| 近40 a毛乌素沙地荒漠化过程研究 |
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| 引用本文： | 闫峰,吴波. 近40 a毛乌素沙地荒漠化过程研究[J]. 干旱区地理, 2013, 36(6): 987-996 |
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| 作者姓名： | 闫峰 吴波 |
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| 作者单位： | （中国林业科学研究院荒漠化研究所， 北京 100091） |
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| 基金项目： | 中央级公益性科研院所基本科研业务费专项（CAFYBB2011003）；中国气象局农业气象保障与应用技术重点开放实验室开放基金项目（AMF201107）资助 |
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| 摘 要： | 毛乌素沙地位于我国北方农牧交错带上，生态环境具有较强的敏感性和脆弱性。采用1977-2010年Landsat数据，运用决策树和非监督分类相结合的方法对近40 a来毛乌素沙地荒漠化过程进行了研究。结果表明：（1）决策树分类和ISODATA非监督分类相结合可快速实现荒漠化地区地物遥感解译，图像总分类精度大于87.28%；（2）近40 a毛乌素沙地流动沙地面积在20世纪90年代末最大，2010年最小；半固定沙地面积在2010年最大，90年代末最小；固定沙地面积在2010年最大，70年代末最小；（3）70年代末荒漠化程度最为严重，流动和半固定沙地面积之和占了毛乌素沙地总面积83.64%；80年代末、90年代末和2010年的流动和半固定沙地面积之和分别占总面积74.51%、77.10%和67.90%；（4）流动沙地、半固定沙地、固定沙地、耕地和水体间的相互转换过程活跃，荒漠化演替过程显著区在70年代末到80年代末主要分布在北部、西北部和南部，80年代末到90年代末主要分布在西部和南部，90年代末到2010年主要分布在西北部、西部、南部和东北部；（5）近40 a毛乌素沙地气温以0.039 ℃/a的平均速度递增，降水则以0.095 mm/a的平均速度递减，气候总体上体现出暖干的趋势。降水是影响荒漠化过程的重要因素，但不是唯一原因，人文因素中的人口、土地利用结构和政策实施等也是影响荒漠化过程重要因素。
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| 关 键 词： | 荒漠化过程 近40 a 毛乌素沙地 |
| 收稿时间： | 2013-01-11 |
Desertification progress in Mu Us Sandy Land over the past 40 years |
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| YAN Feng,WU Bo. Desertification progress in Mu Us Sandy Land over the past 40 years[J]. Arid Land Geography, 2013, 36(6): 987-996 |
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| Authors: | YAN Feng WU Bo |
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| Affiliation: | （Institute of Desertifieation Studies， Chinese Academy of Forestry， Beijing 100091 ， China） |
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| Abstract: | Desertification is one of the most serious environment problems in the world and it does great harm to people's production and living conditions. With the implementation of Reform and Opening policy，Chinese economy has been developed rapidly and the desertification hazard in China has become increasingly serious. Mu Us Sandy Land locates on the farming-pastoral ecotone of Northern China，whose ecological environment shows significant sensitivity and vulnerability. It is very necessary for the managers to master desertification process in Mu Us Sandy Land over the past 40 years and carry out control programs. In this paper，Landsat images from 1977 to 2010 were used as remote sensing data and method coupled with decision tree classification and ISODATA unsupervised classification were used to retrieve desertification process in Mu Us Sandy Land over the past 40 years. Besides，annual average temperature and annual total precipitation from 1971 to 2010 were used to analyze the causes of desertification process. Results showed that：（1） Method coupled with decision tree classification and ISODATA unsupervised classification could be used for remote sensing interpretation in desertification area successfully. The accuracy of classification results was greater than 87.28%. （2） In Mu Us Sandy Land，drifting sandy land area in the late 1990s was the largest and the ones in the late 1980s and 2010 were the second largest and the smallest，respectively. Semi-fixed sandy land area in 2010 was the largest and the one in the late 1990s was the smallest. Fixed sandy land in 2010 was the largest and the one in the late 1970s was the smallest. （3） Over the past 40 years，desertification was the most serious in the late 1970s. The sum of areas of drifting and semi-fixed sandy land was 32 084.0 km2，which accounted for 83.64% of the whole region. The sums of drifting and semi-fixed sandy land areas in the late 1980s，the late 1990s and 2010 were 28 581.6 km2，29 576.3 km2 and 26 047.3 km2，which accounted for 74.51%，77.10% and 67.90% of the total，respectively. （4） Inter-conversions among drifting，semi-fixed，fixed sandy lands，farmland and water body were very active. New drifting sandy land mainly originated from semi-fixed and fixed sandy lands. From the late 1970s to the late 1980s，4 207.2 km2 semi-fixed sandy land and 333.9 km2 fixed sandy land transformed into drifting sandy land. From the late1980s to the late 1990s，4 252.6 km2 semi-fixed sandy land and 1 690.4 km2 fixed sandy land transformed into drifting sandy land. From the late 1990s to 2010，891.0 km2 semi-fixed sandy land and 336.3 km2 fixed sandy land transformed into drifting sandy land. Desertification process changed significantly mainly distribute in the northern，northwest and southern parts of Mu Us Sandy Land from the late 1970s to the late 1980s，in the western and southern from the late1980s to the late 1990s，in the northwest，western，southern and northeast parts of Mu Us Sandy Land from the late 1990s to 2010，respectively. （5） Over the past 40 years，the average annual temperature showed a gradually increasing trend with an average speed of 0.039 ℃/a，while annual precipitation showed a decreasing trend with an average speed of 0.095 mm/a. And the climate of Mu Us Sandy Land showed a warming and drying trend. Meteorological factors such as temperature and precipitation were those primarily affecting desertification，but not the only factors. Human factors such as population，land use structure and policy implementation should also be the other important factors. |
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| Keywords: | desertification progress over the past 40 years Mu Us Sandy Land |
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