Analysis of spatial-temporal characteristics and influence indices of photosynthetically active radiation for vegetation absorption from 2015 to 2020
Absorbed Photosynthetically Active Radiation(APAR)is the solar radiation amount effectively absorbed by vegetation during the photosynthesis process.It is an important indicator of the net primary productivity for vegetation.It is also the functional model of the ecosystem,crop growth model,and net primary important parameters such as productivity models and climate models.Therefore,the absorption of photosynthetically active radiation by vegetation with high spatial resolution and accuracy is of great significance for the study of high-precision regional productivity and light energy utilization.In this study,the CASA model is enhanced by integrating Digital Elevation Model(DEM)data with a resolution of 30 m×30 m as a key input parameter.Combining multi-source remote sensing data and meteorological data,the spatial-temporal distribution of APAR in Jianghan Plain and its influence factors from 2015 to 2020 were investigated.Considering the characteristics of land use distribution in Jianghan Plain,this paper focused on analyzing the spatial-temporal characteristics of farmland APAR in Jianghan Plain.Experimental results reflected the distribution of APAR in Jianghan Plain.(1)The total annual values of APAR from 2015 to 2020 ranged from 3.42×1013 MJ to 3.73×1013 MJ,whereas the overall spatial distribution was consistent with the distribution of vegetation types.(2)The average value of monthly APAR in April and July was higher than other months,showing the characteristics of"double peaks".③In terms of spatial distribution,paddy field APAR showed obvious latitude zonality.In contrast,dryland APAR was just the opposite,which might be attributed to the shift of the planting structure's center of gravity.④Using geographic detectors analysis,12 factors related to vegetation growth(≥10≧accumulated temperature,total annual sunshine hours,annual average temperature,total annual rainfall,farmland planting structure,annual scattered radiation,farmland fertilization,soil type,and soil texture(sand,silt,clay)were analyzed.Results showed that the 12 factors all had significant impacts on the spatial variability of APAR.Specifically,the improved method of CASA can be applied to a wide range of calculations with high spatial accuracy.
photosynthetically active radiationabsorbed photosynthetically active radiationCASA modeldigital elevation modelgeographic detector
国家科技期刊平台
NSTL
万方数据
