Spatial And Temporal Variations Of Rainfall Erosivity At Each Level In Taihang Mountain

In this paper,using the daily precipitation data of 76 meteorological monitoring stations in the Taihang Mountains and its time ranges from 1954 to 2016,through the model test and geostatistical interpolation method,a simple model of rainfall erosivity suitable for the Taihang Mountains and interpolation methods are established.Through Mann-kendall non-parametric test,climate tendency rate,coefficient of variation and wavelet analysis,the changes of rainfall erosivity of different magnitudes in different time scales?interannual,seasonal,monthly,ten years?in the Taihang Mountains are discussed.Characteristics;through the Arcgis software and the center of gravity model,the spatial distribution characteristics of different magnitude rainfall erosivity on each time scale are analyzed.The rainfall of different magnitudes in the Taihang Mountains was analyzed by SPSS18.0 software.The correlation between erosivity and erosive rainfall,latitude and longitude,altitude and ENSO is discussed.The intrinsic response mechanism is discussed.By analyzing the temporal and spatial variation characteristics and influencing factors of rainfall erosivity of different magnitudes in the Taihang Mountains,soil erosion can be Quantity assessment and soil and water conservation measures Perfect to provide technical support,comprehensive full text research the following conclusions can be drawn;1.By comparing the annual rainfall days,annual erosive rainfall,annual rainfall and annual rainfall erosivity in the Taihang Mountains,it can be found that the Wutaishan area has more rainfall days and rainfall,but mostly non-erosion rainfall or Small-scale erosive rainfall,while the rainfall days and rainfall in Xinxiang area are small,but the proportion of large-scale erosive rainfall is relatively large,indicating that it is necessary to divide the rainfall erosivity of the Taihang Mountains into different magnitudes.At the same time,the occurrence and changes of rainfall erosivity in the region are mainly related to rainfall events with less rainfall days and larger rainfall levels.In the case of regional vegetation,soil,topography,slope and slope length,the occurrence of soil erosion in the region is mainly caused by moderate rain and heavy rain.2.The simple model of annual rainfall erosivity in the Taihang Mountains is y=0.182x₁^1.095+5.463x₂^0.982+9.401x₃^1.017+15.258x₄-26.753.the results showed that the annual rainfall erosivity in the Taihang Mountain area showed a slight upward trend,In1996,there was a significant mutation,and there was a main cycle of about 20a and the small cycle changes about 6a;In the change of the year,the changes of rainfall erosivity of different magnitudes are unimodal.From June to September,the rainfall erosivity of each magnitude shows the greater the rainfall level and the higher the concentration within the year.In the seasonal change,spring The risk of soil erosion in autumn and autumn is mainly caused by moderate rain and heavy rain erosivity.In summer,the risk of soil erosion is mainly caused by extraordinarily large rainfall erosivity,and the risk of soil erosion in winter is small.During this period,relevant engineering facilities can be built;On the annual scale,the average annual rainfall erosivity showed a downward trend before the 1990s,but it showed an upward trend after the 1990s.It was mainly related to the frequent occurrence of strong ENSO warm events in the 1990s,and the rainfall erosivity of each magnitude between 2000 and 2016.Both are on the rise,indicating that extreme weather and large-scale circulation have changed dramatically since the beginning of this century,and the magnitude and intensity of rainfall have increased significantly.3.There are significant differences in the annual distribution characteristics of rainfall erosivity in different magnitudes in the Taihang Mountains.The maximum annual ecliptic erosivity and annual average erosive force are both in the Wutaishan area,showing a downward trend and a relatively small coefficient of variation.The maximum values of both the torrential rain erosivity and the extraordinarily heavy rainfall erosivity are in the Anyang area,showing an upward trend with a relatively small coefficient of variation.The minimum rainfall erosivity of each magnitude is mainly distributed in the northwestern part of the Taihang Mountains.Showing an upward trends with a relatively largecoefficient of variation;the gravity of each magnitude of rainfall erosivity migrates to the east and northeast in the spring and summer,and to the south and southwest in the autumn and winter,showing higher rainfall levels and rainfall erosion.The closer the center of gravity is to the characteristics of the southeastern region,this is affected to some extent by the winter and summer monsoons in China.At the same time,the trajectories of the center of gravity of the rainfall erosivity in the rising and falling trend are abruptly changed in the 1970s and 1980s respectively.From 2000 to 2016,the gravity of each magnitude of rainfall erosivity is mainly to the northwest.The direction of movement indicates that the potential risk of soil erosion in the northwestern part of the Taihang Mountains has increased relatively since the beginning of this century.4.There is a significant correlation between rainfall erosivity and erosive rainfall in different magnitudes in the Taihang Mountains.The correlation coefficient is 0.84?P<0.01?.There is no significant negative correlation between rainfall erosivity and latitude and longitude.There was a certain negative correlation between heavy rain and heavy rainfall erosivity and altitude,and the correlation coefficient was above 0.56?P<0.05?.There was a significant positive correlation between summer rain erosivity and altitude,correlation coefficient.It is 0.64?P<0.01?,which indicates that there are relatively few times of heavy rain and extraordinarily heavy rainfall erosivity in the higher elevation of the Taihang Mountains in the spring and autumn,and the number of occurrences of moderate rain erosivity is relatively high.On the contrary,by discussing the correlation between rainfall erosivity and SST anomaly,SOI index and MEI index in the Taihang Mountains,it is found that there is a significant correlation between rainfall erosivity and SST anomaly,with a correlation coefficient of 0.019?P<0.01?.At the same time,when the SST anomaly value is 0.16°C,the regional rainfall erosivity reaches the maximum.It indicates that rainfall erosivity in the Taihang Mountains is mainly affected by erosive rainfall and large-scale circulation.