【作者】 雷丽；

【导师】 程星；

【作者基本信息】 贵州师范大学 ， 环境科学， 2009， 硕士

【摘要】 近年来,随着环境的日益恶化,人们对当今气候环境的变化日益重视,从而相关问题的研究也越来越多。石灰华作为地表次生碳酸钙沉积物,蕴含着丰富的气候环境信息,而受到环境学者尤其是岩溶学者的极大关注。人类活动在一定的流域内进行,所产生的土壤侵蚀效应将在河流中的泥沙含量中有所体现,随着石灰华的连续沉积,泥沙将随之附着在石灰华的沉积物中。流域内土壤侵蚀严重,河流中的泥沙含量就增多,石灰华在沉积过程中所吸附的泥沙就多,石灰华中泥沙含量将随着升高,反之,石灰华中泥沙含量将随着降低。因此石灰华中泥沙含量的变化趋势表征流域内土壤侵蚀的变化趋势。本文通过对贵阳市滴水岩、雅河、花溪平桥和天河潭近期沉积的石灰华层理的刮离,并用物理、化学手段研究了刮离样品中泥沙含量及其沉积年龄,同时对其中泥沙含量和其所在流域内土壤侵蚀变化趋势进行了研究,初步得到以下结论:1.滴水岩石灰华沉积厚度约0.20 cm/a,沉积速率约0.51g·a^-1·cm^-2。滴水岩石灰华中泥沙含量变化趋势表征了该流域内近70年来土壤侵蚀的变化趋势,约从1937年到1991年,该流域内土壤侵蚀呈下降趋势,趋势线为:y=0.0621x+0.7112,斜率0.0621;约从1991年开始,该流域内土壤侵蚀日渐严重,趋势线为:y=-0.0693x+11.578,斜率-0.0693。这主要是因为1991年贵阳市人口迅速增加和城市化发展加剧人类活动以及降雨侵蚀力变化造成的。2.雅河石灰华沉积厚度约0.24 cm/a,沉积速率约0.50g·a^-1·cm^-2。雅河石灰华中泥沙含量变化趋势表征其流域内土壤侵蚀变化趋势。自1978年以来,雅河流域内土壤侵蚀总体上一直呈下降趋势,趋势线为:y=0.0383x+5.3299,斜率0.0383。3.花溪平桥石灰华沉积厚度约0.43cm/a,沉积速率约1.08g·a^-1·cm^-2。平桥石灰华中泥沙含量变化趋势表征花溪河流域内近30年来土壤侵蚀变化趋势。花溪河流域内土壤侵蚀变化约从1977年到1999年总体呈上升趋势,趋势线为:y=-0.0046x+4.6694,斜率-0.0046,变化相对较平缓;约从1999年到2007年期间,总体又呈下降趋势,趋势线为:y=0.0408x+2.716,斜率0.0408,变化相对较快。4.天河潭石灰华沉积厚度约0.50cm/a,沉积速率约1.18g·a^-1·cm^-2。天河潭石灰华中泥沙含量的变化趋势表征其流域内土壤侵蚀变化趋势。从总体上来说,距2007年约19年以来,天河潭流域内土壤侵蚀变化趋势约从1988年到2003年逐渐上升,趋势线为:y=-0.1324x+24.738,斜率-0.1324;约从2003年到2007年期间逐渐下降,趋势线为:y=0.159x+10.307,斜率0.159。这主要是因为实施退耕还林（草）。退耕还林（草）政策的实施对减少区域土壤侵蚀的作用是显著的,是利于流域生态环境改善的。5.大量降水,特别是暴雨对石灰华中泥沙含量影响较明显,降水越多,石灰华中的单位质量泥沙含量越大,1998年的洪水就比较明显。更多还原

【Abstract】 In recent years,with the environment getting worse and worse,we human pay more attention to climatic and environmental changes,thereby research variety of related problems of them.Travertine is a secondary surface calcium carbonate sediments and contains a wealth of information on climate and environment,so environmental scholars especially karst scholars great concern the tufa.Human activities carry out in certain valleys,the effects of soil erosion that result from human activities will be shown in the river silt content and the silt will be attached to the sediment in the travertine with the continuous deposition of travertine.If soil erosion is serious in valley,silt content will increase in river.Silt content in travertine will increase with the increase of silt in river,on the contrary, silt content in travertine will decrease.Therefore,the change trend of the silt content in travertine shows the change trend of soil erosion in valley.In this paper,penman scratched recent travertine deposits of Dishui Rock,Ya River,Huaxi Ping Ridge and Tianhe Pond in Guiyang,researched silt content and age of scratched sample by the physical and chemical means,at the same time,studied the change trend of silt content in sample and soil erosion in valley.Some preliminary conclusions are discussed in the thesis: 1.Travertine deposition thickness is about 0.20cm/a,and the deposition rate is about 0.51 g·a^-1·cm^-2 in Dishui Rock.The change trend of silt content in travertine showed the change trend of soil erosion in valley near 70 years.Soil erosion degree was downward trend from about 1937 to 1991,the trend line:y=0.0621x+0.7112,and the slope was 0.0621.From 1991,soil erosion degree was increasingly serious,the trend line is y=-0.0693x+11.578,and the slope is minus 0.0693. This resulted from increased human activities,which was caused by population rapid increase urbanized development,as well as change of rainfall erosion power in Guiyang in 1991.2.Travertine deposition thickness is about 0.24cm/a,and the deposition rate is about 0.50g·a^-1·cm^-2 in Ya River.The change trend of silt content in travertine shows change trend of soil erosion in Ya River valley.Since 1978,the soil erosion intensity in Ya River valley has been generally downward trend, the trend line is y=0.0383x+5.3299,and the slope is 0.0383.3.Travertine deposition thickness is about 0.43cm/a,and the deposition rate is about 1.08g·a^-1·cm^-2 in Ping Bridge.The change trend of silt content in travertine shows the change tendency of soil erosion in valley near 30-year.Soil erosion degree was upward trend from about 1977 to 1999,the trend line was y=-0.0046x+4.6694,the slope was minus 0.0046;Soil erosion degree was downward trend from about 1999 to 2007, the trend line was y=0.0408x+2.716,the slope was 0.0408.4.Travertine deposition thickness is about 0.50cm/a,and the deposition rate is about 1.18g·a^-1·cm^-2 in Tianhe Pond.The change trend of silt content in travertine shows the change trend of soil erosion in Tianhe Pond valley.On the whole,Soil erosion degree was gradually upward trend from about 1988 to 2003,the trend line was y=-0.1324x+24.738,and the slope was minus 0.1324;Soil erosion degree was gradually downtrend from 2003 to 2007 in Huaxi valley,the trend line was y=0.159x +10.307,and the slope was 0.159.This was mainly caused by returning farmland to forests,which could effectively control soil erosion,reduce natural disaster and was conducive to improving the ecological environment of the basin.5.A large amount of precipitation,especially heavy rain influences obviously silt content in travertine.The unit quality silt content in travertine was larger with more precipitation,and flood was quite obvious example in 1998.更多还原