Effects of Water Level Decline in Lake Urmia, Iran, on Local Climate Conditions

Amir Hossein Dehghanipour,Zahra Kalantari,Massoud Tajrishy,Davood Moshir Panahi,Hossein Mousavi

doi:10.3390/w12082153

Abstract

Lake Urmia in northwestern Iran is the largest lake in Iran and the second largest saltwater lake in the world. The water level in Lake Urmia has decreased dramatically in recent years, due to drought, climate change, and the overuse of water resources for irrigation. This shrinking of the lake may affect local climate conditions, assuming that the lake itself affects the local climate. In this study, we quantified the lake’s impact on the local climate by analyzing hourly time series of data on climate variables (temperature, vapor pressure, relative humidity, evaporation, and dewpoint temperature for all seasons, and local lake/land breezes in summer) for the period 1961–2016. For this, we compared high quality, long-term climate data obtained from Urmia and Saqez meteorological stations, located 30 km and 185 km from the lake center, respectively. We then investigated the effect of lake level decrease on the climate variables by dividing the data into periods 1961–1995 (normal lake level) and 1996–2016 (low lake level). The results showed that at Urmia station (close to the lake), climate parameters displayed fewer fluctuations and were evidently affected by Lake Urmia compared with those at Saqez station. The effects of the lake on the local climate increased with increasing temperature, with the most significant impact in summer and the least in winter. The results also indicated that, despite decreasing lake level, local climate conditions are still influenced by Lake Urmia, but to a lesser extent.

Highlights

Climate conditions in lake basins can be affected by the lake itself, in addition to geographical factors, such as longitude, altitude, and large-scale climate variability [1]
This study showed that Lake Urmia in northwestern Iran affects the local climate of the surrounding area
This study examined whether this decline in water level has altered the influence of Lake Urmia on the local climate

Summary

Introduction

Climate conditions in lake basins can be affected by the lake itself, in addition to geographical factors, such as longitude, altitude, and large-scale climate variability [1]. The combined effects of these factors led to particular natural climate conditions in lake basins [2,3]. On comparing climate parameters and changes in the surface level of the Dead Sea, [8] found that decreasing lake level led to a decrease in relative humidity and cool lake breezes, resulting in increases in temperature and evaporation from the local region around the lake. [9] examined the effects of artificial and natural lakes on the local climate and found that the presence of a lake can either enhance or reduce the impact of large-scale climate changes in the local region around the lake Ref. [9] examined the effects of artificial and natural lakes on the local climate and found that the presence of a lake can either enhance or reduce the impact of large-scale climate changes in the local region around the lake

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