滨岸带微生境特征与水体主要水质指标的相关性分析

发布时间：2018-07-28 20:17

【摘要】：滨岸带是湖泊生态系统中不可缺少的一部分,能扣留和净化污染物,提高生物多样性,提供野生动物栖身地,调制沉积和侵蚀等,也是一个湿地生态恢复的关键领域。滨岸带水质状况受近岸水体的水动力状况、岸线形态与沉积过程、植被特征等微生境的影响,研究其与近岸水体微生境因子的相关性及作用机制,可为滨岸带生态修复提供技术与理论支持。本文对太湖贡湖湾北侧的退圩还湖生态修复区滨岸带不同微生境下水体主要水质指标进行了比较研究,通过CleverChem200全自动水质分析仪等测量各主要水质指标的浓度,采用单因素方差分析检测不同微生境下水质指标的差异性,结合冗余分析法分析各微生境因子与水质指标的相关性,并计算微生境因子对水质数据的解释率。结果表明：1、夏、冬季pH和溶氧在各微生境下的差异不显著,夏季水体溶氧显著低于冬季；植被盖度夏、冬季在各水深之间差异均较大,冬季植被盖度在深水区最高,夏季植被盖度在三个水深间的差异因岸线类型各不相同。2、夏季各主要水质指标均高于冬季,且不同岸线形态段间以及各不同水深采样点问的水质指标的差异性均更大。夏季三种岸线形态段下主要水质指标随水深的浓度变化与冬季存在相反的趋势,平直岸线段TP、NH4+-N和COD的浓度随水深变化的趋势冬、夏相对一致。3、冬季滨岸带植被盖度高的水域,COD浓度较高,TN、TP、NH4+-N和N03--N浓度较低,而夏季滨岸带植被盖度高的水域,COD浓度较低,TN、TP和N03-N浓度较高；冬季凹形岸线段TN、TP、NH4+-N和N03--N的浓度相对较高,而COD在凸形和平直岸线段浓度相对较高,夏季COD在凹形岸线段浓度较高,而TP、NH4+-N在凸形岸线段浓度相对较高；无论夏季、冬季,水体主要营养盐浓度总体上在浅滩区较高,在浅水区和深水区相对较低。4、冗余分析揭示,在冬季,岸线形态特征是影响滨岸带水体主要水质指标差异性最重要的作用因子,植被盖度次之,水深的影响相对较小；而夏季水深对水体主要水质指标的影响相对较大,浅滩区各水质指标总体较高,其次为岸线形态特征和植被盖度。总体上,不同岸线形态段下水质指标随水深的增加呈现不同的变化趋势,各岸线类型采样点问的差异性也不尽相同,构建相对曲折的岸线形态有利于增加水体水质指标在水深间的差异性,增加滨岸带生境的多样性。
[Abstract]:Coastal zone is an indispensable part of lake ecosystem, which can impair and purify pollutants, improve biodiversity, provide wildlife habitat, modulate deposition and erosion, and is also a key area of wetland ecological restoration. The water quality of the coastal zone is affected by the hydrodynamic condition of the inshore water body, the shoreline morphology and sedimentary process, the vegetation characteristics, and so on. The correlation and mechanism between the water quality and the microhabitat factors of the inshore water body are studied. It can provide technical and theoretical support for ecological restoration of coastal zone. In this paper, the main water quality indexes under different microhabitats in the ecological restoration area of Tuexu to Lake Lake in the north side of Gong Lake Bay of Taihu Lake were compared and studied. The concentration of the main water quality indexes was measured by CleverChem200 automatic water quality analyzer. Univariate ANOVA was used to detect the differences of water quality indexes in different microhabitats, and the correlation between microhabitat factors and water quality indexes was analyzed with redundancy analysis method, and the interpretation rate of microhabitat factors to water quality data was calculated. The results showed that there was no significant difference in pH and dissolved oxygen in different microhabitats in the summer, but the dissolved oxygen in water in summer was significantly lower than that in winter, and the vegetation cover in summer was significantly different from that in winter, and the vegetation coverage was the highest in the deep water area in winter. The difference of vegetation coverage in three water depths in summer was due to the difference of shoreline types, and the main water quality indexes in summer were higher than those in winter, and the differences of water quality indexes among different shoreline sections and different water depth sampling points were even greater. The variation of water quality indexes with water depth in summer is opposite to that in winter, and the concentrations of TPN NH _ 4-N and COD in flat coastline are changing with water depth in winter. In summer, the concentration of COD in the waters with high vegetation coverage in the coastal zone is higher than that in the coastal zone in winter, and the concentrations of NH _ 4-N and N _ (03) -N in the coastal zone are lower than those in the coastal zone in summer, while the concentrations of TNTP and N03-N are higher in the waters with high vegetation coverage in the coastal zone in summer. In winter, the concentrations of NH _ 4-N and N _ (03 N) in concave shoreline are relatively high, while the concentrations of COD in convex and straight shoreline are relatively high, COD in summer is higher in concave coastline, and TPN NH4-N is relatively high in convex shoreline. In general, the main nutrient concentrations of water body are higher in the shoal area, and are relatively low in the shallow and deep water areas. The redundancy analysis reveals that the characteristics of the shoreline morphology are the most important factors affecting the difference of the main water quality indexes in the coastal zone in winter. The vegetation coverage was the second, the water depth was relatively small, while the summer water depth had a relatively greater effect on the main water quality indexes, the shoal area had higher water quality indexes, followed by the shoreline morphological characteristics and vegetation coverage. On the whole, the water quality indexes under different shoreline patterns show different trends with the increase of water depth, and the differences of sampling points of different shoreline types are also different. The construction of relatively tortuous shoreline shape is beneficial to increase the difference of water quality index between water depth and the diversity of coastal zone habitat.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X52

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