不同雨强下草场土壤营养物迁移对克鲁伦河水质影响研究

发布时间：2018-04-17 00:33

本文选题：不同放牧强度 + 降雨模拟　；参考：《内蒙古科技大学》2015年硕士论文

【摘要】：克鲁伦河流域草原地处呼伦贝尔草原的核心区，是呼伦贝尔草原的重要的组成部分，在保护我国北方鸟类迁徙、繁衍以及植被环境生态安全方面起到了不可忽视的作用。近年来草地水土流失日益严重，生态环境恶化显著，而降雨和放牧强度作为草地水土流失的主要原因备受学者关注。本文以克鲁伦河流域国内部分为研究区域，通过对不同放牧强度草场开展降雨模拟实验及野外观测试验，对试验区内的土壤及营养元素流失状况进行测试。利用野外观测及室内测试数据，对降雨、营养元素流失、土壤流失进行分析探讨。研究结果表明：克鲁伦河流域三种放牧强度草场产流过程均是先增加后达到稳定状态，降雨径流量随放牧强度的增加而逐渐减少，，同种放牧草场下，坡度的增加与降雨径流的增加呈明显的线性正相关，径流量总体显示为：重度放牧＞轻度放牧＞不放牧（heavy grazing＞light grazing＞No grazing），三种放牧强度草场径流系数体规律显示为重度放牧＞轻度放牧＞不放牧。产流后径流中的泥沙含量及营养元素含量随时间的增加而逐渐降低并达到稳定状态，相同放牧强度草场在三种雨强下的土壤流失及营养元素流失状况为65mm/h＞45mm/h＞20mm/h，三种放牧制度草场的径流量和径流中泥沙含量及营养元素含量符合二项式相关。三种放牧草场的土壤前期含水率显示为表层均维持在0.1g/cm3，但下层相差较大。三种放牧草场最浅入渗深度为10cm，最深为15cm，土壤水分增加量随土层深度的增加而逐渐减小。三种放牧草场在20mm/h的雨强下土壤水分累计增加量最大，均高于45mm/h、65mm/h，不放牧草场的土壤水分累计增加量均大于其它草场。
[Abstract]:Located in the core area of Hulunbeir grassland, Cruren River Basin is an important part of Hulunbeir grassland, which plays an important role in protecting bird migration, reproduction and ecological security of vegetation in northern China.In recent years, soil and water loss of grassland has become more and more serious, and ecological environment has deteriorated significantly. Rainfall and grazing intensity are the main causes of soil and water loss in grassland.In this paper, based on the study area of the Cruren River basin, rainfall simulation experiments and field observation tests were carried out on grassland with different grazing intensities to test the soil and nutrient loss in the experimental area.Based on field observation and indoor test data, rainfall, nutrient loss and soil loss were analyzed and discussed.The results show that:The runoff production process of three grazing intensities in Crohn River basin increased first and then reached a stable state, and the rainfall runoff decreased gradually with the increase of grazing intensity, and under the same grazing pasture, the rainfall runoff decreased gradually with the increase of grazing intensity.The increase of slope has a significant linear positive correlation with the increase of rainfall runoff.The total runoff showed as follows: heavy grazing > light grazing > heavy grazing > light grazing > no grazing. The rules of runoff coefficient of three grazing intensities showed heavy grazing > light grazing > no grazing.The sediment content and nutrient element content in runoff gradually decreased with the increase of time and reached a stable state.The soil loss and nutrient loss of the same grazing intensity grassland under three rainfall intensities were 65mm/h > 45mm/h > 20mm / h, and the runoff and sediment content and nutrient element content in runoff of the three grazing systems were in accordance with binomial correlation.The soil moisture content in the early stage of the three grazing pastures was maintained at 0.1g / cm ~ (-3), but there was a big difference in the lower layer.The shallowest infiltration depth of the three grazing pastures was 10 cm and the deepest infiltration depth was 15 cm. The increase of soil moisture gradually decreased with the increase of soil depth.The accumulative increase of soil moisture in the three grazing pastures was the largest under 20mm/h rain intensity, which was higher than 45mm / h or 65mm / h, and the accumulative increase of soil moisture in the ungrazed pasture was higher than that in other pastures.
【学位授予单位】：内蒙古科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S812.2

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