摘要
根据若尔盖县4次土地沙化监测数据和野外调查资料,对若尔盖县沙化现状及其沙化发展动态特征进行研究。结果表明：若尔盖土地沙化发展非常迅速,2009年的沙化面积是1994年的4.5倍;以沙化程度划分可分为轻度、中度、重度、极重度等4个不同沙化程度等级,其中轻度沙化地占68.93%～75.42%,以沙地类型划分可分为流动沙地、半固定沙地、固定沙地、露沙地等4个沙地类型,露沙地占75.15%～79.63%,根据土地利用划分可分为草地、林业用地、耕地和未利用沙化地,其中沙化草地占78.11%～85.74%;流动沙地、半固定沙地、固定沙地和露沙地年平均扩增速率分别为8.03%、10.34%、13.67%和11.56%,不同用途土地沙化的年均增长速率的大小排序是：草地（11.31%）〉未利用地（10.54%）〉林地（7.03%）〉耕地（0.45%）,轻度、中度、重度和极重度沙化年均扩展速率分别是11.03%、8.68%、9.80%和26.49%,若尔盖县土地沙化正朝着流动沙地减少,固定沙地增加,中度和重度沙化下降,轻度和极重度沙化上升趋势发展;疏干沼泽和超载放牧是引发沙化面积迅速扩大的主要原因;若尔盖县沙化面积中,草地占78.11%～86.32%。因此,在防沙治沙上,重点应摆在沙化草地的治理上。
Based on the data of field experiments and four times data of land desertification monitoring, the status quo of land desertification and dynamic characteristics of desertification development in Ruoergai County, Sichuan province were investigated. The results show that the land desertification in Ruoergai County had been very quickly developing, the desertification area in 2009 is 4.5 times of in 1994; The desertification degree can be divided into 4 different levels, slight, moderate, severe potential and extremely severe, with mild desertification accounted for 68.93% to 75.42%; the sandy land types can be divided into 4 types, such as mobile sand dune, semi fixed sand dune, fixed sand dune and sand exposed dune, with a ratio of 75.15% to 79.63% for sand exposed dune; According to the land use situation, there were 4 types of land uses, including sandy desertification grassland, forestry land, arable desertification land, and unused land, with a ratio of 78.11% ～ 85.74%; Annual average expansion rate were 8.03%, 10.34%, 13.67% and 11.56% for mobile sand dune, semi fixed sand dune, fixed sand dune and exposed sandy, respectively. According to land uses and its desertification rate, annual desertification growth rate ranking was 11.31% for grassland, 10.54 % for unused land, 7.03% for woodland, and 0.45% for arable land, respectively. For different desertification degrees, annual expansion rate was 11.03% for mild, 8.68% for moderate, 9.80% for severe, and 26.49% for very severe desertification, respectively, with decreasing area in mobile sand dune and increase in fixed sandy dune, and with a trend of declines in moderate and severe desertification and rising in mild and very severe desertification in Ruoergai county. Draining the swamp and overgrazing was a major cause of grassland desertification in Ruoergai County. The area of desertified grassland accounted for 78.11% ～ 86.32%, therefore, on desertification, the emphasis should be placed on desertified grassland in Ruoergai County.
出处
《中南林业科技大学学报》
CAS
CSCD
北大核心
2014年第12期124-129,共6页
Journal of Central South University of Forestry & Technology
基金
国家科技支撑计划"西南生态安全屏障决策体系"(2011BAC09B08-07)
关键词
土地沙化
沙化类型
沙化程度
若尔盖高原
四川省北部
desertification
desertification type
desertification degree
Ruoergai Plateau
northern part of Sichuan province
