The Temporal And Spatial Variation Of Soil Salinization Intypical Coastal Area And Application Research Of The Monitoring System

Saline soil is one of the current land problem, widely distributed in more than 100 countries and regions all over the world, and its area is almost 1 billion hectares. Saline soil in China with a total area of 36.3 million hectares, close to 4.88% of the available land area in our country, but only 5.766 million hectares have been reclaimed. As an important reserve land resources, it’s important to the developt and utilize the saline soil. The saline soil are widely distributed in our country, according to its geographical location, saline soil can be divided into inland saline soil and coastal saline soil. In Shandong province, inshore saline soil are the mainly type which distributed in the Yellow River delta and the Laizhou Bay area.Formation and evolution of saline soil water and salt migration is a complicated process, not only influenced by topography, soil parent material, groundwater, the influence of climate and other natural conditions, but also affected by human. As saline soil quality changes quickly which lead to soil degradation, the rational development and utilization of the reserve land resources, the dynamic monitoring and evaluation saline soil water and salt is important, which is the first premise of studying the evolution law of saline soil.The purpose of this paper is to analyze and explore the distribution and evolution law of Shandong inshore saline soil and to realize the general rule of salt and water movement for the design optimization of a set of in situ, parameters and automatic monitoring instruments. The instruments will provide technical support for its development and utilization, and the main conclusions of this paper are as follows:1. The main distribution areas of Shandong inshore saline soil are the Yellow River delta and the Laizhou Bay. Although the two areas of saline soil formation is roughly same, their evolutions are different. The Yellow River delta is in salt deposition stage at present, saline soil type is given priority to with chloride type. Salt distribution has close relationship with terrain, from the flood heights to the slopes, and then other large-scale depression, the direction of the salt content gradually increase. In summer the salt is deposited by the groundwater, during autumn the salt is accumulated in the surface due to the evaporation; While Laizhou Bay is in a desalination stage,, saline soil type is given priority to with chloride- sulfate type and sulfate type. The salt present zonal distribution, it reduced from sea to land. The change of salt in seasons is similar to the Yellow River delta, but due to the deeper groundwater depth, salt can only be accumulated in the middle layer.2. It is easy to alkalify during desalting process in Laizhou bay, the characteristics of the ion is a major cause of lead the salinization types change; The Yellow River delta embedded depth of groundwater, salinity and soil salinity has a good correlation, which also show obvious cyclical changes within a year; Halophytes has obvious indication and desalination in saline soil research.3. The optimization of the automatic monitoring system include: addition of multi-parameter probe, improvement of the probe form and material; using high resolution measurement circuit and combined power supply mode; to add the sleep mode and battery warning function of the central control module; choosing MVC architecture of better compatibility in order to apply to a variety of hardware system.4. The monitoring test of inshore saline soil water and salt migration showed that the soil water and salt will be retarded in the capacity of major regional migration; groundwater will slow down the rate of water and salt migration, increase desalting water demand; Brackish water irrigation in the study area is a feasible method, but the irrigation water quality should not be more than 4.31 g/L.