International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B8, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
boy
(Since July 1)
-16 d
Latitude °s
1
>
128 130 Longitude sou 136 138
Figure 3: Spatial patterns of 11 years (2000-2011) mean
EOS (the date of growing season end) in the NATT.
The numbers in the bracket indicate the calendar years,
which 1 means first half of phenological year, i.e. from
July 1 to December 31, 2 means second half of pheno-
logical year, i.e. from next January 1. Original 0.05 de-
gree resolution result had been aggregated to 0.2 degree
resolution for plotting purpose.
(c)
712 4
-16 d Days
(EOS - SOS)
Latitude °s
1
>
1e 130 Longitude Qu 436 tes
Figure 4: Spatial patterns of 11 years (2000-2011) mean
LOS (the length of growing season) in the NATT. Origi-
nal 0.05 degree resolution result had been aggregated to
0.2 degree resolution for plotting purpose.
and the breakpoint shifted its location inter annually in a
approximately 1.18 degree extent (Fig. 8). In the north
of this boundary, the annual minimum EVI dropped dra-
matically as a function of latitude, however, in the south
of this boundary, the downward trend became gradu-
ally slowing (Fig. 8). In the south of this boundary,
the minimum EVI was generally lower than 0.14, even
lower than 0.12 in some year and reached as low as 0.10,
which might be considered as soil background. And in
the north end, the annual minimum EVI can be as large
as 0.24, approximately twofold than its southern coun-
terpart (Fig. 8).
4 DISCUSSION AND CONCLUSION
This study has two significances:
(d)
EVI
(Annual integral)
Latitude *s
+
>
;
-20 —
-22 -
S 130 ee V 136 n
Figure 5: Spatial patterns of 11 years (2000-2011) mean
LIG (the annual integral of EVI) in the NATT. Original
0.05 degree resolution result had been aggregated to 0.2
degree resolution for plotting purpose.
Table 2: Five-number summary 2 of phenological met-
rics in the NATT area. The phenological metrics were
the average of 11 years.
MinG AMP LIG SIG
Minimum 0.0024 0.0053 2.87 2.19
25% quantile 0.1222 0.0519 89.19 55.60
Median 0.1455 0.0824 110.50 75.11
75% quantile 01779 0.1182 13558 91.79
Maximum 0.3458 0.3003 248.74 148.08
a
SOS - 62.992 «3.916 x Latitude
2
1 14 16
2 Éatitude (dj.
b
Sep + EOS-351.2527 +1.7456 x Latitude
i R°-0.138
12 14 6 8 20 22
Latitude (SJ
Figure 6: Latitudinal gradients of vegetation phenol-
ogy along the transect (a) SOS; (b) EOS. The equations
show the phenological metrics as a function of latitude.
The vertical lines are the temporal standard deviations
of these latitudinal gradients.
1. To our knowledge, this study was the first inves-
tigation of vegetation phenology using an almost
an complete MODIS datasets for the NATT study
area.
2. A ’breakpoint’ was identified in this transect from
a vegetation phenology perspective.
