The Indus basin covers an area of about 1 million km2 (386,000 mi2) and touches 4 countries (China, India, Afghanistan, Pakistan). From its source in the Tibetan plateau the Indus river initially flows north west before bending south to flow south west through Pakistan to the Arabian sea. Snow and glacier melt water is the main water input for this river system as rainfall is low in this region, and is generally concentrated to the monsoon season of July to September. The lower reaches are very braided, meaning the river has many channels, and flow is slow though the arid plains region where evaporation is high. The river ends in a delta which includes numerous mangroves. These mangroves are an important resource not only for wild live and maintaining biodiversity but also for the millions of people who depend on them including fishermen. The system relies strongly on melt water, making it vulnerable to change particularly increased temperatures which will alter the pace at which the glaciers melt meaning (in the long run) river-flow in the Indus will be greatly affected.