کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4572451 1332178 2008 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Linking fragipans, perched water tables, and catchment-scale hydrological processes
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Linking fragipans, perched water tables, and catchment-scale hydrological processes
چکیده انگلیسی

Soils with very slowly permeable fragipans and fragipan-like argillic horizons are extensive throughout the Palouse Region of northern Idaho and eastern Washington, USA. These soils develop seasonal perched water tables (PWTs) under the xeric moisture regime of the region. The objective of this study was to utilize a hydropedology approach to examine the linkages between fragipans, PWTs, and catchment-scale hydrological processes such as soil water storage, runoff, and lateral throughflow. A 1.7-ha catchment dominated by Fragixeralfs (Fragic Luvisols) was instrumented with 135 automated shallow wells to monitor PWTs. Soil water content was measured with water content reflectometry probes, and catchment outflow was measured with a flume. A 35 m × 18 m plot was isolated hydrologically from the surrounding hillslope using tile drains and plastic sheeting to measure perched water outflow. Results show that during the wet winter and spring months, the transition from unsaturated to saturated conditions is accompanied by changes in volumetric water storage of only 4–5%. PWT levels are at the surface of ∼ 26–45% of the catchment soils during periods of high rainfall and snowmelt, thereby generating saturation-excess surface runoff from hillslopes. Observed solute movement via subsurface flow is very rapid and ranges between 2.9 and 18.7 m d− 1 when PWTs are maintained in more-permeable Ap and Bw horizons. Subsurface lateral flow accounts for as much as 90% of the incident precipitation and snowmelt during early spring. Data indicate that the relatively shallow depth to the fragipans and high Ksat in surface soil layers combine to create a very flashy hydrological system characterized by considerable temporal and spatial variation in patterns of saturation-excess runoff.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: CATENA - Volume 73, Issue 2, 15 April 2008, Pages 166–173
نویسندگان
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