Dynamic Simulation of Soil Water,Heat and Salt in Freeze-thaw Stage of Cotton Field with Different Mulched Drip Irrigation Years in Northern Xinjiang Based on SHAW Model
In order to investigate the applicability of the SHAW(Simultaneous heat and water)model in simulating soil hydrothermal and salinity dynamics during freeze-thaw period in long-term drip-irrigated cotton fields in the Northern Xinjiang region,the measured soil data of cotton fields with the starting year of 1998(21 a)for drip irrigation were used to calibrate SHAW model in this study.SHAW model was validated with the data from drip irrigation start years of 2006(13 a),2008(11 a),2012(7 a),and barren land(0 a).The results showed that,with the increasing soil depth,the simulation accuracy of soil temperature was better,and the simulation accuracy of soil water salinity was enhanced and then weakened.Nash coefficient(NSE),root-mean-square error(RMSE)and R2 of simulated soil temperature were 0.713-0.993,0.209-2.498 ℃ and 0.911-0.994,respectively.NSE and RMSE of simulated soil moisture were 0.824-0.967 and 0.009%-0.032%,respectively,and NSE and RMSE of simulated soil salinity were 0.609-0.844 and 0.001-0.012 g/kg,respectively.The results of model validation showed that the simulation accuracy was better with the increase in the number of years of drip irrigation,and NSE of simulated soil temperature was greater than 0.600 and RMSE ranged from 0.143 to 3.213℃in all layers of the drip-irrigated plots of 7,11 and 13 a,except that NSE of soil temperature in the soil layer of 20-60 cm in the barren land was less than 0.600.NSE of soil moisture was greater than 0.670 and RMSE ranged from 0.009%to 0.057%in all soil layers of simulated drip irrigated plots for 0,7,11 and 13 a.NSE of soil salinity for 0,7,11 and 13 a were greater than 0.616 and RMSE ranged from 0.000 to 0.016 g/kg in all soil layers,except for the120-140 cm soil layer with NSE less than 0.600.Overall,SHAW model is an available tool to simulate the soil water,heat,and salt in cotton fields under long-term mulched drip irrigation during the freezing and thawing period in Northern Xinjiang.
SHAW modelFreeze-thaw periodMulched drip irrigationCotton fieldSoil water,heat,and salt
万方数据
维普
