Test And Simulation For Soil Moisture Dynamics In Dune-Meadow-Dune Area In Horqin Sand

Soil is a continuum of space-time variation.Soil moisture which stored in the soil is restricted by precipitation,vegetation,infiltration,evaporation and other factors and to be a critical importance to ecosystem and soil evolution,land productive forces,the formation and development of vegetation.This paper bases on soil physics,soil water dynamics,meteorology and other basic theory,selects the study area in Horqin Sand,bases on the field test data and studies the dynamic changes of soil water of different landscape.At the same time,establishs soil moisture model to simulate.From analysis,gains five main conclusions as follows:(1) Soil moisture in vertical space shows dynamic characters.Three layers to be divided in sandy soil:①dry sand in surface layer(0~20cm);②water active layer(20~180cm);③deep stable layer(180~250cm).The dipartition in meadow is as followed:①volatile layer in surface(0~10cm);②use layer of soil moisture(10~40cm);③deep stable layer(40~80cm).(2) Draw isogram map of soil moisture to analyse the seasonal changes.The dipartition in sandy soil is:①weak loss period of soil moisture(March~May);②accumulation period of soil moisture(June~August);③stable period of soil moisture(September~the second February).In meadow:①water added period from freeze-thaw(March~May);②water added period from rainfall(June~July);③stable period of soil moisture (August);④water loss period in Autumn(September~November);⑤water loss period in Winter(December~the second February).(3) Discuss the impact to soil water storage comes from precipitation.The rusults show that:The dynamic changes of soil water storage show the same trend with the distribution of precipitation and fluctuations of water storage show a significant hysteresis with the changes of precipitation.(4) Utilize multiple correlation analysis to identify the consanguineous correlation between soil moisture and atmospheric environment factors. (5) Analyse the deterministic model of soil moisture and choice time series self-regression model to stimulate soil moisture of the study area.