节点文献
东辽河流域水生态功能分区与控制单元水质目标管理技术
Aquatic Ecoregion and Control-Unit-Based Management Technology of Water Quality Target in Dongliao River Watershed
【作者】 张蕾;
【导师】 卢文喜;
【作者基本信息】 吉林大学 , 水文学及水资源, 2012, 博士
【摘要】 东辽河流域做为辽河的源头区,水环境形势日益严峻,水质性缺水对流域内的工农业生产、居民生活和生态环境造成了严重的影响。目前对东辽河流域水环境特征和水环境管理技术体系缺乏系统深入的研究,尚未建立“污染源—入河排污口—水环境质量”的总量监控体系,不能对污染物排放实施有效的监督管理,难以对东辽河的水环境实现有效保护。因此,本文结合典型重点流域水污染防治的实际需求和国家污染控制的重大需求,在“分区、分类、分级、分期”水环境管理理念指导下,以东辽河流域为研究区,调查分析了流域水生态系统特征,对流域水生态健康状况进行了评价;在此基础上,对影响东辽河流域水生态格局的主要控制因子进行识别,提出了流域水生态功能区与控制单元划分的基本原则及方法;对各控制单元的污染负荷进行模拟计算;应用WASP模型建立了流域污染源排放与河流水质之间的输入-响应关系;研究了控制单元的水环境容量计算和污染负荷削减技术方法,提出了东辽河流域水质目标管理方案。研究成果为保障东辽河流域水生态安全与健康,制订东辽河流域水污染防治总体方案提供技术支持。本文主要包括以下几个方面的内容:1、东辽河流域水生态系统调查与特征分析(1)流域水生态环境调查与分析针对辽河流域自然地理条件的特点,基于“3S”技术、统计资料收集和监测等手段,分别于2010年7月和10月、2011年4月对东辽河水体的物理、化学和水文特征进行了调查与分析,在2010年9月对东辽河水质、河岸带植被、土壤理化性质、底质、水生生物的种类、数量和分布特征等进行了全面调查与分析。野外调查与室内分析结果表明,目前东辽河TN超标最为严重,其次为氨氮、TP和CODMn,水质整体呈V类,大部分监测河段未能达到水功能区的水质目标要求。(2)流域水生态系统健康评价在对东辽河18个断面水文、水质、水生生物、栖息地状况实地调查的基础上,应用层次分析法和模糊综合评价法,建立东辽河流域水生态健康评价指标体系,评价了东辽河水生态系统的健康状况。评价结果表明,东辽河水生态健康的状况为:在18个采样点中,2个健康,1个亚健康,5个临界,10个病态,说明东辽河流域水生态健康状况不容乐观。2、水生态功能区与控制单元的划分根据野外调查结果,参考研究区地形地貌、水文水质、气象、植被、水资源分布状况及社会经济状况等资料,识别影响东辽河流域水生态格局的主要控制因子。建立了东辽河流域一、二、三级水生态功能分区的指标体系,并提出了区划方法,将东辽河流域划分为2个水生态功能一级区、4个水生态功能二级区和13个水生态功能三级区;综合考虑水生态功能三级分区结果、主要污染影响范围、水文单元完整性、行政单元完整性以及流域污染控制可操作性等因素,将东辽河流域划分为14个控制单元。3、控制单元污染负荷核算(1)非点源污染负荷计算首先建立了东辽河流域空间数据库和属性数据库(数字高程模型,土壤类型、土地利用空间和属性数据库);然后应用SWAT模型,将研究区划分为35个子流域和357个水文响应单元,并采用东辽河泉太站点2005-2009年的实测逐月径流数据对模型进行校准和验证,建立东辽河流域非点源污染模拟模型;最后应用建立的非点源污染模拟模型模拟计算了2009年东辽河流域氮、COD等非点源污染负荷量,分析了非点源污染的时空分布特征。(2)点源污染负荷计算根据2009年统计数据及污染源普查数据,应用排污系数法计算点源污染物的排放量。(3)东辽河流域污染源分析通过对东辽河各控制单元污染负荷核算结果的分析表明,东辽河上游氨氮负荷主要来源于畜禽养殖,下游主要来源于农业非点源污染,COD负荷来源于非点源、畜禽养殖、居民生活污染源。总体上,东辽河流域COD和氨氮主要来源于农业非点源和畜禽养殖业,其中农业非点源其对COD和氨氮排放的贡献率分别为22.5%、50%,畜禽养殖对COD和氨氮排放的贡献率为71.8%、34.6%。4、流域污染源排放与河流水质之间的输入-响应关系的建立开发应用流域水质模型(WASP7.3),建立了与控制单元水体特征相适应的东辽河水质模拟模型,分析了东辽河主要污染物(氨氮、COD)的空间分布特征,建立了东辽河水质状况和污染源排放污染物数量之间的响应关系。结果表明,东辽河氨氮和COD在第8段到第10段(辽源市入口到二龙山水库入口处)浓度最大,此河段氨氮浓度在枯水期最大,COD在平水期浓度较大,其余各河段污染物浓度在时间上变化不大。5、控制单元水环境容量的计算确定各断面的设计水文条件和水质目标,依据所建立东辽河水质模拟模型,应用试错法对东辽河水环境容量进行了研究,然后应用层次分析法获得了各控制单元的水环境容量。结果表明:在P25、P50、P75流量保证率和30Q10的四个设计流量下,东辽河的氨氮环境容量分别为1754.75吨/年、720.33吨/年、155.69吨/年/、56.18吨/年;COD环境容量分别为158055.23吨/年、67651.49吨/年、13977.00吨/年、1104.31吨/年6、东辽河水质目标管理方案参考美国TMDL水质管理模式,采用等比分配法将允许负荷分配到各污染源,同时考虑安全临界值,计算了东辽河各控制单元在不同流量模式下的污染负荷削减量,据此提出了东辽河水质目标管理方案。
【Abstract】 Dongliao River watershed, as the headwater region of Liao River, the situation of water environment is imminent. Water scarcity and degraded water quality have posed great threat to the industrial and agricultural production, resident life and ecological environment in Dongliao River watershed. In addition, it is lack of analysis on the water Environment Characteristics and water quality target management technology in Dongliao River watershed. Total quantity control system of pollution source-pollution discharge-water quality is also not established. So it can not implement effective supervision and management of pollutants, causing the water quality control and improvement of Dongliao River in extremely difficulty.The study is based on the actual demand of water pollution control in main typical river and the great demand of national pollution control. Under guidance of "regionalization, classification, grading, staging" water environment management theory, taking Dongliao River as study area, the regional characteristics and health status of aquatic ecosystem were studied, and spatial heterogeneity and drive mechanism of regional environmental factors were identified. The method and technology of aquatic ecoregion and control unit devision were established. The pollution loads in control unit were modeling and calculated. Based on WASP model, the input-response relation between pollution loads and water quality was established. The technology and methods of control-unit-based water environment capacity calculation and pollution loads reduction were studied and control-unit-based management technology of water quality target in Dongliao River watershed was established. The results provide technology support for the security and health of aquatic ecosystem and general scheme establishment of water pollution control in Dongliao River. The main contents include:1. Investigation and characteristic analysis of aquatic ecosystem in Dongliao River watershed(1) The investigation and analysis of aquatic ecosystemAccording to the characteristics of the natural conditions in Dongliao River, the investigation and analysis of physical, chemistry and hydrology characteristic of Dongliao River water body was carried out in July and October2010, April2011. In September2010, water quality, riparian zone vegetation and soil, sediment, the species, quantity and distribution of aquatic organisms were investigated and analyzed. The results showed that the concentration of TN went beyond the standard greatly, then were ammonia nitrogen, TP, CODMn·The water quality was mainly Class V, and monitoring reaches could not come up to the water quality target in functional area.(2) Assessment of aquatic eco-health in the watershedBased on investigation of hydrology, water quality, aquatic organisms and habitat condition, the analytical hierarchy process and fuzzy synthetic evaluation method were used to set up assessment index system of aquatic eco-health and evaluate the aquatic ecos-health grade in Dongliao River watershed. The results showed that among18samplings, there are two health, one sub-health, five threshold, ten morbidity, which illustrate that the aquatic eco-health condition of Dongliao River is not optimistic.2. Aquatic ecoregion and control unit devisionBased on the field investigation results and the related data of Dongliao river (spatial information data, hydrology and water quality, meteorological data, geology geomorphology, vegetation, water source distribution and socioeconomic status), the main control factors that influencing the aquatic ecosystem pattern in Dongliao River watershed were identified and the division method and index system of first, second and third level aquatic ecoregion were also established. Dongliao River watershed can be divided into2Grade I aquatic eco-regions,4Grade II aquatic eco-regions,13Grade III aquatic eco-regions. Considering the Grade III aquatic eco-regions, pollution influence area, integrity of hydrological unit and administration cell, operability of pollution control, Dongliao River watershed can be divided into14control units based on GIS technology.3. Estimation of pollution loads in control unitAccording to the spatial and attribute database of Dongliao River watershed, SWAT model was applied to establish non-point source pollution model. First, the whole watershed was divided into35sub-basins and357HRU. Then the observed monthly streamflow data from2005to2009were used to calibrate and validate the model. Finally, the model was used to simulate the non-point source pollutant loads (nitrogen, COD) in2009, analyze the temporal and spatial distribution characteristics of non-point source pollution.(2) Estimate the point source pollution loadAccording the statistical data and pollution source census data, pollution discharging coefficient method was used to estimate the discharge amount of point source pollutants.(3) Pollutant source solution analysisThrough the analysis of pollution loads accounting results, the ammonia nitrogen load in upstream mainly came from livestock and poultry raising, and the ammonia nitrogen load in downstream mainly came from agricultural non-point source pollution. The COD load mainly came from livestock and poultry raising, agricultural non-point source pollution and domestic discharge. In general, the ammonia nitrogen and COD loads were mainly from livestock and poultry raising, agricultural non-point source pollution. The contribution rates of agricultural non-point source pollution to ammonia nitrogen and COD loads were22.5%,50%, respectively, and that of livestock and poultry raising were71.8%、34.6%, respectively.4. Establishment of input-response relationship between pollutant and water qualityApplied WASP7software, the water quality of control unit in Dongliao River is modeled, which explains the temporal and spatial distribution characteristics of ammonia nitrogen and COD. Then the response relationship of water quality with pollution load was set up. The results showed that the concentration of ammonia nitrogen and COD were highest in segment8and10, which was located in the Liaoyuan city, and the concentration of ammonia nitrogen in this segment was highest in dry period, while the concentration of COD in this segment was highest in normal water flow period. The concentration of pollutants in other segments changed little in temporal and spatial distribution.5. Calculation of water environment capacity in control unitAccording to the water quality target and design hydrological conditions, the input-response relationship of pollutant and water quality was applied to calculate the water environment capacity of control unit using the trial-and-error method. The AHP (the analytic hierarchy process) was used to calculate the weighted ratio of the water environment capacity in each control unit to the water environment capacity of the study area, and the water environment capacity was allocated in each control unit. The results showed that the NH3-N environmental capacities in25%,50%,75%assurance rate and30Q10design flow in Dongliao River was1754.75t/a,720.33t/a,155.69t/a,56.18t/a, respectively. The COD environmental capacities in25%,50%,75%assurance rate and30Q10design flow in Dongliao River was158055.23t/a,67651.49t/a,13977.00t/a,1104.31t/a.6. Control-unit-based management technology of water quality target in Dongliao River watershedBased on the TMDL in total load control technology of pollutants in watershed, the ration apportionment method was used to allocate permitting pollution load to point source and non-point source and the margin of safety was also considered. Then the reduction load of pollution was calculated according to different flow pattern. Finally the control-unit-based water-quality target management technology scheme for Dongliao River was proposed.
【Key words】 Dongliao River; aquatic ecoregion; water quality model; non-point sourcepollution model; water quality target management;