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Flood disaster recovery in China
Li Maosong, Song Jiqing, Bai Wenbo, Wu Yongfeng, Liu Buchun, Wang Chunyan and
Wang Xiufen, Laboratory of Agro-Natural Disaster Reduction, Institute of Environment and
Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences,
Key Laboratory of Agro-Environment & Climate Change, Ministry of Agriculture
F
looding is the second largest meteorological disaster in
China. Floods have a detrimental effect on people’s lives,
cause economic loss and destroy the environment.
Furthermore, the secondary effects and indirect costs of flood
disasters have caused long-term effects in local societies, regard-
less of their level of development. Taking action to prevent floods
and to reduce their impact is essential.
China is located in the world-famous monsoon area, and resultantly
frequently suffers flooding. From the 1960s, China has experienced
almost annual flood disasters, especially in the years 1963, 1975, 1991,
1998, 2003 and 2007. During the rainy season from May to August,
the flood disasters mainly concerned the Yangtze, Huaihe and Pearl
Rivers, which distribute for the main rice production regions of China.
The statistics show that the rice paddies affected by flood disaster
in the main rice production regions of China was about 244,000
hectares on a yearly average in the 1960s. From the 1970s to the
1990s the affected area expanded steadily. In the 1990s, it soared to
1,070,000 hectares, and between 2000 and 2007 it reached as much
as 648,000 hectares on average.
Rice is an indispensable staple food, especially in the large areas of
Asia, Latin America and Africa, which are characterized by semitrop-
ical climates with alternating rainy and dry seasons.
1
The current
demand for rice exceeds its production. This situation
will worsen given the world’s increasing population and
the decline in arable land. Production in regions where
rice cultivation is subjected to stresses, such as the
seasonal flooding that occurs during the rice-growing
season, particularly in the lowlands of South, Southeast
and East Asia. Furthermore, this flood disaster-affected
condition of rice paddies will be even more severe in the
future, as trends in the frequency and intensity of floods
events are closely related to changes in the patterns of
precipitation and river discharge, and thereby also to other
long-term changes in the global warming. All these trends
are expected to continue, with the exception of the
reduced seasonal variation, which is not expected to be
the case in southern China. It is a matter of urgency to
take measures for flood disaster recovery in China.
Ratooning rice alleviates economic losses after
catastrophic flooding in Luxian county
Catastrophic flooding occurred from 8-10 July 2007 in
Luxian county, in the Sichuan province of China. The
county was substantially affected, with the submergence
of farmlands covering more than 35,073 hectares and
an inundation time of 60-92 hours. The rice was in its
blooming stage, and about 78 per cent of the rice
paddies were severely affected. According to the results
of previous studies, rice, with an inordinate metabolic
physiology, cannot normally assimilate and respire in
submerged conditions. At the same time, rice changes
from reproductive growth to vegetative growth, a
process that is accompanied by dedifferentiation.
2
The
propagule phenomenon, which refers to the generation
of new individual leaves and ears from internodes,
occurred after the water had fully receded for four days
– that is to say, rice has the ability to regenerate.
If effective measures are not taken after a flood disaster,
this results in wilting rice and rebirth rice growing
together in uncut-stem rice paddies. The rice grew in an
undesirable condition and the plant carbohydrates were
largely consumed, which resulted in serious growth
damage. Submergence affected the bourgeoning, growth
and yield of the rebirth rice, while the original rice was
almost unharvestable, which would result in potential
large-scale yield losses.
Based on previous studies and experimental results,
countermeasures against flood disaster were based on
Flooding in Luxian county, China
The flood disaster in Luxian county, China 2007 (upper) and the
countermeasure against it, to apply with fertilizer on ratooning rice (lower)
Source: IEDA, CAAS, China/Bai Wenbo