TITLE:
Applying the Moisture Availability Index (NTDI) over Vegetated Land in Central Asia: Mongolian Steppe
AUTHORS:
Abdelmoneim A. Mohamed, Reiji Kimura
KEYWORDS:
Drought, Mongolian Steppe, Central Asia, NTDI, Moisture Availability (ma)
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.6 No.14,
October
28,
2014
ABSTRACT: The intensity of
recent droughts and the uncertainty of moisture variability in the context of
increasing temperatures and decreasing precipitation have affected the
Mongolian grassland. Mongolia typifies the steppe terrain and semiarid to arid
continental climate that extends across much of Central Asia. In semi-arid
areas like Mongolian steppe, vegetation type and distribution are directly
relate to the amount of water that plants can extract from the soil. An index
for assessment of moisture availability (ma:
defined as the ratio of actual to reference evapotranspiration) was developed,
namely NTDI [1]
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003400300031003800340037003500380031000000
. NTDI (Normalized Day-Night Surface
Temperature Difference Index) is defined as the ratio of the difference between
the maximum daytime surface temperature and the minimum nighttime surface
temperature, to the difference between the maximum and minimum surface
temperatures estimated from meteorological data by applying energy balance
equations. A verification study conducted at Liudaogou River Basin of the Loess
Plateau, China, indicated the capability of NTDI to estimate ma accurately, (R2=0.97,p
08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003400300031003800340037003500380031000000
. In Bayan Unjuul, Mongolia, application of
NTDI during the growing season showed a significant inverse exponential
correlation with ma (R2=0.86,p