黄淮海平原地区防护林网冬小麦生产力模拟的初步研究

A Preliminary Study on Modelling Winter Wheat GPP of Farm Shelterbelts in Huang-Huai-Hai Plain of China

防护林对农田生产力的影响是一个复杂的过程,需要对多种网格进行综合监测。遥感技术为多网格、同步定量评价防护林体系对作物产量的影响提供了有力支持。本研究以黄淮海平原为例,使用增强型遥感图像时空融合方法(ESTARFM)融合多源遥感影像,通过基于遥感的光能利用效率模型,模拟黄淮海防护林网内农田总初级生产力(gross primary producivity,GPP)。结果表明:(1)冬小麦GPP实测值与模拟值具有显著的线性相关性,平均相对误差为15.62%,决定系数(R2)达0.8596。可见,建立的GPP模型具有较高的模拟精度;(2)从遥感获取的10个网格冬小麦GPP情况来看,网格间农田生产力存在较大的空间变异性。本研究初步揭示了基于遥感影像融合方法,定量估算防护林网内农田GPP的可行性,为进一步探讨防护林对农田生产力的影响提供了重要手段。

The effects of shelterbelt system on farmland productivity are complex, which need an integrated monitoring of multiple shelternets. Remote sensing provided a promising tool for monitoring those effects in multiple shelternets synchronously. In case of Huang-Huai-Hai plain, multi-source remote sensing images were fused based on enhenced spatial and temporal adaptive reflectance fusion model（ESTARFM） to inverse gross primary productivity（GPP） of winter wheat with light use efficiency model in farmland shelterbelt. Results indicated that：（1） based on the light use efficiency model and images fusion, simulated GPP had signaficant linear correlation with measurements. The determination coefficient of measured and simulated values of wheat GPP is 0.8596 with an average relative error of 15.62%. As a result, the light use efficiency model had higher calculation accuracy.（2） We found highly spatial heterogeneity in GPP which modeled in 10 nets of Shelterbelts. This study preliminary revealed the feasibility of quantitative estimation of the GPP in farmland shelterbelts based on the remote sensing image fusion. Our work provided an important tool to further investigate the effecst of shelterbelts on farmland productivity.