跳至主要内容

Prediction of Soil Salinity Using Multivariate Statistical Techniques and Remote Sensing Tools

Soil salinity refers to the amount of salts in the soil and it can be estimated by measuring the electrical conductivity (EC) of an extracted soil solution. It is considered an important component of ecosystem degradation in the world’s dry lands and can lead to desertification and other form of land degradation, such as salinization.  

Some extensive research efforts have been made by international scholars to monitor and predict saline soils using remote sensing and statistical analysis methods. In this study, the authors would explore the potential multivariate statistical analysis, such as principal component analysis (PCA) and cluster analysis to identify the most correlated spectral indices and rapidly predict salt affected soils.

Sixty six soil samples were collected for ground truth data in the investigated region. A high correlation was found between electrical conductivity and the spectral indices from near infrared and short-wave infrared spectrum. Different spectral indices were used from spectral bands of Landsat data. Statistical correlation between ground measurements of Electrical Conductivity (EC), spectral indices and Landsat original bands showed that the near and short-wave infrared bands (band 4, band 5 and 7) and the salinity indices (SI 5 and SI 9) have the highest correlation with EC. The use of CA revealed a strong correlation between electrical conductivity EC and spectral indices such abs4, abs5, abs7 and si5. The principal components analysis is conducted by incorporating the reflectance bands and spectral salinity indices from the remote sensing data. The first principal component has large positive associations with bands from the visible domain and salinity indices derived from these bands, while second principal component is strongly correlated with spectral indices from NIR and SWIR.

Overall, it was found that the electrical conductivity EC is highly correlated (R2 = -0.72) to the second principal component (PC2), but no correlation is observed between EC and the first principal component (PC1). This suggests that the second component can be used as an explanatory variable for predicting EC. Based on these results and combining the spectral indices (PC2 and abs B4) into a regression analysis, model yielded a relatively high coefficient of determination R2 = 0.62 and a low RMSE = 1.86 dS/m. Therefore, the generated regression model is considered as an efficient and rapid tool to predict soil salinity over arid region, such as southern Tunisia.

Article by Moncef Bouaziz, et al, from Tunisia and Germany.

Full access: http://t.cn/EbyUA2f
Image by DanoAberdeen, from Flickr-cc.

评论

发表评论

此博客中的热门博文

Incorporation of High-Altitude Balloon Experiment in High School Science Classrooms

High-altitude balloon is a balloon, filled usually with helium or hydrogen that ascends into an area called “near space” or stratosphere. The most common type of high-altitude balloons are weather balloons. Other purposes include use as a platform for experiments in the upper atmosphere. Modern balloons generally contain electronic equipment such as radio transmitters, cameras, or satellite navigation systems, such as GPS receivers. The mission of the High-Altitude Balloon Experiment (HABE) is to acquire supporting data, validate enabling technologies, and resolve critical acquisition, tracking, and pointing (ATP) and fire control issues in support of future space-based precision pointing experiments. The use of high-altitude balloons offers a relatively low-cost, low-vibration test platform, a recoverable and reusable payload, worldwide launch capability, and a 'near- space' emulation of the future space systems operational scenarios. More recently, several university...
1 条评论
阅读全文

Electron Spin and Proton Spin in the Hydrogen and Hydrogen-Like Atomic Systems

Read full paper at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=52202#.VIj7tMnQrzE Author(s) Stanisław Olszewski * Affiliation(s) Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland . ABSTRACT The mechanical angular momentum and magnetic moment of the electron and proton spin have been calculated semiclassically with the aid of the uncertainty principle for energy and time. The spin effects of both kinds of the elementary particles can be expressed in terms of similar formulae. The quantization of the spin motion has been done on the basis of the old quantum theory. It gives a quantum number n = 1/2 as the index of the spin state acceptable for both the electron and proton ...
发表评论
阅读全文

The Influence of Heated Soil in Crop of “Tamaris” Tomato Plants on the Biological Activity of the Rhizosphere Soil

Tomato is a plant with high heat requirements and sensitive to cold weather and frost. The optimum temperature for the growth of tomato plants is between 21˚C and 27˚C during the day and between 17˚C and 21˚C at night. The soil temperature is also very important for plant growth. The optimum soil temperature for tomato cultivation should be within the range 15˚C - 18˚C. Besides, the proper development of the root system depends on the optimal temperature of the soil. A temperature below 14˚C reduces and inhibits the growth of the root system and encourages the development of fungal and bacterial diseases. In this study, the authors aimed to evaluate the effect of heated soil on the population of bacteria, fungi and nematodes inhabiting the soil of tomato cultivar “Tamaris” growing in peat and coconut substrates. The experiment was carried out in 12 treatments and in 3 replications (one slab was one replication). The soils were tested in two different types of containers: cylinders...
发表评论
阅读全文