摘要干旱是对农业影响最大的自然灾害之一。随着遥感技术的发展,基于遥感的 区域干旱监测成为了主流手段之一。本文利用 NOAA/AVHRR 数据获取了全国 耕种区域植被状态指数(VCI),分析了 1982-2010 年全国耕种区域干旱的时空 变化特征及其与气候因子的相关关系。结果表明,1982-2010 年我国耕种区域干 旱发生高频区和重旱区主要都集中在西北地区和黄淮海平原;而干旱趋势倾向率 则呈现出一定的季节性和地域性,春、夏两季全国绝大多数耕种地区干旱程度逐 年减弱,秋、冬两季,北方以及西北地区干旱程度逐年加重,南方则为减弱趋势。 而相关性分析表明,VCI 与平均气温和平均风速的相关性最强,而与平均降水量 和平均本站气压的相关性最弱,从不同区域角度上来看,青藏地区 VCI 与气候 因子的相关性最强,西北地区最弱;VCI 与气候因子的时滞性分析表明,平均气 温、最低气温和平均风速的滞后影响并不显著,平均降水量和日照时数滞后期为 1 个月,平均本站气压为 2 个月,总的来说,VCI 与同期以及前 1 月的气候因子 相关性最高。69261
该论文有图 9 幅,表 5 个,参考文献 42 篇。
毕业论文关键词:耕种区域 干旱 VCI 气候因子 相关系数
Drought Trends and Its Correlation with Climate Factors in Farming Areas of China from 1982 to 2010
Abstract
Drought is one of the natural disasters that have the most significant impacts on agriculture. Regional drought monitoring based on remote sensing has become mainstream with the development of remote sensing technology. In this study, the vegetation condition index (VCI) data recorded from 1982 to 2010 in farming areas of China were obtained using the advanced very high resolution radiometer (AVHRR) data, and the temporal and spatial variations in each drought were analyzed. The relationships between drought and climate factors were also analyzed. The results showed that from 1982 to 2010, the farming areas that experienced frequent and severe droughts were mainly concentrated in the northwestern areas and the Huang-Huai Plain. While the trends in the drought distribution presented a certain difference seasonally and regionally. In spring and summer, the drought conditions of the most farming areas decreased over time. Moreover, in autumn and winter, the drought conditions decreased over time in southern farming areas and increased in northern areas. A correlation analysis showed that the VCI had a high correlation with the mean temperature and wind velocity, and had a low correlation with the mean precipitation and atmospheric pressure. Perspective from different areas, the correlation between the VCI and climate factors was the biggest in the Tibetan Plateau and the smallest in the northwestern region. Lag analysis between the VCI and climate factors showed that the temperature, extreme maximum temperature and wind velocity did not have obvious effect on the VCI. While the VCI showed a one- month lag period as a response to the precipitation and sunshine duration and a two- month lag period as a response to the atmospheric pressure. In general, the VCI had the biggest correlation with the climate factors in the same period and last month.
Key Words: farming area drought VCI climate factor correlation coefficient
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摘要Ⅰ
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