农田溪流氮磷滞留能力调控的试验操纵模拟

发布时间：2018-03-27 12:19

本文选题：源头溪流　切入点：氮磷滞留　出处：《合肥工业大学》2015年硕士论文

【摘要】：源头溪流是河流水系的重要组成部分,其具有的氮磷营养滞留和调节功能对调控和减轻下游水体氮磷污染具有重要意义。为揭示人工操纵对源头溪流氮磷滞留的调节作用,设计正挑交错型丁坝、下挑羽翼型丁坝、单级滚水坝和多级滚水坝4种人工调控措施,以NaCl为保守示踪剂、以NH4Cl和KH2PO4为营养盐,开展野外示踪试验。在此基础上,利用OTIS模型模拟溶质扩散转化规律,通过对调控前后暂态存储指标、养分螺旋指标变化情况的比较,解析人工操纵对河流氮磷滞留效应的影响。此外,本研究还对深潭和曲折沟渠两种典型渠道形态开展了氮磷滞留特征分析,主要成果如下：(1)深潭的AS、TS和As/A值较曲折沟渠大,但其α值则较后者低1个数量级；深潭沟渠λ-NH4+较λs-NH4+高2～3个数量级,Vf-NH4+较Vf-SRP高1～2个数量级,U-NH4+较U-SRP高2～3个数量级,而曲折沟渠的λ-NH4+与λs-NH4+、Vf-NH4+与Vf-SRP数值上较为接近,U-NH4+较U-SRP仅高出1～2个数量级,表明深潭和曲折沟渠对于氮磷滞留潜力存在差异,且深潭对NH4+的滞留能力较SRP更强一些。(2)丁坝调控示踪试验研究表明：增设丁坝后,实验渠段的粗糙度f增大,交换系数α平均增大1个数量级；与无丁坝情形相比,1.5、2.5和3m间距的正挑交错型丁坝As/A增幅分别为27.27%、34.05%和21.48%, Fmed200增幅分别为191.10%、154.59%和179.89%; Vf-NH4、Vf-SRP、U-NH4和U-SRP增加幅度均较大,平均增加1个数量级；与无丁坝情形相比,2、4 m间距下挑羽翼型丁坝As/A增加幅度分别为105.41%和75.68%, Fmed200增幅分别为240.27%和153.40%；下挑丁坝调控前后SW值的变化规律为2m间距4m间距无丁坝,而Vf和U变化规律均为2m间距4m间距无丁坝,表明丁坝有助于提高溪流氮磷滞留能力。(3)滚水坝调控示踪试验表明：增设滚水坝后,实验渠段的粗糙度f和As/A的值均显著增大；单级滚水坝调控前、后的a值变化不明显,而多级滚水坝则显著增大；30cm和50cm高度单级滚水坝较无水坝的Fmed200值分别增大1.44倍和3.83倍,Vf-SRP分别增大2.5和8.1倍,Fmed200、Vf-NH4、Vf-SRP分别增大3.17和18.96倍；多级滚水坝较无水坝的50cm30cm分别增大4.39、5.3和4.92倍。单级滚水坝调控氮磷滞留能力表现为无水坝,多级滚水坝为有水坝无水坝。(4)多元统计分析结果表明：流量Q对溪流暂态存储潜力和氮磷滞留能力影响较大；溪流的暂态存储作用与氮磷滞留关系密切,通过人工调控措施增强溪流的暂态存储能力,有利于提高溪流氮磷滞留效应。
[Abstract]:The source stream is an important part of the river system, its nitrogen and phosphorus nutrient retention and regulation function are of great significance in regulating and reducing the nitrogen and phosphorus pollution in the downstream water body, in order to reveal the regulation effect of artificial manipulation on the nitrogen and phosphorus retention in the source stream. Four artificial control measures are designed: staggered spur dike, lower wing type spur dam, single stage rolling dam and multistage rolling dam. Field tracer tests are carried out with NaCl as conservative tracer and NH4Cl and KH2PO4 as nutrient salts. OTIS model is used to simulate solute diffusion and transformation law. By comparing the changes of transient storage index and nutrient spiral index before and after regulation and control, the effects of manual manipulation on the retention of nitrogen and phosphorus in rivers are analyzed. The characteristics of nitrogen and phosphorus retention in deep pool and zigzag channel are also analyzed. The main results are as follows: 1) the ASTs and As/A values of deep pool are larger than that of zigzag channel, but the 伪 value is one order of magnitude lower than that of the latter. The values of 位 -NH _ 4 and 位 -NH _ 4 are 2 ~ 3 orders of magnitude higher than that of 位 s-NH4. The values of 位 -NH _ 4 and 位 s-NH4 Vf-NH _ 4 are only 1 ~ 2 orders of magnitude higher than those of U-SRP, and the U-NH _ 4 is 1 ~ 2 orders of magnitude higher than that of U-SRP, and the values of 位 -NH _ 4 and 位 s-NH4 Vf-NH _ 4 are only 1 ~ 2 orders of magnitude higher than those of U-SRP. The results show that there are differences in the potential of nitrogen and phosphorus retention between deep pool and zigzag channel, and the retention capacity of deep pool to NH4 is stronger than that of SRP. The tracer test results show that the roughness f of experimental section increases with the addition of groin. The average exchange coefficient 伪 increased by one order of magnitude, and the As/A increases of the crisscrossed spur dams with a spacing of 1.52.5 and 3m were 27.2734.05% and 21.48% respectively, the Fmed200 increases were 191.104.59% and 179.89%, respectively, and the increases of Vf-NH _ 4 and U-SRP were larger, with an average increase of 1 order of magnitude. Compared with the case without spur dike, the increase of As/A is 105.41% and 75.68%, the increase of Fmed200 is 240.27% and 153.40% respectively, and the change rule of SW value before and after the regulation is that the distance of 2 m to 4 m is not dike, and the increase of Fmed200 is 240.27% and 153.40, respectively. The variation rule of V _ f and U is that there is no groin with 2m spacing and 4m spacing, which indicates that dike can improve the retention capacity of nitrogen and phosphorus in stream. The tracer test of rolling dam shows that the roughness f and As/A of experimental section increase significantly after adding rolling dam. Before the single stage rolling dam is controlled, the change of a value is not obvious, while the Fmed200 value of the multistage rolling dam increases significantly by 1.44 times and 3.83 times than that of the single stage rolling dam with 50cm height of 30 cm and 3.83 times respectively, and the Fmed200 value of Fmed200m Vf-NH _ 4N _ (Vf-SRP) increases by 3.17 and 18.96 times, respectively. The 50cm30cm of multistage rolling dam was 4.395.3 and 4.92 times higher than that of non-dam respectively. The control capacity of nitrogen and phosphorus retention of single-stage rolling dam was no dam. The results of multivariate statistical analysis show that the flow rate Q has a great influence on the transient storage potential and nitrogen and phosphorus retention capacity of stream, and the transient storage effect of stream is closely related to nitrogen and phosphorus retention. The enhancement of the transient storage capacity of streams by artificial control measures is beneficial to improve the retention effect of nitrogen and phosphorus in streams.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X712;X52

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