四川省西北地区沙化土地驱动机制研究

Research on driving mechanism of desertification land in Northwest area of Sichuan province

采用文献收集法,结合川西北实际情况,筛选出典型自然和人为因子,分析因子变化趋势及与沙化面积变化相关性。采用主成分分析法,研究了川西土地沙化的驱动机制。结果表明,近60年来,川西北年平均气温、年大风日数呈显著上升趋势,和沙化面积变化显著正相关(P=0.000);年降水量波动较大但总体保持平稳,其相关性不显著;年平均风速有明显减小趋势,和沙化面积变化显著负相关(P=0.014);总人口、畜牧产值、大牲畜存栏数、牛羊肉产量等人为因子均明显增长,且和沙化面积显著正相关(P≤0.009);分析认为,川西北土地沙化是自然和人为因子综合作用的结果,总人口、牧业产值、大牲畜存栏数、年平均风速、年平均温度组成的第1主成分是川西北土地沙化的主要驱动力,其贡献率为59.174%。

Combined with the actual situation in Northwest area of Sichuan Province, the typical natural and the man-made factors were selected based on the literature collection method. The correlation of transformation between factors and desertification area and the trend of factor change were analysed. Moreover,the driving mechanism of desertification land in northwest Sichuan province was researched, using the principal component analysis（PCA） method. The results show that：（1） in the past 60 years, the significantly rise of annual average temperature and annual gale days were found. Meanwhile, the significantly positive correlation（P=0.000） in between average temperature, annual gale days and desertification area change were found;（2） Annual precipitation was fluctuated but overall remained stable, no significant correlation was found in between it and desertification area;（3） Moreover, the significantly negative correlation（P=0.014） in betweet annual average wind and desertification area were found, with the decreasing of the annual average wind speed. In addition, the significantly increased and significantly positive correlation（P≤0.009） also were found on total population, animal husbandry output value, large livestock number, beef and mutton output. The causation of desertification land in Northwest of Sichuan resulted by comprehensive action of natural and man-made factors. The main driving force of desertification land in Northwest of Sichuan Province is consituted of comprehensive action of total population, animal husbandry output value, large livestock population, annual average wind speed, and annual average temperature, its contribution rate is 59.174%.