China Officially Recognizes Link between Deforestation and Summer Flooding

Back to Map Page August, 1998 Beijing, China China’s Xinhua news agency reported this August that the government plans to prevent further deforestation in response to the severity of this summer’s floods. Although China’s major rivers have flood frequently, and sometimes disastrously, for thousands of years, the extreme floods of 1998 are now blamed partly on recent development in the country, both clearing of forests and the draining of lakes and wetlands that could act as water reserves, withholding floodwaters upstream and reducing flood volumes in lower floodplains. More than 2,000 people died and nearly 14 million have been left homeless in this summer’s floods on the Chang Jiang (Yangtze), Songhua, and other rivers. (See satellite image showing the flooded Yangtze in August, below.  (Image from NOAA; to see full-size images see the NOAA web site link, at bottom of page.)   Large water-covered areas show August flooding on the Chang Jiang (Yangtze River). Image from the National Oceanic and Atmospheric Administration (NOAA).  In an announcement on August 14 the Chinese cabinet asserted that it would forbid the clearing of new forest lands. The announcement also promised to strengthen reforestation efforts in order to help reduce the future catastrophic floods like those that went on most of the summer this year. A recent report by the Worldwatch Institute in Washington, DC reported that 85% of the trees have been cleared from the Chanjiang basin, in response to population growth, the need for more arable land, and the expansion of towns and cities. Forest cover can reduce flooding because trees and other vegetation use water in the soil and also help retain soil on hill slopes. Also implicated in the flooding is increased sediment in the rivers—a result of upstream development, agriculture, logging, and subsequent erosion. Accumulated mud reduces the rivers’ capacity to hold floodwaters, making floods more severe when the rainy season arrives in the mountains. The Chinese government has also recognized the importance of lost lakes, once temporary impoundments for floodwaters. More than a third of the lakes in the Changjiang river basin have been drained for farmland in the past 40 years. The map below shows the location of several major rivers that experienced higher than normal flooding this summer. Chief among these are the Chang Jiang (Yangtze), Huang He (Yellow River) and Songhua rivers. To read more, see Environmental Science, A Global Concern, Cunningham and Saigo, 5th ed. Floods and flood control, general principles: pages 334-336 Flood hazards: 357-358 Erosion: pages 235-237 Environmental Science, Enger and Smith, 6th ed. Floods and floodplains: pages 230-231 Soil erosion: pages 246-249 Back to Map Page feedback form | permissions | international | locate your campus rep | request a review copy digital solutions | publish with us | customer service | mhhe home Copyright ©2001 The McGraw-Hill Companies. Any use is subject to the Terms of Use and Privacy Policy. McGraw-Hill Higher Education is one of the many fine businesses of the The McGraw-Hill Companies.