基于Landsat 8 TM卫星数据的玉米灌浆期旱情监测
玉米灌浆期旱情的快速监测是进行合理灌溉和灾害评价的重要依据,冠层含水量和冠层温度是玉米旱情遥感监测的重要指标,研究综合冠层含水量指数和温度指数优点的新型干旱指数对提高玉米旱情遥感监测精度具有重要意义。本研究以灌溉区大田玉米为研究对象,利用Landsat 8 TM卫星数据把,冠层含水量指数MSI2与温度指数LST结合构建了冠层水分温度指数(CTWDI),并对研究区2014—2016年大田玉米灌浆期旱情进行监测。结果表明,CTWDI与灌浆期玉米冠层含水量极显著相关(r=0.719**),CTWDI可以较好的反应灌浆期高覆盖度玉米水分状况。基于CTWDI的灌浆期玉米干旱监测结果与实际情况相符,且Kappa系数均高于57%,改进了玉米生育中后期的旱情监测方法。因此,可以利用 CTWDI对玉米灌浆期高覆盖度条件下的干旱监测。
英文摘要:
Rapid detection of drought regime in the grain filling of maize is the basis of rational irrigation and disaster assessment. Canopy water content (MSI 2) and temperature (LST) are important indices of remote sensing monitoring of drought regime in maize. The new drought index combined the canopy water content and temperature has vital importance on improving accuracy of remote sensing monitoring of drought regime. We used the maize fields in 71 Group, the fourth division in Xinjiang as the object, using the data of Landsat 8, synthesizing the MSI 2 and LST to establish the canopy water and temperature index (CTWDI), and monitoring the drought regime of maize field at grain filling stage in 2014-2016. The results show that there is significant correlationship between CTWDI and canopy water content at grain filling (r=0.719**), CTWDI can preferably reflect the canopy water content at grain filling under high coverage. The monitoring result based on CTWDI is coincide with the practical, and the coefficient of Kappa is more than 57%, improved drought monitoring method in the middle and later growth stage of Maize. Therefore, the CTWDI can be used for the drought regime monitoring at grain filling in maize under high coverage.
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