Sistan Basin

The Sistan Basin is a very dry place.

It sits in Iran and Afghanistan. Rivers flow from high mountains into this land. This water makes shallow lakes. These lakes are called hamuns. Sometimes the lakes dry up. This makes it hard for people to live there. People use reeds from the water for food and fuel. Long ago, many people lived here. They built big cities near the rivers. Now, the land is mostly empty and sandy.

The Sistan Basin is a very dry place.

It sits in parts of Afghanistan and Iran. Rivers flow from high mountains into this land. Most of this water comes from the Helmand River. This river gets its water from melting snow.

The water flows into shallow lakes called hamuns. There are three main lakes now. They are Hamun-e Puzak, Hamun-e Sabari, and Hamun-e Hirmand. Sometimes floods join the lakes into one big lake. But the area can also face long droughts. Between 1998 and 2005, the lakes dried up completely. This makes life hard for people. They need the water for farms and fishing. They also use reeds from the lakes for fuel and building.

Many people lived here a long time ago. One old city is called the Burnt City. It was built in 3100 B.C. Other old cities are now covered by sand. You can still see old water paths in the ground. Today, not many people live in this area.

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.

The Sistan Basin is a massive inland endorheic basin. An endorheic basin is a land area where water does not flow to the ocean. Instead, water collects in internal lakes or marshes. This basin covers parts of southwestern Afghanistan and southeastern Iran. It is one of the driest regions on Earth. It is often subject to very long periods of drought.

The basin's watershed is a complex system of rivers. These rivers flow from high mountains into freshwater lakes. Eventually, the water reaches the saline Godzareh Depression. This depression is part of the larger Sistan terminal basin.

The hydrology of the basin depends on the Helmand River. This river drains the largest watershed in the area. It is fed mainly by snowmelt from the Hindu Kush mountains. Other smaller rivers also contribute water to the system. At the lowest point of the basin, several shallow lakes exist. These lakes are called hamuns. In the past, there may have been a single Hamun Lake. Today, there are three distinct lakes.

The three hamun lakes have specific locations and water sources. The first is Hamun-e Puzak, which sits mostly in Afghanistan. It receives water from the Khash River and the Shelah Charkh channel. The second is Hamun-e Sabari, which is split between Afghanistan and Iran. It is fed by the Farah River, the Harut River, and the Parian branch of the Helmand. The third is the largest, Hamun-e Hirmand, located entirely in Iran. Most of the Helmand River's water flows into this lake via the Rud-e Sistan channel.

Water levels in these lakes change dramatically over time. During periods of heavy flooding, the hamuns join into one large lake. Roughly once every 20 years, floods create an overflow. This overflow travels through the Shela Rud, a normally dry river. This water then terminates in the Godzareh Depression. In 1885, an exceptional flood filled that depression for three years. However, recent years have seen the opposite effect. During a drought from 1998 to 2005, the hamuns dried up completely.

The ecology and economy of the region rely on these wetlands. Local people depend on agriculture for their survival. This farming requires snowmelt and rainfall from high mountains. The water supply fluctuates severely, creating survival problems for human settlements. The wetlands also provide vital raw materials. For example, reed beds provide food for livestock. People also use reeds for cooking fuel and heating fuel. Reeds are used to build structures and create various handicrafts. When water is available, fishing and hunting provide important income. When the drought arrived, the local economy collapsed. This also destroyed the ecological system and damaged irrigation in the Helmand delta.

The Sistan Basin has a very deep history of human habitation. Sophisticated cultures have lived here for more than 5,000 years. One notable site is Shahr-e Sukhteh, or the "Burnt City," in Iran. It was built in 3100 B.C. near a branch of the Helmand River. People likely abandoned it 1,000 years later due to climate changes. Another Bronze Age site, Shahdad, is located further west near the Lut desert. In Afghanistan, the medieval hubs of Kang and Zaranj are now covered by sand.

Archaeologists have found many significant remains throughout the basin. In the Dasht-e Margo and Chakhansur areas, old irrigation canals are still visible. Elsewhere, sand has buried agricultural fields and filled canals with silt. On Mount Khajeh, a basalt hill, researchers found a citadel complex. They also found the remains of a Zoroastrian fire temple. Other major sites include Dahan-e Gholaman, a likely capital of the ancient satrapy of Zranka. Ram Shahristan was another ancient capital of the Sistan region. Today, the area is sparsely populated due to these harsh conditions.