Estimation of Actual Crop Coefficients Using Remotely Sensed Vegetation Indices and Soil Water Balance Modelled Data

Remote Sensing

Isabel Pô๺s¹  Teresa A. Paço¹  Paula Paredes¹  Mário Cunha²  Luís S. Pereira¹  Gabriel Senay³ 

[1]LEAF—Linking Landscape, Environment, Agriculture and Food, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal

[2] E-Mails:

[3]Centro de Investigação em Ciências Geo-Espaciais (CICGE), Rua do Campo Alegre, 4169-007 Porto, Portugal

[4] E-Mail:LEAF—Linking Landscape, Environment, Agriculture and Food, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal

关键词: actual basal crop coefficient;    evapotranspiration;    evaporation coefficient;    fraction of ground cover;    remote sensing;    NDVI;    SAVI;    SIMDualKc model;    water stress coefficient;   

DOI  :  10.3390/rs70302373

来源: mdpi

【 摘 要 】

A new procedure is proposed for estimating actual basal crop coefficients from vegetation indices (K_{cb VI}) considering a density coefficient (K_d) and a crop coefficient for bare soil. K_d is computed using the fraction of ground cover by vegetation (f_{c VI}), which is also estimated from vegetation indices derived from remote sensing. A combined approach for estimating actual crop coefficients from vegetation indices (K_{c VI}) is also proposed by integrating the K_{cb VI} with the soil evaporation coefficient (K_e) derived from the soil water balance model SIMDualKc. Results for maize, barley and an olive orchard have shown that the approaches for estimating both f_{c VI} and K_{cb VI} compared well with results obtained using the SIMDualKc model after calibration with ground observation data. For the crops studied, the correlation coefficients relative to comparing the actual K_{cb VI} and K_{c VI} with actual K_cb and K_c obtained with SIMDualKc were larger than 0.73 and 0.71, respectively. The corresponding regression coefficients were close to 1.0. The methodology herein presented and discussed allowed for obtaining information for the whole crop season, including periods when vegetation cover is incomplete, as the initial and development stages. Results show that the proposed methods are adequate for supporting irrigation management.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.