为对遥感估产模型中的重要参数光能利用率epsilon_(max)取值进行优化,本研究基于植被光合模型( VPM)与农作物单位面积产量统计数据、MOD09A1遥感数据、气象站点数据,对河南省2001 2015年农田生态系统epsilon_(max)时空演变及其影响因素进行研究.结果表明,20012015年各市县epsilon_(max)均值在0.072 ~ 1.034 g /MJ,epsilon max较高的区域分布在东部黄淮海平原,整体上呈现出中部和北部高,西部和南部较低的空间分布特征,时间尺度上存在较大年际波动.epsilon_(max)均值与化肥施用量、CO_2含量之间的相关系数分别为0.585和0.335,epsilon_(max)与植被指数拟合较好.研究区气候类型以秦岭淮河为界,南部的亚热带气候区冬季温度较高,降雪较少,坡度因素对作物光能利用效率影响较小.较高的光温水平对epsilon_(max)促进作用更加明显,农业灌溉可以有效克服降水较少对作物的负面影响.因此,在遥感估算模型估算过程中,需要充分考虑epsilon_(max)的时空分布差异.
英文摘要:
In order to optimize the value of light energy utilization epsilon_(max) of important parameters in remote sensing estimation mode, this paper studied the spatiotemporal evolution of epsilon_(max) of farmland ecosystem in Henan province from 2001 to 2015 and its influencing factors based on vegetation photosynthetic model ( VPM) , the statistical data of crop yield per unit area,MOD09A1 remote sensing data and meteorological station data. The results showed that the average epsilon_(max) of each county in the period from 2001 to 2015 was 1.442.92 g /MJ,and the region with higher epsilon_(max) was located in the Huang-Huai-Hai plain in the east. The overall spatial distribution characteristics were high in the middle and north,and low in the west and south. There were large interannual fluctuations on the time scale. The correlation coefficient between the average epsilon_(max) ,chemical fertilizer application amount and CO_2 content were 0.585 and 0.335, respectively. epsilon_(max) and vegetation index were well fitted. The climate types in the study area were bounded by the Huaihe River in the Qinling Mountains. The subtropical climatic regions in the south had higher winter temperatures and less snowfall,and the slope factors had little effect on the crop light energy utilization efficiency. The higher light temperature level had a more pronounced effect on epsilon_(max) ,and agricultural irrigation could effectively overcome the negative impact of less precipitation on crops. Therefore, it was necessary to fully consider the spatial and temporal distribution differences of epsilon_(max) in the estimation process of the tele estimation model.