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对珠海市花岗岩小流域的地表径流及其常量离子和溶解Si含量进行了每周1次、连续1年的观测和分析.结果表明:在大气降水过程中,坡面漫流贡献了沟谷径流的主要部分;在非降水时段,地下水则成为沟谷径流的主要补给源.溶解Si,Na+,HCO3-和Cl-构成沟谷径流的主要化学成分.滨海小流域地表化学径流的阴离子主要源自以CO2及黄铁矿氧化成因的H2SO4为介质的花岗岩的自然化学风化过程、海盐的干湿沉降过程以及酸的干湿沉降过程(约以1:1:1的贡献).滨海小流域径流中NO3-与SO42-比值大于1,而在同一生物气候带内西江径流的相应值小于1,揭示流域岩性差异和人类活动导致的大气酸沉降组成差异是决定径流化学组成的主要因素.华南滨海花岗岩小流域化学风化过程对CO2的消耗通量为(0.35～1.37)×105mol·km-2·a-1.
The surface runoff and its contents of constant ions and dissolved Si in granite small watershed of Zhuhai City were observed and analyzed once a week for one year.The results show that during the precipitation process, , And groundwater became the major recharge source for valley runoff during non-precipitation period.The dissolved Si, Na +, HCO3- and Cl- constitute the major chemical components of runoff from the valley.The anions of surface runoff from the coastal watershed are mainly derived from CO2 and yellow The natural chemical weathering of granite with H2SO4 media, the wet-dry sedimentation process of sea salt and the wet-dry deposition of acid (about 1: 1: 1 contribution) - the ratio is greater than 1, while the corresponding value of Xijiang runoff in the same bioclimatic zone is less than 1, revealing that the compositional differences of atmospheric acidity caused by lithological differences and anthropogenic activities are the major factors determining the chemical composition of runoff. The CO2 fluxes of the weathering process are (0.35 ~ 1.37) × 105mol · km-2 · a-1.