Study Of Soil Water Characteristics Of Secondary Oak Forest Of Zhongshan Scenic

In this paper, the soil physical properties and main hydrological processes ofthe yellow-brown under the secondary oak forest on Purple Mountain were studied,and variations of soil moisture with its influencing factors were analyzed. Theresults are as follows:(1) Gravel content of the soil in test area is accounting for79.49%, and gravelcontent made its tendency to increase gradually overall as from the soil surface tothe deep soil layers. Sand, silt and clay content made its tendency to decreasegradually on the contrary.(2) The average soil bulk density of the soil in test area is1.47g/cm~3, capillarywater holding capacity is23.51%, the maximum water holding capacity is about26.65%, soil capillary porosity is35.36%,4.85%in non-capillary porosity, totalporosity is40.21%. In addition to soil bulk density, other indicators are graduallyreduced with soil depth gradually increase.(3)Soil maximum water holding capacity and soil silt content was significantlycorrelated, the correlation coefficient was0.976, it was also significantly related tothe soil clay content, the correlation coefficient was0.947, and soil bulk densityshowed a negative correlation with soil maximum water holding capacity. Thecorrelation coefficient was-0.943.(4)In test areas, the infiltration rate of the surface soil is much larger than thelower soil, and shows the regularity of diminishing. It also shows that tall arborunderstory soil infiltration rate is greater than the infiltration rate of the bushsurrounding soil. Soil early infiltration rate and soil silt content, soil total porosityand soil capillary porosity presents significantly correlated, the correlationcoefficients were0.768,0.760and0.669, soil stability infiltration rate and soilnon-capillary porosity were significantly related with correlation coefficient of0.733.(5)Maximum of monthly average soil moisture occurred in August, andminimum occurred in April. Variation of soil moisture is proportional to the changesof precipitation. When precipitation increased sharply, an upward trend in each layershowed roughly as follows: by the topsoil deep going, soil moisture incrementsgradually reduced. In the vertical direction, the highest value of each month soilmoisture occurred on the soil surface, and with the soil depth increased, soilmoisture depth profile showing the wave trends. (6)Soil moisture was affected by both precipitation and air temperature. Bylinear fitting to conclude that the impact of precipitation on soil moisture changeswas significantly stronger than the impact of air temperature. And the impact ofprecipitation and air temperature on the changes of soil moisture performancesantagonism, which led to the emergence of the maximum and minimum values of soilmoisture.(7)Through quantitative study on the surface runoff and subsurface flows, Itshows secondary oak forest soil runoff and precipitation were significantlycorrelated, from the surface to the depth of soil, the impact of precipitation onsubsurface flows were on the rise.