By Faranak Bakhtiari

Parishan Wetland: West Asia's largest freshwater at drought tipping point

July 20, 2020 - 22:40

TEHRAN –Parishan Wetland, the largest freshwater lake in Iran and West Asia, dried up in recent years and is struggling to death due to excessive groundwater withdrawal.

Parishan is located in Kazerun County, Fars Province, and receives only a very small amount of water from Feeder Rivers and the whole lake or wetland is a protected area, as it is considered a globally significant wetland ecosystem.

Wetlands play a significant role in the natural cycle and, as one of the most important natural habitats on earth are of great importance in sustaining wildlife, providing fresh water, and maintaining biological balance, so their extinction has devastating effects on nature.

Moreover, attracting tourists, mass migration of migratory birds from around the world, reproduction of fish and other aquatic species, and creating a suitable environment for the life of special plants in that area are among other beneficiaries of these ecosystems.

Ezatollah Raeisi Ardakani, professor at Shiraz University and Iran's father of groundwater hydrology told IRNA on Monday that wetlands evaporate water, water evaporation lowers the temperature and creates humidity, the lake's humidity satisfies the water needs of the plants around the lake, whether pasture, agriculture or forest.

He went on to explain that migratory birds that come around the lake spread their feces around the lake, forest, and agricultural lands and as manure fertilize the surrounding lands.

In addition to Parishan, Fars province has two other freshwater lakes called Kaftar and Arzhan. But the most important wetland in the province is Parishan, which is recognized in the Ramsar Convention as an international wetland of importance that must be protected, but in recent years, the wetland has faced severe crises.

Water withdrawal way above rainfall rate

In the past, the amount of water harvested from the lake was proportional to the amount of rainfall, Raeisi lamented. 

For example, in 1981, two million cubic meters of water was harvested from the lake, which was proportional to the rainfall of that time, but in recent years water withdrawal from this wetland is not consistent with current rainfall, he added.

And more than 28 million cubic meters of water is extracted, which, along with several cultivations, has been very effective in emptying groundwater aquifers, he further regretted.

In salt lakes, the water becomes saltier with a little more water withdrawal, so water is harvested to a certain amount, while in freshwater lakes there is no such restriction, and people deepen the wells to have more water and this causes the lake water to dry out, he explained.

"Currently, the groundwater level of the lake is about 5 meters below sea level, which if the water withdrawal continues in the same way, the water can drop by 10 or 15 meters," he emphasized.

Strengthening groundwater aquifer 

Nothing is more effective than the level of the groundwater aquifer in the lake's revival, he stated, adding, even if the rainfall increases, the problem will not be solved until the groundwater aquifer is improved, and there is no other way but to reduce the harvest.

Raeisi added that measures such as shutting down illegal wells, placing meters on permitted wells, and setting a certain amount of quota for permitted wells could be a solution.

"The Ministry of Energy intends to transfer 10 million cubic meters of water from Nargesi Dam to the lake, but given that the lake has a capacity of 70 to 80 million cubic meters, probably cannot solve the problem," he noted.

Over-harvesting by drilling wells 

There are about 300 illegal wells and 650 permitted ones around the lake that draw water without any restrictions or limitations, Hamid Zahrabi head of the provincial department of environment said.

The gas power plant, which is located near the lake, has 2 wells, which draw 1,200 cubic meters of water in every 24 hours in winter and 1,700 to 2,000 cubic meters in summer, he noted, stating, obviously, every year 500 to 600 thousand cubic meters of water is significant and will have dire consequences.

Plant and animal species 

Zohrabi also noted that after the lake has dried up, the submerged aquatic vegetation has disappeared, but reeds have grown more in the wetland, especially in late winter and spring.

Fish, benthos, and phytoplankton have also been completely extinct and have not been seen since the early 1390s (falling on 2011-2021), he lamented, adding, migratory birds are no longer seen in the lake, but animals such as monkeys and foxes and some native birds are found in the area.

Due to the uncontrolled harvesting of agricultural lands, in recent years it has increased from one crop to several; in addition to the groundwater resources declined sharply, he regretted.

Parishan wetland management plan and other plans to rehabilitate the wetland have been prepared, but some responsible bodies have not taken this issue seriously, he added.

Programs such as dredging the lake bed and waterways entering the lake, conducting watershed management operations to prevent sediment from entering the lake, educational programs and training courses for public awareness, implementing a sustainable agricultural pilot project in Qaleh Narenji village, preventing land-use change around the lake are among the plans that have been carried out in this regard, he concluded.

Why wetlands should be protected?

Wetlands, as the most important natural ecosystem, are one of the most vital, fertile, complex, and sensitive habitats on earth, which are of special importance and their preservation and protection is a basic goal.

Wetlands are of great economic, social, and ecological importance. Local communities are also dependent on the functions of the wetland in terms of livelihood and face problems with decreasing wetland production.

Parishan wetland is also of special importance as the largest freshwater wetland in Iran and West Asia, but in recent years, this wetland has been depleted due to various factors, and many plant and animal species have been degraded.

Human and natural causes of drought in this wetland are both to blame, but poor management is undeniable; actions such as reducing planting periods, preventing new wells, and controlling the amount of water withdrawn by wells can prevent further depletion of groundwater and help revitalize the wetland.


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