Answer:
Rivers transport particles, from fine ones such as silt in turbid water to coarser ones such as sand, gravel, and boulders associated with bed-load transport. The speed and turbulence of currents enable transportation of these materials. When riverbed gradient or the river flow diminishes, particles tend to drop out.
Explanation:
The Khmer civilization was mainly developed by Indian cultural importance. Buddhism was flourished side by side with the offering prayer of Shiva and Hindu Gods, both the religions combined with the worship or devotion of the idolized king. Many Indian scholars, artists, and religious teachers were attracted to the Khmer court. Small temples set on stepped pyramids next appeared during the Khmer period. The Khmers opposed and then fought returned wars against the Annamese.
I believe the answer you're looking for is temperature and precipitation.
Climate is based on the amount of rainfall (i.e. a rainforest) or the temperature (i.e. a tropical climate)
The country's inability to supply enough food or jobs for its rapidly growing population.