Madugundu Rangaswamy, Al-Gaadi Khalid A, Tola ElKamil, Kayad Ahmed G, Jha Chandra Sekhar
Precision Agriculture Research Chair, King Saud University, Riyadh, Saudi Arabia.
Precision Agriculture Research Chair, King Saud University, Riyadh, Saudi Arabia; Department of Agricultural Engineering, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia.
Saudi J Biol Sci. 2017 Feb;24(2):410-420. doi: 10.1016/j.sjbs.2016.10.003. Epub 2016 Oct 8.
A study was conducted to understand the potential of Landsat-8 in the estimation of gross primary production (GPP) and to quantify the productivity of maize crop cultivated under hyper-arid conditions of Saudi Arabia. The GPP of maize crop was estimated by using the Vegetation Photosynthesis Model (VPM) utilizing remote sensing data from Landsat-8 reflectance (GPP) as well as the meteorological data provided by Eddy Covariance (EC) system (GPP), for the period from August to November 2015. Results revealed that the cumulative GPP for the entire growth period of maize crop was 1871 g C m. However, the cumulative GPP determined as a function of the enhanced vegetation index - EVI (GPP) was 1979 g C m, and that determined as a function of the normalized difference vegetation index - NDVI (GPP) was 1754 g C m. These results indicated that the GPP was significantly higher than the GPP ( = 0.96, = 0.0241 and RMSE = 12.6%). While, the GPP was significantly lower than the GPP ( = 0.93, = 0.0384 and RMSE = 19.7%). However, the recorded relative error between the GPP and both the GPP and the GPP was -6.22% and 5.76%, respectively. These results demonstrated the potential of the landsat-8 driven VPM model for the estimation of GPP, which is relevant to the productivity and carbon fluxes.
开展了一项研究，以了解陆地卫星8号在估算总初级生产力（GPP）方面的潜力，并量化沙特阿拉伯超干旱条件下种植的玉米作物的生产力。利用植被光合作用模型（VPM），通过陆地卫星8号反射率遥感数据（GPP）以及涡度协方差（EC）系统提供的气象数据（GPP），对2015年8月至11月期间的玉米作物GPP进行了估算。结果显示，玉米作物整个生长周期的累积GPP为1871 g C m。然而，作为增强植被指数-EVI（GPP）函数确定的累积GPP为1979 g C m，作为归一化差异植被指数-NDVI（GPP）函数确定的累积GPP为1754 g C m。这些结果表明，GPP显著高于GPP（ = 0.96， = 0.0241，均方根误差RMSE = 12.6%）。而GPP显著低于GPP（ = 0.93， = 0.0384，RMSE = 19.7%）。然而，GPP与GPP和GPP之间记录的相对误差分别为-6.22%和5.76%。这些结果证明了由陆地卫星8号驱动的VPM模型在估算GPP方面的潜力，这与生产力和碳通量相关。
