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Titel |
Satellite-based analysis of recent trends in the ecohydrology of a semi-arid region |
VerfasserIn |
M. Gokmen, Z. Vekerdy, W. Verhoef, O. Batelaan |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1027-5606
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Digitales Dokument |
URL |
Erschienen |
In: Hydrology and Earth System Sciences ; 17, no. 10 ; Nr. 17, no. 10 (2013-10-07), S.3779-3794 |
Datensatznummer |
250085945
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Publikation (Nr.) |
copernicus.org/hess-17-3779-2013.pdf |
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Zusammenfassung |
We present a regional framework for an integrated and spatiotemporally
distributed assessment of human-induced trends in the hydrology and the
associated ecological health of a semi-arid basin where both human
activities (i.e. agriculture) and natural ecosystems are highly groundwater
dependent. To achieve this, we analysed the recent trends (from year 2000 to
2010) in precipitation, evapotranspiration (actual and potential) and
vegetation greenness (i.e. NDVI) using a combination of satellite and
ground-based observations. The trend assessment was applied for the
semi-arid Konya Basin (Turkey), one of the largest endorheic basins in the
world.
The results revealed a consistent increasing trend of both yearly
evapotranspiration (totally 63 MCM yr−1 from croplands) and mean NDVI
(about 0.004 NDVI yr−1 in irrigated croplands), especially concentrating
in the plain part of the basin, while no significant trends were observed
for the precipitation and potential evapotranspiration variables. On the
contrary, a consistent decreasing trend of both yearly evapotranspiration
(totally −2.1 MCM yr−1) and mean NDVI (−0.001 NDVI yr−1) was
observed in the wetlands, which also cannot be explained by trends in
precipitation and potential evapotranspiration. The emerging picture suggest
that the greening trend of the vegetation and increasing of
evapotranspiration in the plain are related to land cover changes (i.e.
conversion into irrigated croplands) and to the intensification of the
supplementary irrigation for agriculture, which in turn caused drying out of
some wetlands and the natural vegetation which mostly depend on
the groundwater, the main source of irrigation water as well.
Our study presented an example of the utility of spatially and temporally
continuous RS data in assessing the regional trends in hydrological and
ecological variables and their interactions in a spatially distributed
manner in a semi-arid region, which can also be adapted to other regions.
Such spatiotemporally distributed analysis at the basin level is
particularly important considering that most of the water management
interventions also take place at this scale. |
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