Investigating uncertainty of climate change effect on entering runoff to Urmia Lake Iran

Abstract

The largest lake in Iran, Urmia Lake, has been faced with a sharp decline in water surface in recent years. This decline is putting the survival of Urmia Lake at risk. Due to the fact that the water surface of lakes is affected directly by the entering runoff, herein we study the effect of climate change on the runoff entering Urmia Lake. Ten climate models among AOGCM-AR4 models in the future time period 2013–2040 will be used, under the emission scenarios A2 and B1. The downscaling method used in this research is the change factor-LARS method, while for simulating the runoff, the artificial neural network was applied. First, both the 30-yr and monthly scenarios of climate change, temperature, and precipitation of the region were generated and weighted by the Beta function (β). Then, the cumulative density function (cdf) for each month was computed. Calculating the scenarios of climate change and precipitation at levels of 25, 50, and 75% of cdf functions, and introducing them into LARS-wg model, the time series of temperature and precipitation in the region in the future time period were computed considering the uncertainty of climate variability. Then, introducing the time series of temperature and precipitation at different risk levels into the artificial neural network, the future runoff was generated. The findings illustrate a decrease of streamflow into Urmia Lake in scenario A2 at the three risk levels 25, 50, and 75% by, respectively, −21, −13, and −0.3%, and an increase by, respectively, 4.7, 13.8, and 18.9% in scenario B1. Also, scenario A2 with its prediction of a warm and dry climate suggests more critical conditions for the future compared to scenario B1 and its cool, humid climate

Identifying vulnerable areas of aquifer under future climate change (case study: Hamadan aquifer, West Iran)

“…The weighting approach used in this study suggests that some GCMs are more suitable for predicting temperature changes while other GCMs are more suitable for predicting precipitation changes. Similar to previous studies in different regions of Iran (e.g., Naderi, 2015;Gohari et al, 2013;Razmara et al, 2013;Meshkin Nejhad et al, Fig. 12 Groundwater head contours in the steady state condition (1991)(1992) 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 Num Naderi, 2015;Gohari et al, 2013), but the study area, that is located in the west of Iran, depends on the emission scenario, thus the basin will experience wetter or dryer condition.…”

“…Climate change studies in Iran indicate that most parts of the country will experience drier condition in future (Morid and Massah Bavani, 2008;Gohari et al, 2013;Razmara et al, 2013;Naderi 2015). Regarding the role of precipitation and runoff in aquifer recharge, both factors were considered in this study and a model was developed for Hamadan aquifer to determine its response to future climate change conditions .…”

Environmental degradation at Lake Urmia (Iran): exploring the causes and their impacts on rural livelihoods

“…Climatic variability and irregular precipitation in the semi-arid area of north-western Iran have always led to significant fluctuations in Lake Urmia water levels, with the last maximum being reached in the mid-1990s (Fathian et al 2014;Jalili et al 2016;Taravat et al 2016). Nevertheless, during the last few decades, a substantial decrease in precipitation, higher air temperatures and persistent drought periods have been recorded (Delju et al 2013;Razmara et al 2013;Shadkam et al 2016;Taravat et al 2016;Sanikhani et al 2017;Arkian et al 2018). Consequently, direct inflow into the lake has diminished while the evaporation rate increased, in turn leading to increased water demand by the agricultural sector (ULRP 2015).…”

Climate change and anthropogenic impacts on the rapid shrinkage of Lake Urmia

“…For example, Delju et al () used maximum temperature and precipitation records of a synoptic station in the Urmia Basin, and noted a 9.2% decrease in rainfall and 0.8 °C increase in the maximum temperature for the period 1964–2005. The lake is even under more threat (Abbaspour et al , ; Razmara et al , ) under the potential dry conditions in future. For example, Abbaspour et al () applied a hydrodynamic model and postulated that under very dry conditions, the lake will be dried up in 10 years.…”