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

Abstract

Abstract. 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•10 9 m 3 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.

Impacts of climate change and water resources development on the declining inflow into Iran's Urmia Lake

“…SI 1Urmia basin location (a) and the surface area changes from 1984 to 2014, derived from LandSat imagery (b) (Shadkam et al, 2016) …”

“…Climate change was the main contributor to the inflow reduction (about three fifth) and caused an inflow reduction of 28% over the study period. Shadkam et al (2016) assessed the impact of a lowest and highest representative concentration pathways (RCPs) (Moss et al, 2010) on the inflow to Urmia Lake in next century. Their results showed that the effect of climate change is likely to continue in both lowest and highest scenarios.…”

Analysis of the Effects of Water Management Strategies and Climate Change on the Environmental and Agricultural Sustainability of Urmia Lake Basin, Iran

“…Urmia Lake, the largest lake in Iran and the second most saline lake in the world, has been dying during the last two decades and this has resulted in similar or even greater socio-environmental impacts to the disaster of the Aral Sea [5].…”

Information Mining of Spatio-Temporal Evolution of Lakes Based on Multiple Dynamic Measurements

“…Since ancient times, lakes are closely related with human survival and development and play an irreplaceable role in runoff regulation, agricultural irrigation, transportation, urban and rural water supply, aquaculture, and maintaining ecological balance (Johnson et al, 2001). The lake evolution here is mainly affected by both natural factors (crustal movement, sediment deposition, and climate change) (Shadkam et al, 2016) and human activity (reclaiming farmland from lakes, urban expansion, and construction of large-scale water conservancy projects) (Yao et al, 2006;Wei et al, 2005a). Along with the population growth and the development of productive forces, the effects of human intervention on nature and ecological environment increased, which accelerated the evolution of lakes (Xiao et al, 2012).…”

“…A number of studies have been proposed for the evolution of lakes, studies on lake mainly focus on the lake changes at different time scales (Sironić et al, 2016), the landscape pattern evolution (Liu et al, 2014;Wu et al, 2016), the evolving types and causes of lakes (Jambrina-Enríquez et al, 2017;Shadkam et al, 2016), the impact of water pollution (Grochowska et al, 2015;Sevindik et al, 2014;Williamson et al, 2009), the management of water resources (Li et al, 2017;Zębek, 2014), and so on. The core concept of most methods is to calculate the total change of the lakes' area.…”