【作者】 姚锐；

【导师】 鲍光淑；

【作者基本信息】 中南大学 ， 矿产普查与勘探， 2003， 博士

【摘要】 岩石的风化作用同时参与了短时间尺度和长时间尺度的全球碳循环，科学揭示岩石风化对碳循环影响的机制和程度，对于全球碳循环研究、全球变化研究有重要意义，不仅可以部分地解决“遗漏汇”问题，还能为完善碳循环模型作贡献。 本文首先评述了当前岩溶、岩石风化以及碳循环的研究现状和存在问题，探讨了硅酸盐岩和碳酸盐岩在不同时间尺度上的碳汇意义，全面分析了影响岩石风化的多种因素及其控制机理。针对传统岩溶研究在区域尺度研究上的不足，将遥感和GIS方法引入数据获取、处理及分析过程中，实现了数据和研究成果从点源向区域面上的尺度转化。为此，作者详细讨论了从多波段遥感数据提取地质信息以及空间数据的插值、订正等方法，并进行了相应的实验研究。 在此基础上，作者一方面依据成熟的GEM-CO₂模型，对中国的岩石风化的碳汇效应进行了完整而全面的估算，对其空间分布格局进行了深入分析，填补了我国在岩石风化的碳汇效应估算方面的空白；另一方面，作者基于桂林岩溶试验场十余年来的连续定点观测数据，选取平均气温、降水、土壤呼吸和NPP为影响因素，经过观测数据的极差标准化，基于反应面分析模型的模型原型选择；变量的共线性诊断；及参数估计与显著性分析等过程，建立了碳酸盐岩溶蚀速率模型。显著性检验表明，该模型具有良好的拟合优度，并且99.5％的显著性水平下仍然显著成立。为将此模型推广应用到珠江流域，使用遥感数据和TEPC模型计算得到珠江流域NPP以及土壤呼吸强度数据。同时利用本文第三章计算的气候数据，最终计算得到中国珠江流域的溶蚀率以及碳汇的空间分布及值域。对热带亚热带岩溶的典型区域—珠江流域岩溶作用的碳汇效应进行的实验表明：珠江流域年溶蚀量为8159612.303t碳酸钙，碳979153.48t，其中1／2的碳，约489576.74t来自大气或土壤CO₂。通过和其它模型的对比，各模型估算的结果数量级相同，说明本文建立的热带亚热带岩溶区溶蚀率模型是可信的。更多还原

【Abstract】 Rock weathering caused by the carbonic acid reaction with minerals to produce dissolved bicarbonates which are carried by rivers to the oceans is an important part in carbon cycle. The process causes significant carbon dioxide consumption, the accurate calculation of which may partly explains the missing sink of carbon and may do some contribution to the research in Global Change.The CO2 uptake by carbonate dissolution (which is also called karstification) on the continents is counterbalanced by the CO2 release by carbonate precipitation in the ocean. The same is not true for silicate weathering. Silicate weathering is more important than carbonate weathering as a long-term control on atmospheric CO2.Rock weathering is controlled by a great range of factors which includes rock property, climatic conditions, CO2 concentration in atmosphere/soil, vegetation and so on. Analyses of the influences of factors to rock weathering show that sometimes the weathering process may be controlled mainly by one factor, but in most cases rock weathering is controlled by all factors integratedly.A global erosion model (GEM-CO2) developed by Amiotte Suchet allows to calculate the flux of atmospheric/soil CO2 consumed by chemical erosion of continental rocks. In the thesis, the CO2 consumption by rock weathering in China is estimated based on GEM-CO2 and the Chinese Resources and Environment Database, and its distribution is show in a GRID map with a spatial resolution of 1000m*1000m. The total carbon consumption is about 4.72*107TC/a, about 52.65% of which are caused by carbonate and 47.35% of which are caused by silicate. The model results are close to previous estimation by other researches. The flux of CO2 consumed by rock weathering increases where carbonate rock outcrops are more abundant and when drainage intensity increases. The results show that the main consumption of CO2 is localized in Guangxi province, Guizhou province, Chongqin, North Hubei province, and Southwest of Hunan province, because of large area with a high proportion of carbonate rocks and high humidity.Karstification is a good connector of Geological processes and Biological processes. Many methods are tried in order to accurately estimate the karst solutional speed and then the CO2 consumption by karstification, such as analyzing elements in river, dissolution kinetics, dissolution survey experiments and so on. In the thesis, the karst solutional speed is estimated by a model. Analyses of the influences of some factors to karstification get following conclusions: 1 .Temperature and precipitaion are main climatic factors involving in karstification. There is an obvious positive correlation between the karst solutional speed and precipitation. But it’s not the same between the karst solutional speed and temperature. Temperature influences karstification in a more complex way; 2.Biological processes influences karstification through increasing the acidity of water by metabolic outcome, and then accelerating the reaction between water and rock and hastening the releasing of Calcium element from soil. The intensity of biological process can be assessed with the value of NPP(Net Primary Productivity); 3.As part of reactor, the soil CO2 drives karstification, which can be verified by the positive correlation between the concentration of [HCO3 ] in river or in spring and the CO2 concentration in soil. There is a positive correlation between the intensity of soil respiration and the CO2 concentration in soil.Based on above knowledge and data from continuous experiments and observations, a karst solutional speed model in tropic and subtropical zone in China is developed to describe the relationship between karst solutional speed and temperature, precipitation, NPP, and intensity of soil respiration. The data was non-dimensionized to improve the comparability of different parameters. The archetype of the model was selected with Response Surface Analysis. The effect of correlations between independent factors was analyzed. And the regression equation was worked out更多还原