This document summarizes a presentation on the impacts of drought on grain production in China. It discusses how drought has frequently and severely affected around 25-30 million hectares of cropland in China each year. Using statistical data and modeling, it finds that between 1990-2005, drought reduced annual grain production by an average of 28 million tons and impacted overall food security by 6%. The years 1996-2000 experienced the most severe drought conditions according to this analysis.

1. International Conference on Climate Change and Food Security, November 8, 2011
Impacts of agro-drought on grain
production in China
Zhihao Qin, PhD, professor
Institute of Agro-Resources and Regional Planning
Chinese Academy of Agricultural Sciences
Beijing 100081, China
Email: zhihaoqin@163.com

2. Drought in Yunnan
The contents
• Background
• Objectives
• Methodology
• Results and analysis
• Conclusion

3. Climate in China
The climate of China is complex, diverse, and unique, with a monsoon-
controlled pattern showing clear latitudinal and longitudinal differentiation. The
annual rotation of four seasons (spring, summer, autumn, and winter) with
coincident heat and rainfall is a well-known feature of Chinese climate.
Formation of Chinese
climate is subject to the
interaction of four main
regimes that govern
climatic dynamics in China:
subtropical monsoon,
tropical monsoon,
plateau monsoon,
I West wind circulation regime
and west-wind II Subtropical monsoon regime
III Tropical monsoon regime
circulation. VI Equatoric monsoon regime
V Tibetan Plateau monsoon regime

4. Drought is the most
powerful natural force
shaping impact on
agriculture.
In China drought is
catastrophic: frequent,
serious
Each year drought occurs in
various parts of China, with an
average acreage of 20-25 Mha
Agriculture in China:
Arable land 100 M ha
Cropping area 155 M ha
Grain area 100 M ha
Grain production 500 M t

5. Climate in China is a typical monsoon pattern. With
rainfall
Drought has been a frequent climatic event in China.
2007 drought in Guangxi and Hunan. 2008 in southwest
and northwest China
Since 2009, China has been continuously attacked by
severe drought events, with 2009 in north China plain,
2010 in southwest China, and this year 2011 in middle
Yangtze River Basin and southwest China.
2011 is a big drought year in China, spring and summer,
drought. It is said that this drought was the biggest within
the last 60 years.

6. Drought intensity for 2001-2005
Heilongjiang
Jilin
Liaoning
Xinjiang
Inner Mongolia 1 2
Hebei
4 Shanxi Shandong
Qinghai
Gansu
Shaanxi Henan Jiangsu
Anhui 3
Tibet Sichuan Hubei
<5% Zhejiang
6 Jiangxi
Hunan
5-10% Guizhou Fujian
Yunnan
10-15% Guangxi Guangdong 1 Beijing
2 Tianjin
15-25% 3 Shanghai
4 Ningxia
5 5 Hainan
>25% 6 Chongqing

7. Drought monitoring in China
August 2005
May 2005
Based on MODIS data

8. 图2 全国旱情遥感监测(2009年3月下旬)
MODIS + 降水 监测结果
特旱 正常
重旱 湿润
中旱 过湿
轻旱 云
说明：旱情等级划分，见表1的注解

9. 图1 全国耕地旱情遥感监测(2009年5月中旬)
特旱 正常
重旱 湿润
中旱 过湿
轻旱 云
非耕地
说明：旱情等级划分，见表1的注解

10. Objective of the study
Economically drought reduces the productivity of cropland to
threaten food security in a country like China with giant
population and relatively limited cropland resources.
Environmentally water shortage and high temperature as a
result of drought can alter soil organic carbon (SOC) dynamics
to affect climate changes in regional and global scales.
Objective: to quantify drought’s impact on grain
production and food security in China.

11. Methodology
To link drought with food security and climate change
Drought Water and temperature stress
Productivity decline Biome
Residues, manure, CO2, CH4,
Production
leaching
Soil fertility
SOC change
Food security
Climate change

12. Data for the analysis
Available statistic data on drought in China
• Drought statistics in China
Only cropping acreage under drought effects are available,
with three levels of severity:
Slight drought: 10-30% of productivity decline
Moderate drought: 30-50% decline
Severe drought: >50% of productivity decline

13. Drought intensity index
Percentage of drought area to total cropping acreage
Taking moderate drought as unity
w1 Ai1 + w1 Ai 2 + w3 Ai 3
DI i =
Ait
where DIi is the drought intensity index for province i; Ai1, Ai2 and
Ai3 are the cropping acreages under drought at slight, moderate and
severe levels, respectively, in province i; Ait is the total cropping
acreage in province i; and w1, w2 and w3 denote the weights of
drought at slight, moderate and severe levels, respectively.
Taking moderate drought as unity, we give w1=P1/P2=0.45, w2=1,
and w3=P1/P2 =1.78 in the study.

14. Drought-induced loss of grain production
Computation according to cropping structure
n n
Fd = ∑Fdi =∑[Ri Ai1Yi (1− P ) + Ri Ai2Yi (1− P ) + Ri Ai3Yi (1− P )]
1 2 3
i=1 i=1
where i denotes province i; n is total number of provinces (n=30); Fdi
is drought-caused food production loss in province i; Ri is the fraction
of grain cropping area to the total cropping area in province i; Ai1, Ai2
and Ai3 are the cropping areas under drought at slight, moderate and
severe levels, respectively, in province i; Yi is the yield of grain
cropping in province i; and P1, P2 and P3 denote the rates of yield
drop under drought at slight, moderate and severe levels, respectively.
The rates can be determined as the conservative medians, i.e. P1=20%,
P2=45% and P3=80%

15. Drought impact index
To represent the impact of drought on grain production, as
percentage of drought-induced loss to the total production
Fd
Rd = ×100%
Fp F
where Rd represents the impact of drought on food security,
and Fp is the food production without drought.

16. Procedures for analysis of drought’s impacts on grain
production and climate change in China.
Statistic data The supported
Food production Drought data Cropping & other data databases
DNDC model
Models on drought & Models on drought &
Cropland SOC
food relationship SOC relationship
Drought’s impact on Drought’s impact on
food production SOC dynamics
Evaluation of drought’s impacts

17. Results and analysis
• Drought attack on agriculture in China in
recent years
• Spatial variation of drought intensity in China
• Annual loss of grain production due to
drought attacks
• Impact of drought on food security in China
• Relationship between drought intensity and its
impact on food security in China

18. Change of cropping areas under various
Arable land: 130 Mha
levels of drought attack Cropping acreage: 155Mha
20000
Slight
(a)
17500 Moderate
Severe
Drought acreage (Kha)
15000
12500
10000
7500
5000
2500
0
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Year

19. Change of agro-drought intensity in China
26
24
22
Drought intensity ( %)
20
18
16
14
12
10
8
6
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Year

20. Drought Intensity
(a) 1990-1995 (b) 1996-2000
(c) 2001-2005 (d) 2005
<5% 5-10% 10-15% 15-25% >25%

21. Actual and potential
food productions in
China
Difference between
actual and potential
food productions in
China

22. Impact of drought on food security of China
10
9
8
Impact ( %)
7
6
5
4
3
2
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Year

23. Drought-induced food production loss
(a) 1990-1995 (b) 1996-2000
(c) 2001-2005 (d) 2005
<100Kt 100-500 500-1000 1000-2000 >2000Kt

24. Spatial variation of drought impact on food production
(a) 1990-1995 (b) 1996-2000
(c) 2001-2005 (d) 2005
<2% 2-5% 5-10% >10%

25. Relationship between drought-induced food
production loss and drought intensity in China
55
(a)
50
45
y = 1.9747x + 0.5781
40 2
R = 0.9784
Loss (mt)
35
30
25
20
15
10
5 7 9 11 13 15 17 19 21 23 25 27
Drought intensity %

26. Relationship between drought’s impact on food
production loss and drought intensity in China
11
(b)
10
9
y = 0.3838x + 0.3265
8 2
R = 0.9933
Impact %
7
6
5
4
3
2
5 7 9 11 13 15 17 19 21 23 25 27
Drought intensity %

27. Conclusion
Each year 25-30 Mha of cropping land were under drought attack.
Drought intensity was 13.8% on average between 1990-2005, with maximum
of 25% and minimum of 6%.
Drought induced 28 Mt of grain production loss, shaping an impact of 6% to
total grain production in China, shaping an impact of 3% in
minimum and 10% in maximum on food security in China
1996-2000 had the severest drought, with an intensity of 15.11% on average
and an annual food production loss of 32Mt, leading an impact of 6.1%.
Greater impacts of drought on grain production were observed in Northeastern
China and Northwestern China regions, including Shanxi, Shaanxi, Jilin
Heilongjiang and Inner Mongolia provinces.
Quantitatively an increase of 1% in drought intensity might lead to 2 Mt of
food production loss, and an impact of 0.4% on total grain production.

28. Thank you!