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Razyeh Lak, Javad Darvishi and Ali Mohammadi
Hydrogeochemistry, sedimentology and propose action plan to achieve salvation Urmia Lake
Preface
The comprehensive study project of Urmia Lake
has been started in Geological Survey of Iran
since 2007.
The project is focused on pathology of the Lake
and the most appropriate solution to save Lake
which is the greatest environmental hazard of
the century.
The special significance of Urmia’s National Park
• Urmia Lake is one of the important protected area in the word and perhaps, there is no such place in the world as considerable as Urmia Lake for foreign custodians of environment.
• Unesco has selected nine point emphatic protection in global program of “Man and Biospher” one of the selected points is Urmia Lake
• Ramsar Convention (1970) with 120 countries as members, has selected 20 meres for emphatic protection which Urmia Lake is one of them.
درياچه اروميه هاي ويژگيمشخصات و
37o, 5`38 تاo, 16` N Latittitude
45o, 10` 46 تاo E longtitude
5000 – 6000 Km2 Area
31500 Km3 Water volume
140 – 144 Km length
63 Km Width (Maximum)
16 Km Width (minimum)
6 – 14 m Depth
51801 Km2 Catchment area
388 mm/yr Average rainfall in basin
56 / 34 Mm3/yr Total discharge of rivers
980 -1200 mm/yr Average evaporation of the Lake surface
1278 – 1280 m Lake altitude to S.L.
17oc –35 oc Water tempreture
217 –350 Mg/lit Rate of salinity
%55 - %60 Rate of relative humidity
Physiographic features of Urmia Lake have been indicated in the table
Features of catchment basin and major rivers
Climatology
Remote sensing
Sedimentology
Hydrogeochemistry and brine evolution
Paleoenvironment
Water table fluctuation
The impact of man-made structures on environment
Presenting appropriate solution
The study of economic salt and brine
Investigation subjects
There has been a rational and positive relationship between rainfall
and water table variations, but since 2000, the relationship has been
removed and sea level of the Lake doesn’t follow the rainfalls
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Water table
variable
Climatology of catchment area 30 years precipitation records
Perecipitation
Compared with two Lakes in
Iraq and Turkey, it is revealed
that after 3 years of drought
and normalization of rainfalls,
the W.T. of two Lakes were
increased but w.t. of Urmia
Lake is decreasing as before
Water table variation
from 1976 to 2011
Remote Sensing
studies
Materials and method
Water:
• Sampling of catchment area waters
• Sampling of Lake brine (from 2007 to 2013)
• Chemical analysis of waters by flame photometer, ICP
• Monitoring of brine evolution
• determination of economical potential of Ions
Sediment:
• 120 meters cores (13, maximum 10 meters cores )
• 300 subsamples of sediments
• ICP-OES, XRD, grain size analysis, SEM
• Processing of data
• Interpretation
• Result and suggestion
Useful vessel for sampling in middle of the Lake
Field work and sampling equipment
Core sampling network
نتایج
درشت بلور شفاف ژيپس، 16رخساره
مورد مطالعه مغزهرسوبات موجود در سه ايو انطباق رخساره اي چينهستون
Stratigraphy of column indicates that the Lake has nearly had Lacustrine deposited with 5-6 m thickness since 13000 years ago
16
-50
cm
Kelt & Shahrabi, 1987
17
Paleoclimate records from Lakes in Africa and southern Asia
3000 6000 0 BP
Water table fluctuation during 80 years
6.8
Water table decline is nearly 7m but salt is deposited on the floor and perhaps in the deepest part of the Lake, salt has deposited with more than 5 m thickness
Hydrography of the Urmia Lake before salt deposited In the time of decreasing the w.t. of the Lake, hydrography has been
changed by salt deposition and converted to salt pan
Hydrogeochemistry of catchment and type of water
21
كم آبي
خشك
روند تكامل
شورابه
Changing of major Ions of brine to 3 conditions , wet, semi arid and arid from 2007 to 2011 During the time, sodium value is decreased comparing to Mg value so that Mg value will be more than Na which indicates huge amounts of Halite have been deposited on Lake’s floor and sodium has passed from solution phase to solid phase
23
2002 and 2005
Brine evolution diagram (after Hardie and Euguster, 1978).
24
Waren, 2001
Ecological W.T.
In fact, changing course of the Lake’s conditions is changing course of a sedimentary basin from formation to death. This course should be occurred during long geological times, but unfortunately, it occurred during one decade. To rescue the Lake, previous conditions should be returned (a reversed trend must be happened) which is very difficult and by only management of existing water resources, it is impossible
GSI proposed plan for rescue the Lake
• It is necessary to save the Lake step-by step
• decrease of concentration and volume of
salt before recharge is good for reserving
water resources.
• In fact, the density can be reached to lower
than 1.3 by decreasing salts which is done
with less volume of fresh water.
1. Partial extraction of remained salts from
Lake’s floor, economic exploration from
salts and concentration a salt processing
unit
2. Extraction of economic evaporated salts
from Lake’s saltwater and subsequently
concentration decrease of salt during in
taking and saving the Lake from certain
death
Created opportunity beside great threat
• Solved elements in Lake’s brine are
economic
• Based on former researches, the Lake has 5
billion cubic meters salts and 10 billion
qubic meters halite including economic
minerals such as Silvite, Carnalite,
Magnesite and other evaporated minerals
for final development of brine
• At present brine is enriched of Mg and Na
Explaining detailed steps: 1- systematic samplinng of sediments, salts and brines
from basin
2- the area with highest density is selected as target area for brine sampling
3- experimental extraction:
• Saltwater sampling (nearly 2500 liters)
• Labratory construction and installment of metal pans to study the evaporation trend.
• The study of crystallizations trend.
• Constant measurement of volume, density , pH, brine temperature.
• The method is to plot profiles for 6 areas of the lake.
• The profiles have started from lakes margin and coastal salts and extended to lakes water in the center
• In each profile, 10-12 exploration core were diged in every 500 m – and in every digging well salt samples were surveyed at the maximum depth of one meter on every 10 cm (10cm-intervals).
The study of economical value of salts
مقایسه امالح و نمک های بخش شمالی و جنوبی
پل )محل برداشت نمونه اول و دوم در ضلع شمالی و جنوبی جاده
(شهید کالنتری
محل های نمونه برداری از بندر رحمانلو
محل های نمونه برداری از دهکده توریستی باری
محل نمونه برداری از ساحل کاظم خان داشی
Considering that every year remarkable amounts of salt enter the lake, the salt can be extracted at least as much as annual Input of salt (nearly 2 to 5.2 million tons in year) especially potasium and magnasium salts and through this, area's economy will be developing.
Studies and operations for modern and industrial extraction of salt from Urmia lake are as follows:
• In 1959,ministry of industries and mines at that time, invited an expert of installment of Dead sea salt extraction named Block to study the salt deposits of the lake and to train technical staff for Urmia lake. He suggested annual production of 50 thousand tons potash from the lake.
• Iran's petrochemical company studied the chemical composition of the lakes water to meet essential salt in 1956. The study of valuable salts of the lake was performed with – financial support of underprivileged foundation and consulting engineers of energy and industry in 1989.
• Geological Survey of Iran started the project of extraction economical ions from the Urmia Lake with emphasis of environmental condition. Save the Urmia lake is the main goal of the plan.
Result of salt and brine extraction
Extractable salts of the lake followed by solar evaporation processes and filtering process include halite, potash, magnisum compositions, sodium and brome, each of them can produce other beneficial chemicals by technological processes. These chemical are magnesium oxide, metal magnesium, Potasium, chloridric acid, brome, Amonium Hydroxide etc.
Action plan proposed
Considering that sedimentary environment has converted from lake to playa and a very thick layer of salt has deposited on the floor, entering of fresh water with low volume cannot save the lake.
• 1-Tactful management of water resource especially in agricultural section is necessary to control the destruction trend.
• 1- Dividing the lake into smaller parts and conserving the deeper part at the first step.
• 2. Extracting salt with economic usage especially magnesium, sodium sulfate and other valuable evaporite minerals.
• 3- Using private sector and foreign consultants who are experts in saline lakes
partitioning the lake and saving each part
separately.
part1
Part 2
Part 3
Part 4
Thank you for your attention
