evaluation of natural resource management watershed hydrology a hawaiian prospective n.
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  1. Evaluation of Natural Resource Management:Watershed Hydrology, a Hawaiian Prospective Ali Fares Associate Professor of Watershed Hydrology NREM600: Evaluation of Natural Resource Management

  2. The Hydrologic Cycle. Precipitation. Measuring Precipitation. Runoff. Surface and Groundwater Storage. Lakes and Reservoirs. C A S E S T U D Y Great Salt Lake of Utah. C A S E S T U D Y The Aral Sea of Uzbekistan. Wetlands. Groundwater. Evaporation. Condensation. Climate and Weather. Overview. Climate. Air Currents. Ocean Currents. Tilt of the Earth’s Axis. Monitoring Climate Change. Weather. Temperature. Air Pressure. Humidity. Heating. Wind Speed and Direction. Weather Modification. P O L I C Y I S S U E. Floods. Drought. P O L I C Y I S S U E. Hydrologic Cycle, Climate, & Weather: Outline NREM600: Evaluation of Natural Resource Management

  3. Hydrology • The scientific study of the properties, distribution, and effects of water on the earth's surface, in the soil and underlying rocks, and in the atmosphere. • HYDROLOGY is the science of water that is concerned with the origin, circulation, distribution and properties of water of the earth. NREM600: Evaluation of Natural Resource Management

  4. “Water is a limited natural resource and a public good fundamental for life and health. The human right to water is indispensable for leading a life in human dignity. It is a prerequisite for the realization of other human rights.” • “The human right to water entitles everyone to sufficient, safe, acceptable, physically accessible and affordable water for personal and domestic uses.” • 26 November 2002 – United Nations COMMITTEE ON ECONOMIC, SOCIAL AND CULTURAL RIGHTS NREM600: Evaluation of Natural Resource Management

  5. What’s a Watershed? • WATERSHED, or CATCHMENT, is a topographic area that is drained by a stream, that is, the total land area above some point on a stream or river that drains past that point. • The watershed is often used as a planning or management unit. Natural environment unit. NREM600: Evaluation of Natural Resource Management

  6. Ala Wai Canal Watershed NREM600: Evaluation of Natural Resource Management

  7. Oahu’s Watersheds NREM600: Evaluation of Natural Resource Management

  8. NREM600: Evaluation of Natural Resource Management

  9. Oahu’s Watersheds NREM600: Evaluation of Natural Resource Management

  10. Water Cycle NREM600: Evaluation of Natural Resource Management

  11. Components of hydrologic cycle Location % of total Oceans (salt water) 97.5 Fresh water 2.5 Icecaps and glaciers 1.85 Groundwater 0.64 Lakes, rivers, soil, atmosphere 0.01 NREM600: Evaluation of Natural Resource Management

  12. Why do we study geology? NREM600: Evaluation of Natural Resource Management

  13. Geology of Hawaii • Hawaiian islands are comprised of large, gently dipping shield volcanoes. The lavas, young and basaltic, are extremely permeable and make up the principal aquifers. • All of the major islands in the Hawaiian chain consist of essentially of one or more shield volcanoes which are primarily composed of extremely permeable, thin basaltic lava flows. • Interbedded with the flows are a few ash beds. • Basalts comprising the HI islands are especially permeable due to their young age and more importantly to the thin layers of lava flows. NREM600: Evaluation of Natural Resource Management

  14. Geology of Hawaii • The lavas which stands above the sea level are thought to range in age from over 5 million years to only few minutes as it is the case in the Big Island of Hawaii. • This is especially important as many of the water-bearing in lava flows are associated with the surface and near-surface portions of flows. • The older islands are deeply dissected (ridges, valleys, and alluvial fans • The younger islands are relatively smooth, and the original shape of the volcanoes are apparent. NREM600: Evaluation of Natural Resource Management

  15. Intermittent stream hydrology Dike impounded system NREM600: Evaluation of Natural Resource Management

  16. Peterson, G&G & WRRC NREM600: Evaluation of Natural Resource Management

  17. Groundwater • Water infiltrating through the rocks may accumulate in two principal types of ground water bodies: • 1) High-level bodies impounded with compartments formed by impermeable dikes that have intruded the lava flows, and, to a much lesser extent, high-level bodies perched on ash beds on soil or soil interbedded with flows on unconformities, or other relatively impervious lava flows. • Basal water bodies floating on and displacing salt water. Freshwater layer system and perched water NREM600: Evaluation of Natural Resource Management

  18. Groundwater systems • The principal source of fresh groundwater in HI is the roughly lens-shaped basal water body floating on and displacing denser sea water. • The depth to the bottom of fresh water is a few tens of meters to several hundred meters. • The thickness of the transition zone varies from only a few meters, in undisturbed areas, to 300 meters in parts of southern Oahu where extensive development of basal lens has occurred. NREM600: Evaluation of Natural Resource Management

  19. NREM600: Evaluation of Natural Resource Management

  20. Water use on Oahu Year Number of wells1882 - 15 flowing wells and 3 non-flowing wells1930 - 700 wells (half for sugarcane production)1985 - 1635 wells (including wells, tunnels, and shafts) 383 – irrigation 247 – public supply 1005 – other2002 - 2077 known wells NREM600: Evaluation of Natural Resource Management

  21. Groundwater Issues In Hawaii • Ground water resources are limited however, demands are growing. • Contamination of water resources with different pollutants • Salt water intrusion • Land use change: diversified ag, invasive species,… NREM600: Evaluation of Natural Resource Management

  22. Hawaii has a wide range of climatological areas which depend on elevation and geographic position on each individual island. • The windward or North through Northeast facing sections of the islands generally have a consistent year-round supply of trade winds that bring brief showers • The wetter period of the year in windward areas depends on the individual island and the elevation, but generally occurs in the spring months. NREM600: Evaluation of Natural Resource Management

  23. Climate Types NREM600: Evaluation of Natural Resource Management

  24. Water Resources of Oahu Left: Inside Halawa Shaft; Concerned about war, work on the new water source began on December 6, 1941 Byron Alcos, superintendent of the Waiahole Irrigation Co., shines a light on the source of the Waiahole water at the north portal. (By George F. Lee, Star Bulletin). NREM600: Evaluation of Natural Resource Management

  25. Waiahole Ditch • The system intercepts water from natural dikes beginning at the 790-foot elevation in Kahana Valley, and uses a series of connecting tunnels to ferry the water. The journey toward the Leeward side begins in Waiahole Valley at what is known as the North Portal main tunnel, a cave dug out a quarter-mile deep at the 752-foot elevation level in the Koolau Mountains. • There, the water disappears in a deafening rush into the pitch-black, chilling recesses of the mountain. It reappears three miles later at the 699-foot level at Waiawa in Leeward Oahu. Gravity transports the ditch water across the Leeward plain, where farmers and other users pump it out. The ditch ends at a large reservoir in Honouliuli. • On this day, a meter kept dry by a continuously burning kerosene lantern in the North Portal indicates 4 millions gallons a day have passed the station. Another 4 million gallons of water a day naturally seeps into the ditch between the North Portal and Waiawa, giving operators the total amount flowing through the ditch. • But no matter which way you send the water, the flow will remain perpetual, Alcos said. • "You cannot shut down the system unless you dam it up and concrete it," he said NREM600: Evaluation of Natural Resource Management