Potential of solar-induced chlorophyll fluorescence (SIF) to access long-term dynamics of soil salinity using OCO-2 satellite data and machine learning method

• DOI: 10.1016/j.geoderma.2024.116855
• Publication Date: 2024-03-14T12:36:17Z
• Authors: Ruiqi Du; Youzhen Xiang; Junying Chen; Xianghui Lu; Yuxiao Wu; Yujie He; Ru Xiang; Zhitao Zhang; Yinwen Chen
• Keywords: OCO-2; GOSIF; Spaceborne observations; Science; Soil salt; Q; Solar-induced fluorescence; 01 natural sciences; 0105 earth and related environmental sciences

The accumulation of soil salt becomes a worldwide widespread phenomenon, being major threat to global production. As an environmental stress, salinity can reduce the vegetation photosynthetic activity. Solar-induced chlorophyll fluorescence (SIF) is electromagnetic signal actively released by during photosynthesis. SIF not only capture lower activity due stress promptly, but also less affected atmosphere and background. However, ability observation detect remains unclear. Here, we use standardized solar-induced iluorescence index (SIFI) from time series (2000 ∼ 2020) OCO-2 based product (GOSIF) develop model. results show that: identify (EC ≥ 2 4 dS m−1) class scale. SIFI calculated at May August (hereafter SIFI5-8) optimal sensitivity indices for rainfed cropland, herbaceous cover, irrigated shrubland, grassland. SIFI10-11 forest sparse vegetation; (2) By comparison, ovrerall classification accuracy predicted above 70 %. order cropland > bare area grassland shrubland cover (3) During least three-quarters period 2000 2020, was 4.9 Mkm2; (4) annual change rate content generally between −0.05 0.05 m−1 yr−1. Soil in South Africa West Asia increased greatly with 0.02 0.03 These demonstrate estimate salinity, providing new perspective explaining evaluating variation.