摘要
以农牧交错带南部的甘肃省环县为研究对象，以1949～2010年共61年的16个自然和社会经济统计数据为样本，采用主成分分析法，对引起土地荒漠化的自然因子与人为因子进行了定量分析。结果表明：（1）在环县土地荒漠化发展过程中，人为因素的贡献率为53．77％，自然因素的贡献率为21．79％，自然与人为因素共同作用的贡献率为6．76％。在环县60年的荒漠化发展过程中，人为因子的影响处于较高水平，单独的自然因素以及自然和人为因素共同的作用强度较低；（2）在环县荒漠化发生发展过程中起决定作用的是人类活动，气候条件对于荒漠化的发展只起影响作用而不是决定作用。其中自然因子的影响主要是气温持续升高、降雨量减少、空气相对湿度下降、蒸发量增大导致干旱和土壤干层的发育，抑制了植物的生长，降低了植被覆盖度及土壤的抗冲蚀能力。而较强的风力及暴雨量的增加加速了土壤侵蚀；人为因子的影响主要是人口急剧增长、农业人口过大、大面积垦殖导致不合理的土地利用，以及超载放牧引起草场大面积退化直接导致了环县土地荒漠化扩展。
Taking Huan County of Gansu province located in the south part of agriculture pasture ecotone as a research subject, a quantitative analysis on the natural factor and anthropogenic factor of desertification are investigated by principal component analysis with 16 sets of data as sample, which including social （natural factor） and economic （anthropogenic factor） data from 1949 to 2010. Results show that： 1） During the process of desertification in Huan County, natural and human factors contribution rates are 53.77% and 21.79%, respectively, and their combined contribution rate is up to 6.76%. In this process, the impacts of anthropogenic human factor are relatively strong while the solo natural factor or natural-anthropogenic interaction is relatively weak; 2） during the process of desertification, human activity plays a decisive role while climate condition affects the desertification process to a lesser extent. The impacts of natural factors include drought and development of soil dried layers, inhibition of crop＇s growth, decreases of vegetation fraction and soil erosion resistance ability caused by continuous rise of temperature, rainfall decrease and low air moisture, as well as higher evaporation discharge. And the strong wind and torrential rain accelerate soil erosion. Anthropogenic factors include rapid increment of population and excess of agricultural population, large acreage of soil exploitation resulting irrational land usage, and large area of grassland deterioration caused by overgraze, which directly bringing about the extension of desertification of Huan County.
出处
《土壤通报》
CAS
CSCD
北大核心
2013年第2期296-301,共6页
Chinese Journal of Soil Science
基金
中国科学院战略性先导科技专项(XDA05050403)
甘肃省自然基金项目(1107RJZM105)
中国科学院水利部水土保持研究所黄土高原旱地农业国家重点实验室项目(10501-303)资助
关键词
土地荒漠化
自然因素
人为因素
定量分析
黄土丘陵沟壑区
农牧交错带
Soil desertification
Natural factor
Anthropogenic factor
Quantitative analysis
Hilly and gully region ofthe Loess plateau
Agriculture pasture ecotone
