Water Cycle Basics

What is a Watershed? An area of land that drains all of the streams and rainfall to a common outlet such as a river or bay.

Narragansett Bay Watershed

Groundwater/Types of Aquifers Confined Aquifer: solid bedrock separating it from the earth’s surface; confined by a rock layer that does not transmit water in any appreciable amount, or is impermeable. Less likely to become contaminated. Unconfined Aquifer: the aquifer formation extends essentially to the land surface; re-charged by precipitation; contamination from earth’s surface could seep down into it. Aquifer: Anywhere that water is stored underground; a layer of sediment or rock in the underground through which water can flow through. Bedrock Aquifer: another common type of aquifer; solid rock, like granite, with cracks in it that water can seep through. Deep below the earth’s surface. Sand and Gravel Aquifer: one common type of aquifer in RI; simply wet areas of sand and gravel – they look a lot like what happens if you dig a deep hole at the beach Aquifers can be either:

What can affect water quality? Type of Precipitation (rain, snow) Rainfall intensity Rainfall duration Rainfall amount Land use Vegetation Soil type Elevation Topography, especially slope of the land Dissolved oxygen pH Temperature Pesticides, fertilizers Chemicals, oils and grease Detergents Litter/rubbish

Source of Groundwater Contamination

Swamp Freshwater marsh Vernal pond Tidal/salt marsh Many others! (bog, fen, mangrove swamp) Types of Wetlands: What is a wetland? Areas where water covers the soil, or is present either at or near the surface of the soil all year or for varying periods of time during the year. Water saturation (hydrology) largely determines how the soil develops and the types of plant and animal communities living in and on the soil. May support both terrestrial and aquatic species. Nature’s way of cleaning the water! Prolonged presence of water creates conditions that favor the growth of specially adapted plants (hydrophytes) and promote the development of characteristic wetlands (hydric) soils.

SWAMP

FRESHWATER MARSH

VERNAL POOL

SALT MARSH