Priority evaluation of land salinization monitoring area based on danger degree and risk pattern

The purpose of the study was to improve the pertinence and accuracy of salinization monitoring and control. The main data sources for this paper include agricultural land classification database, 1:500 000 spatial distribution data of saline-alkali land, China earth international exchange station climate data daily value sata set (V3.0), 1:1 000 000 soil database data, 1:1 000 000 spatial distribution data of soil texture in China, land change survey database and other data of Heilongjiang Province. With the support of the above data, on the one hand, research starts from the connotation of land salinization, filtered out land risk assessment factor from numerous factors, include landform, soil texture, evaporation and precipitation ratio, groundwater mineralization, regional sensitivity, land use level, the relationship between land salinization and its correlation was analyzed by the grey correlation model, and used the grey correlation model to analyze the correlation between these factors and land salinization, in order to verify the rationality of the selection of indicators, based on this, carry out grid training and accuracy test, formed land salinization assessment model. On the one hand, started from the extension of land salinization, screened out the resistance factors of soil salinization diffusion or migration, and constructed a resistance surface, used the minimal cumulative resistance model to evaluate the risk pattern of land salinization landscape. After the above work was completed, then with the help of ArcGIS spatial analysis function, superimposed the evaluation results of land salinization danger and land salinization landscape risk pattern, Formed land salinization type zones and monitoring levels. This paper takes Heilongjiang Province as an example to apply the method, the main research results were summarized as follows: 1) In terms of the salinity danger of the land, the land salinization danger of the salinity risk of severe and above land were mainly distributed in the southwestern part of the Songnen Plain, moderately distributed in the north-central part of the Songnen Plain and the northeastern part of the Sanjiang Plain. The light and below were mainly distributed in the great and small xing'an ridge and the southeastern mountainous areas. Eastern Songnen Plain and Southern Sanjiang Plain. 2) In terms of risk pattern, the severe and above were not only distributed in the central and northern parts of the Songnen Plain, but also in the central and northern parts of the Songnen Plain. In addition, there were also a small distribution in the northeastern and southeastern mountain areas of the Sanjiang Plain; moderately except in the Songnen Plain. The northern part and the northeastern part of the Sanjiang Plain were distributed, in the Middle and Central South of the Songnen Plain, the central and western parts of the Sanjiang Plain, and the southeastern mountain areas were also distributed; the mild and the following risk patterns were mainly distributed in the great and Small Xing’an Ridge, in addition to Sanjiang there was a small distribution on the southern edge of the plains and southeastern mountains. 3) The monitoring level of salinization in Heilongjiang Province showed the overall pattern of the west > east > central, northern and southern regions, the high-level and medium-level monitoring areas were mainly distributed in the western, southwestern, northern parts of the Songnen Plain, and the northeastern part of the Sanjiang Plain, the low-level monitoring areas were mainly distributed in the eastern part of the Songnen Plain, in the south of the Sanjiang Plain, and in the southeastern mountain areas, non-monitoring areas were mainly distributed in the large and Small Xing'an Mountains. The conclusion is that the land salinization monitoring area identification technology based on the risk and landscape ecological risk pattern takes into account the connotation of salinization and the extension of salinization, which provides scientific basis for the monitoring and prevention of land salinization.