楠溪江香鱼栖息环境调查及其产卵场水文、水动力特性研究

发布时间：2018-01-10 00:16

本文关键词：楠溪江香鱼栖息环境调查及其产卵场水文、水动力特性研究　出处：《中国水利水电科学研究院》2017年硕士论文　论文类型：学位论文

【摘要】：楠溪江位于浙江省温州市北部瓯江下游北岸永嘉县境内,流域自然条件良好,山水风景宜人,人文景观独特,鱼类资源丰富,其中楠溪江香鱼是历史闻名的洄游性鱼类,由于人类活动导致已濒临灭绝。在国家大力推进生态文明建设的方针指导下,探索合理的水资源开发方式,同时保护与恢复楠溪江重要保护物种香鱼,最大限度发挥楠溪江的自然生态功能和社会服务功能,致力推动形成人水和谐的河流开发模式和绿色发展模式具有重要意义。本文以濒危物种香鱼为目标鱼类,运用资料分析、野外调查与数值模拟相结合的方法,评估了楠溪江香鱼栖息环境,分析了产卵场水文、水动力特性。论文主要研究内容和结论如下:(1)楠溪江干流水质状况调查与评价。调查指标包括:pH、水温、透光度、DO、COD、NH3-N、TP、TN等。结果表明,楠溪江供水工程以上河段水质整体良好,各采样点均为弱碱性,DO浓度较高,水温适宜,透明度良好,NH3-N、TP、TN等浓度较低;楠溪江供水工程以下河段为感潮河段,水体含沙量较高,透明度差,DO浓度低,TN和TP浓度较高,COD严重超标。总体而言,楠溪江干流上、中游河段水质较好,楠溪江供水工程以下河段水质相对较差。(2)楠溪江干流水生生物调查与评价。调查内容有浮游植物、浮游动物和底栖动物。楠溪江干流浮游植物共有6门68种,其中硅藻39种,为主要优势种;浮游动物共有16种,主要是桡足类和轮虫类,分别占32%和31%;底栖动物共有14种,水生昆虫占50%。总体而言,楠溪江干流浮游植物丰富,浮游动物和底栖动物多样性较低。(3)楠溪江干流水文情势分析。采用水文变动指标方法(IHA法)分析石柱水文站长系列逐日平均流量结果表明,1957～2012年期间楠溪江干流径流量的年际变化总体呈不显著的下降趋势;年内天然径流呈现双峰型,前峰发生于6月份,一般由梅雨形成,后峰发生于8～9月份,主要由台风雨形成;汛期形成多次持续时间较短的洪峰,非汛期低流量出现次数较少,单次持续时间较长。(4)香鱼产卵期水文特性分析。将IHA指标体系与关键性涨落水过程相结合,筛选出25项水文指标,对香鱼产卵期(9～10月)的水文特性进行了分析。结果表明,在产卵期内产卵场逐日平均流量呈波动式的下降,高、低流量过程频繁交替,且持续时间较短,关键性落水次数远高于涨水次数。(5)流量变化对香鱼产卵场位置和面积的影响。以0.5～1.0 m作为产卵场适宜水深判定条件,分别得到不同流量级下香鱼产卵场的位置和面积。当流量由小到大时,产卵场位置由深潭周围向浅滩,再向岸边滩地逐渐变化,产卵场面积先增大后减小,当流量为75m3/s时,产卵场面积最大。(6)香鱼产卵场水动力特性分析。以9月多年平均流量77.25 m3/s作为香鱼产卵期的特征流量,分析了流速、傅汝德数、流速梯度和动能梯度的适宜范围。结果表明,香鱼产卵场流速适宜范围为0.43～1.07m/s,傅汝德数适宜范围为0.19～0.48,产卵河段断面流速梯度适宜范围为12.88×10-3～14.47×103 s-1,断面动能梯度适宜范围为9.24× 10-3～9.88× 10-3 J · kg-1 · s-1。
[Abstract]:Nanxi River is located in Zhejiang city of Wenzhou Province in the north of Oujiang River downstream of the north shore of Yongjia County, the natural conditions in good landscape, pleasant scenery, unique cultural landscape, rich in fish resources, of which Nanxi River is the historic fish migratory fish, caused by human activities has been on the verge of extinction. In the country to vigorously promote the construction of ecological civilization under the guiding principles, explore the development of the way the water resources reasonably, and protect the protection and restoration of important species in Nanxi River to maximize Ayu, Nanxi River's natural ecological function and social service function, promoting the formation of rivers has important significance in development mode and green development model of human water harmony. The endangered species is Ayu fish, using the methods of field investigation and data analysis. Combining numerical simulation, evaluation of Nanxi River Ayu habitat, analyzes the spawning hydrological and hydrodynamic characteristics. The main research contents and conclusions are as follows: (1) the investigation and evaluation of water quality status of Jianggan Nanxi. The survey indicators include: pH, water temperature, transparency, DO, COD, NH3-N, TP, TN etc.. The results show that the water supply project in Nanxi River over the river water quality overall good, the sampling points are weakly alkaline, the concentration of DO high water temperature is appropriate, good transparency, NH3-N, TP, TN and other low concentration; Nanxi River water supply project is in the lower reaches of the tidal river, water sediment concentration is high, poor transparency, low concentration of DO, TN and TP was high, COD seriously exceed the standard. Overall, the middle reaches of Nanxi River River, good water quality, water supply in Nanxi River the project in the lower reaches of the water quality is relatively poor. (2) the Jianggan water health survey and evaluation of biological investigation contents of phytoplankton, zooplankton and benthic animal animal in Nanxi River. A total of 6 phytoplankton phyla and 68 species, including 39 species of Bacillariophyta, was the dominant species in planktonic animal; There are 16 species, mainly copepods and rotifers, accounted for 32% and 31%; there are 14 species of benthic animal, aquatic insects accounted for 50%. overall, the Nanxi River river is rich in phytoplankton, planktonic and benthic animal animal diversity is low. (3) analysis of Nanxi Jianggan hydrological situation. The change of using water index method (IHA) analysis of hydrological station daily average flow series columns results show that during the period from 1957 to 2012 the Jianggan runoff interannual variation of overall was not significantly decreased; the natural runoff years in Shuangfeng, before the peak occurred in June, by a Meiyu formation, after peak occurred in 8 ~ September, the main formed by the rain flood season; the formation of several short duration peak, non flood season and low flow frequency less, a single longer duration. (4) analysis of the hydrological characteristics of Ayu spawn. IHA index system and the key process of combining water rose Together, screened 25 hydrological indicators, to smelt the spawning period (9 ~ October) of the hydrological characteristics were analyzed. The results showed that spawning during the spawning period in average daily flow rate declines, volatility is high, low flow process of frequent alternation, and lasted for a short time, the key number is far higher than the water drowning the number. (5) the flow changes affect the location and size of the spawning field of Ayu. From 0.5 to 1 m as the spawning grounds of suitable water depth conditions, different flow levels Ayu spawning sites and area were obtained. When the flow rate, spawning location by deep pools around to the bank, and then gradually to the Shore Beach changes in spawning area increased first and then decreased, when the flow rate is 75m3/s, the largest spawning area. (6) analysis of hydrodynamic characteristics of Ayu spawn. Average flow of more than 77.25 years in September as m3/s Ayu spawning characteristic flow analysis, flow velocity, Fu Ru De number, the suitable range of velocity gradient and kinetic energy gradient. The results showed that Ayu spawning velocity suitable range is 0.43 ~ 1.07m/s, the number of suitable ranges from 0.19 to 0.48 Fu Rude, spawning reach velocity gradient appropriate range of 12.88 * 10-3 to 14.47 * 103 S-1 section, kinetic energy gradient suitable range is 9.24 * 10-3 to 9.88 * 10-3 J - kg-1 - s-1.

【学位授予单位】：中国水利水电科学研究院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S931

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