本文選題：南流江 + 城市河段　； 參考：《廣西師范學(xué)院》2015年碩士論文

【摘要】：隨著南流江流域城鎮(zhèn)化進(jìn)程的加速,農(nóng)村人口大量涌入城市,城市化面積突飛猛進(jìn)般擴(kuò)張及人口激增,一方面造成典型城市河流天然匯水區(qū)域大幅減少,另一方面工業(yè)廢水、生活污水的大量排放,氮、磷等營(yíng)養(yǎng)元素隨污水進(jìn)入水體及底泥中,一部分發(fā)生化學(xué)轉(zhuǎn)化為其他污染物,一部分被浮游植物,如藍(lán)藻等吸收富集,其余大部分進(jìn)入底泥富集,在一定條件下釋放,造成二次污染。南流江是廣西北部灣獨(dú)流入海諸河中流域面積最廣、水量最豐富的河流,流域面積9705.8平方公里,多年平均徑流量77.4億立方米。然而,其河水流速緩慢,自凈能力差,水生態(tài)環(huán)境十分脆弱。近年來(lái),由于流域城鎮(zhèn)快速發(fā)展,周邊廠礦、流域農(nóng)業(yè)發(fā)展及居民生活對(duì)河流造成嚴(yán)重水體污染,河流水質(zhì)不斷惡化。本文通過(guò)對(duì)南流江流域上、中、下游城區(qū)河段(分別為玉州區(qū)、博白縣、合浦縣)典型斷面上覆水與底泥營(yíng)養(yǎng)鹽調(diào)查分析,揭示了流域城區(qū)河段營(yíng)養(yǎng)鹽富集特征及影響因子,并對(duì)流域營(yíng)養(yǎng)鹽污染狀況進(jìn)行了評(píng)價(jià),為流域城區(qū)河段水生態(tài)環(huán)境改善提供科學(xué)建議。本文主要結(jié)論如下:1.從上覆水及底泥營(yíng)養(yǎng)鹽富集特征上看,全流域上中下游不同斷面DO平均水平為7.02mg/L,p H為6.8mg/L,上覆水TP平均含量為1.87mg/L,粒度以粉砂粒級(jí)為主,沉積物TN平均含量為1.2g/kg,TP為0.09g/kg,TOC為9.8g/kg,TC為17.4g/kg。營(yíng)養(yǎng)鹽含量具有排污口斷面大于自然河流斷面特點(diǎn),DO、pH、沉積物TN、沉積物TP具有自上游向下游降低特點(diǎn),而水體TP呈現(xiàn)相反變化。2.利用Pearson相關(guān)系數(shù)法對(duì)營(yíng)養(yǎng)鹽之間相關(guān)性進(jìn)行了探討。得出沉積物TN與TP之間、沉積物TP與上覆水TP、TOC與TC間均具有顯著相關(guān)關(guān)系,而TOC與DO之間具有顯著負(fù)相關(guān)關(guān)系。沉積物TN、TP含量呈現(xiàn)出與粘土顆粒負(fù)相關(guān)、粉砂顆粒正相關(guān)關(guān)系。3.利用沉積物污染分級(jí)評(píng)價(jià)法、單因子污染指數(shù)及內(nèi)梅羅綜合污染指數(shù)法對(duì)流域沉積物進(jìn)行污染評(píng)價(jià)。得出合浦河段斷面最優(yōu),博白河段內(nèi)梅羅指數(shù)普遍位于1以上,污染狀況最差。排污口處底泥污染較自然河流沉積物明顯嚴(yán)重。4.河岸緩沖帶對(duì)于河流水體與河岸物質(zhì)交換、改善河流水生態(tài)環(huán)境具有重要意義。本文認(rèn)為合理規(guī)劃河岸緩沖帶類(lèi)型及寬度及跨流域調(diào)水是解決南流江流域水生態(tài)問(wèn)題的重要途徑。
[Abstract]:With the acceleration of urbanization in the Nanliu River Basin, the rural population is pouring into the city, and the urbanization area is expanding by leaps and bounds and the population is increasing rapidly. On the one hand, the natural catchment area of the typical urban rivers has been greatly reduced, on the other hand, the industrial wastewater has been greatly reduced. A large amount of domestic sewage discharge, nitrogen, phosphorus and other nutrients into the water and sediment with the sewage, some chemical transformation into other pollutants, some phytoplankton, such as cyanobacteria absorption and enrichment, the rest into sediment enrichment, Release under certain conditions, resulting in secondary pollution. The Nanliu River is the most extensive and abundant river in the Beibu Gulf of Guangxi, with an area of 9705.8 square kilometers and an average annual runoff of 7.74 billion cubic meters. However, its water flow rate is slow, its self-purification ability is poor, the water ecological environment is very fragile. In recent years, due to the rapid development of cities and towns, the surrounding factories and mines, the agricultural development of the basin and the residents' lives, the river has been polluted seriously, and the water quality of the river has been deteriorating. Based on the investigation and analysis of the overlying water and sediment nutrients on the typical sections of the upper, middle and lower reaches of the Nanliu River Basin (Yuzhou District, Bobai County, Hepu County, respectively), the characteristics of nutrient enrichment and the influencing factors in the river reach of the basin are revealed in this paper. The status of nutrient pollution in the river basin was evaluated to provide scientific advice for the improvement of the ecological environment of water in the river reach of the watershed. The main conclusions of this paper are as follows: 1. According to the characteristics of nutrient enrichment in overlying water and sediment, the average do level of different sections in the upper and lower reaches of the basin is 7.02 mg / L / L H is 6.8 mg / L, the average content of TP in overlying water is 1.87 mg / L, the grain size is mainly silty sand, and the average TN content of sediment is 1.2 g / kg TP = 0.09 g / kg ~ (-1) TOC = 9.8 g / kg 路kg ~ (-1) TC = 17.4 g / kg 路L ~ (-1). The nutrient content in the sediment was lower than that in the upstream and downstream, while the TP in the water showed the opposite change. 2. The nutrient content in the sewage outlet was larger than that in the natural river section, and the pH value of the sediment was higher than that of the natural river section. Pearson correlation coefficient method was used to study the correlation between nutrients. The results show that there is a significant correlation between TN and TP, TP and TOC and TC, while there is a significant negative correlation between TOC and do. The content of TNT TP in sediments was negatively correlated with clay particles and positively correlated with silt particles. The pollution assessment method of sediment pollution classification, single factor pollution index and Nemero comprehensive pollution index were used to evaluate the pollution of river basin sediments. It is concluded that the section of Hepu reach is the best, and the Mello index of Bobai reach is generally above 1, and the pollution is the worst. The sediment pollution at the sewage outlet is more serious than that of the natural river sediment. Riparian buffer zone is of great significance for the exchange of water body and river bank material and the improvement of river water ecological environment. In this paper, it is considered that rational planning of the type and width of riparian buffer zone and water transfer across river basins is an important way to solve the problem of water ecology in Nanliujiang River Basin.
【學(xué)位授予單位】：廣西師范學(xué)院
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：X824;X522

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本文編號(hào)：2062725