CE 547 Term Project:

Environmental Setting of Oahu, Hawaii

Marwin Shendo

Background Objective:

The Island of Oahu is the 3^rd largest island Use ArcMap as a tool to display the different

of the State of Hawaii and by far the most types of environmental setting on the island.

populated island. Approximately 75% of Download data from GIS resources on the

state’s total population lives on the island. world wide web and display maps on rainfall,

Oahu was formed by 2 by the eroded loose surface waters, soils, and current land use/land cover

ends of the Wainae and Koolau volcanoes. on the island of Oahu, Hawaii.

Rainfall:

Rainfall is the main source of freshwater on Oahu. The quality of the rainwater affects both surface and groundwater quality. Rainfall is also characterized by maximum annual rainfall at high altitudes and steep gradients which exceeds 275 inches at times.

Surface Water:

Over thousands of streams and hundred watersheds have been identified on the island. Most if not all the streams originate in the rocky mountain core areas and expire near or at the cost. Streams on the island are flashy because of high-intensity rainfall, small drainage basin, steep slopes, and little channel storage. Most flow perennially throughout their entire course, others over parts of their course, and the remaining streams flow during certain months of the year.

Stream Gages: Are used to determine stream flow and

discharge at varies sites on the island. Gages determine wet and

dry seasons from year to year (map1 w/graphs) as well as month to month (map2 w/graphs)

depending mainly on rainfall.

Soils: Land Use/Land Cover:

National Resources Conservation Service Increases in population in the 20^th century (Graph 1) reflects the current land use/land cover

has identified 12 soil orders or major soil on the island of Oahu. As of 2000, 34% of the land on Oahu was classified as

types in the U.S. 11 have been found in the agriculture, 40% conservation(forest, range land, wetland, etc..), and 26% urban

State of Hawaii, only 9 are found on Oahu. development showing quite a bit of different from prior years (map3).

Conclusion:

The Island of Oahu is the 3^rd largest island in the State of Hawaii

and the most populated with about 890,000 people living on the

island. The island was formed by two volcanoes and landscape

ranges from costal plains to steep mountains. Rainfall is greatest

in mountain ranges of the island and lowest in the southwestern area.

Most streams begin in the mountains and terminate at the coast. Streams

commonly flow perennially in the interior area of the island and where Future work:

rainfall is constant. Rainfall also affects the stream flow and discharge at After looking over the data I could incorporate other

selected gauging stations and are highly variable. data such as how natural and human related

factors control surface water quality. Such as

There are 9 soil orders found on Oahu and population increases reflect the urban development and agricultural land use.

current land-use patterns on Oahu. As of 2000, 34% of the land was classified Use the stream gauges to determine which organic

as agriculture, 40% conservation, and 26% urban. compounds are from urban development,

and which are associated with agriculture use of fertilizers

.