吉林省西部土壤沙化、盐碱化和草原退化演变的时空过程研究

A STUDY ON THE PROCESS OF GRASSLAND DEGRADATION, LAND SALINIZATION AND SOIL DESERTIFICATION IN THE WEST OF JILIN PROVINCE

基于地理信息系统平台,对吉林省西部1986年、1996年和2000年的土壤沙化、盐碱化和草原退化(简称"三化")专题数据、土地利用状况数据、基础地理数据、人文和经济统计数据等进行融合处理和分析。结果显示:(1)15年间,吉林省西部地区草场退化速率呈增加趋势,草地面积大幅度减少,尤以松原、白城、洮南和通榆的草场退化情况严峻。整个西部的草地重心从通榆和大安交界处向东北方向漂移,幅度有11km。(2)吉林省西部地区盐碱化土地面积明显增加。盐碱化主要集中在洮南南部和乾安、前郭,呈西北-东南方向延伸。盐碱地重心一直在通榆和大安交界处。(3)尽管沙地面积略有减少,但是呈不稳定状态,有从通榆向大安、镇赉、乾安、松原推进的趋势。沙地重心从通榆中部向东漂移,距离达30km。(4)西部地区的"三化"空间动态变化特征是呈边缘扩充、内部充填等增加模式和边缘退缩、成片退缩等减少模式。

Grassland degradation, land salinization and soil desertification(DSD) are typical ecoenvironmental problems in the west of Jilin Province. Based on a GIS platform, the land use information from 1986,1996 and 2000 are processed and analyzed. Some results are concluded as follows: ①Grassland degradation rate grew faster in the study period of 15 years, which appear as the rapid decrease of grassland in area. The most severe places occur in Songyuan, Baicheng, Taonan and Tongyu. The gravity centre of the grassland in the whole west is moving from the border of Tongyu and Da'an towards to northeast, giving a distance about 11km. ②The salinized land is obviously increased in area and degree, which are mainly distributed in the south Taonan and Qian'an, Qianguo, appearing a northwest-southeast stretching. The gravity centre of the salinized land did not move much, which located in between Tongyu and Da'an. ③The soil desertification is slightly decreasing in area, but it appear unstable, which tends to moving from Tongyu towards Da'an, Zhenlai, Qian'an and Songyuan. Meanwhile the gravity centre of the soil desertification is shifting from the middle of Tongyu to the east with a distance about 30 km.④The spatial variation characteristic of the DSD in western Jilin Province appear many types of pattern, such as edge expansion, inwards filling, marginal deflation, and region deflation, etc.