农田溪流深潭地貌格局营养盐滞留特征及其对人为干扰的响应

发布时间：2018-04-02 19:24

  本文选题：人工深潭　切入点：暂态存储　出处：《合肥工业大学》2017年硕士论文

【摘要】：不同类型源头溪流对氮磷等营养盐滞留和调节能力不同,经过人为干扰后的溪流对下游水体氮磷营养盐的滞留研究具有重要意义。为揭示深潭地貌格局的农田溪流以及人为干扰试验对氮磷营养盐的暂态存储以及滞留情况,选择NaCl为保守示踪剂、NH_4C1和KH_2P0_4为添加营养盐,采取恒速连续投加的方式,开展9次现场示踪实验,其中,后四次是在深潭段等距离放置土袋通过人为干扰的方式进行的。基于OTIS水质模型的分析研究,通过干扰前后自然平直河段与深潭段暂态存储指标以及营养螺旋指标的比较,解析人为干扰试验对溪流暂态存储和氮磷营养盐滞留的影响,并对模拟参数进行参数灵敏性分析以及水文参数进行多元统计分析,得到以下主要成果:(1)深潭地貌格局的农田溪流深潭段的OTIS模拟的水文参数D A、As、α均值分别为 0.116rm~2·s~(-1)、0.357m~2、0.380m~2、5.86×10~(-4)s~(-1),平直段水文参数D、A、As、α均值分别为 0.162m~2·s~(-1)、0.167m~2、0.071m~2、4.11×10~(-3)s~(-1);利用扰动分析法进行参数灵敏度的排序发现,深潭段和平直段四个主要模拟参数D、A、As、α参数灵敏性排序结果均为AAsαD。(2)自然条件下,深潭段F200 med均值为21.97%,平直渠段Fe200med均值为27.97%,且绝大多数平直段高于深潭段,说明自然条件下平直段暂态存储能力比深潭段更强一些;人为干扰后,深潭段F200 med均值为23.94%,平直段Fe200med均值为23.19%,深潭段较平直段偏大,说明人为干扰后深潭段暂态能力明显增强且高于平直段。(3)干扰前后,Sw-NH~(4+)和Sw-SRP值均表现为深潭段远小于平直段,说明深潭段对于氮磷营养盐滞留能力强于平直段,且深潭段和平直段Sw值与国内外同等尺度的溪流Sw值相当;干扰后,深潭段溪流的氮磷营养盐滞留能力明显提高,Vf和U值等有不同程度的增大、Sw值下降幅度较大;深潭段的干扰试验,不仅提高了深潭段对氮磷营养盐的滞留能力,也改变了下游平直段对氮磷营养盐的滞留能力。(4)深潭渠段与平直渠段的多元统计分析表明,深潭段基本水力参数q与Ω对溪流暂态存储能力影响较大,平直段中暂态存储指标间存在着不同程度的相关关系;在φw、φA、Ts和Ls方面,深潭段与平直段暂态存储存在显著差异性。
[Abstract]:The retention and regulation of nitrogen and phosphorus by streams from different sources are different. It is important to study the retention of nitrogen and phosphorus nutrients in the lower reaches of streams after human disturbance.In order to reveal the transient storage and retention of nitrogen and phosphorus nutrients in farmland streams of deep pool geomorphologic pattern and artificial interference test, NaCl was selected as conservative tracer to add nutrients, and the method of constant speed continuous feeding was adopted.Nine field tracer experiments were carried out, of which the latter four were carried out by artificial interference at the same distance in deep pool.Based on the analysis and study of OTIS water quality model, the effects of human disturbance test on the transient storage and nitrogen and phosphorus nutrient retention of streams were analyzed by comparing the transient storage indexes and nutrient spiral indexes between the natural plain reach and deep pool section before and after the disturbance.The sensitivity analysis of simulation parameters and the statistical analysis of hydrological parameters are carried out.寰楀埌浠ヤ笅涓昏�佹垚鏋�:(1)娣辨江鍦拌矊鏍煎眬鐨勫啘鐢版邯娴佹繁娼�娈电殑OTIS妯℃嫙鐨勬按鏂囧弬鏁癉 A,As,伪鍧囧，

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