Decline of Nazca:
Nazca dissolved around 700 CE. This decline is commonly said to be caused by earlier natural disasters. This includes drought, flooding from El Nino in late Decembers and drastic weather. These were overwhelming factors, along with their surrounding neighbors and heavier population.
Decline of Chavin
The flourishing state began to decline in 300 BC. Many historians have concluded that the Chavin decline was due to changes within the working communities, region slowing down, violent conflicts, and overly-domesticated land. Trade and income of goods began to slow down which decreased profit and surplus items. As the Chavin population increased, disorder broke out in the land. After many years the Chavin culture began to deteriorate. Archeologists have found that sites where ceremonies and religious practices were deserted by 500 BC.