新疆荒漠化现状、成因及对策

新疆远离海洋、深居内陆、地形封闭、干旱缺水,沙漠戈壁包围绿洲,绿洲呈分散分割状。森林覆盖率1.68%,盆地中心分布着两大沙漠,生态环境脆弱。40多年来,新疆在改造沙质荒漠化、土壤盐渍化、水域治理、中低产田等荒漠化治理中,取得了重大成就,同时,人口也增长了2.9倍,人类活动使生态平衡失调。荒漠化土地总面积79.59×10⁴km²,其中沙质荒漠化面积52.05×10⁴km²;盐碱土总面积847.6×10⁴hm²,现有耕地中31.1%的面积受到盐碱危害;山区云杉林已减少2.3×10⁴hm²,落叶松减少2.4×10⁴hm²,平原林退化更为严重;80%的草场均有不同程度的退化,产草量下降35.4%~75.8%;湖泊较70年代减少一半,耕地土壤肥力下降。根据新疆荒漠化发生发展的特点与原因,总结防治经验,形成有效的防治方法、措施与体系,新疆的荒漠化是可以防治的。

Status, Causes and Countermeasures of Desertification in Xinjiang

Xinjiang has an area of desertified land 79.59×10⁴ km², showing as sandy desertification, soil salinization, vegetation degradation, lake and wetlands shrinkage, fertility decrease, and so on, of which an area of sandy desertified land is 52.05×10⁴ hm² (the desert area is 43.0×10⁴ km²), in 80 of 87 counties or cities in Xinjiang, there are desert and drifting sand disaster. And the saline alkali land is 8.476×10⁶ hm², in current cultivated land, roughly 31.1% of the available cultivated land is threatened by saline alkali disasters in Xinjiang. About 50% of the available cultivated land are low yield. The quality and quantity of forest reserves in mountains have been reduced. Euphrates poplar forest in the plains and shrubs and forest in the river valleys have been seriously damaged. The area of grassland has decreased and the yield has reduced, especially inedible and inferior grass community has increased. Obvious changes have taken place in many rivers and lakes over the last four decades, compared with 1970s, there is only 50% of the lakes remained. On control of desertification in Xinjiang, major rivers and lakes have been managed. Afforestation method of narrow belts with small grids were implemented, more over, the idea of building up a comprehensive shelter network, e.g., combining arbors with shrubs and herbs, as well as combining belts with pieces and grids, was put forward. Till 1995, 4.88×10⁴ hm² of shelter forest has been afforested and 47.09×10⁴ hm² of natural vegetation has been conserved. Meanwhile, 240×10⁴ hm² of grassland has been improved. In addition, 63.4×10⁴ hm² of desert vegetation has been recovered and 13.33×10⁴ hm² of desertified land has been rehabilitated. Using the measures of drainage, irrigation, ground leveling, fertilizer application, and afforestation, till 1996, 8.91×10⁴ km of drainage ditches have been dug and 63.89×10⁴ hm² of saline alkali land have been ameliorated. Through improving the farmland environment, applying fertilizer, popularizing the new agricultural technology, 54.95×10⁴ hm² of low yield or middle yield lands were improved from 1988 to 1995 in Xinjiang. Compared with 1987, the mean yield of grain of 1995 had increased by 1 305 kg·hm^-2, the cotton yield by 480 kg·hm^-2, oil crop by 300 kg·hm^-2, and sugar crop by 1.29×10⁴ kg·hm^-2. In summary, in future, on the control of desertification in Xinjiang, control system should be organized firstly, which would not only prevent and control desertification, but also promote economic development, and meet the needs of plant protection, moderate exploitation and save resources. Second, rational measures should be adopted. Third, management regimes which include an administrative department, a science and technology department, and the population, should be constructed. The action to control desertification should be taken as follows: ① Control the increment of population effectively and lessen the pressure of human activities on land resources. ② Strengthen administration of water resources and build up a water saving and high yield agriculture system. ③ Develop economy but protect the environment at the same time. ④ Strengthen education and improve people's ideas about environment protection. ⑤ Strengthen oasis protection and improve shelter network.