Experiments And Simulation Of Water Transformation In Mu Us Sandland

Water is essential for agricultural production,and the amount of water used in agriculture is73.4 percent of the total water consumption in the country.But the backward management model makes the water efficiency of farmland in our country is only 43% of developed countries.Mu Us Sandland,located in the semi-arid region of northwest China,and the regional surface water is severely lacking due to its geographical location restriction and the severe distribution of rainfall.Over the past 30 years,water resources have tended to decline in the double effects of climate and human activity,natural rainfall and soil water can not meet the needs of crop growth,and water resources become a major obstacle to the development of local agriculture.To study the water consumption of crops in arid areas,make the local groundwater resources reasonably utilize and promote the improvement of the ecological environment,we selected a farmland in Mu Us Sandland as the studyarea,combined with the collected data,field investigation and in situ tests,the relationship bewtween the crops and water has been analysized,and we used the SWAP modle simulated the water conversion of farmland.Crop transpiration is an important aspect of studying the water dissipation of farmland.The flow of plant stem showed obvious diurnal variation,there was almost no flow at midnight but undulation at daytime combined influences of radiation,temperature and vapor pressure et al.The weather factors that determine the rate of stem flow in sunny days are mainly net radiation and atmospheric temperature,which are relative humidity and net radiation in rainy days.Reference to FAO56,the crop coefficient during 2014 and 2015 has been estimated,and the correlation between measured and calculated evapotranspiration was analyzed,which results showed that crop coefficient method can accurately calculate the local farmland actual evaporation amount.SWAP model has been applied in many practical applications around the world.We also used the SWAP model to simulate the water cycle of different hydrological years in arid semi-arid regions,and the results shows the content of simulated and measured values fit well,we can use the SWAP model for water migration simulation in the study area.