HSI RIVER

Wade-Giles romanization Hsi Chiang, also spelled Si Kiang, Pinyin Xi Jiang, English West River longest river of southern China. It flows generally eastward for 1,216 miles (1,957 km) from the Yunnan highlands to the South China Sea and drainsalong with the Pei, Tung, and the Pearl riversa basin 173,000 square miles (448,000 square km) in extent. It is shorter than the other important Chinese riversthe Yangtze and the Huang Ho (Yellow River)but it delivers an enormous quantity of water, and its volume of flow is second only to that of the Yangtze. The name Hsi River is more narrowly applied only to its lower course. The Hsi River itself drains an area of about 127,000 square miles (329,000 square km) of southern China and northern Vietnam. More than half of the river's basin is mountainous and lies between 9,900 and 1,650 feet (3,000 and 500 m) above sea level; more than 40 percent of the rest of the basin is occupied by hills between 330 and 1,650 feet (100 and 500 m) high. The lowlands of the river's delta account for less than 5 percent of the total drainage area. Most of the mountains and hills in the basin are composed of limestone, and the river has cut a cavernous valley through them. The riverbed is broken by rapids and gorges, and its walls are often high and steep; the landscape is of the type known as karst, in which the limestone rocks are honeycombed with tunnels and openings, so that much of the drainage runs underground, and deep sinks or swallow holes abound. The Hsi's main headstream is generally considered to be the Nan-p'an River, which rises in the Yunnan-Kweichow plateau region at an elevation of about 6,900 feet (2,100 m) but drops a total of 5,900 feet (1,800 m) in the first 530 miles (850 km) of its course, which flows in a southeasterly direction through Yunnan province. It then forms part of the border between Kweichow province and the Chuang Autonomous Region of Kwangsi for a distance of about 535 miles (860 km). Southeast of the town of Ts'e-heng, the river receives the Pei-p'an River and is then known as the Hung-shui River. This section of the river flows for about 400 miles (640 km) through a narrow valley with high, mountainous banks dropping down about 850 feet (260 m). Its bedbetween 165 and 1,000 feet (50 and 300 m) wideis broken by rocky rapids that are less than 3 feet deep and difficult to navigate. For the first 75 miles (120 km) of its course the Hung-shui continues to form part of the Kweichow-Kwangsi border, flowing in an easterly direction until just before it reaches the town of Chiu-t'ien-o, where it makes a great bend to the south and flows through Kwangsi. At Kung-ch'uan it turns northward and then resumes its easterly direction. At Shih-lung the river receives the Liu River, its major left- (north-) bank tributary, and is then called the Ch'ien River. This shortest section of the river is no more than 75 miles long, the river dropping about 50 feet (15 m) in this distance. The channel grows dramatically, occasionally achieving depths of 280 feet (85 m). For almost half its length, the Ch'ien flows through the narrow, rock-strewn Tat'eng Gorge between the cities of Wu-hsan and Kuei-p'ing, at the end of which it receives its major right-bank tributary, the Y River, and is then called the Hsn River. This section flows for about 120 miles (190 km) in an easterly direction, dropping a further 55 feet (17 m) and receiving the Jung River on the right bank at T'eng-hsien and the Kuei River on the left bank at Wu-chou (Ts'ang-wu) on the Kwangtung province border. Below Wu-chou, where it enters Kwangtung province, the river is known as the Hsi River. Its valley consists of a series of winding gorges and wide hollows. The Sanjung and Lingyang gorges narrow to widths of 230 to 260 feet (70 to 80 m) and are about 250 feet (75 m) deep. Throughout its 130-mile (210-kilometre) length the Hsi drops only about 30 feet (10 m), flowing to the east until it joins with the Pei River at San-shui. It then turns south through the vast Pearl River Delta, also called the Canton Delta, before emptying into the South China Sea west of Macau. The delta is formed by three main riversthe Hsi, the Pei, and the Tung. At San-shui, the Hsi and Pei are joined by a short channel and then divide. The larger branch, the Hsi, bends to the south and forms the western border of the delta, while a lesser branch, the Fo-shan Chih-liu, flows eastward into the delta itself. The Tung flows from the east and enters the delta's main channel, the Pearl River (Chu Chiang), which begins just above Canton. Canton lies west of the point where the Tung flows into the main channel; Hong Kong stands to the east and Macau to the west of the entrance to the Pearl River Estuary, which is about 18 miles (29 km) wide. Covering an area of about 1,500 square miles (3,900 square km) in southeastern Kwangtung province, the delta is a complex network of river branches and channels, divided by islands of alluvial soil and by hills that were once coastal islands. The fertile islands are only slightly above sea level and are protected from the sea by a system of flood dikes. Forests cover much of the mountainous region of the Hsi River's basin, especially in the north and west, the stretch along the border of Kweichow province being the most heavily forested. The more important trees are the pine, the fir, the camphor, the tung, and bamboo. In the eastern part of the basin, in the low places of the maritime zone and in the valleys, the vegetation is mostly cultivated and includes rice, peanuts (groundnuts), sugarcane, hemp, tobacco, and fruit. The river contains an abundance of freshwater fish, and the waters of the Pearl River Delta are utilized as fishponds. Throughout the mountainous part of its course, the river has but little relationship to the peoples who live in its vicinity. Most settlement occurs in small valleys or in plains between mountains, known as patse. The villages are isolated, compact agricultural units. River towns become more frequent in the hilly part of the Kwangsi region, where the river is an artery of commerce; towns include Kung-ch'uan, Ch'ien-chiang, Lai-pin, Kuei-p'ing, T'eng-hsien, and Wu-chou. The Pearl River Delta is one of the most densely populated regions of China. The entire region is intensively cultivated. Rice is the most important crop, but in the cooler, drier climate of the west wheat, corn (maize), sorghum, beans, and potatoes are also grown. An intricate irrigation system includes more than 1,200 miles (1,900 km) of flood dikes. The waters are also used as fishponds. The delta's many channels are vital to Canton's international commerce, as well as to trade with the interior. The Hsi River's rate of flow more than doubles in the summer season. Most of the large flow results from the summer monsoon rains, when torrential floods may occur and frequently do cause catastrophic damage. The river is at its lowest during the winter dry period. Fluctuations in the water level during the year may vary by as much as 80 feet (25 m) at Wu-chou; in the lower course and the delta, variations in the level are less. Especially dangerous are the delta floods that result from a combination of flooding rivers and high tides. The Hsi River is the great commercial waterway of South China, linking Hong Kong, Canton, Macau, and other delta centres with Wu-chou and the interior. In flood time, the river is navigable for vessels drawing 16 feet (5 m) as far upstream as Wu-chou. The Hsi River basin contains more than 9,000 miles (14,500 km) of water routes, of which more than 6,800 miles (11,000 km) are in use. Steamships can sail along more than one-third of the total length of the waterways, while Chinese junks and small craft ply all the navigable waters. Navigation is hampered by low water on many tributaries and by rapids on some sections of the river. In several places, as on the Y River, river craft are pulled over the rapids with hand-worked windlasses. During low-water periods, transportation ceases on some rivers, including the Tung and the Pei. The water routes do not form an integrated system, however. Canton, the largest city in the basin, does not have direct access to either the Hsi or the Pei. The channels that connect the city to the water routes of the basin are winding and mud-filled and are navigable only by shallow-draft boats. Because most of the river branches of the delta are shallow, oceangoing vessels cannot reach Canton but must dock at Huang-pu-chiang (Whampoa), 10 miles (16 km) downstream.