2015 Research & Innovation Day Program

A one day showcase of applied research, social innovation, scholarship projects and activities.https://first.fanshawec.ca/cri_cripublications/1002/thumbnail.jp

Hydroclimate of the Lake Urmia Catchment Area: A Brief Overview

Lake Urmia in Iran, the largest land-locked water body in Iran and the second largest hypersaline lake in the world has experienced a drastic 90% decline in its surface area due to decrease in water supply beginning in the mid-1990s. The effect of climate variability under current warming condition versus the human induced hydro-chemical imbalance as the primary cause(s) of such a drastic change remains a matter of considerable debate. Water supply to the lake is from a 52,000 km2 catchment area through 13 perennial and seasonal tributaries. Using 65-year long hydro-climatological time series from nine major meteorological stations across the region combined with land surface temperature (LST) data we examine the impact of climate variability on water inflow to the lake. Our study shows that the abrupt 21.4% shift in precipitation and 50.8% decline in water flow to the lake occurred in 1995 while a positive 1°C shift in atmospheric temperature and 1.37°C increase in land surface temperatures took place in 1997. Temperature and precipitation time series present low coherency with water inflow to the lake. This evidence along with the sub-decadal cyclicity in the annual mean temperature suggests the anthropogenic activities in the catchment area may have carried out an important role in the current progressive imbalance in water availability to the lake. Telecommunication between the hydroclimate condition across the Lake Urmia catchment area and the climate variability over the North Atlantic region was inferred from wavelet analysis of temperature and NAO index time series

The rise and demise of the world's second largest hypersaline lake; the past is prologue to the future of Urmia Lake

Urmia Lake, the largest hypersaline lake in the Middle East, has seen a 90% reduction in its surface area during the last 30 years due to decreased water supply to the lake. The drastic environmental degradation of the lake is a national concern but there are contrasting views on how to proceed. While one group blames the natural climate cycles, the other seeks experts to investigate the reasons for the lake's desiccation. However, there is a paucity of robust decadal to millennial scale data of climate variability and thus the main causes behind the reduction of the lake are the subject of huge debates. Difficulties in establishing a robust chronology made it challenging to decipher the existing paleoclimate records from Urmia Lake. This study, for the first time, has provided a well-calibrated chronology and investigated climate variability and hydrology of the region since 11,600 BP. Comparative calibrated radiocarbon ages from different sediment constituents extracted from 0.65- and 5.4-meter intervals in the sediment core suggest a 560- and 719-year correction for reservoir effect on bulk sediment and fecal pellets radiocarbon dates, respectively. Down-core variations in paleo-dust, paleo-hydrology and paleo-redox proxies at an average resolution of 2.5 yr suggest several episodes of wet and dry conditions associated with high and low lake levels. Variation in XRF profiles of Al and Si covary closely with the record of North Atlantic ice rafted debris events and Holocene reconstruction of sunspots, indicating the influence of climate forcing on the hydrological condition of the Urmia Lake. Paleo-rainfall reconstruction reveals that the mean annual precipitation (MAP) over the Urmia Lake region has varied from 183 to 372 mm y (super -1) and suggests wet conditions were dominant during the early Holocene and dry conditions became more frequent toward the late Holocene. Considering the facts that the drastic reduction in the Urmia Lake surface area appeared during the last 30 years and the 55-year mean annual precipitation over the lake returned an average of 340 mm- very close to maximum Holocene paleo-rainfall reconstruction - it can be concluded that the extensive anthropogenic activities and poor water management over the last few decades had more impact on water availability to the lake compare to natural climate cycles

The rise and demise of Iran’s Urmia Lake during the Holocene and the Anthropocene: “what’s past is prologue”

Urmia Lake in NW Iran was the world’s second largest hypersaline lake until three decades ago, when it began to lose ~ 90% of its surface area due to dwindling water input and enhanced evaporation. To help discern the role of natural vs anthropogenic factors in the rapid demise of Urmia Lake, we present a high-resolution, multi-proxy reconstruction of climate, and hydrological variability from the lake’s sediments. We identify several episodes of wet and dry conditions over the past 11,300 years, and an atmospheric teleconnection between the climate of the interior of West Asia and the North Atlantic region. Estimates of mean annual precipitation based on chemical weathering indices range between 174 and 401 mm year−1 during the Holocene. A combination of geochemical proxies, pollen reconstruction, and the absence of any evaporite horizons throughout the Holocene period point to the prevailing role of human impact on the current vanishing of Urmia Lak