Estimation of wheat production by the integration of MODIS and ground data

摘要

This paper presents a methodology capable of combining Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) imagery and ancillary data to estimate durum wheat production in Tuscany (Central Italy). First, the phenological stages of winter wheat are simulated by the use of an agro-meteorological model (Syrius 4.1). Next, MODIS NDVI images at 250 m spatial resolution are utilized to identify fields likely grown with winter wheat. The multitemporal NDVI profiles of these fields are then integrated with Syrius 4.1 outputs through a previously developed procedure in order to simulate wheat above-ground biomass and harvest index. This allows the computation of wheat yield, which, combined with relevant cropped area, provides provincial wheat production estimates. The methodology is tested using ground and MODIS data taken over four Tuscany provinces where winter wheat is widely cultivated. The accuracy of all estimated variables (wheat cropped area, yield and production) is finally evaluated against provincial statistical data. The results of this experiment indicate that the accuracy of wheat cropped area estimation and yield simulation is variable, but interannual production variations are reproduced well for all provinces.