喀斯特岩溶裂隙对地下径流和氮素垂直渗漏的影响
发布时间：2018-10-20 20:24
【摘要】：为了探究水土漏失过程对岩溶裂隙发育形态的响应,采用野外模拟降雨试验,研究了裂隙出露型岩土(XL)、裂隙埋藏型岩土(XM)两种结构形态岩溶裂隙对地下径流及氮素垂直渗漏的影响,并以全土微区(QT)为对照。结果表明:裂隙出露型岩土(XL)、裂隙埋藏型岩土(XM)和全土(QT)3个处理中地下径流对降雨的响应时间表现为XLXMQT,其初始地下径流产流时间分别是29,77,139min,XL和XM初始地下径流产流时间分别比QT减少了79.14%,44.60%;降雨产流阈值分别为20.64,55.06,94.90mm,以QT的降雨产流阈值为基准,XL和XM的降雨产流阈值分别减少了78.25%,41.98%;地下径流达到稳定的时间分别为59,107,169min,稳定径流速率分别为42.09,42.36,38.24mm/h。不同结构形态岩溶裂隙下XL全氮、硝态氮渗漏浓度最高,浓度均值分别为11.64,10.45mg/L,除XM外,XL、QT在降雨结束前地下径流中的全氮、硝态氮浓度基本达到稳定;不同结构形态岩溶裂隙下全氮渗漏量表现为XLXMQT,硝态氮渗漏量表现为XMXLQT,地下径流中氮素输出的主要形式为硝态氮,其比例约占全氮渗漏量的82.32%~90.12%,而铵态氮渗漏量占全氮渗漏量的比例不足2%。裂隙的存在,尤其是出露地表裂隙的存在,增加了微区底部单位面积土壤地下径流速率,同时还增加了微区底部单位面积土壤氮素渗漏量,喀斯特地区普遍存在的裂隙结构促进了水分入渗,加剧了地下径流中氮素的渗漏。本研究相关结果可为喀斯特地区水土漏失机制的探索以及物质迁移模型的构建提供科学依据。
[Abstract]:In order to investigate the response of soil and water loss process to karst fissure development, field simulated rainfall experiment was used. The effects of karst fissures on underground runoff and vertical leakage of nitrogen in two structural forms of (XL), fractured rock and soil (XM) are studied and compared with (QT) in whole soil microarea. The results show that the response time of underground runoff to rainfall in the three treatments of (XL), buried (XM) and (QT) is XLXMQT,. The initial groundwater runoff generation time is 297139min XL and XM initial groundwater runoff respectively. The rainfall runoff threshold of XL and XM was reduced by 79.14 and 44.60 mm, respectively, and the threshold value of rainfall runoff was 20.64 ~ 55.06 ~ 94.90 mm, respectively, and that of XL and XM was reduced by 78.25 ~ 41.98 mm / h, respectively, and the time of stabilization of underground runoff was 5910 7169 min and the steady runoff rate was 42.36 mm / h and 38.24 mm / h respectively. Under different structural forms of karst fissures, the XL total nitrogen concentration is the highest, the mean concentration of nitrate nitrogen is 11.64 ~ 10.45 mg / L, respectively. Except for XM, the total nitrogen concentration of XL,QT in underground runoff before the end of rainfall is basically stable. The total nitrogen leakage under different structural forms of karst fissures shows that the leakage of XLXMQT, nitrate nitrogen is the main form of nitrogen output in underground runoff of XMXLQT, and the main form is nitrate nitrogen. Its proportion is about 82.32% of total nitrogen leakage, while the proportion of ammonium nitrogen leakage to total nitrogen leakage is less than 2%. The existence of fissures, especially in exposed surface cracks, increases the rate of soil underground runoff per unit area at the bottom of the microzone, and also increases the amount of soil nitrogen leakage per unit area at the bottom of the micro-area. The crack structure in karst area promotes the infiltration of water and increases the leakage of nitrogen in underground runoff. The results of this study can provide scientific basis for the exploration of soil and water loss mechanism and the construction of material migration model in karst area.
【作者单位】： 中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室;中国科学院环江喀斯特生态系统观测研究站;中国科学院大学;
【基金】：国家重点基础研究发展计划项目(2015CB452703) 国家重点研发计划项目(2016YFC0502403) 国家自然科学基金项目(41671287)
【分类号】：S157.1
本文编号：2284299
[Abstract]:In order to investigate the response of soil and water loss process to karst fissure development, field simulated rainfall experiment was used. The effects of karst fissures on underground runoff and vertical leakage of nitrogen in two structural forms of (XL), fractured rock and soil (XM) are studied and compared with (QT) in whole soil microarea. The results show that the response time of underground runoff to rainfall in the three treatments of (XL), buried (XM) and (QT) is XLXMQT,. The initial groundwater runoff generation time is 297139min XL and XM initial groundwater runoff respectively. The rainfall runoff threshold of XL and XM was reduced by 79.14 and 44.60 mm, respectively, and the threshold value of rainfall runoff was 20.64 ~ 55.06 ~ 94.90 mm, respectively, and that of XL and XM was reduced by 78.25 ~ 41.98 mm / h, respectively, and the time of stabilization of underground runoff was 5910 7169 min and the steady runoff rate was 42.36 mm / h and 38.24 mm / h respectively. Under different structural forms of karst fissures, the XL total nitrogen concentration is the highest, the mean concentration of nitrate nitrogen is 11.64 ~ 10.45 mg / L, respectively. Except for XM, the total nitrogen concentration of XL,QT in underground runoff before the end of rainfall is basically stable. The total nitrogen leakage under different structural forms of karst fissures shows that the leakage of XLXMQT, nitrate nitrogen is the main form of nitrogen output in underground runoff of XMXLQT, and the main form is nitrate nitrogen. Its proportion is about 82.32% of total nitrogen leakage, while the proportion of ammonium nitrogen leakage to total nitrogen leakage is less than 2%. The existence of fissures, especially in exposed surface cracks, increases the rate of soil underground runoff per unit area at the bottom of the microzone, and also increases the amount of soil nitrogen leakage per unit area at the bottom of the micro-area. The crack structure in karst area promotes the infiltration of water and increases the leakage of nitrogen in underground runoff. The results of this study can provide scientific basis for the exploration of soil and water loss mechanism and the construction of material migration model in karst area.
【作者单位】： 中国科学院亚热带农业生态研究所亚热带农业生态过程重点实验室;中国科学院环江喀斯特生态系统观测研究站;中国科学院大学;
【基金】：国家重点基础研究发展计划项目(2015CB452703) 国家重点研发计划项目(2016YFC0502403) 国家自然科学基金项目(41671287)
【分类号】：S157.1
【相似文献】
相关期刊论文 前2条
1 雒文生;宋星原;;林区地下径流计算方法的实验研究[J];水土保持学报;1990年03期
2 李丽娇;张奇;;一个地表-地下径流耦合模型在西苕溪流域的应用[J];水土保持学报;2008年04期
，本文编号：2284299
本文链接：https://www.wllwen.com/kejilunwen/nykj/2284299.html
