Sistan Basin

The Sistan Basin is a very dry part of the world.

It sits in parts of southwestern Afghanistan and southeastern Iran. This area is what scientists call an endorheic basin. This means the water does not flow out to the ocean. Instead, rivers flow from high mountains into lakes and marshes. The water eventually reaches a salty place called the Godzareh Depression. The Helmand River is the most important part of this system. It carries much of the water from melting snow in the Hindu Kush mountains.

At the lowest part of the basin, there are shallow lakes. These lakes are known as hamuns. Long ago, there may have been only one single Hamun Lake. Now, there are three separate lakes. The first is Hamun-e Puzak, which is mostly in Afghanistan. The second is Hamun-e Sabari, which sits in both Afghanistan and Iran. The third is the largest, called Hamun-e Hirmand. It is located entirely in Iran. Most of the Helmand River flows into this lake through a channel called the Rud-e Sistan. During big floods, these lakes can join together into one huge lake.

Water is very important for the people living in this region. They use the water for farming and for fishing. The wetlands also provide many useful things from nature. For example, people use reeds from the lakes to make fuel for cooking. They also use reeds to build structures and make handicrafts. However, the water levels change a lot over time. There are times of big floods and times of long droughts. Between 1998 and 2005, the hamun lakes dried up completely. This made it very hard for people to survive and earn money.

This dry land has a very long history of people living there. People have built cultures in the Sistan Basin for over 5,000 years. One famous place is Shahr-e Sukhteh, which means the "Burnt City." It was built in 3100 B.C. in Iran near a branch of the Helmand River. People left that city about a thousand years later. They might have left because the river changed its path. Other old cities, like Kang and Zaranj, are now covered by sand. You can still see old canals used for watering crops in some areas.

There are many other interesting things to find in the basin. On Mount Khajeh, you can find the remains of a fire temple. This temple belonged to a group called the Zoroastrians. There is also a large site called Dahan-e Gholaman. Some experts believe this was a capital city for an ancient land called Drangiana. Another ancient capital was named Ram Shahristan. Today, the area is not very crowded with people. Most of the land is quite empty and dry. Many of the old farming fields are now buried under shifting sand.