Soil salinity is one of the serious environmental problems ravaging the soils of arid and semi-arid region, thereby affecting crop productivity, livestock, increase level of poverty and land degradation. Hyperspectral...Soil salinity is one of the serious environmental problems ravaging the soils of arid and semi-arid region, thereby affecting crop productivity, livestock, increase level of poverty and land degradation. Hyperspectral remote sensing is one of the important techniques to monitor, analyze and estimate the extent and severity of soil salt at regional to local scale. In this study we develop a model for the detection of salt-affected soils in arid and semi-arid regions and in our case it’s Ghannouch, Gabes. We used fourteen spectral indices and six spectral bands extracted from the Hyperion data. Linear Spectral Unmixing technique (LSU) was used in this study to improve the correlation between electrical conductivity and spectral indices and then improve the prediction of soil salinity as well as the reliability of the model. To build the model a multiple linear regression analysis was applied using the best correlated indices. The standard error of the estimate is about 1.57 mS/cm. The results of this study show that hyperion data is accurate and suitable for differentiating between categories of salt affected soils. The generated model can be used for management strategies in the future.展开更多
From 2007 to 2017,large-scale green tides occurred every year in the Yellow Sea of China,and Ulva prolifera was the main species leading to the green tide.In this study,we used the Polymerase chain reaction and 3'...From 2007 to 2017,large-scale green tides occurred every year in the Yellow Sea of China,and Ulva prolifera was the main species leading to the green tide.In this study,we used the Polymerase chain reaction and 3'Rapid-amplification of c DNA ends technique to amplify the nr DNA-LSU and IGS sequences in U.prolifera and one species of Blidingia.These techniques showed 3259 bp of nrD NA-LSU and 3388 bp of IGS in U.prolifera and 3282 bp nr DNA-LSU and 3059 bp IGS in Blidingia sp.At the same time,tandem repeats,short dyads,palindromic and multiple simple repeat sequences in the IGS sequence were found by analyzing the structure of the IGS sequence in U.prolifera and Blidingia sp.G+C contents of the IGS sequence in U.prolifera and Blidingia sp.were 52.42% and 53.09%,respectively.We divided the U.prolifera into two types according to the morphological characteristics.Although the specimens of U.prolifera from the Qingdao coastal area,Jiangsu coastal area and the Yellow Sea have different morphologies,their ITS and IGS sequences are almost identical.Therefore,the main species of the green tides in the Qingdao coastal area,Jiangsu coastal area and the Yellow Sea are the same and have the same origin.展开更多
文摘Soil salinity is one of the serious environmental problems ravaging the soils of arid and semi-arid region, thereby affecting crop productivity, livestock, increase level of poverty and land degradation. Hyperspectral remote sensing is one of the important techniques to monitor, analyze and estimate the extent and severity of soil salt at regional to local scale. In this study we develop a model for the detection of salt-affected soils in arid and semi-arid regions and in our case it’s Ghannouch, Gabes. We used fourteen spectral indices and six spectral bands extracted from the Hyperion data. Linear Spectral Unmixing technique (LSU) was used in this study to improve the correlation between electrical conductivity and spectral indices and then improve the prediction of soil salinity as well as the reliability of the model. To build the model a multiple linear regression analysis was applied using the best correlated indices. The standard error of the estimate is about 1.57 mS/cm. The results of this study show that hyperion data is accurate and suitable for differentiating between categories of salt affected soils. The generated model can be used for management strategies in the future.
基金supported by the National Key R&D Program of China(Nos.2016YFC1402102 and 2016YFC 1402104)the National Natural Science Foundation of China(No.41276134)。
文摘From 2007 to 2017,large-scale green tides occurred every year in the Yellow Sea of China,and Ulva prolifera was the main species leading to the green tide.In this study,we used the Polymerase chain reaction and 3'Rapid-amplification of c DNA ends technique to amplify the nr DNA-LSU and IGS sequences in U.prolifera and one species of Blidingia.These techniques showed 3259 bp of nrD NA-LSU and 3388 bp of IGS in U.prolifera and 3282 bp nr DNA-LSU and 3059 bp IGS in Blidingia sp.At the same time,tandem repeats,short dyads,palindromic and multiple simple repeat sequences in the IGS sequence were found by analyzing the structure of the IGS sequence in U.prolifera and Blidingia sp.G+C contents of the IGS sequence in U.prolifera and Blidingia sp.were 52.42% and 53.09%,respectively.We divided the U.prolifera into two types according to the morphological characteristics.Although the specimens of U.prolifera from the Qingdao coastal area,Jiangsu coastal area and the Yellow Sea have different morphologies,their ITS and IGS sequences are almost identical.Therefore,the main species of the green tides in the Qingdao coastal area,Jiangsu coastal area and the Yellow Sea are the same and have the same origin.