Geoscience Reference
In-Depth Information
Fig. 2 Annual average
temperature in degrees Celsius
(a) and precipitation in mm per
year (b) within the Mahanadi
River Basin (color red) and the
Aral Sea Region (color blue),
based on data from Mitchell and
Jones (
2005
). Running average
(10 years) is shown by the black
thin lines
Table 2 Average seasonal temperature and precipitation at the beginning and the end of twentieth century
for the Mahanadi River Basin (MRB) and the Aral region
Temperature (
o
C)
Precipitation (mm yr
-1
)
Mahanadi River Basin
1901-1955
1956-2000
1901-1955
1956-2000
Dry season
24.44
24.74
198
190
Wet season
25.93
26.16
2,470
2,358
Aral region
1901-1950
1983-2002
1901-1950
1983-2002
Growing season
14.7
15.5
192
193
Non-growing season
-0.1
1.54
354
381
Figure
3
shows the seasonal T changes and their spatial distribution in both regions.
Destouni et al. (
2010
) have already reported how they used the difference in seasonal
T change for the Aral region to distinguish and quantify different regional T change
components (DT) and their different drivers, and associated changes in ET (DET) and
latent heat flux (DF) in that region. In the following, we will follow the same approach to
also distinguish, quantify and directly compare with the previous Aral region results
corresponding change components and drivers within the MRB.
3.2 Estimating Irrigation Effects from Temperature Seasonality
In the MRB, the basin-average T increase during the Wet Season is 0.23 C, which is
smaller than the T change of 0.30 C during the Dry Season. From these seasonal change
differences, which are consistent with more irrigation water being used and thereby leading
to more cooling in the Wet Season (7 km
3
) than in the Dry Season (4 km
3
), along with the
