A Three-Dimensional Index for Characterizing Crop Water Stress

Remote Sensing

Jessica A. Torrion¹  Stephan J. Maas⁴  Wenxuan Guo²  James P. Bordovsky³ 

[1]Northwestern Ag Research Center, Montana State University, Kalispell, MT 59901, USA

[2]Monsanto Company, 700 Chesterfield Pkwy W, Chesterfield, MO 63017, USA

[3] E-Mail:

[4]Texas A&M AgriLife Research and Extension Center, 823 W US 70, Plainview, TX 79072, USA

[5] E-Mails:

[6]Department of Plant and Soil Science, Texas Tech University, 3810 4th Street, Lubbock, TX 79415, USA

[7] E-Mail:

关键词: cotton;    water stress;    irrigation;    remote sensing;    soil brightness;    ground cover;    temperature;    fusion technique;   

DOI  :  10.3390/rs6054025

来源: mdpi

【 摘 要 】

The application of remotely sensed estimates of canopy minus air temperature (Tc-Ta) for detecting crop water stress can be limited in semi-arid regions, because of the lack of full ground cover (GC) at water-critical crop stages. Thus, soil background may restrict water stress interpretation by thermal remote sensing. For partial GC, the combination of plant canopy temperature and surrounding soil temperature in an image pixel is expressed as surface temperature (Ts). Soil brightness (SB) for an image scene varies with surface soil moisture. This study evaluates SB, GC and Ts-Ta and determines a fusion approach to assess crop water stress. The study was conducted (2007 and 2008) on a commercial scale, center pivot irrigated research site in the Texas High Plains. High-resolution aircraft-based imagery (red, near-infrared and thermal) was acquired on clear days. The GC and SB were derived using the Perpendicular Vegetation Index approach. The Ts-Ta was derived using an array of ground Ts sensors, thermal imagery and weather station air temperature. The Ts-Ta, GC and SB were fused using the hue, saturation, intensity method, respectively. Results showed that this method can be used to assess water stress in reference to the differential irrigation plots and corresponding yield without the use of additional energy balance calculation for water stress in partial GC conditions.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland