The latest pictures show that the water level is raised by at least 36 cm in Lake Urmia and coastal waves are observed once again on the water body. It is heart warming and I am still praying for the Lake. Too sad for me, cause once it was one of the main aspects and features of my home town. I spent my childhood swimming in this lake and now my heart is broken when I am looking at the seen. May god help us saving the lake, Amen!!
After being done with Runoff time series, it is inevitable challenge the groundwater time series. As I mentioned before (1, 2, 3), I think coastal aquifers have very significant affect on the lake itself. Their flux to the lake or even the salinity intrusion from lake to the aquifer are the consequences of this interaction.
Most of the researchers used to handle this interaction with Darcy's law (Darcy, 1856), while others try to control it by the chemical components that transfers between lake and aquifer. Such methods are useless for me cause I don't have any observation data on chemical components and/or hydraulic conductivity between lake and aquifers. Thus, I tried to solve it by simplifying the problem.
Figure 1 shows the potential elevation of the aquifer in comparison with lake water level. As a potential depth of influx/drainage it can be used as the potential depth which would affect the lake surface at most correlated wells near the shore line or from underneath.
Fig.1. Schematic of potential influx/outflow between lake and coastal aquifers
For this, in the first place an iso-correlation map between lake and coastal aquifer will be generated. In the next stage an iso-correlation map with different lag times (Cross-correlation) will be investigated also. Then, proper wells (i.e. most correlated ones) will be selected and iso-height maps of water level in aquifers will be recognized. Then the potential depth between lake and aquifer will be calculated by subtracting the Lake water level from wells' water level.
This values could be positive or negative which defines the availability of GW in flux/draining the lake, which would be very handy in my calculation. In addition, I will not loose site of depth while using a semi-water budget or mass balance equation while all variables have dimensions in length.
Please do not hesitate to share your point of view with me
By: Ali Mirchi, Kaveh Madani and Amir AghaKouchak for Tehran Bureau
New research shows Iran’s most famous lake has shrunk by nearly 90% since the 1970s. Scientists urge action
Lake Urmia in Iran on 8 August 2010 Photograph: Alessandro Marongiu / Demotix/Alessandro Marongiu / Demotix/Demotix/Corbis
In the late 1990s, Lake Urmia, in north-western Iran, was twice as large as Luxembourg and the largest salt-water lake in the Middle East. Since then it has shrunk substantially, and was sliced in half in 2008, with consequences uncertain to this day, by a 15-km causeway designed to shorten the travel time between the cities of Urmia and Tabriz.
Historically, the lake attracted migratory birds including flamingos, pelicans, ducks and egrets. Its drying up, or desiccation, is undermining the local food web, especially by destroying one of the world’s largest natural habitats of the brine shrimp Artemia, a hardy species that can tolerate salinity levels of 340 grams per litre, more than eight times saltier than ocean water.
Effects on humans are perhaps even more complicated. The tourism sector has clearly lost out. While the lake once attracted visitors from near and far, some believing in its therapeutic properties, Urmia has turned into a vast salt-white barren land with beached boats serving as a striking image of what the future may hold.
Desiccation will increase the frequency of salt storms that sweep across the exposed lakebed, diminishing the productivity of surrounding agricultural lands and encouraging farmers to move away. Poor air, land, and water quality all haveserious health effects including respiratory and eye diseases .
The people of the north west – mainly Azeris and Kurds – are raising their voices. The Azeris, one of Iran’s most influential ethnic groups and about a third of the country’s population, venerate Urmia as a symbol of Azeri identity, dubbing it “the turquoise solitaire of Azerbaijan”. The region is also home to many Kurds, who are demanding a bigger say in the management of the lake to improve the livelihood of Kurdish communities.
President Hassan Rouhani has shown he is listening, referring to Urmia during his election campaign, and subsequently promising the equivalent of $5 billion to help revive the lake over ten years. Solutions, however, require agreement on the main causes of the problem, and this motivated a group of concerned Iranian researchers in the United States, Canada, and United Kingdom to carry out an independent, first-hand assessment beginning in 2013. Because of the unavailability of reliable and consistent ground-truth data, the team used high-resolution satellite observations over the past four decades to estimate the lake’s physiographic changes.
Lake Urmia, Iran 1972-2014
The results of this investigation, which recently appeared in the Journal of Great Lakes Research, revealed that in September 2014 the lake’s surface area was about 12% of its average size in the 1970s, a far bigger fall than previously realised. The research undermines any notion of a crisis caused primarily by climate changes. It shows that the pattern of droughts in the region has not changed significantly, and that Lake Urmia survived more severe droughts in the past.
The lake’s surface area naturally varies to some extent between wet and dry seasons and the situation has eased somewhat with seasonal precipitation that occurred since September. But the magnitude and timeline of the shrinkage – frequently attributed by the Iranian water authorities to years of below-average precipitation – are unquestionably beyond the ordinary, and suggest that the lake may have reached a “tipping point” leading to sudden death. If Lake Urmia is to be revived, the authorities must look urgently at the construction of dams and irrigation projects designed to boost agri-business and meet growing regional water demand.
The tragic demise of the Aral Sea in central Asia is a chilling precedent. Once one of the world’s largest lakes, the Aral Sea faded away due to diversion of water for agriculture from its tributaries, the Amu Darya and Syr Darya rivers. The Aral Sea became a hallmark of poor agricultural water management in the Soviet era. Over the course of five decades its surface area dropped to less than 10% of its original extent in the 1960s
It is ironic that the collapse of Lake Urmia and other Iranian water bodies such as Shadegan, Gav-Khuni, Bakhtegan, Anzali, and Hamouns comes in the country where the 1971 Ramsar Convention was signed. As a pioneering intergovernmental treaty for conservation and sustainable use of wetlands, Ramsar envisaged action by both national governments and international co-operation.
Just five years later, in 1976, UNESCO (the United Nations Educational, Scientific and Cultural Organisation) designated Lake Urmia a biosphere reserve toencourage sustainable development grounded in community involvement and sound science.
Given the far-reaching socio-economic effects, and human health impacts that may extend beyond Iran’s borders, Lake Urmia’s collapse requires active involvement of international organisations that can provide expertise and financial resources, even if their efforts to help are complicated by sanctions blocking financial transactions. These include UNESCO, the United NationsDevelopment Programme (UNDP), the Global Environment Facility (GEF), the World Bank, World Climate Research Programme (WCRP), European Commission Joint Research Centre (JRC) and World Health Organization (WHO).
On the bright side, growing public awareness about water scarcity, mismanagement and waste may pave the way for re-establishing a balance between natural water supply and water demand. The three provinces that share the Lake Urmia basin - East Azerbaijan, West Azerbaijan, and Kurdistan - and the Iranian government have joined forces to devise promising restoration ideas, including stopping dam construction, managing the existing reservoirs and regulating the use of the agricultural lands. Such changes could augment the lake’s inflow, limit additional surface water and groundwater withdrawal, and mitigate salt blowouts and sand storms.
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However, this is barely enough for any realistic optimism. Demand-side management plans to reduce the basin’s water use must go in effect immediately, and proposals for water transfer - which have had harmful ecological and socio-economic side-effects in other parts of Iran - need drastic revision. There is an obvious need, too, for schemes to compensate current water-users for any losses.
While international help is important, Iranians must lead restoration efforts, for Lake Urmia and other water bodies. Iran’s push for development is taking a toll on the nation’s water resources in a mostly arid and semi-arid country as short-sighted projects transfer water to supply inefficient agriculture and growing urban areas. Without a pragmatic action plan, the country faces severe water stress.
The authors were all involved in the independent investigation of Lake Urmia. Ali Mirchi is a postdoctoral research associate at the Department of Civil and Environmental Engineering, Michigan Technological University; Kaveh Madani is a lecturer in Environmental Management at the Centre for Environmental Policy, Imperial College London; Amir AghaKouchak is an assistant professor at the Department of Civil and Environmental Engineering, University of California, Irvine
The largest lake in Iran is shrinking rapidly, threatening tourism and health.
The surface area of Lake Urmia — a vast, shallow, saltwater lake in northwestern Iran — has declined 88 percent since the 1970s due to water diversions siphoning supplies away from the freshwater rivers that supply the lake, according to a study published in the Journal of Great Lakes Research in March. Tourism in the region has fallen with the water levels, and serious health risks are on the rise as dust storms pick up salts from the exposed lake bottom and sweep them across towns and farm fields.
In the infographic below, the satellite images show the change in lake area between 1975 and 2015, while the graphs track changes in the lake’s water levels.
Lake Urmia, a large lake in Iran, is shrinking because too much water is being pulled from the rivers that feed it. Click image to enlarge.
Codi Yeager-Kozacek contributed reporting to this graphic, which is the first in a five-week series documenting threats to the world’s largest lakes. Click here to read Circle of Blue’s report about Lake Urmia and other endangered lakes and here to view an interactive map of threats to the 20 largest lakes in the world.
Tomorrow is my 3rd thesis report day. I am now finished with the presentation and I just started to do analysis on groundwater.
In the first place, I started with Pearson correlation coefficient. Result are very interesting, as I mentioned before, there is a strong evidence that groundwater and lake have strong relations. Accounting for a probable cross-correlation lag between lake and ground water, it sounds like interaction between these two are inevitable. AS you can see in Fig.1 Pearson correlation coefficient in West bank of the Lake is negative while positive correlations are observed in the East bank of the lake.
Fig.1. Iso-correlation map of the Lake Urmia, defining the negative correlation coefficient for the West (Left) and positive correlation for the East (Right) bank
This values some how make sense while, the incline of the terrain in the West bank is more rapid and sharp. Fig. 2 shows a schematic representation of geological features in the Lake Urmia. In the West bank of the lake, groundwater elevation changes in reverse order with the lake and decreases when the lake water level increase. On the other hand, in East bank, lake water level and ground water elevation changes in the same way. This could be an evidence to recognize that, salinity intrusion is more severe in the East bank of the lake (East Azerbaijan) while the West bank plays more active role in interaction.
Fig. 2. Schematic of lake Urmia and the possible interaction between lake and coastal aquifer
The latest satellite view of Lake Urmia (Source: Campaign on Lake Urmia Rescue Telegram Channel).
Fig. 1. Nasa Aqua satellite view of Lake Urmia and remaining water in the North of the Lake (Dec 21, 2015)
Fig. 2. LandSat image about the project of linking Zarrine and Simine River in the South of lake as one of the main rescue projects (November 21, 2015)
As I discussed previously, I am a true believer of existence of interaction between coastal aquifer and Lake Urmia water level. Many authorities and politicians refuse to accept the theory and there are some research articles based on rejection of existence of such an interaction.
Recently I used to publish a conference paper (ASCE, EWRI 2015) about the interaction of water level in some random coastal aquifers in West coast of the Lake Urmia basin and water level in the Lake itself. I used a soft computational method named "Decision Tree" to manipulate my model. It is based on Entropy and probability. Evidence and results of this model are in agreement with a theory of existence of such interaction in Coastal aquifer.
Fig. 1 shows the schematic relation between lake and coastal aquifer which I believe that exist in the hydrological process. In general in closed basin lakes, such interaction is one of the main hydrological variables that should be considered and studied carefully.
Fig. 1. Schematic of interaction of coastal aquifer and Lake Urmia in balance
So I used to select some random wells just near to the west coast of the lake. You can find the position of this wells in Fig. 2. Data in east coast is not ready for use for now and I will try to manipulate them a.s.a.p. Followingly, a Pearson correlation coefficient test between Lake water level and water level in wells is done and interesting results are shown in Fig. 3 with a radar chart including the direction of such relations.
Fig. 3. Correlaogram radar chart
Fig. 2. Position of wells in west coast of the Lake
It is obvious that, there is strong linear relationship specially in North and South of the basin all with negative values. Same analysis on probability distribution function of lake water and water level in wells showed strong similarities in shape and moments of distribution. I have done some investigations on the structure of cross-correlations in time and space between lake and coastal aquifer. Two samples of such investigation are shown in Fig. 4. You can see seasonality and strong interaction between lake and coastal aquifer. As shown in Fig. 3 and 4, these two stations (Station 1 and 6) have the most impact on the interaction.
Fig. 4. Cross-correlation between lake water level and water level in wells of station 1 and 6
I though a model may reveal more detailed structure of the relation, so I used to select a probabilistic one. As entropy concept is very popular now a days I used DT for manipulation of data and calibrated my tree. Here is the scatter plot of my model in Fig. 5. As you can see these are strong estimation result and I personally satisfied with the results.
Fig. 5. Scatter lot of DT model
That is all I was eager to share for now!
So I think I proved my theory at least to some extent. You may find out my paper's abstract in Related page in my weblog and/or download the whole article from ASCE library.
