EGI OpenIR  > 研究系统  > 荒漠环境研究室
塔里木盆地西北缘典型下垫面的风蚀潜力及风蚀过程研究
郑泽浩
学位类型博士
导师冯广龙 ; 冯广龙
2016
学位授予单位中国科学院大学
学位授予地点北京
学位专业自然地理学
关键词风蚀 强风事件 风蚀量 粉尘释放机制 塔里木盆地
摘要阿克苏地区位于塔里木盆地西北缘,具有典型的大陆性干旱气候特征,同时也是中国重要的沙尘源地之一。本文选择阿克苏地区的枣园、棉田和沙漠绿洲过渡带三种典型的下垫面,在2012和2013两个观测周期,通过野外实地动态监测试验,分析塔里木盆地的沙尘通量特征,及空气动力学参数,并总结了研究区的风蚀特征。利用野外取样及室内测定,分析了表层土壤的团聚体分布,揭示蠕、跃与悬移的释放潜力;利用观测的研究区的风蚀特征,结合母壤团聚体以及风蚀物团聚体粒度分布的研究分析,阐明了该地区的粉尘释放的物理机制;使用DPM粉尘释放模型对研究区的沙尘通量进行了模拟研究;并以此为基础,结合研究区的粉尘释放的物理机制和其他本文的结论,运用流体力学相关方程,完善了该粉尘释放模型。主要结论如下: (1)过渡带潜在可蚀性含量及悬移含量最大,特别是<50um的能够长距离传输的潜在含量很高。说明过渡带不仅仅是沙尘暴的沙源,而且能够长距离传输,影响其它地区的空气质量。三种下垫面的潜在蠕移含量很小,说明不是主要的沙尘运动形式。以chandler和Chepil 建立的土壤团聚体和土壤流失量关系为模型进行计算,结果为:过渡带>棉田>果园,这和直接观测的沙尘通量特征的结果是一致的。 (2)研究区三个下垫面的强风事件有着显著的不同:过渡带强风事件的风向主要集中在SEE、E和NWW这3个方向,棉田和果园强风事件的风向则主要集中在N、NE、NNE和ENE这4个方向。过渡带的强风事件的数量、强度和持续时间都远高于其它两个实验区。空气动力学参数的分析表明过渡带有最低的摩阻风速、最小的零位移平面高度和最小的空气动力学粗糙度,而果园有最高的摩阻风速、最大的零位移平面高度和最大的空气动力学粗糙度。通过现场观测结合野外取样及空气动力学参数的理论分析,表明过渡带的潜在风蚀强度最大,因此在风蚀的治理上,过渡带应该被重点考虑。 (3)通过BSNE和creep sampler进行沙尘水平通量和风蚀量的观测,发现在棉田和果园实验区观测到的沙尘水平通量只有约10%符合高度的幂函数,过渡带实验区的沙尘水平通量则完全符合幂函数。过渡带实验区的风蚀量远多于其他两个实验区,棉田实验区的风蚀量大于果园实验区,差别的主要原因是不同的田间措施和植被覆盖共同造成的。 (4)沙尘水平通量的结构、Sensit所观测的跃移活动特征以及风蚀物的团聚体粒度分布共同表明:研究区的粉尘释放机制主要依赖空气动力的拖曳和抬升,而并非前人所述的跃移冲击。 (5)利用DPM模型模拟了研究区的粉尘释放特征,模拟结果显示,跃移通量的模拟值和实测值较一致,而粉尘释放通量的模拟值却远低于实测值。剖析了DPM模型的运行的物理机制,结合本研究的部分结论,找出了模拟值和实测值出现偏差的原因是DPM模型的运行机制和研究区的粉尘释放机制不太相符造成的。在前人工作的基础上,推导出了空气动力引起的粉尘释放的通量表达式,完善了DPM模型对研究区粉尘释放的模拟。
其他摘要The Aksu region within the Tarim Basin is a major source of windblown dust in China due to the arid climate and vast areas under intensive irrigated crop production. This present study focus on the soil wind erosion of Tarim Basin.The objectivity of this study was to investigate wind erosion process and aerodynamic properties of three typical underlying surfaces (Cotton, Orchard and Oasis – desert transition zone) by outdoor experiment and lab analysis. The soil aggregate was measured, and the creep, potential saltation and suspension were estimated. The results as followed: (1)The calculated potential soil loss by chandler (1941) and Chepil (2005) equations were followed: Transition> cotton >orchard, and it was consistent with measured results. The aerodynamic properties was measured, the results showed that Transition zone had lowest friction velocity, zero plane displacement and aerodynamic roughness, and Orchard had highest lowest friction velocity, zero plane displacement and aerodynamic roughness, indicated that Transition zone had highest potential wind erosion. Therefore, mitigation of soil winderosion and fine-particle emission should be considered inTransition zone. 2)The high wind events was concentrated in April and May in study region. The number and intensity of high wind events of transition zone more than the other treatments. The high wind events were concentrated in three wind direction of SEE, E and NWW from Transition zone, and was concentrated in N, NE, NNE and ENE in cotton and orchard. (3)The only 10% sand horizontal flux data was fit the power function from cotton and orchard by BSNE collected. While the all horizontal flux data was fit the power function from Transition zone. The amount of soil loss of Transition zone more than other treatments, indicated that the field operation and vegetation has great effect on the soil wind erosion. Transition zone has highest potential suspension, particular in a diameter less than 50um that could have long transportation. Transition zone not only was dust source for dust storm, but also could have long transportation and have effect on air quality for other place. The potential creep was little in three treatments, indicated that the creep was not a main wind erosion form. (4)The structure of sediment flux, the saltation activity characteristics observed by Sensit and the aggregated particle size distribution of sediment trapped by BSNE together showed that the main dust emission mechanism was not depend on saltation, but mainly depend on the aerodynamic. DPM modelwas used to simulate dust emissionin ot the study area, and saltation fluxes of simulated values and measured values were consistent, however, for sediment emission flux (sediment vertical flux) , the simulation values were far lower than the measured values. (5)Analyzed the physical mechanism DPM model and combined with parts of conclusions of this study, then find out the reasons of errors occurring between the simulated values and measured values in using DPM mode to simulate the study area’s dust emission. Based on the previous work, deduced a expression of dust emission which caused by aerodynamic and improved the DPM model.
学科领域自然地理学
语种中文
文献类型学位论文
条目标识符http://ir.xjlas.org/handle/365004/14741
专题研究系统_荒漠环境研究室
作者单位中科院新疆生态与地理研究所
推荐引用方式
GB/T 7714
郑泽浩. 塔里木盆地西北缘典型下垫面的风蚀潜力及风蚀过程研究[D]. 北京. 中国科学院大学,2016.
条目包含的文件
条目无相关文件。
个性服务
推荐该条目
保存到收藏夹
查看访问统计
导出为Endnote文件
谷歌学术
谷歌学术中相似的文章
[郑泽浩]的文章
百度学术
百度学术中相似的文章
[郑泽浩]的文章
必应学术
必应学术中相似的文章
[郑泽浩]的文章
相关权益政策
暂无数据
收藏/分享
所有评论 (0)
暂无评论
 

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。