is the study of water and its properties, scientific laws, and distribution.
Hydrologists study surface water and groundwater and their interactions,
which are part of the water
water is freshwater we see above ground. It includes streams, lakes,
ponds and wetlands. Groundwater is
freshwater that lies beneath the earth's surface. Most groundwater
is stored in aquifers. Aquifers
are areas underground where rock and soil are very porous.
features of streams and rivers undergo constant change. Throughout
a single day we may observe changes in water level, salinity, water
flow speed, discharge (the amount of water passing a point on the
river in a given amount of time), and sediment load (the amount
of soil and gravel suspended in the water). These changes are caused
by water input into the river. Rain and melting snow increase the
amount of freshwater in rivers. Rain falls directly into rivers,
and rainwater and melted snow on land surrounding the river runs
downhill into the river.