Agriculture Reference
In-Depth Information
Conclusions
D rought is a significant problem for Portugal. Droughts have become more
fr equent and severe since the 1980s, seriously affecting agricultural produc-
tio n. A drought early warning system is being developed. In this regard, var-
io us drought indices and satellite data are being studied. Such a system will
he lp better manage droughts and alleviate economic and social impacts.
C ooperation between governmental and associate institutions is a must for
su ch a system to succeed and help concerned farmers and industries.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
ACKNOWLEDGMENTS We are grateful to the Ministry for Agriculture, Rural Devel-
opment and Fisheries, Institute of Hydraulics, Rural Engineering and Environment
(I HERA), Office of Planning and Agro-Food Policy (GPPAA), Directorate General
fo r Forests (DGF), and Institute of Financing and Support to Agriculture and Fish-
er ies Development (IFADAP) for supplying relevant information incorporated in
th is chapter. We also thank Alvaro Silva and Sofia Moita of the Climate and En-
vi ronment Department of Portuguese Meteorological Institute for providing GIS
m aps and to Mario Pereira for his suggestions in reviewing the text.
[193
Line
——
7.3
——
Norm
PgEn
Note
1. “Semiarid” and “dry subhumid” mean areas, other than polar and subpolar
re gions, where the ratio of annual precipitation to potential evapotranspiration
fa lls within the range from 0.05 to 0.65 (United Nations Convention to Combat
D esertification, 1997).
[193
References
As rar, G., E.R. Kanemasu, and M. Yoshida. 1985. Estimates of leaf area index
from spectral reflectance of wheat under different cultural practices and solar
angle. Remote Sens. Environ. 17:1-11.
Bi cheron, P., and M. Leroy. 1999. A method of biophysical parameter retrieval
at global scale by inversion of a vegetation reflectance model. Remote Sens.
Environ. 67:251-266.
Cooper, D.I., C. Asrar, and T.R. Harris. 1989. Radiative surface temperatures
of the burned and unburned areas in tallgrass prairie. University of Arizona,
Tucson.
D uchemin, B., and P. Maisongrande. 2002. Normalisation of directional effects in
10-day global synthesis derived from VEGETATION/SPOT: I. Investigation
of concepts based on simulation. Remote Sens. Environ. 81:90-100.
G arcía-Haro, F.J, S. Sommer, and T. Kemper. 2002a. Variable multiple endmember
spectral mixture analysis (VMESMA): A high performance computing and
environment analysis tool. Remote Sens. Environ. (Under Review)
G arcía-Haro, F.J., F. Camacho-de Coca, and J. Meliá. 2002b. Retrieval of biophysi-
cal parameters using directional spectral mixture analysis. In: Recent Advances
in Quantitative Remote Sensing, J. Sobrino (Ed.), Universitat de Valencia, Tor-
rente, Valencia, September 16-20, 2002, pp. 963-971.
Gibbs, W.J., and J.V. Maher. 1967. Rainfall deciles as drought indicators. Bureau
of Meteorology Bulletin. 48. Commonwealth of Australia, Melbourne.
 
Search WWH ::




Custom Search