Detection model of soil salinization information in the Yellow River Delta based on feature space models with typical surface parameters derived from Landsat8 OLI image

Abstract

The Yellow River Delta, with the most typical new wetland system in warm temperate zone of China, is suffering from increasingly serious salinization. The purpose of this study is to utilize five typical surface parameters, including Albedo (the surface Albedo), NDVI (vegetation index), SI (salinity index),WI (humidity index), and I Fe2O3 (Iron oxide index), to construct 10 different feature spaces and, then, propose two different kinds of monitoring models (point-to-point model and point to line model) of soil salinization. The results showed that the inversion accuracy of the I Fe2O3 feature space detection index based on the pointto-point model was the highest with R 2 ¼0.86. However, the inversion accuracy of Albedo-NDVI feature space detection index based on the point-to-point model is the lowest with R 2 ¼0.72. This is due to the fact that NDVI is not sensitive enough to indicate the status of vegetation grown in the region with low (disturbance of soil background) and high (influenced by the saturation effect) vegetation coverage. The chemical weathering is also a primary cause of soil salinization, during which Fe 2 O 3 is formed by the reaction of oxygen present in the atmosphere with primary Fe 2þ minerals in the soil .Therefore, the AlbedoÀI Fe2O3 feature space detection index based on the point-to-point model has a stronger applicability to monitor the information of soil salinization in the Yellow River Delta. This above point-to-point detection model can be utilized as a better approach to provide data and decision support for the development of agriculture, construction of reservoirs, and protection of natural ecological system in the Yellow River Delta.

Soil Salizanation Information in the Yellow River Delta Based on Feature Surface Models Using Landsat 8 OLI Data

“…Yellow River Delta has the most integrated new-born salinization system in China [1], [2]. It has prominent soil salinization and fragile ecological environment because of less precipitation, large evaporation, serious uneven drought and flood, and significant seasonal dry and wet alternation [2]- [4]. Soil salinization has critically restricted the development of regional agricultural economy in the Yellow River Delta [5]- [7].…”

“…Soil salinization has critically restricted the development of regional agricultural economy in the Yellow River Delta [5]- [7]. Thus, it is urgent to obtain the soil salinization information, which can provide decision supports for the prevention and governances of soil salinization [2], [8]- [11].…”

“…Traditional studies on soil salinization are mostly based on field measurements, which are characterized by expensive cost, time-consuming and small spatial scale [1], [2], [12]- [16]. During the past decades, remote sensing and Geographic Information System technology have provided a fast and accurate new approach to obtain the salinization information of large-scale regions [2], [17]- [22].…”

“…Zhang et al [28] had explored the relationship between modified soil adjusted vegetation index (MSAVI) and salinity index (SI) based on the Landsat OLI image and field survey data and then proposed the salinization remote sensing information extraction model. However, only the linear relations between different feature space parameters has been considered in most previous relative studies, which has ignored the complicated impacts of biological and abiotic factors on salinization process [2], [29], [30].…”

Spatial–temporal change patterns of vegetation coverage in China and its driving mechanisms over the past 20 years based on the concept of geographic division

“…Vegetation is a general term for all types of plant communities covering the surface of the Earth. As the most important constituent unit of the ecosystem, vegetation is a natural 'link' connecting soil, atmosphere and water and thus plays an important role in improving the ecological environment and promoting material circulation and energy conservation (Pan et al 2000;Ma and Veroustraete 2006;Chakraborty et al 2018;Guo et al 2020b). As the main body of terrestrial ecosystems, vegetation is exceedingly sensitive to the changes of various factors due to the influence of climate, geomorphology, soil and other natural and man-made factors.…”