辽宁省土地沙漠化现状成因及发展趋势

The current situation, forming factors and development tendency of land desertization in Liaoning province

辽宁北部处于内蒙古科尔沁沙地“百里翰海”的南缘。受其影响、气候干旱、降水稀少、蒸发强烈、大风频繁、植被稀疏、土地沙化、赤丘荒坨 ,错落起伏 ,生态环境十分脆弱。尤其是多年来人口剧增、盲目垦植、超载放牧、樵木为薪等不合理的人为活动 ,使生态环境进一步恶化 ,不仅沙漠化土地面积增加迅速 ,而且受风沙威胁的区域越来越广 ,危害越来越重。主要表现在 :1.风剥沙丘 ,耕地草场沙化、退化。沙漠化土地平均每年以 93.6 5万亩的速度扩展 ;2 .淤塞河道、水库和渠系 ;3.风旱及沙尘暴灾害逐年加剧。本文结合“辽宁省土地沙漠化发育程度分区图”阐述了沙漠化土地的分布规律和危害特征 ,探讨了其形成因素 ,在一定时期内土地沙漠化将继续扩大 ,但速度将会明显减缓。

The northern part of Liaoning Province lies to the south of Kerqin Desert of Inner Mongolia. Under the influence of the desert, the climate at this region is dry. The rain is rare. The evaporation is strong. The strong wind is frequent. The vegetation is few. The land is desertized. The bare hills are scattered here and there. Further more, especially in recent years, the ecological environment has been deteriorated by the explosive population and the irrational activities such as blind cultivation、 over herding and cutting trees to burn. While the desertized land increased sharply, the threaten area is larger and larger and the hazard is more and more serious.Main problems are: 1 For wind erosion and sand covering, the land and the meadow desertized and degenerated. The area of the desertized land increased by average 624 3 km 3/a. 2 Silting up river course, reservoir and channel. 3 The disasters of wind, drought, sand and dust storm are serious year by year. On the basis of the distribution of land desertization growth degree of Liaoning Province, the article points out the distribution law of land desertization and the feature of the hazard of Liaoning Province. And it also discussed its forming factors and its development tendency in which the speed of desertization would decrease obviously although the desertized land increased in certain period.