![Hier klicken, um den Treffer aus der Auswahl zu entfernen](images/unchecked.gif) |
Titel |
Modeling the annual soil erosion rate in the mouth of river Pineios' sub-basin in Thessaly County, Greece. |
VerfasserIn |
Ioanna Ilia, Constantinos Loupasakis, Paraskevas Tsangaratos |
Konferenz |
EGU General Assembly 2015
|
Medientyp |
Artikel
|
Sprache |
Englisch
|
Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 17 (2015) |
Datensatznummer |
250108811
|
Publikation (Nr.) |
EGU/EGU2015-8607.pdf |
|
|
|
Zusammenfassung |
Erosion is a natural – geomorphological phenomenon, active through geological time that is
considered as one of the main agents that forms the earth surface. Soil erosion models
estimate the rates of soil erosion and provide useful information and guidance for
the development of appropriate intervention and soil conservation practices and
strategies. A significant number of soil erosion models can be found in literature;
however, the most extensively applied model is the Revised Universal Soil Loss
Equation (RUSLE) established in 1997 by Renard KG, Foster GR, Weesies GA,
McCool DK and Yoder DC. RUSLE is an empirically based model that enables the
estimation of the average annual rate of soil erosion for an area of interest providing
several alternative scenarios involving cropping systems, management methods
and erosion control strategies. According to RUSLE model’s specifications five
major factors (rainfall pattern, soil type, topography, crop system, and management
practices) are utilized for estimating the average annual erosion through the following
equation:
A=RxKxLxSxCxP,
PIC
where A is the computed spatial average soil loss and temporal average soil loss per unit
area (tons ha-1 year-1), R the rainfall-runoff erosivity factor (MJ mm ha-1h-1 year-1), K
the soil erodibility factor (tons h MJ-1 mm-1), L the slope - length factor, S the slope
steepness factor, C the cover management factor and P the conservation support practice
factor. L, S, C and P factors are all dimensionless.
The present study aims to utilize a GIS-based RUSLE model in order to estimate the
average annual soil loss rate in the sub-basin extending at the mouth of Pineios river in
Thessaly County, Greece. The area covers approximate 775.9 km2 with a mean
slope angle of 7.8o. The rainfall data of 39 gauge station from 1980 to 2000 where
used in order to predict the rainfall-runoff erosivity factor (R). The K-factor was
estimated using soil maps available from the European Soil Portal with a grid cell size
of 500Âm and a soil map of Thessaly at a scale of 1:150.000. The LS-factor was
calculated from a 30-m digital elevation model. The C-factor was calculated by
processing a Landsat ETM satellite image, acquired on 11 November of 2014, with a
spatial resolution of 30 m. The P-factor in absence of available data was set to
1.
The outcomes of the analysis, in the form of annual soil loss rate maps, indicated that an
extended part of the area is undergoing moderate erosion. The maximum soil loss in the area
of interest was estimated to have a value of 42.86 (tons ha-1 year-1), with a close relation
to areas with high LS values covered by Natural grasslands and Sclerophyllous
vegetation. The results of the presented model can be used as a simple but efficient tool
assisting local resource planners to optimize land management in terms of identifying
areas of high erosion probability. Also the results constitute an effective tool of
predicting possible future changes in land-use as well as in soil erosion evolution. |
|
|
|
|
|