| In this paper,The Community Land Model version 4.5(CLM4.5)driven by the atmospheric forcing data of CRUNCEP date was used to simulate soil moisture and soil temperature in Qinghai-Xizang Plateau from 1981 to 2016.The simulated soil moisture data and soil temperature data were compared with the observation data of the monitoring network,in four areas(i.e.Nagri,Shi quanhe,Nagqu,Maqu)in different climate zones and vegetation conditions and eight sets of soil moisture(i.e.ERA-Interim,CFSR,CFSv2,JRA-55,GLDAS-NOAH,GLDAS-CLM,GLDAS-MOS,GLDAS-VIC).This paper compares and analyzes the data from 1981-2016 Northwest Institute of Eco-Environment and Resources,CAS soil temperature and moisture,Using correlation coefficient(R),root mean square error(RMSE),mean bias(Bias),unbiased mean-square root error(ubRMSE)and standard deviation ratio(SDV),etc.,to compare the simulation performance of the soil moisture products to the observed values.Search for the long and large scale soil temperature and moisture products suitable for the Qinghai-Xizang Plateau.Furthermore,the long-time series,large-scale and high-precision simulation results were used to analyzed the temporal and spatial variations of soil moisture and soil temperature in the plateau.(1)For soil temperature,the simulation results can reproduce the dynamic process and change details of the two layers of soil moisture over time.Although the result is less than the observed soil temperature,it is the closest to the observed value,and has a close relationship with the observed value.(2)Soil moisture,soil freezing period can not show the dynamic characteristics of soil moisture;the dynamic process characteristics of the two layers of soil moisture change over time were characterized by non-freezing period simulation results,GLDAS-NOAH and GLDAS-CLM products,which showed the best in both error statistics and correlation.GLDAS-MOS,GLDAS-VIC,ERA-interim and CFSv2 products on the value of an observation to depict the effect is not ideal,although to acertain extent can show parts of the change trend of soil moisture,and JRA-55 products cannot describe regional soil temperature and moisture.(3)The simulation results show that the temporal variation and spatial distribution of soil moisture in the two layers of the plateau in the past 36 years are the same,the soil moisture in the deep layer is obviously higher than that in the shallow layer,and the spatial distribution of the soil moisture in the plateau presents wet and shallow wetlands in the northwest,deep high humidity distribution characteristics.The spatial variability of soil moisture in two layers of plateau is basically the same.The overall soil moisture in spring and winter mainly increases with the increase of soil moisture in the northwestern part of summer and autumn,and increases in the east except the southeast,95% confidence test in most areas.(4)Soil temperature in two layers of the plateau showed obvious seasonal periodic changes.From the beginning of spring,the soil temperature gradually increased until it reached the peak in summer and then decreased gradually.The soil temperature in the whole plateau increases from north to south in a stepwise manner.The southern part of the plateau is the high soil temperature region.The north part of the plateau is the low soil moisture region.The soil temperature in the northern part of the Qaidam basin is obviously higher than the surrounding area.The long-term trend of soil temperature in two layers of Qinghai-Xizang Plateau in the four seasons from1981 to 2016 is the same,showing a significant upward trend(by 95% of the significant level),especially in spring and autumn... |
PDF Full Text Request