| Because of its sensitive nature of the underlying surface, desert get response to global change firstly especially to climate change, and realize feedback effects in the process of interaction, therefore, research on the land-gas exchange in the desert system has extremely important significance for the fragile desert environment. Existing studies have shown that the surface layer soil heat stored, in particular, the role of soil temperature should not be ignored in the desert energy balance closure. The Badain Jaran Desert has special underlying surface and long time series observation data, the study of the soil temperature can rich Chinese desert soil temperature system research samples, and provide theoretical support for desert-gas system energy balance. This article analyzed the soil temperature observation data and meteorological data of the badain jaran temple in2011year, preliminary results and conclusions are as follows:(1) Mean monthly soil temperature under the conditions of different depth of the Badain Jaran Temple approximate sine curve. The rise of temperature in winter and spring alternate seasons has a smaller influence to deep soil temperature than the shallow soil. Mean monthly soil temperature is peaked in August, month average minimum temperature above60cm soil depth is January, below is February, and exists hysteresis phenomenon. Month average temperature significant changes mainly concentrated in the season transition period of the summer half year and winter half year, with the increase of depth, annual range in soil temperature gradually decreased; the whole year cycle is roughly sine curve, soil temperature peaked during the summer, fall to the lowest during winter, with the increase of soil depth, diurnal range become more and more smaller.The soil temperature diurnal variation curve of10-40cm significantly dynamic than the others. In vertical distribution, the lowest soil diurnal temperature is January, the minimum soil temperature exists hysteresis phenomenon. The soil diurnal temperature are peaked in August, above100cm soil depths appear hysteresis phenomenon, while the below depths are not obvious.(2) After a summer precipitation,the hysteresis phenomenon was observed in lowest temperature and highest temperature of10cm,20cm depth.10cm soil layer has most significant response to rainfall,with the increase of precipitation, the soil temperature decreased extremely.the soil temperature of20cm and40cm also declined, but the decline was less than10cm depth. Using Morlet complex wavelet transform to analyzed data of soil temperature after the summer precipitation, there are40to64days and20to35days change cycle. Among the20to35days change cycle exist high-low temperature alternating four shocks and have the full performance.40to62days has the biggest time scale of modulus maximum value and its cycle change is the most obvious.(3) After the analysis of partial correlation, we found temperature, precipitation, relative humidity, average wind speed, maximum wind speed, sunshine time and short wave radiation have an impact on soil temperature, relative humidity and soil temperature has a negative correlation, the other factors are positively correlated with soil temperature, air temperature is the strongest factor. With the increase of soil depth, air temperature, influence of short wave radiation, sunshine hours, relative humidity, average wind speed, maximum wind speed weakened gradually, with the increase of soil depth, the change of rainfall is not obvious.(4) The soil temperature of the Badain Jaran Temple is simulated by least-squares regression, principal component regression and partial least-squares regression model respectively. Results show that the simulation accuracy of the least squares regression and principal component regression model is low, while the partial least-squares regression model is higher than the others. Therefore, it is better by using partial least-squares regression model to simulate soil temperature of the Badain JaranTemple. |
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