为了快速、无损地监测花生冠层LAI,获取其长势信息,于2014年通过大田试验选用5个品种花生作为供试品种,使用ASD Field Spec Hand Held便携式野外光谱仪采集花生不同生育时期的冠层高光谱数据,同时使用SUNSCAN冠层分析系统实测花生冠层...为了快速、无损地监测花生冠层LAI,获取其长势信息,于2014年通过大田试验选用5个品种花生作为供试品种,使用ASD Field Spec Hand Held便携式野外光谱仪采集花生不同生育时期的冠层高光谱数据,同时使用SUNSCAN冠层分析系统实测花生冠层叶面积指数(LAI),并应用光谱微分技术和统计分析技术,分别分析4种光谱形式和6种植被指数与LAI的相关关系,建立估算模型。结果表明:高光谱反射率及其光谱变换形式中最优波段与LAI的相关性均极显著,其中一阶微分光谱ρ'在793nm波段处构建的估测方程对花生冠层LAI的估算效果最好(r=-0.5391,P<0.01,RE=0.2497),其模拟值与实测值的拟合度达极显著水平(R=0.4435,P<0.01);一阶微分光谱ρ'在734nm波段处LAI的实测值与模拟值的拟合效果最好(R=0.5485,P<0.01)。6种植被指数所选的最优组合波段与LAI均通过了0.01水平的显著性检验(r≥0.5731,P<0.01),其中归一化植被指数NDVI[760,976]对花生冠层LAI的估算效果最好(r=-0.6421,P<0.01,RE=0.2167),模拟值与实测值的拟合度达极显著水平(R=0.6731,P<0.01),且优于ρ'对LAI的估算效果;LAI实测值与模拟值拟合效果最好的为DVI[760,976](R=0.6893,P<0.01)。研究结果表明一阶导数光谱和植被指数对花生冠层LAI的估算精度均较高,植被指数的估算精度尤高,研究同时进一步证实了导数光谱和植被指数能较好地消除土壤、大气等环境背景信息的影响。展开更多
With routine meteorological data from 1951 to 2009 at Jinzhou City,the variation characteristics of the temperature,precipitation,sunlight,wind speed and evaporation were analyzed.The results showed that the annual av...With routine meteorological data from 1951 to 2009 at Jinzhou City,the variation characteristics of the temperature,precipitation,sunlight,wind speed and evaporation were analyzed.The results showed that the annual average temperature increased significantly and sunshine decreased in the last 59 years at Jinzhou city.Annual precipitation and the average speed were significantly decreased.Evaporation augmented and the average evaporation was 3.1 times than the average precipitation.The sunshine time was positively correlated with evaporation and was negatively correlated with annual precipitation.展开更多
文摘为了快速、无损地监测花生冠层LAI,获取其长势信息,于2014年通过大田试验选用5个品种花生作为供试品种,使用ASD Field Spec Hand Held便携式野外光谱仪采集花生不同生育时期的冠层高光谱数据,同时使用SUNSCAN冠层分析系统实测花生冠层叶面积指数(LAI),并应用光谱微分技术和统计分析技术,分别分析4种光谱形式和6种植被指数与LAI的相关关系,建立估算模型。结果表明:高光谱反射率及其光谱变换形式中最优波段与LAI的相关性均极显著,其中一阶微分光谱ρ'在793nm波段处构建的估测方程对花生冠层LAI的估算效果最好(r=-0.5391,P<0.01,RE=0.2497),其模拟值与实测值的拟合度达极显著水平(R=0.4435,P<0.01);一阶微分光谱ρ'在734nm波段处LAI的实测值与模拟值的拟合效果最好(R=0.5485,P<0.01)。6种植被指数所选的最优组合波段与LAI均通过了0.01水平的显著性检验(r≥0.5731,P<0.01),其中归一化植被指数NDVI[760,976]对花生冠层LAI的估算效果最好(r=-0.6421,P<0.01,RE=0.2167),模拟值与实测值的拟合度达极显著水平(R=0.6731,P<0.01),且优于ρ'对LAI的估算效果;LAI实测值与模拟值拟合效果最好的为DVI[760,976](R=0.6893,P<0.01)。研究结果表明一阶导数光谱和植被指数对花生冠层LAI的估算精度均较高,植被指数的估算精度尤高,研究同时进一步证实了导数光谱和植被指数能较好地消除土壤、大气等环境背景信息的影响。
文摘With routine meteorological data from 1951 to 2009 at Jinzhou City,the variation characteristics of the temperature,precipitation,sunlight,wind speed and evaporation were analyzed.The results showed that the annual average temperature increased significantly and sunshine decreased in the last 59 years at Jinzhou city.Annual precipitation and the average speed were significantly decreased.Evaporation augmented and the average evaporation was 3.1 times than the average precipitation.The sunshine time was positively correlated with evaporation and was negatively correlated with annual precipitation.
