Giosan et al., in their study "Fluvial landscapes of the Harappan civilisation", make clear that the Ghaggar-Hakra fluvial system was not a large glacier-fed Himalayan river, but a monsoonal-fed river. They concluded that the Indus Valley Civilisation prospered when the monsoons that fed the rivers diminished around 5,000 years ago. When the monsoons, which fed the rivers that supported the civilisation, further diminished and the rivers dried out as a result, the IVC declined some 4000 years ago. This in particular effected the Ghaggar-Hakra system, which became an intermittent river and was largely abandoned. Localized Late IVC-settlements are found eastwards, toward the more humid regions of the Indo-Gangetic Plain, where the decentralised late Harappan phase took place.