Symposium on Remote Sensing for Resources Development and Environmental Management / Enschede / August 1986 
415 
A preliminary study on NOAA images for non-destructive estimation 
of pasture biomass in semi-arid regions of China 
Ding Zhi 
Institute of Xinjiang Biology, Pedology, and Desert, Academia Sinica, China 
Tong Qing-xi, Zheng Lan-fen & Wang Er-he 
Airbone Remote Sensing Center, Academia Sinica, China 
Xiao Qiang-Uang, Chen Wei-ying & Zhou Ci-song 
National Meteorological Bureau, China 
ABSTRACT: advanced very nigh reaolution rediometer data from the JMOAA meteorological satellite 
have been used to study the vegetation biomass in the Xinjiang regions in China. The major 
data from NOAA was aquired with meteorological ground station by the ational meteorological 
bureau. For assessment of vegetation biomass the two channels of multispectral data were to 
form the Normalized Difference(ND). The spectral bands of these channels were 0.55—0.68 urn, 
and 0.725—1.10 um..The Normalized Difference value is very sensitive to the existance vege 
tation. The digital processing technique was used for estimation of the relationship between 
the Normalized Difference and vegetation biomass production. The ND data of the satellite 
images were conpared to field-sampling biomass data. It was found that the relationship bet 
ween the two values above was positive and satisfactory. The regression coefficient even ap 
proached 0.95. These results show that non-destructive methods for the estimation of the ve 
getation is prospective and effective. 
This paper, will deal with the principles, methods, and procedures for nOn-destructive esti 
mation of pasture biomass with NOAA images. Ideal results have been obtained, and thus fill 
in the gaps in the methods of non-destructive estimation pasture biomass in Chica. 
1. INTRODUCTION 
1.1 Physical geographic conditions in the 
test area 
The Xinjiang the pasture area has more than 
400,000 KM^.The test area is mainly situated 
in the Middle and Lower Tarim River Basin, 
Xinjiang, and 1ies ( roughly between 40°30'N— 
41°30 N, and 83 30 E—87°30 E. The sampling 
location lies approximately between 40°30 — 
41°30'N, and 84°30'—87°F(Fig.l), and is lo 
in the interior Tarim Basin with mountainous 
surroundings far from the ocean. It is semi- 
arid desert climate in warm temporete zone 
with much dry wind, strong vaporation, rare 
preciptation, long sunshine and tremendous 
temperrature alternation. The annual precip 
tation is 25.1—51 mm., and the annual vapo 
ration is very high 2,100—2,900 mm.. 
In this region there are salty-desert typed 
soil and central asian desert typed plants, 
such as popular diversifolia, phyagmites com 
munis, and alhagi pseudoalhagi, etc. 
The test area is located in an alluvial p- 
lain at the northern margin of the Taklamakan 
Desert, and is a representative of arid region 
1.2 NOAA satellite 
It is a polar orbiting, sun-synchronous, ope 
rating satellite in the TIROS-N series of spa 
cecraft. NOAA is characterized by high resolu 
tion. Images covering the whole world are able 
to be received twice a day. NOAA has a view 
field of 2,700 km wide, on which the NOAA ad 
vanced very high resolution radiometer(AVHRR) 
sensor is mounted. The first effective chan- 
nel(CHi) is visible red with a wavelength of 
0.55—0.68 um, and the second one(CHp) is near 
infrared with a wavelength of 0.725--1.10 vim 
which are sensitively and directely suitable 
for estimation of biomass and the chloropyli 
green leaf interaction.(Tal.1) (Townsheng 
and Tucker, 1984) 
As well known, the Beijing Receiving Sta 
tion of NOAA Satellites was built in Beijing 
of China in 1983. The center in Beijing has 
a circle coverage with a radius of 2,500km. 
§nd most of the Chinese territory iscovered, 
including the Xinjiang region. The possibi 
lities ox orbiting cloud-free imagery are 
g reatly enhanced, especially, in the grow 
ing season of vegetation. 
Four to six orbiting data for one satel 
lite can be received in the Beijing Receiv 
ing Station of NOAA satellite, due to NOAA’s 
polar orbiting, sun synchronous and opera 
tional satellite, and NOAA operates with a 
coupie, sight or twelve orbits per day cou 
ld be obtained. It is svailable for monito 
ring changes in pasture biomass and estima 
ting crop production to receive one or two 
orbiting N0AA?s images, because of the NOAA’s 
advantages, and it is also valuable to col 
lect whole data from the growing season in 
spring to withered season in fall, thus itis 
is convenient to observe crop growing situ 
ations and their dynamic changes. In addi 
tion, if there are several rainfalls, chan 
ges in crops with preciptation- may be ob 
tained. Simultaneously, no matter during the 
day or night, data are effectively received, 
and thermo-inertia changes in soil moisture 
and water content of plant nay be known and 
the dynamic evolution in plant an advanta 
geous condition may be monitored. It is un 
comparable for MSS, which covers once every 
1® day and the cycle duration is too long, 
If rainy or cloudy days are encountered, 
there is no way to get evident data, and an 
other 18 days will be needed to wait, during 
which plants may mature, further more, in 
that time span, if rain falls again, plants 
will grow at atremendous rate, thus there 
is no chance to get data on the changes in 
plant maturation. As a result, the NOAA is 
able to obtain data covering the whole pro-