吉林省西部属半干旱温带，年蒸发量2.6倍于降雨量，气温从冬季-30℃至夏季的35℃，这一特殊的气候条件使得该地区近地表的土体兼具季冻土、盐渍土与分散土三种特殊土的特性，导致主要环境地质问题为：湿地减少→干涸；草地退化→盐渍化→荒漠化，牧场缩减；道路冻胀翻浆、堤坝边坡失稳，砼构筑物寿命缩短，生态环境严重恶化。.为了减缓草原土地退化、启动了大型引水工程，在温度场、湿度场周期作用下会引起以盐渍化时效性为核心的系列变化。提炼出三个关键科学问题：①盐渍化结构性参数的时效性与分布规律；②以结构变化为核心的水－热－盐－结构四场耦合土体盐渍化环境系统演化机理；③脆弱环境盐渍土复垦与大型引水工程互馈效应机理。本项目拟综合运用工程地质学、微观土力学、土化学、非饱和土力学、模型试验等多学科交叉方法，建立考虑大型引水工程的多场耦合模型，探索寒旱区土体盐碱化环境系统演化机理，为寒旱区盐渍土复垦与可持续发展提供示范。

The farming-pastoral zone belong to semiarid area in the west of Jilin province, annual evaporation capacity is 2.6 times of precipitation, the temperature is minus 30℃ in winter and 35℃ in summer, the special climatic conditions formed the special features of the soils near the surface with the characteristics of seasonal frozen soils, salinized soils and dispersive soils at the same area, which gives rise to the main environmental geological problems are as follows: wetland shrinkage→ dry up; grassland degeneration→ salinization→ desertification, pasture reduced; road frost heave and frothing, slope failure of embankment, the life-span shortened for concrete structure, ecological environment seriously deteriorated..In order to slow down grassland degeneration, a large scale diversion project has been built up, under the effect of temperature and humidity a kernel series change of time dependent salinization can be occurred, three key scientific problems is presented as follows: ① Time dependency and distribution law of the salinization structural parameters; ② Evolution mechanism of geological environmental system by mainly microstructure and coupled of Hydro-Thermal-Salt-Micro structure four phases for the salinization; ③ Mechanism of mutual feedback effect between large scale diversion project and salinization soils reclamation in vulnerable environment. This research project will comprehensively apply the interdisciplinary including Engineering Geology, Micro Structural Soil Mechanics, Soil Chemistry，Unsaturated soil mechanics and many other theories, to set up multi phases coupling model take into account of the large scale diversion project, to explore the evolution mechanism of salinization environment system in cold and semiarid area, to provide an example of sustained development for salinization reclamation in cold and semiarid area. .