农业干旱遥感监测指数及其适用性研究进展

 干旱是影响农作物生长发育的主要气象灾害,且在全球气候变暖背景下,中国呈现出增多增强的干旱化趋势。本文综述主要遥感干旱指数的最新研究进展,并对其优缺点进行比较,分析了各类农业干旱遥感监测指数的适用性:1)与土壤水分指标密切相关的各指数比较适宜于农业旱情早期预警及土壤干旱型农业旱情监测,对作物生长前期未封垄时,植被覆盖度低,土壤裸露情况下有很好的监测效果;2)表征作物形态及生理指标的各指数比较适宜于农业作物生长过程中,尤其是在封垄后,植被覆盖度较高的时期的旱情监测;3)各类综合干旱指数的适用性广阔,可以根据作物整个生长过程中的不同时期进行改良调整,但由于需要大量参数计算保证其精度,限制了实际应用。

Comparison of typical remote sensing drought indexes and their adaptability in agriculture

Of all the kinds of agro-meteorological disasters, drought is the main meteorological disaster affecting crop growth, the maximum damage to agricultural production. A trend of increasing drought in China has been observed due to the global warming. The paper reviews the latest progress in the drought indexes by remote sensing, combined with the characteristics of crop growth cycles, and compares the applicabilities of various drought indexes in different crop growth durations. It is concluded that the drought indexes which are closely related to the soil moisture index are suitable for the prophase of crop growth duration, such as the growth periods, in which the vegetation coverage is low, or not sealing ridge, or soil bareness. The vegetation morphological and physiological drought indexes are more suitable for the agricultural crop growth process, especially after the vegetation sealing ridge and other vegetation coverage higher periods. The applicability of any kindof comprehensive drought index is broad and can be improved to adapt to different crop growth durations, but a large number of parameters need to be calculated to ensure the accuracy, which limits theirs practical application.