PROGRESS IN GEOGRAPHY ›› 2012, Vol. 31 ›› Issue (7): 921-932.

• Original Articles •

The Study on the Reflectance Spectral Characteristic of Salt-Affected Soil in Typical Oasis of the Middle Reaches of Tarim River

ZHANG Fei1,2, TASHPOLAT Tiyip1,2, DING Jianli1,2, MAMAT Sawut1,2, HAN Guihong1,2, GUI Dongwei3,4, SUN Qian1,2

1. 1. College of Resources and Environment Science, Xinjiang University, Urumqi 830046, China;
2. Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi 830046, China;
3. Xinjiang Institute of Ecology and Geography, CAS, Xinjiang 830011, China;
4. Cele National Station of Observation & Research for Desert-Grassland Ecosystem in Xinjiang, Cele 848300, China
• Received:2011-10-01 Revised:2012-02-01 Online:2012-07-25 Published:2012-07-25

Abstract: With the economic development and the population increase, unreasonable land development has caused ecological problems such as degradation, while soil salinization becomes a major concern in arid and semi-arid areas. It is a basic work to study the spectrum characteristics of soil salinization by using remote sensing technology to achieve the monitoring and evaluation of soil salinization at regional scale, and to establish the relationship between ground data and remote sensing data. In this paper, the author takes the delta oasis of Weigan and Kuqa rivers located in the middle reaches of Tarim River as study areas by using spectroscopy technology and multivariate analysis technology method. This paper studies the correlations between salt-affected soil chemical properties and reflectance spectrum in the middle reaches of Tarim River. Firstly, ASD spectrometer was used to measure spectral data in surface features. The spectral data should be removed from the equipment itself and the external conditions such as noise. Aiming at this experimental application study, we chose appropriate methods from the existing spectral matching processing technologies such as spectral absorption index. Secondly, the paper focused on retrieving soil chemical characteristic parameters (including ions, electricity conductivity, salt content, pH, TDS) from the hyperspectral data. By using single-correlation analysis, the quantifying regression models between salinized soil reflectance and soil ions, electricity conductivity, salinity, pH, TDS were established. It is shown that the correlation coefficient of salt content is 0.746, of sulfate ion is 0.908, of total dissolved solid is 0.798 and of electricity conductivity is 0.933. The result achieved a good effect. To sum up, the result of this research will produce a significant meaning for the research on the saline-alkali soil in the arid area. Furthermore, since a large part of Xinjiang belongs to the arid area, taking the delta oasis of Weigan and Kuqa rivers as the study areas has realistic meanings to the environmental research in the arid area.