Orographic uplifting is usually defined as the forceful rising up of air mass from a low elevated region a high elevation region, as the wind strikes the mountain and travels over the high mountains. When the air mass rises upward, it undergoes expansion, and gradually cools due to the low atmospheric pressure at the higher elevated region. With subsequent cooling, condensation takes place, and under favorable and correct conditions, it results in the precipitation.
There are many places on earth where orographic uplifting takes place such as in the western ghat of India and the southern part of Andes.
Negative impacts of siltation identified include destruction, of fish breeding areas, flooding, poor water quality affecting human and animal use and increased resource user conflicts.
