| In order to study the rules of rain redistribution of Salix canopy in the Mu Us Sandy Land,this experiment was carried out in the Mu Us Sandy Land in Wushen Banner,Ordos City.The growth conditions of the local forestry department's long-term tending years were selected as 3 years,5 years,and 7 years.Good Salix tests are carried out by observing meteorological data such as rainfall and temperature in the field,measuring the water-holding characteristics and retention capacity of the litter layer indoors,and also measuring the physical properties of the woodland soil bulk density and porosity.Analyze and compare the characteristics of Salix canopy interception,stem flow and through rain of different tending years;compare the water-holding characteristics and retention capacity of litter,and compare and analyze the hydrological characteristics of the soil layer;finally,the different The rainfall interception of tending period Salix sylvestris is simulated and predicted by the modified Gash model,and the applicability of the model is discussed,in order to provide a scientific and reliable method for local soil and water conservation.The following main results are obtained through research and analysis:(1)The through rainfall,stem flow and outside rainfall of Salix forests of different tending years are all significantly positively correlated.The linear equation model is used to reflect the relationship between through rainfall,stem flow and outside rainfall.,R2 is above 0.95;the effect of power function fitting between the rainfall outside the forest and the interception is the best.(2)The total volume of litter in the three different tending years of Salix forests is7a>5a>3a;the maximum water holding capacity and the effective interception volume are both 7a>3a>5a;the effective interception rate is in order 3a>5a>7a,the maximum blocking rate is consistent with the effective blocking rate.(3)On the whole,the soil bulk density of Salix forests with different tending years ranges from 1.41 to 1.69 g·cm-3,and the soil bulk density of Salix forests with a tending period of 3 years is the largest;three Salix forests with different tending years have the largest soil bulk density.The average porosity ratio is in order of 7a(0.75)?5a(0.71)?3a(0.67).The soil three-phase comparison of Salix forest with the tending period of 7 years is more reasonable,and the soil physical properties have been improved.(4)By calculating the weight coefficient,it is concluded that the total clearance has the greatest impact on the physical properties of the forest soil in the study area,and the bulk density has a small impact on the physical properties of the forest soil.The maximum water holding capacity and the mean value of total porosity of soil in Salix sylvestris forest with different tending years increased with the extension of tending years.The correlation analysis of the pore structure shows that when the careless time is 3a,the impact of the pore structure of the forest land soil is the most.(5)The modified Gash model was used to simulate the rainfall interception of Salix in the study area with three different tending years:the interception of Salix canopy with the tending years of3,5,and 7years are54.6mm,67mm,48.6mm,and the stem flow Respectively 4.78mm,5.1mm,5.1mm,the simulated value is lower than the measured value,the penetration rainfall are respectively 224.3mm,232.5mm,214.9mm,the simulated value is higher than the measured value;overall,the modified Gash model can be It is suitable for simulating the process of rainfall interception by the Salix canopy,and can provide a reliable method for the study of soil and water conservation and hydrological cycle in this area. |
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