HR: 11:35h
AN: H52B-06    [Abstracts]
TI: Headwater Hydrology in Costa Rica
AU: * bolton, s
EM: sbolton@u.washington.edu
AF: College of Forest Resources University of Washington, Box 352100 , Seattle, wa 98195-2100, United States
AU: james, c
EM: chrisja@u.washington.edu
AF: College of Forest Resources University of Washington, Box 352100 , Seattle, wa 98195-2100, United States
AU: Chen, C
EM: majerle@comcast.net
AF: College of Forest Resources University of Washington, Box 352100 , Seattle, wa 98195-2100, United States
AU: Harris, J
EM: justih@u.washington.edu
AF: College of Forest Resources University of Washington, Box 352100 , Seattle, wa 98195-2100, United States
AB: Tropical hydrology, especially headwater hydrology, has not received much attention in the scientific literature. Recently there have been reports on soil moisture and saturated conductivity but there are still few reports on streamflow. Scientists and managers often rely on information gathered in temperate climates that may or may not reflect tropical hydrology or biology. In temperate climates, especially in North America, knowledge about stream hydrology and biology of unmanged systems (reference condtions) is used to guide stream restoration efforts. Stream degradation is also a problem in the tropics, but there are few long-term studies of unmanaged streams that can be referred to when trying to understand how these streams historically functioned. We present a preliminary analysis of headwater streams in La Cangreja National Park, Costa Rica. Baseline data collection of streamflow, precipitation and air and water temperature was begun in January 2003. Permanent stream habitat plots as well as adjacent permanent riparian forest habitat plots were also installed. La Cangreja National Park lies in the tropical wet forest and premontane wet forest Holdridge Life Zones. There is a distinct rainy season from May to November. About 4000 mm of rain falls each year. Streamflow responds very quickly to rainfall during the rainy season. Stream levels have been observed to rise up to 0.3 m in 15 minutes during intense rainstorms and fall back to lower levels almost as quickly after the rainfall ceases. This ‘flashy' response goes against common wisdom of forests acting as sponges and having slow responses to precipitation events.
DE: 1804 Catchment
DE: 1860 Streamflow
DE: 1879 Watershed
SC: Hydrology [H]
MN: 2007 Joint Assembly