Describe the interrelationship of the hydrologic cycle, streams, floods, and landslides.
The volume of water that falls as precipitation in southeast Alaska averages more than 100 inches a year for the
region. Despite the amount, most of this precipitation runs off the land into lakes and streams as surface water, and
only a small amount filters into deeper layers as groundwater.
The interrelationship of fresh water, surface water, groundwater, and the ocean systems—the hydrologic cycle—is
shown in Figure 96. The earth's capacity to accept, store, and yield water depends on the type, size, number, and
degree of interconnections that can store and conduct groundwater. The relative amount of water retained in,
released to, or rejected from the ground depends on the nature and distribution of materials present in the shallow
parts of the earth's crust.
Sand and gravel store large amounts of water and transmit it readily. These permeable deposits are referred to as
groundwater aquifers. Clay may contain as much or more water per cubic foot than sand and gravel, but it holds
water in such small pores that it cannot be transmitted to wells in usable quantities—it is impermeable. Compact
bedrock that contains water only in fractures is also impermeable. Impermeable material acts as a barrier to water
movement through the ground.
Copyright 1998-2004, UAA-ISER.
): The cycle of
movement from the
to the earth and back to the
The description of the transport of water substance between the earth, the atmosphere, and the seas. Or In
hydrologic terms, the natural pathway water follows as it changes between liquid, solid, and gaseous states