The Attacking Ocean (21 page)

Figure 9.1
Map showing locations in
chapter 9
.

Much of this cultivation took place in wetland environments, such as those of the Lower Yangtze delta, where wild rice, adapted to marsh environments, once abounded. Such rice appears to have spread into the
Yangtze valley around fourteen thousand to thirteen thousand years ago, when climatic warming brought trees and other new plant forms northward. This indigenous rice is long extinct, but some of its traits passed down the generations to become part of domesticated forms.

The low-lying coastline with its lakes and marshes may have been an ideal environment for rice cultivation, but the farmers had to cope with ever-changing sea levels, especially around 5000 to 4000 B.C.E., when sea levels were several meters above modern levels, just before glacial melting slowed. Lake Taihu, south of the Lower Yangtze River, a region of marshes, ponds, and larger bodies of water, was a magnet for hunter and rice farmer alike in 5000 B.C.E.

Excavations at a waterlogged site near Kuahuqiao, some two hundred kilometers southwest of Shanghai, tell us of struggles with an encroaching ocean at a time when warmer conditions and a strengthening summer monsoon brought higher rainfall and more severe flooding after 7000 B.C.E.
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The village would have been near invisible among the grass and reeds of the coastal wetlands, a cluster of thatched dwellings set on piles above the swampy, often waterlogged ground. Only dogs barking, the sounds of children at play, the pounding of mortars, and the scent of woodsmoke would have told of human habitation. What is now called Kuahuqiao lay at a strategic point between upland valleys and coastal wetlands along Hangzhou Bay. The first settlers arrived around 6000 B.C.E., settling among swamps at a time when today’s lowland terrain was not fully formed and sea levels were rising, not only in the East China Sea but also globally. They cleared the scrub ground cover and planted small amounts of rice. Apparently the planting was a success, for rice pollen grains soon become common in the surviving occupation levels. So do the ova of a parasite worm that is associated with both humans and pigs.

After about a century, rising water flooded the site. So the inhabitants moved, something that was relatively easy for them to do. Local populations were thin on the ground; there was plenty of land above water level and abundant land for crops, humans, and animals. The water apparently receded, for later generations of rice farmers moved back to Kuahuqiao. The excavators believe that the inhabitants grew rice in fields
that were flooded regularly, then burned off and manured with animal dung to enhance crop yields. They turned the soil with shovel-like artifacts made from pig shoulder blades. We know from the excavations that cattails grew thickly around the cultivated fields, themselves an important food source and useful raw material for a variety of purposes. Not that these were full-time rice farmers, for they also relied on wild plants and hunting, while dogs and pigs roamed their settlement.

Generations of farmers occupied the same general location for as long as four hundred years. Judging from the thicket of house piles underfoot, the village was rebuilt many times until about 5550 B.C.E., when marine flooding apparently caused by rising sea levels made cultivation impossible.

Even before then, the farmers had to handle encroaching saltwater, but they apparently did so with some success, for the earliest rice cultivation
in eastern China took hold in slightly brackish coastal reed swamps. From the earliest days of agriculture, the new farmers cleared much indigenous vegetation and managed the coastal marsh environment with fire. At the same time, they appear to have taken careful steps to control the amount of tidal seawater that reached their fields. They would have used artificial dikes to retain nutrient-rich freshwater, to prevent catastrophic flooding, and to provide the consistent water regime that rice requires.

Figure 9.2
A shovel from Hemudu with a blade made from a water buffalo scapula. Author’s collection.

Kuahuqiao is by no means unique, but the rice-farming population in the Lake Taihu region was never large, concentrated as it was in wetland and swamp areas along the humid Lower Yangtze and on either side of Hangzhou Bay to the south of modern-day Shanghai. We have but occasional snapshots of these farmers, one from Hemudu, a village in the same general location but at a lower elevation where silt deposition from river floods and sea level changes exposed more land. Like Kuahuqiao, Hemudu lay in an ideal environment for cultivating rice, especially after 5000 B.C.E., when wild nut-bearing trees declined in the face of warmer and wetter conditions and people may have turned to rice as their staple.
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Hemudu covers an area of about four hectares, occupied on at least four occasions, starting as early as 5000 B.C.E. The main occupation ended some four hundred years later, around 4600 B.C.E. The village lay in a forested landscape surrounded by ponds, where the people apparently processed rice on a large scale, but whether it was fully domesticated is a matter for continuing debate. Certainly rice was an important component in daily life, grown in waterlogged landscapes where excellent preservation conditions have yielded beautifully made mortice and-tenon-joined building planks and hoes with blades made from water buffalo shoulder blades.

Small villages like Hemudu nestled among wetlands, where human occupation ebbed and flowed with rising sea levels, changing flood conditions, and sediment buildup. Over thousands of years, small-scale agriculture combined with foraging and hunting slowly gave way to more intensive rice cultivation with fully domesticated forms. Population densities remained low in the Lower Yangtze until around the later fifth millennium B.C.E., when they rose rapidly. Domesticated rice grown in
wetlands is highly productive; inevitably farming populations now exploded and the delta landscape became more crowded. Much larger, more permanent settlements flourished, most of them lying close to extensive rice paddies, protected from sea surges by coastal marshes. As populations rose and villages grew larger, so the waters of the Yangtze became a greater threat than rising sea levels.

THE YANGTZE (sometimes called the Cháng Jiang) is the longest river in Asia and the third longest in the world. It rises on the Tibetan Plateau, then flows 6,418 kilometers across southwestern, central, and eastern China before discharging through an extensive delta into the East China Sea near Shanghai. Dozens of tributaries and smaller streams, and also numerous lakes, contribute water to the Yangtze as it drops from an altitude of about 4,900 meters to sea level. Before the building of the Three Gorges Dam in Hubei Province, oceangoing vessels could sail as far as 1,609 kilometers along what is sometimes called the Golden Waterway. Like a hydrological octopus, the Yangtze and its many tributaries and nearby lakes affect the rise and fall of sea levels thousands of kilometers from its source. The story of sea level changes and their effects on those who live in the Yangtze delta involves not only changes in coastal geography, but also the vagaries of a river plagued with monsoon-generated floods.

Like the Nile, the Yangtze bears a huge silt load downstream, much of it ending up at the coast. Some 170 million cubic meters of silt once flowed downstream to the coastal plain annually—before the construction of the Three Gorges Dam, which reduced the sediment load significantly. The river lies on a rainfall frontier, created by the north-moving summer monsoon. Regions south of the Yangtze receive their rainfall in May and June. To the north, rains come in July and August. Inevitably, a strong monsoon leads to heavy flooding and disaster, usually between May and August. The river overflows its banks and inundates thousands of hectares of the surrounding landscape. Villages are swept away, thousands are drowned, and crops are decimated. The casualties from twentieth-century Yangtze floods alone have killed over 300,000 people.
In 1931, 40,000 people perished in a major flood; 30,000 drowned in a 1954 inundation and an additional 200,000 died from starvation and disease. A villager who lived through the 1954 disaster told a reporter from the
Washington Post
that “the corpses were put in coffins but they could not be buried. They were just stacked up.”
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The year 1998 brought the worst floods in forty-four years, which killed more than 4,000 people and left 13.8 million homeless. A total of 240 million Chinese, a figure equivalent to the population of the entire United States, were affected directly by rising water.

Over the past thousand years, the intervals between major floods have shortened.
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Between 618 and 907 C.E., major inundations occurred about every eighteen years, increasing to every four to five years during the Song and Qing Dynasties (960 to 1911). Since 1950, the recurrence has been about every three years and perhaps changed during the past quarter century to about every four. Data from flood gauges recorded since the nineteenth century shows that the peak water level has also increased, from about 27.4 meters in 1870 to about 30 meters in 1954. Now the levels are even higher. At the same time, the duration of the peak water level has increased from about six hours in 1973 to just over three days in 1998. More flooding may also be occurring in the Yangtze delta owing to more frequent outbreaks of heavy rainfall caused by global warming.

For thousands of years, farmers living along the Yangtze’s banks adjusted fairly readily to even severe inundations, for the numerous lakes on either side of the river handled much of the overflow. However, the rapid population growth and industrialization of the past century have raised the stakes, especially as sea level rises now present a serious threat to cities in the Yangtze delta.

The history of Chinese sea level fluctuations is hard to decipher. We know that sea levels retreated somewhat after 4000 B.C.E. as a result of local crustal adjustments, additional glacial meltwater in the ocean that tilted continental shelves upward, and also water loading, a global phenomenon described in
chapter 1
. Then the coastline tended to stabilize for several thousand years, during the apogee of Chinese imperial civilization, the level changing perhaps no more than a quarter of a centimeter a year.

For all its catastrophic river floods, the Yangtze became a breadbasket of rice growing during the more stable sea level centuries, and assumed great importance in later Chinese history. Over the centuries after the abandonment of Hemudu, population densities rose, villages grew larger, and towns came into being where artisans and traders flourished. Specialist workers began to exploit the mineral wealth of the Yangtze valley—copper, tin, lead, and salt.

Of all these commodities, salt was in many respects the most vital, for it was an essential to subsistence farmers relying on predominantly carbohydrate diets.
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It was also valuable for hide processing. The major salt deposits lay to the north, which may have led to contacts with communities as far away as the Huang He River valley. Salt was to become a major trade commodity in later times, especially with the rise of the Shang civilization in the Huang He River valley after 2000 B.C.E. Copper abounded in the Middle and Lower Yangtze region, while lead and tin came from deposits south of the river. All of this activity resulted in growing contacts between north and south, especially with the emergence of intensely competitive states in the Yellow River valley, where copper and bronze technology reached a high level of sophistication.

The farmers of the Yangtze delta thrived off long-distance trade. Between about 3400 and 2250 B.C.E., the Liangzhu culture prospered in the region, still a farming society based on paddy farming of two rice species, and still a society where most people lived in silt houses along rivers or along shorelines, which must have given them at least some protection against floods and sea surges. By now, however, local society was much more sophisticated. Liangzhu became a small state presided over by a wealthy elite. We know their leaders from their burials, which contain elaborately incised ceremonial jades, symbols of military and ritual power. The jade trade was an important part of this society, whose lords wore silk garments and prized ivory and lacquer artifacts.

Liangzhu extended from Lake Taihu south of the Yangtze as far north as Nanjing and into the present-day Shanghai region. Its cultural influence spread over an enormous area, as far north as the Shang civilization capital at Anyang near the Yellow River. Much of the major activity lay inland, away from the delta lowlands, but it is clear that the adoption of
more sophisticated, high-yielding rice cultivation provided the base for a much more elaborate farming society, but one where many people were still forced to move as sea levels fluctuated and in response to major river floods. By this time, however, sea levels had more or less stabilized to modern levels, which made the farmers’ task somewhat easier than in earlier centuries.