly limited (RCP2.6) inflow can be just enough to meet the EFRs by implementing the reduction irrigation plan. However, under more rapid climate change scenario (RCP8.5) reducing irrigation water use will not be enough to save the lake and more drastic measures are needed. Our results showed that future water management plans are not robust under climate change in this region. Therefore, an integrated approach of future land-water use planning and climate change adaptation is therefore needed to improve future water security and to reduce the desiccating of this hypersaline lake.

Introduction

To supply food and energy for growing populations, humans have developed reservoirs and extract water for irrigation (Biemans et al., 2011). Furthermore, climate change has a significant impact on the natural hydrological cycle and amplifies water scarcity in (semi)-arid regions (Haddeland et al., 2014, Fernandes et al., 2011, Santos et al., 2014). Consequently, managing water for a growing population without harming natural resources is becoming a serious challenge. In this paper, we assess this challenge in Urmia basin, where the second largest permanent hypersaline lake in the world is drying up (Karbassi et al., 2010).

Urmia Lake, in north-western Iran, is an important internationally recognized natural area designated as a RAMSAR site and UNESCO Biosphere Reserve (Eimanifar and Mohebbi, 2007). It is a home to many species along with a unique brine shrimp species (Asem et al., 2012). Urmia Basin supports a variety of agricultural production systems and activities as well as livestock. The basin is located in a politically tensed region bordering both Iraq and Turkey. It is linguistically and culturally diverse area dominated by two ethnic groups, Azeri Turks and Kurdish (Henareh et al., 2014).

Over the last 40 years, the water level and surface area of Urmia Lake have declined (Rokni et al., 2015) by 80% (AghaKouchak et al., 2015). As a result, the salinity of the lake has sharply increased which is disturbing the ecosystems, local agriculture and livelihoods, regional health, as well as tourism. (UNEP, 2012). Several studies have warned that the future of Urmia Lake could become similar to the Aral Sea, which has dried up over the past several decades and severely affected the surrounding people with windblown salt storms (Torabian et al., 2015). The population around Urmia Lake, however, is much denser compared to the Aral Sea and many more people are at risk (UNEP, 2012). Local reports have indicated that thousands of people around the lake have already abandoned the area (RadioFarda, 2014). It has been estimated that people living within 500 km2 of the Lake location, are at risk (Torabian et al., 2015), which could amplify economic, political and ethnic tensions in this already volatile region (Henareh et al., 2014).

Previous studies have indicated that the lake desiccation is probably caused by a combination of human activities and climate change (AghaKouchak et al., 2015, Fathian et al., 2014, Hamzekhani et al., 2015, Hassanzadeh, 2010, Jalili et al., 2015). The area of the agricultural lands has more than tripled over the last 40 years supported by a considerable number of reservoirs and a large irrigation network (Iran Ministry of Energy et al., 2014). There has also been a significant decrease in precipitation and an increasing trend in average maximum temperature during the same period (Fathian et al., 2014, Delju et al., 2013). This has caused the most extreme droughts in the basin over the last few decades during the mid-1990s (Tabari et al., 2013). These trends have affected the inflow into the lake (Fathian et al., 2014) which has been recognized as the main reason of the lake shrinkage (Hassanzadeh et al., 2012). Some studies have estimated how much water is needed to restore and protect the ecology, water quality and quantity of the lake (Abbaspour and Nazaridoust, 2007). However, they have not included the important role of climate change which is likely to reduce the precipitation and run-off in both near-term (Kirtman et al., 2013) and long-term future (Collins et al., 2013).

To secure enough food and income for a growing population in the basin, the initial government water resources plan intended to increase the irrigated area by 25% supported by additional dams and reservoirs. More recently, a new plan has been proposed aiming to restore and preserve Urmia Lake. This plan proposes to stop all reservoir developments and reduces irrigation water allocation by 40%. However, it is still unclear if the water use reduction plan, which is about to start and has large socio-economic impacts, is able to restore and preserve the lake under future climate change.

The main objective of this study was to assess the impacts of future water resources management plans under climate change on the water inflow into Urmia Lake during the 21st century. To address this objective we first developed a method to estimate the annual and monthly environmental flow requirement (EFRs) to preserve vulnerable hypersaline lake ecosystems especially in a lack of precise ecological data. By applying the method, we quantified how much water is needed to preserve Urmia Hypersaline Lake. Then, we developed future projections of total inflow into the lake, using the Variable Infiltration Capacity (VIC) hydrological model (Liang et al., 1994), including an irrigation and reservoir module (Haddeland et al., 2006, Haddeland, 2006). The model was forced with statistically bias-corrected General Circulation Models (GCMs) outputs from a low and high representative concentration pathways (RCPs) (Moss et al., 2010). In addition, to study the impact of the water resources plans on the future inflow, the two proposed plans plus the current, and the naturalized (without any irrigation and reservoirs) situations were applied in the model. The simulated inflow was compared with the annual and monthly estimated EFRs to assess the possibilities of Urmia lake restoration and preservation under different climate change and anthropogenic scenarios.

Section snippets

Study area

Urmia Lake is formed at the lowest point within the closed Urmia basin (UNDP, 2014). The area of the lake has reduced from ~ 6100 km2 in 1995 to ~ 1500 km2 in 2014 (Fig. 1) followed by > 7 m decline in the water level (Supplementary Information S1). The lake is relatively shallow (maximum depth 16 m) and thus vulnerable to evaporation (Meijer et al., 2012). There are 17 permanent rivers and 12 seasonal rivers which terminate at Urmia Lake. The average inflow into the lake has declined from around

Materials and methods

The methodological framework for this study is shown in Fig. 2. Future scenarios for daily flow into the lake were calculated using the VIC hydrological model forced by bias-corrected outputs from five GCMs, using the representative concentration pathway (RCP) 2.6, lowest; (Van Vuuren et al., 2011) and 8.5, highest; (Riahi et al., 2011), for 2010–2099 and for 1971–2000 (control) in combination with four different anthropogenic scenarios (40 simulations). Historical naturalized inflow from the

Evaluation of control simulation of river discharge

Simulated inflows for control period 1971–2000 of five GCMs were compared with those based on the historical WFD also with observed values to evaluate the overall performance of the VIC-irrigation and reservoir model (Fig. 3). Boxplots for simulated mean annual inflows based on the five GCMs corresponded well with boxplots of the observed values (Fig. 3). However, the median values are slightly overestimated for MIROC and GFDL and underestimated for HadGEM2 and IPSL compared to observations.

Impact of uncertainties in modelling framework

Our modelling results are affected by different uncertainties related to the climate forcing and model application. First of all, due to significant biases in GCM data, we used bias corrected climate forcing data as input to the VIC hydrological model. The statistics for simulated discharge for the control simulations of the GCMs generally correspond well with the simulations based on the WFD dataset and observed discharge values (Fig. 3). This showed that the bias-correction method was

Conclusions

In this study we assessed how water resources plans can fulfil Urmia Lake inflow requirements under different climate change scenarios. The results showed that the water resources plans are not robust to changes in climate. In other words, if future climate change is limited due to rapid mitigation measures (RCP2.6) the new strategy of reduction of irrigation water use can contribute to preserve Urmia Lake. However, this water management strategy is insufficient to preserve the lake under

References (68)

  • Collins, M., R. Knutti, J. Arblaster, J.-L. Dufresne, T. Fichefet, P. Friedlingstein, X. Gao, W.J. Gutowski, T. Johns,...
  • A. Delju et al.

    Observed climate variability and change in Urmia Lake Basin, Iran

    Theor. Appl. Climatol.

    (2013)
  • A. Eimanifar et al.

    Urmia Lake (northwest Iran): a brief review

    Saline Systems

    (2007)
  • F. Fathian et al.

    Identification of trends in hydrological and climatic variables in Urmia Lake basin, Iran

    Theor. Appl. Climatol.

    (2014)
  • L.F.S. Fernandes et al.

    Model of management and decision support systems in the distribution of water for consumption: case study in North Portugal

    European Journal of Environmental and Civil Engineering

    (2011)
  • H. Golabian

    Urumia Lake: Hydro-ecological stabilization and permanence

  • I. Haddeland

    Anthropogenic Impacts on the Continental Water Cycle

    (2006)
  • I. Haddeland et al.

    Anthropogenic impacts on continental surface water fluxes

    Geophys. Res. Lett.

    (2006)
  • I. Haddeland et al.

    Hydrologic effects of land and water management in North America and Asia

    Hydrol. Earth Syst. Sci.

    (2007)
  • I. Haddeland et al.

    Global water resources affected by human interventions and climate change

    Proc. Natl. Acad. Sci.

    (2014)
  • U.T. Hammer

    Saline Lake Ecosystems of the World

    (1986)
  • F.G. Hamzekhani et al.

    Environmental management in Urmia Lake: thresholds approach

  • N. Hanasaki et al.

    An integrated model for the assessment of global water resources–part 2: Applications and assessments

    Hydrol. Earth Syst. Sci.

    (2008)
  • E. Hassanzadeh

    Determining the Effect of Constructing Hydraulic Structureson Declining the Urmia Lake Level

    (2010)
  • E. Hassanzadeh et al.

    Determining the main factors in declining the Urmia Lake level by using system dynamics modeling

    Water Resour. Manag.

    (2012)
  • S. Hempel et al.

    A trend-preserving bias correction–the ISI-MIP approach

    Earth System Dynamics

    (2013)
  • K.A. Henareh et al.

    Water flows toward power: socioecological degradation of Lake Urmia, Iran

    Soc. Nat. Resour.

    (2014)
  • R. Hurkmans et al.

    Water balance versus land surface model in the simulation of Rhine river discharges

    Water Resour. Res.

    (2008)
  • Iran Ministry of Energy, Deputy of Water and Wastewater, Macro Planning Bureau

    The National Water Master Plan Study in the Aras, Sefidrood, between Sefidrood and Haraz, Atrac and Urmia: Agricultural Water Use Study in Urmia Lake Basin, Report Number: 2385070–4420-19464, ISI-MIP

    (2014)
  • Iranian Student News Agency (ISNA)

    Urmia Lake Still Needs 12 Billion Cubic Meters Water

    (2016)
  • S. Jalili et al.

    The influence of large-scale atmospheric circulation weather types on variations in the water level of Lake Urmia, Iran

    Int. J. Climatol.

    (2012)
  • S. Jalili et al.

    Climate variability and anthropogenic effects on Lake Urmia water level fluctuations, northwestern Iran

    Hydrol. Sci. J.

    (2015)
  • B. Kirtman et al.

    Near-term Climate Change: Projections and Predictability

  • X. Liang et al.

    A simple hydrologically based model of land surface water and energy fluxes for general circulation models

    Journal of Geophysical Research: Atmospheres (1984–2012)

    (1994)
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