|Freshwater||293||24||No||1010||Kottelat, M. and T. Whitten, 1996|
|Conservation||China, with a large and expanding population and a remarkable record of economic growth, has the potential to affect the global environment as well as the ecosystems within its borders. Water shortages throughout the country, especially in urban areas, may become an even more serious issue as future growth in water usage threatens to outpace supplies. Most of the nationâ€™s rivers, especially in urban areas, are seriously polluted. A wastewater discharge permit system is being implemented, however, along with a pollution levy system by which polluters pay the cost of cleanup. About 14 per cent (1993) of the total land area in China is forest and woodland, but deforestation is threatening the habitats of many of the thousands of species that dwell there, some of them unique to China. There has also been a rapid increase in the amount of desert land, and soil erosion is a serious problem taking a toll on agriculture production. Efforts are under way to improve the situation, however. Reforestation programs are being undertaken, a large proportion of which are also aimed at providing fuelwood. Sand-break forests have been built to combat desertification.To preserve animal habitat, the Chinese government has set up 400 nationally protected areas covering 3 per cent of the total land area, and it has signed a number of international agreements relating to conservation. Two recent synopses of Chinese freshwater species cover 800 and 1010 species, respectively. Several works deal with the fauna of provinces, basins, or islands. All of these works are in Chinese and not easily available. About 90 species are believed to be endangered and one, the carp @Cyprinus yilongensis@ from Yunnan, has been confirmed as extinct as Lake Yilong was drained dry for 20 days in 1981. A recovery program has been initiated for sturgeons, with the continuous release of fry into the Yangtze River. The following information is to be sought: - Existence of conservation plans; - Information on major aquatic habitats or sites within the country; - Current major threats to species; - Future potential threats to species; - Contact(s) for further information.|
|Geography and Climate||
China can be divided into six major geographic regions, each of which contains considerable diversity in terrain and topographic relief:
The Northwest: This region consists of two basins, the Junggar Pendi on the north and the Tarim Basin on the south, and the lofty Tian Shan mountain chain. The Tarim Basin has the vast, sandy Takla Makan Desert, the driest desert in Asia. Dunes in its interior rise to elevations of about 100Â meters. The Turpan Pendi, the largest area in China with elevations below sea level, commands the southern entrance of a major pass through the Tian Shan. The Junggar Pendi is primarily a region of fertile steppe soils supporting irrigated agriculture, although it contains some areas of sandy and stony desert.
The Mongolian Borderlands: Located in north central China, this is a plateau region of mainly sandy, stony, or gravel deserts that grade eastwards into steppe lands with fertile soils. The flat to rolling plains are partitioned by several barren, flat-topped mountain ranges. Along the eastern border is the higher, forested Da Hinggan Ling (Hinggan Mountains).
The Northeast: Comprising all of Manchuria east of the Da Hinggan Ling, the Northeast region incorporates the Manchurian Plain and its bordering uplands. The plain has extensive tracts of productive soils, and the uplands are hilly to mountainous, with numerous broad valleys and gentle slopes. The Liaodong Bandao (Liaodong Peninsula) extending to the south, is noteworthy for its good natural harbours.
North China: This region lies between the Mongolian Borderlands on the north and the Yangzi River Basin on the south and consists of several distinct topographic units. The Huangtu Gaoyuan on the northwest is formed by the accumulation of loess. The loosely packed loess is readily subject to erosion, and the plateauâ€™s surface is transected by sunken roads, vertical-walled valleys, and numerous gullies. The region is extensively terraced and cultivated. The Huabei Pingyuan, the largest flat lowland area in China, consists of fertile soils derived from loess. Most of the plain is under intense cultivation. To the east, the Shandong Qiuling (Shandong Highlands) on the Shandong Bandao (Shandong Peninsula) consist of two distinct areas of mountains flanked by rolling hills. The rocky coast of the peninsula provides some good natural harbours. To the southwest are the Central Mountains, which constitute a formidable barrier to north-south movement.
South China: This region embraces the Yangzi Gorges and the topographically diverse regions to the south. The Yangzi Gorges consist of a series of basins with fertile alluvial soils. These lowlands are criss-crossed with waterways, both natural and artificial, and dotted with lakes. The Sichuan Basin, located to the west, is enclosed by rugged mountain spurs of the Central Highlands and constitutes a relatively isolated area of hilly terrain. The area is known for its intensive terrace farming. The highlands of South China extend from the Tibetan Plateau east to the sea. In the west, the deeply eroded Yunnan-Guizhou Plateau is bordered by a series of mountain ranges separated by deep, steep-walled gorges. One of the worldâ€™s most scenic landscapes is found in eastern Guizhou Province, where the terrain is dominated by tall limestone pinnacles and pillar-like peaks. To the east are the largely deforested and severely eroded Nan Ling hills, and along the coast are the rugged Southeastern Highlands, where bays with numerous offshore islands provide good natural harbours. Lying south of the Nan Ling hills is the Xi Jiang Basin, predominantly a hilly area with infertile soils; the numerous streams of this region, however, are bordered by fertile, flat-floored alluvial valleys. The broad delta plain of the Zhu Jiang (Pearl River) is commonly called the Canton delta.
The Tibetan Plateau: The high, mountain-rimmed plateau of Tibet occupies the remote southwestern extremity of China. The worldâ€™s highest plateau region, Tibet has an average elevation of about 4,877Â meters above sea level. Bordering ranges include the Himalayas on the south, the Pamirs and Karakorum on the west, and the Kunlun and Qilian Shan on the north. The surface of the plateau is dotted with salt lakes and marshes, is crossed by several mountain ranges, and also contains the headwaters of many major rivers of southern and eastern Asia, including those of the Indus, Ganges, Brahmaputra, Mekong, Yangzi, and Huang He (Yellow River). The landscape is bleak, barren, and strewn with rocks.
The Asian monsoon exerts the primary control on Chinaâ€™s climate. In winter, cold, dry winds blow out of the high-pressure system of central Siberia, bringing low temperatures to all regions north of the Yangzi River and drought to most of the country. In summer, warm, moist air flows inland from the Pacific Ocean, producing rainfall in the form of cyclones. There is much less rain further from the sea and on leeward sides of mountains. The remote basins of the northwest receive little precipitation. Summer temperatures are remarkably uniform throughout most of the country, but winters are characterized by extreme variations in temperature between north and south. Southeastern China, from the Yangzi Gorges southwards, has a subtropical climate that becomes distinctly tropical in the extreme south. Summer temperatures in this region average 26Â°C. Average winter temperatures decline from 18Â°C in the tropical south to about 4Â°C along the Yangzi River. An average of eight typhoons a year, mainly between July and November, bring high winds and heavy rains to the coastal areas. The mountainous plateaus and basins to the southwest also have subtropical climates, with considerable local variation. As a result of higher elevations, summers are cooler, and as a consequence of protection from northerly winds, winters are mild. The Sichuan Basin, which has an 11-month growing season, is noted for high humidity and cloudiness. Rainfall, especially abundant in summer, exceeds 990 millimeters annually in nearly all parts of southern China. North China, which has no mountain ranges to form a protective barrier against the flow of air from Siberia, experiences cold, dry winters. January temperatures range from 4Â°C in the extreme south to about -10Â°C north of Beijing and in the higher elevations to the west. July temperatures generally exceed 26Â°C and, in the Huabei Pingyuan, approach 30Â°C. Almost all the annual rainfall occurs in summer. Annual precipitation totals are less than 760 millimeters and decrease to the northwest, which has a drier, steppe climate. Year-to-year variability of precipitation in these areas is great; this factor, combined with the possibility of dust storms or hail, makes agriculture precarious. Fog occurs on more than 40 days a year in the east and on more than 80 days along the coast.The climate of Manchuria is similar to, but colder than, that of North China. January temperatures average -18Â°C over much of the Manchurian Plain, and July temperatures generally exceed 22Â°C. Rainfall, concentrated in summer, averages about 510 to 760 millimeters in the east but declines to about 300 millimeters west of the Da Hinggan Ling. Desert and steppe climates prevail in the Mongolian Borderlands and the northwest. January temperatures average below -10Â°C everywhere except in the Tarim Basin. July temperatures generally exceed 20Â°C. Annual rainfall totals less than 250 millimeters, and most of the area receives less than 100 millimeters. Because of its high elevation, the Tibetan Plateau has an arctic climate; July temperatures remain below 15Â°C. The air is clear and dry throughout the year, with annual precipitation totals of less than 100Â millimeters everywhere except in the extreme southeast.
Ref. Microsoft, 1996
The three longest river systems in China are the Yangzi, Huang He, and Xi Jiang, all of which flow in a generally west to east direction to the Pacific Ocean. About 50 per cent of the total land area of China drains to the Pacific. Ten per cent drains to the Indian and Arctic oceans. The remaining 40 per cent have no outlet to the sea and drain to the arid basins of the west and north, where the streams either evaporate or percolate to form deep underground water reserves. The Tarim He is principal among these streams.The northernmost major stream of China is the Amur, which forms most of the northeastern border with Russia. The major river of North China is the Huang He, called "Chinaâ€™s Sorrow" because of its devastating flooding throughout history. The Yangzi River of central China is the longest river in Asia. A major transport artery, the Yangzi rises near the source of the Huang He, has a vast drainage basin, and enters the sea at Shanghai. The most important river system of southern China is the Xi Jiang. Most of the important lakes of China are situated along the middle and lower Yangzi Gorges. The two largest in the middle section are Dongting Hu and Poyang Hu. In summer, they increase their area by two to three times, serving as reservoirs for excess water. The Tibetan Plateau contains many large saline lakes. The largest of these is the marshy Qinghai Hu.
Freshwater sites of exceptional biodiversity interest are the Wuhan lakes, Dongtin Lake, and Yunnan lakes.
Ref. Kottelat, M. and T. Whitten, 1996