Compounding effects of human activities and climatic changes on surface water availability in Iran (original) (raw)

Assessing the impact of climate change on water resources in Iran

Water Resources Research, 2009

As water resources become further stressed due to increasing levels of societal demand, understanding the effect of climate change on various components of the water cycle is of strategic importance in management of this essential resource. In this study, we used a hydrologic model of Iran to study the impact of future climate on the country's water resources. The hydrologic model was created using the Soil and Water Assessment Tool (SWAT) model and calibrated for the period from 1980 to 2002 using daily river discharges and annual wheat yield data at a subbasin level. Future climate scenarios for periods of 2010-2040 and 2070-2100 were generated from the Canadian Global Coupled Model (CGCM 3.1) for scenarios A1B, B1, and A2, which were downscaled for 37 climate stations across the country. The hydrologic model was then applied to these periods to analyze the effect of future climate on precipitation, blue water, green water, and yield of wheat across the country. For future scenarios we found that in general, wet regions of the country will receive more rainfall while dry regions will receive less. Analysis of daily rainfall intensities indicated more frequent and larger-intensity floods in the wet regions and more prolonged droughts in the dry regions. When aggregated to provincial levels, the differences in the predictions due to the three future scenarios were smaller than the uncertainty in the hydrologic model. However, at the subbasin level the three climate scenarios produced quite different results in the dry regions of the country, although the results in the wet regions were more or less similar.

Impacts of future land cover and climate change on the water balance in northern Iran

Hydrological Sciences Journal

We evaluated the potential impacts of future land cover change and climate variability on hydrological processes in the Neka River basin, northern Iran. This catchment is the main source of water for the intensively cultivated area of Neka County. Hydrological simulations were conducted using the Soil and Water Assessment Tool. An ensemble of 17 CMIP5 climate models was applied to assess changes in temperature and precipitation under the moderate and high emissions scenarios. To generate the business-as-usual scenario map for year 2050 we used the Land Change Modeler. With a combined change in land cover and climate, discharge is expected to decline in all seasons except the end of autumn and winter, based on the inter-model average and various climate models, which illustrated a high degree of uncertainty in discharge projections. Land cover change had a minor influence on discharge relative to that resulting from climate change.

Climate Change and the Future of Water Management in Iran

Middle East Critique, 2015

Iran is a large country in the Middle East, which is an extremely arid region. Like its neighbors, severe droughts and population growth have intensified Iran's water shortage problems in the past two decades. Furthermore, climate change has the potential to impose additional economic and social pressure on it and all Middle Eastern countries. Thus, how future climate change will interact with socioeconomic and political conditions in the region is an important issue. In this article I discuss the influence of climate change, plans for mitigation of climate change, and projects of water resilience for the period 2010 -2050 in southern Iran. I suggest ways to improve indigenous participation in crafting economic solutions to climate change, as climate change impacts directly on water resources at the local level. I also discuss how local level water solutions may affect regional and national water policy in the future.

On The Effects of Climate Change and Global Warming on Water Resources in Iran

In this paper, the effects of climate change on nationwide Iranian climate and water resources were investigated by a trend analysis of temperature, precipitation and river flow. The Mann-Kendal trend test was applied to the time series of monthly temperature and precipitation derived from satellite images. The mean monthly stream-flow data associated with representative stream gages of 6 major Iranian catchments was investigated for detecting any possible trend. Furthermore, the standardized precipitation index (SPI) was computed with the observed precipitation relative to 44 selected stations distributed throughout Iran. The results suggested a long-term increasing trend in temperature all over the country, while a statistically significant decreasing trend in precipitation was observed for north western and south eastern Iran. The results also suggested a decreasing trend in the available water resources across the country which is in agreement with the negative trend of satellite derived precipitation detected for some parts of the country. A decreasing trend was also observed in the SPI index indicating that the occurrence of severe/extreme long lasting droughts in some parts of the country might be attributed to the effects of climate change and global warming.

Impacts of future climate and land use change on water yield in a semiarid basin in Iran

Land Degradation & Development, 2020

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Water resources availability under different climate change scenarios in South East of Iran

Journal of Water and Climate Change

The comprehensive large-scale assessment of future available water resources is crucial for food security in countries dealing with water shortages like Iran. Kerman province, located in the south east of Iran, is an agricultural hub and has vital importance for food security. This study attempts to project the impact of climate change on available water resources of this province and then, by defining different scenarios, to determine the amount of necessary reduction in cultivation areas to achieve water balance over the province. The GFDL-ESM2M climate change model, RCP scenarios, and the CCT (Climate Change Toolkit) were used to project changes in climatic variables, and the Soil and Water Assessment Tool (SWAT) was used for hydrological simulation. The future period for which forecasts are made is 2020–2050. Based on the coefficient of determination (R2) and Nash–Sutcliffe coefficient, the CCT demonstrates good performance in data downscaling. The results show that under all cl...

Adaptation of surface water supply to climate change in central Iran

Optimal reservoir operation changes and adaptation strategies for the Zayandeh-Rud River Basin's surface water supply system are examined for a changing climate during the 2015–2044 period. On average, the monthly temperature in the basin is expected to increase by 0.46–0.76 °C and annual precipitation is expected to decrease by 14–38% with climate change, resulting in a reduction of the Zayandeh-Rud's peak stream flow and the amplitude of its seasonal range. Snowfall decrease in winter months will generally lead to an 8–43% reduction in annual stream flow under climate change. A reservoir operation model is developed and optimal reservoir operation strategies are identified for adaptation of the basin's surface water supply to climate change in the face of the increasing water demand. Results indicate that the reservoir drawdown season starts two months earlier under climate change. Smaller storage levels and greater water releases must incur to meet the increasing water demand. The optimized water release can provide sufficient water for non-agricultural water demand, but agriculture will experience more severe water shortage under a changing climate. Having the highest vulnerability, the agricultural sector should be the main focus of regional management plans to address the current water challenge and more severe water shortages under climate change.

Assessing future drought conditions under a changing climate: a case study of the Lake Urmia Basin in Iran

Water Supply, 2019

This study was conducted to assess the impacts of climate change on drought over the Lake Urmia basin, Iran. Drought events for 2011–2040, 2041–2070, and 2071–2100 were analyzed based on the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI) and were compared with the adopted baseline period (1976–2005). The SPI and SPEI were calculated using the precipitation and temperatures obtained from the second-generation Canadian Earth System Model (CanESM2) under Representative Concentration Pathway (RCP) 2.6 and RCP 8.5 as optimistic and pessimistic scenarios respectively. The results of SPI analyses revealed that under RCP 2.6 the frequency of droughts is almost constant while under RCP 8.5 drought frequency increased especially in the period 2071–2100. The calculated SEPI under both scenarios and during all future periods predict that the frequency and duration of droughts will increase. Generally, the difference between the SPI and ...

Battling Water Limits to Growth: Lessons from Water Trends in the Central Plateau of Iran

Environmental Management, 2021

The Zayandeh-Rud River Basin in the central plateau of Iran continues to grapple with water shortages due to a water-intensive development path made possible by a primarily supply-oriented water management approach to battle the water limits to growth. Despite inter-basin water transfers and increasing groundwater supply, recurring water shortages and associated tensions among stakeholders underscore key weaknesses in the current water management paradigm. There was an alarming trend of groundwater depletion in the basin's four main aquifers in the 1993-2016 period as indicated by the results of the Mann-Kendall (MK) test and Innovative Trend Analysis (ITA) of groundwater volume. The basin's water resources declined by more than 6 BCM in 2016 compared to 2005 based on the equivalent water height (EWH) derived from monthly data (2002-2016) from the GRACE release 5. The extensive groundwater depletion is an unequivocal evidence of reduced water availability in the face of growing basin-wide demand, necessitating water saving in all water use sectors. Implementing an integrated water resources management plan that accounts for evolving water supply priorities, growing demand and scarcity, and institutional changes is an urgent step to alleviate the growing tensions and preempt future water insecurity problems that are bound to occur if demand management approaches are delayed.

Agricultural Water Use in Lake Urmia Basin, Iran : An Approach to Adaptive Policies and Transition to Sustainable Irrigation Water Use

2012

The Lake Urmia positioned in a closed basin in northwest Iran, positioned at altitude 1250 m above the sea level, and has been rapidly drying since 1990. The lake water level has declined to 1271.58 m in 2008 from the last highest record 1277.80 m in 1994. The lake water volume has fluctuated during the observation period and shows a drop from of 32 to 14.5 million cubic meters, while the lake salinity has increased from 205 to 338 g/l due to the evaporation and water inflow reduction. In the Lake Urmia basin, there has been an increase in public awareness of the possible environmental threat and the unpleasant socio-economical consequences on the region's inhabitants. The main aim of this study is to assess the current water use pattern in the Urmia Lake basin system with emphasis on the agricultural subsystem , and to propose adaptive measures and sustainable water management scenarios. The study shows that the main cause for these changes are the diversion of rivers and streams for agricultural irrigation; agriculture is a sector with one of the highest water demands, and frequent drought in early 2000s exacerbated the situation. In addition, a growing population and the increased development of agricultural land has led to an increase in unsustainable practices which have an unpredictable impact on the Lake Urmia ecosystem. This study investigates sustainable water use strategies for Lake Urmia basin, and considers economic and environmental factors, including the loss of valuable ecosystems that highlights social and ethical issues for the current and coming generations.