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通过在野外试验地和室内模型上进行模拟降雨试验,研究粤北地区不同石漠化阶段的土壤退化特点和变化过程。结果表明:随着石漠化程度的加深,不同石漠化阶段的土壤理化性质差异显著,并与地上生物量和植被盖度呈相关性;当雨强大于60mm/h时,中度和重度石漠化土地的土壤地表侵蚀量呈现较大的波动性,产流后35min内重度石漠化样地的地表土壤侵蚀总量是轻度石漠化样地的7倍多;坡度和雨强对中度石漠化土地的土壤漏失量影响不大,体积越大的裂隙、漏斗产生的土壤漏失量反而越小;重度石漠化阶段是石漠化地区土壤退化过程中一个重要的转折阶段,在这个阶段中,形成多种水土流失的运移途径,土壤退化进入到一个突变的状态。
Through the simulated rainfall experiment in field and indoor models, the characteristics and process of soil degradation in different stages of rocky desertification in northern Guangdong were studied. The results showed that with the deepening of the degree of rocky desertification, there were significant differences in soil physical and chemical properties at different stages of rocky desertification, and were correlated with aboveground biomass and vegetation coverage. When the rainfall intensity was greater than 60mm / h, moderate and severe The surface soil erosion of rocky desertification land shows great fluctuation, and the total surface soil erosion of heavy rocky desertification area is more than 7 times of the light rock desertification sample within 35min after runoff. The slope and rainfall intensity Soil loss of medium rocky desertification land has little effect on soil loss, the larger the volume of cracks, the funnel produces less soil leakage but smaller; severe rocky desertification is the process of desertification desertification soil degradation process is an important turning point In this stage, a variety of soil and water loss migration pathways are formed, and soil degradation enters into a mutated state.