北疆棉花NDVI与气象因子的相关性分析

棉花NDVI与气象因子的分析为及时、有效地开展棉花生产管理工作提供了重要的科学依据。利用2000—2012年棉花生长期的MOD13Q1数据和逐日降水量、平均气温、最高气温和最低气温资料，采用相关分析方法分析了棉花NDVI的变化特征以及气象因子对棉花NDVI的影响。结果显示：棉花NDVI随着生长期呈现有规律的变化，先迅速增大后逐渐减小；由于研究区是灌溉农业区，棉花NDVI与降水量的相关系数较小，且未通过显著性检验；棉花NDVI与平均气温、最高气温和最低气温强相关，相关系数在0.7750~0.9500之间，考虑不同温度因子积温与棉花NDVI相关系数大小和其平均值，平均气温积温呈现较好的相关性及稳定性，最高气温积温相关性较低，最低气温积温相关性最大。总之，棉花NDVI能较好地反映棉花长势，与降水量无显著关系，最低气温的积温是影响棉花生长的重要因素。

Correlation Analysis Between Cotton NDVI and Meteorological Factors in Northern Xinjiang

The analysis between cotton NDVI and meteorological factors provides an important scientific basis for the timely and effectively to carry out the management work of cotton production. Based on MOD13Q1, rainfall, daily mean temperature, daily maximum temperature and daily minimum temperature during the growth period of cotton from 2000 to 2012, the author analyzed the variations characteristics of cotton NDVI and the effects of meteorological factors on cotton NDVI by using correlation analysis method. The results showed that: the cotton NDVI changed regularly with the growth of cotton, which increased rapidly and then decreased gradually. The correlation coefficient was small between the cotton NDVI and rainfall, and did not pass the significant test because the study area was irrigated agricultural area. The cotton NDVI and temperature strongly correlated, and the correlation coefficient was 0.7750-0.9500. Considering the correlation coefficients between cotton NDVI and accumulate temperature of different temperature types and their average values, the accumulated temperature of average temperature showed good correlation and stability with the cotton NDVI, the accumulated temperature of high temperature had little correlation with the cotton NDVI, the accumulated temperature of minimum temperature had a high correlation with the cotton NDVI. In short, the cotton NDVI could better reflect the cotton growth and had no correlation with rainfall, and the accumulated temperature of minimum temperature was one important factor for the growth of cotton.