 |
| Titel |
The use of the linear reservoir concept to quantify the impact of changes in land use on the hydrology of catchments in the Andes |
| VerfasserIn |
W. Buytaert, B. Bièvre, G. Wyseure, J. Deckers |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 8, no. 1 ; Nr. 8, no. 1, S.108-114 |
| Datensatznummer |
250005390
|
| Publikation (Nr.) |
 copernicus.org/hess-8-108-2004.pdf |
|
|
|
|
|
| Zusammenfassung |
| The high Andes region of South Ecuador (The Páramo) is characterised by a cold
and wet climate. Most soils of the Páramo region are Andosols and Histosols, with a very high
water retention capacity that is affected irreversibly by drying. This key property of Páramo
soils buffers catchment outflow, resulting in an almost uniform outflow pattern which,
notwithstanding the variability in rainfall, can be very variable in space and time. These soils
serve as the most important reservoir of drinking and irrigation water for the densely populated
inter-Andean depression region. The Páramo has long served only as an extensive grazing area but
recent population pressure and land scarcity have increased cultivation. Two small Páramo
catchments (about 2 km2) were monitored intensively for precipitation and discharge
for over a year to assess the effect of such land-use changes on the hydrological properties.
One catchment is in an undisturbed area and grazed intensively while in the other, local farmers
started intensive drainage for cultivation of potatoes about five years ago. The linear
reservoir concept has been used to assess the overall retention capacity of the catchments in
terms of both peak response and base flow. In this model, every catchment is considered as a
series of independent parallel reservoirs, each characterised by mean residence times (T). In every
catchment, three major mean residence times can be distinguished. In the undisturbed catchment,
an immediate response, characterised by a T of 5.4 hours, is followed by a slower response with
a T of 44.3 h. The base flow has a mean T value of 360 h. The response of the cultivated
catchment is similar with T values of 3.6 h, 27.2 h and 175 h, respectively. As a result, in
the disturbed catchment, water release is about 40% faster than in the undisturbed catchment,
so that the base flow falls rapidly to lower levels. The linear reservoir model is a simple
way of quantifying the impact of land use changes on the water regulation capacity of Páramo
catchments.
Keywords: linear reservoir, Páramo, mountain hydrology, land use changes, Ecuador |
| |
|
| Teil von |
|
|
|
|
|
|
|
|