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

Abstract

Urmia Lake, the world second largest hypersaline lake, has decreased in size over recent decades primarily because inflow has diminished. This has caused serious socio-environmental consequences similar to those of the Aral Sea disaster. By using the Variable Infiltration Capacity (VIC) model, this study estimates the relative contributions of climate change and water resources development -which includes construction of reservoirs and expansion of irrigated areas -to changes in Urmia Lake inflow over the period . The model results show that decreases in inflow generally follow observed decreases in precipitation, though the variability in inflow is more pronounced than the variability in precipitation. The results also suggest that water use for irrigation has increased pressure on the basin's water availability and has caused flows to decrease by as much as 40% during dry years. On the other hand, the presence of reservoirs positively contributed to water availability during relatively dry years and did not significantly reduce lake inflow. By accelerating irrigation expansion in the basin, reservoirs have, however indirectly, contributed to inflow reduction. Our results show that annual inflow to Urmia Lake has dropped by 48% over the study period. About three fifths of this change was caused by climate change and about two fifths was caused by water resources development. The results of this study show that to prevent further desiccation of Urmia Lake it will be necessary both to develop national plans to reduce irrigation water use and to develop international plans to address climate change.

Dimming in Iran since the 2000s and the potential underlying causes

“…However, it is worth noticing that despite the fact that the amount of R a is maximum during summer, the maximum amount of CSR S is received in May at the stations Urmia and Bandarabbas. This fact may be due to higher amount of aerosol and/or humidity stemming from evaporation from the Lake of Urmia (Stone, 2015;Shadkam et al, 2016a;Shadkam et al, 2016b;Moghaddasi et al, 2017) and Persian Gulf during summer, which may lead to more scattering effects at the stations Urmia and Bandarabbas, respectively. The results of the trend analysis of annual mean CSR S during 1998-2015 are represented in Table 2.…”

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

“…The results of some research studies [7][8][9][10] also confirmed that human factors have a greater impact on drying Urmia Lake than climatic factors. Shadkam et al [11] examined the effects of climate change and the development of water resources (including constructing dams and increased irrigated agriculture) on the reduction of inflow to the Urmia Lake during the period of 1960 to 2010. The results showed that the annual inflow to Lake Urmia decreased by 48% during the studied period.…”

Effect of Irrigation Depth Reduction, Planting Date and Cropping Pattern on Water Productivity in West Lake Urmia, Iran

“…The Nazloo-Chai River, 25 km long, irrigates 32 400 ha of lowlands of the Nazloo District and rises from the slopes of the mountains of the Iran-Turkey border, flows from west to east and finally discharges into Lake Urmia (Taifeh Rezaee et al, 2014). The study area has an arid to semi-arid climate (Shadkam et al, 2016). The average annual rainfall was 333 mm in the period 1951-2015.…”