mountain ridges accompanied by plateaus and river basins. It is dominated by the Hindu Kush range, the western extension of the Himalayas that stretches to eastern Tibet via the Pamir Mountains and Karakoram Mountains in Afghanistan's far north-east. Most of the highest points are in the east consisting of fertile mountain valleys, often considered part of the "Roof of the World". The Hindu Kush ends at the west-central highlands, creating plains in the north and southwest, namely the Turkestan Plains and the Sistan Basin; these two regions consist of rolling grasslands and semi-deserts, and hot windy deserts, respectively. Forests exist in the corridor between Nuristan and Paktika provinces (see East Afghan montane conifer forests), and tundra in the north-east. The country's highest point is Noshaq, at above sea level. The lowest point lies in Jowzjan Province along the Amu River bank, at above sea level. Despite having numerous rivers and reservoirs, large parts of the country are dry. The endorheic Sistan Basin is one of the driest regions in the world. The Amu Darya rises at the north of the Hindu Kush, while the nearby Hari Rud flows west towards Herat, and the Arghandab River from the central region southwards. To the south and west of the Hindu Kush flow a number of streams that are tributaries of the Indus River, such as the Helmand River. One exception is the Kabul River which flows in an easterly direction to the Indus ending at the Indian Ocean. Afghanistan receives heavy snow during the winter in the Hindu Kush and Pamir Mountains, and the melting snow in the spring season enters the rivers, lakes, and streams. However, two-thirds of the country's water flows into the neighboring countries of Iran, Pakistan, and Turkmenistan. As reported in 2010, the state needs more than US$2 billion to rehabilitate its irrigation systems so that the water is properly managed. The northeastern Hindu Kush mountain range, in and around the Badakhshan Province of Afghanistan, is in a geologically active area where earthquakes may occur almost every year. They can be deadly and destructive, causing landslides in some parts or avalanches during the winter. The last strong earthquakes were in 1998, which killed about 6,000 people in Badakhshan near Tajikistan. This was followed by the 2002 Hindu Kush earthquakes in which over 150 people were killed and over 1,000 injured. A 2010 earthquake left 11 Afghans dead, over