 |
| Titel |
Modelling the impact of prescribed global warming on runoff from headwater catchments of the Irrawaddy River and their implications for the water level regime of Loktak Lake, northeast India |
| VerfasserIn |
C. R. Singh, J. R. Thompson, J. R. French, D. G. Kingston, A. W. Mackay |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 14, no. 9 ; Nr. 14, no. 9 (2010-09-13), S.1745-1765 |
| Datensatznummer |
250012422
|
| Publikation (Nr.) |
 copernicus.org/hess-14-1745-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
| Climate change is likely to have major implications for wetland ecosystems,
which will include altered water level regimes due to modifications in local
and catchment hydrology. However, substantial uncertainty exists in the
precise impacts of climate change on wetlands due in part to uncertainty in
GCM projections. This paper explores the impacts of climate change upon
river discharge within three sub-catchments of Loktak Lake, an
internationally important wetland in northeast India. This is achieved by
running pattern-scaled GCM output through distributed hydrological models
(developed using MIKE SHE) of each sub-catchment. The impacts of climate
change upon water levels within Loktak Lake are subsequently investigated
using a water balance model. Two groups of climate change scenarios are
investigated. Group 1 uses results from seven different GCMs for an increase
in global mean temperature of 2 °C, the purported threshold of
''dangerous'' climate change, whilst Group 2 is based on results from the
HadCM3 GCM for increases in global mean temperature between 1 °C and 6 °C. Results from the Group 1 scenarios show varying responses between
the three sub-catchments. The majority of scenario-sub-catchment
combinations (13 out of 21) indicate increases in discharge which vary from
<1% to 42% although, in some cases, discharge decreases by as much
as 20%. Six of the GCMs suggest overall increases in river flow to Loktak
Lake (2–27%) whilst the other results in a modest (6%) decline. In
contrast, the Group 2 scenarios lead to an almost linear increase in total
river flow to Loktak Lake with increasing temperature (up to 27% for 6 °C), although two sub-catchments experience reductions in mean
discharge for the smallest temperature increases. In all but one Group 1
scenario, and all the Group 2 scenarios, Loktak Lake water levels are
higher, regularly reaching the top of a downstream hydropower barrage that
impounds the lake and necessitating the release of water for barrage
structural stability. Although elevated water levels may permit enhanced
abstraction for irrigation and domestic uses, future increases in hydropower
generation are limited by existing infrastructure. The higher water levels
are likely to exacerbate existing ecological deterioration within the lake
as well as enhancing problems of flooding of lakeside communities. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|