Arguments - Trends
|Arable land is a precious
resource for China's agriculture. Most of the country is covered by steep mountains (see
Map 1), stony deserts, or dry grasslands (see Map 2), which are unsuitable for
agriculture. The land is suitable for cultivation only in the South, the East, the
Northeast, and in some small areas of the extreme Northwest (see Map 3).
For many years the true area of China's cultivated land was severely underestimated. Many
authors used the official estimate of about 95 million hectares. However, we now know that
the area of China's cultivated land is much larger. According to our analysis, by the
mid-1990s it was in the range of 132-136 million hectares. Our estimate confirms previous
calculations by other authors. The new data also show only a slight decline in the area of
cultivated land in China in recent years, primarily due to agricultural restructuring, but
also due to infrastructure expansion. Some land has also been lost because of natural
disasters, primarily flooding.
Description of the Problem
|Here we discuss the
the true area of China's cultivated land?
the regional and provincial trends?
the causes of land-use change in China?
reconstruction of China's cultivated land area (at the national level)
|IIASA's LUC Project
has recently received detailed statistics from the Chinese State Land Administration that
describe increases and decreases of various types of cultivated land in China. These data
are available for the provincial and county levels. They are based on a series of land
surveys conducted during the past few years to improve Chinas (crop) land
statistics. Due to the enormous size of Chinas agricultural area, it was not
possible to cover all areas at once, but each year a larger land area was surveyed and
corrected. We can therefore expect that estimates for recent years are more accurate than
estimates from the late 1980s. Table 3 shows the main national-level results. As can be
seen from column 5 in Table 1, the reported area of cultivated land increased from 122.3
million ha in 1988 to 131.1 million ha in 1995. This was not due to wondrous cropland
expansion, but simply reflects the increasing accuracy of Chinese land-use statistics in
recent years. Since the late 1980s, Chinese politicians have become very concerned with
the danger of cropland loss, and great efforts have been undertaken to monitor ongoing
land-use changes and correct the underreported cropland "stock" data. Currently
the Chinese agricultural census is processed, which will most likely further improve the
land use data.
|The new data from the
Chinese State Land Administration can be used to estimate the amount of underreporting in
recent years. Table 1 gives the national totals for cultivated land at the beginning
(column 1) and at the end of each year (column 5), as well as the corresponding increases,
decreases, and net changes (columns 2-4).
As can be seen from comparing column 5 for a given year with column 1 of the next year,
there is a discrepancy in the reported area of cultivated land. The changes in cultivated
land (increases and decreases) do not add up to the initial cultivated land area for the
subsequent year. The reason for this discrepancy is underreporting China's stock of
To correct this discrepancy, we make two assumptions. (1) We assume that the "flow
data" (increase or decline) are relatively correct. (2) We also assume that the most
recent (the 1995 year-end) estimate of the total cultivated land area is the most
accurate. With these two assumptions, we can recalculate the amount of underreporting in
previous years. Columns 6, 7, and 8 show the results of this reconstruction. For instance,
the 1995 year-end estimate of the cultivated area was 131.1 million ha (columns 8 and 5).
If we subtract the 1995 net change in cultivated land (409,100 ha), we get the initial
1995 cultivated land area, which is, of course, equivalent to the 1994 year-end area
(column 7 in 1995 and column 8 in 1994). By repeating this simple procedure for all
previous years, we can reconstruct China's cultivated land area from the reported land-use
changes (which we consider more accurate than the estimate of the total stock).
The difference between the reported (column 5) and reconstructed (column 8) area of
China's cultivated land is the amount of underreported land (column 6). In the late 1980s
and early 1990s, the amount underreported was around 10 million ha. By 1994, it had
declined to about 2 million ha.
Note that this calculation is based on the Chinese State Land Administration's estimate of
the area of cultivated land, which was already significantly higher than the numbers
reported in the Statistical Yearbook of China. For 1988, the State Land Administration had
reported a cultivated land area of 122.6 million ha (beginning of year), while the
Statistical Yearbook published an estimate of 95 million ha (with known
|Our calculations show
that the cultivated land area must have been even larger than the initial estimate of the
State Land Administration. We can conclude that at the beginning of 1988, China had a
(corrected) cultivated land area of 132.8 million ha; it declined slightly by 1.72 million
hectares (or 1.3%), to 131.1 million hectares by the end of 1995.
and provincial trends
|China has eight major
economic regions: North, Northwest, East, Central, South, Southwest, Plateau, and
Northwest. The largest net loss of cultivated land between 1988 and 1995 was reported in
the Northwest, which had a net decline of almost 400,000 ha. It is interesting that this
region also had, by far, the largest overall changes in cultivated land (an
approximately 880,000 ha increase and an almost 1.28 million ha decrease).
By far the lowest net loss of cultivated land was reported in the South, where it
declined by just 11,000 ha or 0.1% (see Table 1). One economic region, the Plateau, even
reported a small net increase of cultivated land between 1988 and 1995: according to our
data, it increased 15,000 ha or 1.6%.
|We have also used the
recent data from the Chinese State Land Administration to analyze land-use changes at the
provincial level. As can be seen from Table 3, significant areas of cultivated land were
lost in the provinces of Inner Mongolia (more than 212,000 ha) and Sichuan (151,000 ha).
However, with a loss of over 360,000 ha, the province of Shaanxi had the largest net loss
of cultivated land, which declined by almost 6.4%.
The largest relative net loss of cultivated land was reported from Shanghai (which is not
only a city but has counties with agricultural areas as well). It lost almost 10% of its
cultivated area. With a more than 7% decline, Beijing also had a significant net loss of
cultivated land. The only significant net increase of cultivated land was reported from
Xinjiang (157,000 ha or 4.2%). (See Figure 1)
is causing land-use change in China?
|The data also provide
insight into some of the driving forces that cause land-use changes in China. Table 4
provides details about various causes of increases and decreases in cultivated land.
||By far the most important reason
for the decline in Chinas cropland has been agricultural restructuring.
Due to massive changes in consumer demand, it has become much more profitable for Chinese
farmers to grow vegetables and fruit than rice or wheat. While most of the crop harvest is
still "collected" by the state procurement system at relatively low producer
prices, the farmers can often sell vegetables and fruit for a good price on the
"free" farmers' markets in cities and towns. In other words, the entrepreneurial
initiative of Chinese farmers explains a good part of the cropland loss in China. Of the
total net decline of 1.7 million ha of cropland, 1.2 million ha were lost due to the
conversion of cropland to horticulture; another 226,000 ha of cultivated land were
converted to fish ponds. This, of course, reflects the growing consumer demand for fish.
||The resource base for food
production has certainly been diminished by the loss of cultivated land due to construction
activities. These activities include all construction by state-owned units (cities, towns,
mining, factories, railways, highways, water reservoirs, and public buildings) and
construction by rural communities (rural roads, township and village enterprises, rural
water reservoirs, offices, education and sanitation, rural private resident housing). On
balance, China lost some 980,000 ha of cultivated land to construction activities between
1988 and 1995. These losses were reported in almost all provinces; however, as might be
expected, they were especially high in Jiangsu and Guangdong provinces. Construction
activities have certainly caused some loss of cropland in China, particularly around
booming coastal agglomerates such as Beijing and Shanghai. These losses may be more
serious than cropland losses of equivalent size elsewhere in China, because they are in
high-productivity areas in close proximity to large numbers of consumers. The losses are
also permanent: no one can expect that a highway or housing complex will ever be returned
to cropland. However, we have to put these trends into perspective. All losses due to
construction activities between 1988 and 1995 combined have affected some 0.75% of the
total cultivated land in China. During the same period, Chinese farmers increased the
cultivation area by almost 2.2 million ha. This reclamation of marginal or previously
unused land represents 1.7% of the total cultivated area.
||The third largest land-use change
in China has been reforestation of previously cultivated land. Some 970
million ha were reforested between 1988 and 1995, especially in the provinces of Shaanxi,
Inner Mongolia, and Yunnan. While these losses of cropland may have somewhat diminished
Chinas agricultural land resources, they will certainly help to prevent or reduce
environmental disasters in the future, such as desertification or flooding. In the end,
these forests may be as important for Chinas food security as an equivalent area of
||Finally, we must mention natural
disasters. Between 1988 and 1995 China lost 856 million ha of cultivated land due
to disasters - mainly flooding and droughts.
As documented by recent data from the State Land Administration, the great majority of
Chinas land-use changes are related to agricultural restructuring. This, in essence,
is a "healthy response" by Chinas farmers to the gradual emergence of
consumer markets in Chinas food sector. It is a further step away from the
command-and-control land-use system that hampered Chinas agricultural sector for
almost 30 years. This land conversion is also a sign that the grain-centered state
procurement system needs further reform. Farmers' income from grain production must
increase if the state wants to boost or at least maintain cereal production levels.
There has certainly been some decline of cropland in China, but the areas
affected are tiny compared with the total cultivated area. The principal reason for
land-use changes is the greater market orientation of Chinese farmers, who have
restructured their cultivation areas for more profitable products. Some cultivated land
has also been used for environmental protection (reforestation). The losses of cultivated
land to construction and infrastructure expansion are in the order of less than 1% (only
in some hot spots are they higher). Compared with the excessive conversion of natural and
agricultural land due to urban sprawl and infrastructure construction in North America and
Europe, loss of cultivated land in China is minimal.
Arable Land: Trends
Impact Data Quality Prediction Error Intervention
Revision 2.0 (First revision published in 1999)
- Copyright © 2011 by Gerhard K. Heilig. All rights reserved. (First revision: Copyright © 1999 by IIASA.)