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通过在粤北石漠化地区选取不同石漠化阶段样地,进行人工降雨模拟试验,研究粤北石漠化地区水文过程。结果表明:随石漠化程度的加深,地表植物对雨水最大截留量不断下降,其中以重度→极重度阶段降幅最大,达6倍多。土壤持水量在重度→极重度石漠化阶段发生转折。地表径流在中度和重度石漠化土地上具有相同特征,但在与轻度和极重度石漠化土地中差异明显。当雨强为30~50 mm/h时,产流35 min内总径流量以中度石漠化样地最高;当雨强为51~60 mm/h时,以极重度石漠化样地最高;而当雨强为61~70 mm/h时,则以重度石漠化样地最高。在各石漠化阶段样地上以雨强35 mm/h进行人工模拟降雨60 min,有0.6%~2.71%雨水被植被及枯落物截留;2%~53.31%雨水被土壤吸收;2.18%~7.37%雨水转化为地表径流;41.8%~93.41%雨水渗漏形成地下水。
Through the selection of different stages of rocky desertification in the rocky desertification area of northern Guangdong, artificial rainfall simulation tests were conducted to study the hydrological processes in the rocky desertification areas of northern Guangdong. The results showed that with the deepening degree of rocky desertification, the maximum retention of rainwater on the surface plants continued to decrease, of which the maximum degree of severe → extreme severeness dropped by more than 6 times. Soil water content in heavy severe extreme desertification stage turning point. Surface runoff has the same characteristics on moderate and severe rocky desertification land, but differs significantly from those on mild and very severe rocky desertification. When the rainfall intensity is 30-50 mm / h, the total runoff of 35 minutes of runoff is the highest in medium rocky desertification samples. When the rainfall intensity is 51-60 mm / h, The highest; when the rainfall intensity is 61 ~ 70 mm / h, the area with heavy rocky desertification is the highest. Rainfalls were intercepted by vegetation and litter at a rate of 35 mm / h for 60 min in each stage of rocky desertification. Rainwater from 2% to 53.31% was absorbed by the soil; 2.18% 7.37% rainwater is converted into surface runoff; 41.8% ~ 93.41% rainwater seeps to form groundwater.