Decline of the Indus Valley Civilisation is still elusive. All excavations near the coastal part of the Indus however proved that the decline of this ancient civilisation occurred suddenly between 1800 BC and 1700 BC. Earlier some western historians denoted the Vedic people were barbarous and they devastated the earlier civilisation and built up their own. Now the modern research proved that Vedic civilisation was diminished not by the external aggression but by the frequent flood and other natural disaster at that time. It was proved by Kenneth Kennedy in the year 1994. After this examination the debate regarding the decline of Indus Valley Civilisation curtained and also proved wrong of the previous research done by Sir Mortimer Wheeler who stated that Indus Valley civilisation ended in the massive aggression. He stated it while he discovered a group of 37 skeletons found in various parts of Mohenjo-Daro, and passages in the Vedas referring to battles and forts. Such theories of a violent end have been partly proved by the discovery in Mohenjo-Daro of human remains that indicated a violent cause of death. Some of the scholars also denoted Mohen jo- Daro as a "mounds of dead". However such evidence was not persistent as most other cities showed an absence of a massacre. The possibility of the Aryans being involved in such war content seems unlikely, especially since recent excavations have shown that the Aryans arrived almost 500 years after the decline of the major Indus Valley Civilisation`s cities.

Effects On Urbanisation in Indus Valley Civilisation
The theory of climatic factors causing the decline has been gaining credibility, in the light of the recent research. Around 2000 BC major ecological changes began taking place in the Indus Valley. While the tectonic changes caused the creation of a dam in the lower Indus, that created the frequent floods and disaster in the fertile the plains of the coastal part of Indus. This effected in the rural and the urban life and lifestyle of that region. Many Indus Valley Civilisation cities show signs of having been abandoned and then rebuilt, indicating they were frequently flooded. This led to the annihilation of the entire civilisation. The urban cities were no longer built with the care they were earlier, broken mud-bricks were used for construction and no attention was paid to a proper sewage system. Also the average rainfall in the area began decreasing as the area slowly began turning into the desert it is today.

Rural Decline in Indus Valley Civilisation
The main livelihood of the inhabitants of Indus valley is agriculture. They are mainly based on the agricultural products for livelihood. Such major climatic changes created the devastating effect in economy and in the social life. The influence the big cities had on the rest of the region was based largely on the amount of grain they stocked in their granaries. Once agricultural production declined the influence of the cities declined and eventually the region went into a state of anarchy. It created the political tension in the internal life of the Indus Valley civilisation.