Catchment characteristics and soil and water chemistry of the San Francisco basin and subbasins, Ecuador

In this study, the Mean Transit Time and Mixing Model Analysis methods are combined to unravel the runoff generation process of the San Francisco River basin (73.5 km**2) situated on the Amazonian side of the Cordillera Real in the southernmost Andes of Ecuador. The montane basin is covered with cloud forest, sub-páramo, pasture and ferns. Nested sampling was applied for the collection of streamwater samples and discharge measurements in the main tributaries and outlet of the basin, and for the collection of soil and rock water samples. Weekly to biweekly water grab samples were taken at all stations in the period April 2007-November 2008. Hydrometric data, Mean Transit Time and Mixing Model Analysis allowed preliminary evaluation of the processes controlling the runoff in the San Francisco River basin. Results suggest that flow during dry conditions mainly consists of lateral flow through the C-horizon and cracks in the top weathered bedrock layer, and that all subcatchments have an important contribution of this deep water to runoff, no matter whether pristine or deforested. During normal to low precipitation intensities, when antecedent soil moisture conditions favour water infiltration, vertical flow paths to deeper soil horizons with subsequent lateral subsurface flow contribute most to streamflow. Under wet conditions in forested catchments, streamflow is controlled by near surface lateral flow through the organic horizon. Exceptionally, saturation excess overland flow occurs. By absence of the litter layer in pasture, streamflow under wet conditions originates from the A horizon, and overland flow.

Planning methodologies for analysis of land use/water quality relationships /

Mode of access: Internet.

Introducing WAVE - water alliances for voluntary efficiency : hotel water management for the 21st century.

Mode of access: Internet.

Our air, our land, our water : environmental quality in the Great Lakes Basin /

"September 1988"--P. 3.

Reorganization plan no. 16 of 1950 : transferring the functions of the General Services Administration relating to assistance to local school districts and water pollution control to the Federal Security Agency : report.

Also in Congressional serial volume 11368.

Report on water management studies on public lands of western United States.

Includes bibliographical references.

Agricultural drainage and salt management in the San Joaquin Valley : final report, including Recommended plan and First-stage environmental impact report /

Volume 2 consists of Appendices C-G and first-stage environmental impact report.

Transportation: land, air, water.

At head of title: Since time began.

A biological and water quality survey of Sugar Creek and tributaries, Crawford County, Illinois, August-September, 1992 /

"IEPA/WPC/93-063."--Cover.

Biological and water quality survey of three tributaries to the Sangamon River : South Fork basin, Mosquito Creek and Long Point Slough, September thru November, 1989 : Staff Report /

"May 1991."

Biological and water quality survey of the Vermilion River Vermilion County, Illinois, 1994 /

"May 1995."

Fox River Watershed investigation : Stratton Dam to the Illinois River, phase II : hydrologic and water quality simulation models, part 1, methodology and procedure for development of HSPF models /

"May 2007"--T.p.

Effects of thinning and a wildfire on sediment production rates, channel morphology, and water quality in the upper South Platte River watershed /

"Spring 2004."

Soil and water conservation needs : a national inventory /

Includes bibliographical references (p. 89).