【摘要】：隨著社會經(jīng)濟(jì)的發(fā)展,城市化、工業(yè)化和農(nóng)業(yè)現(xiàn)代化的推進(jìn),水量匱乏和水體污染已成為不可忽略的問題。山地湖庫具有封閉性較強(qiáng)、水流遲緩,換水周期較長、自凈能力低,更是面臨著水質(zhì)急劇惡化、水生態(tài)功能退化等挑戰(zhàn)。以濃度控制為主的傳統(tǒng)水環(huán)境管理技術(shù)已不能滿足要求,必須向以水環(huán)境容量為基礎(chǔ)的總量控制發(fā)展。與大型平原湖庫不同,山地城市湖庫具有水域面積有限、水體深、湖灣較多、湖底地形坡度大、受自然地形地貌影響具有面源污染初期效應(yīng)突出等特點(diǎn),不能直接套用水環(huán)境容量的計算方法。本文以典型山地城市封閉水體—龍景湖為例,根據(jù)山地湖庫水文水質(zhì)特征,結(jié)合模擬分析和數(shù)學(xué)分析,研究了龍景湖水環(huán)境容量的變遷,為龍景湖水質(zhì)保持和水環(huán)境治理提供科學(xué)依據(jù),也為山地湖庫水環(huán)境容量的計算提供借鑒。論文主要研究內(nèi)容如下:對龍景湖污染源和入湖污染負(fù)荷進(jìn)行了調(diào)查和分析,采用FCWQA模型、綜合營養(yǎng)狀態(tài)指數(shù)和單因子評價法對龍景湖水質(zhì)進(jìn)行了分區(qū)評價。龍景湖主要污染負(fù)荷來自上游來水和園區(qū)內(nèi)面源污染。水質(zhì)處于Ⅲ類~Ⅳ類,基本處于輕度富營養(yǎng)化,部分月份為中度或重度富營養(yǎng)化。水質(zhì)季節(jié)性變化顯著,分區(qū)水質(zhì)差異較大,主要污染指標(biāo)為COD、TN和TP。根據(jù)龍景湖的自然地理特征,將龍景湖劃分11個計算單元,選用有機(jī)物模型計算COD穩(wěn)態(tài)水環(huán)境容量,選用狄龍模型計算湖心區(qū)和河道部分TN、TP穩(wěn)態(tài)水環(huán)境容量,采用合田健模型計算臥龍石庫灣、江南園林庫灣、北方園林庫灣、西部園林庫灣的穩(wěn)態(tài)水環(huán)境容量,計算得到龍景湖水環(huán)境容量COD 678.71 t/a,TN25.471 t/a,TP 1.853 t/a。龍景湖庫灣水動力條件較差,采用解析公式法求解的穩(wěn)態(tài)水環(huán)境容量準(zhǔn)確性值得商討,采用龍景湖EFDC三維水動力水質(zhì)模型建立污染負(fù)荷—水質(zhì)響應(yīng)關(guān)系,采用線性疊加及分擔(dān)率場計算龍景湖6個庫灣四個季節(jié)的動態(tài)水環(huán)境容量,對庫灣的穩(wěn)態(tài)水環(huán)境容量進(jìn)行修正,修正后龍景湖全年水環(huán)境容量:COD 709.654 t/a,TN 28.128 t/a,TP 2.065 t/a。水環(huán)境容量計算結(jié)果表明,龍景湖水環(huán)境容量四季差異顯著,水環(huán)境容量夏季最大,冬季最小,各計算單元水環(huán)境容量差別較大,湖心區(qū)水環(huán)境容量最大,庫灣區(qū)水環(huán)境容量值較小,西部園林庫灣水環(huán)境容量最小。對比分析龍景湖全湖和各分區(qū)的水環(huán)境容量和入湖污染負(fù)荷,分季節(jié)計算各重點(diǎn)控制單元的剩余水環(huán)境容量和污染物削減量,龍景湖全湖COD和TN水環(huán)境容量均有剩余,TP削減量為1.767 t/a。對各重點(diǎn)控制單元污染物削減計算,發(fā)現(xiàn)各控制單元COD均有剩余容量,TN一般在冬季需要削減,TP全年需要削減,TP屬于重點(diǎn)控制指標(biāo)。西部園林庫灣、江南園林庫灣TN、TP剩余容量較小,需要著重控制。
[Abstract]:With the development of social economy, urbanization, industrialization and agricultural modernization, water shortage and water pollution have become problems that can not be ignored. Mountain lakes and reservoirs have strong closure, slow water flow, long water exchange period, low self-purification ability, and are faced with the challenges of rapid deterioration of water quality and degradation of water ecological function. The traditional water environment management technology based on concentration control can not meet the requirement, and must be developed to the total quantity control based on the water environment capacity. Different from large plain lakes and reservoirs, mountainous city lakes and reservoirs have the characteristics of limited water area, deep water body, more lake bay, large slope of lake bottom topography and obvious initial effect of non-point source pollution due to the influence of natural topography and geomorphology. The calculation method of water environmental capacity cannot be directly applied. Taking Longjing Lake, a closed water body in typical mountainous cities, as an example, according to the characteristics of hydrology and water quality of mountain lake reservoir, combined with simulation analysis and mathematical analysis, the changes of water environmental capacity of Longjing Lake are studied. It provides scientific basis for water quality maintenance and water environment control of Longjing Lake, and also provides reference for the calculation of water environment capacity of mountain lake reservoir. The main contents of this paper are as follows: the pollution sources of Longjing Lake and the pollution load into the lake were investigated and analyzed. The water quality of Longjing Lake was evaluated by using FCWQA model, comprehensive nutrition state index and single factor evaluation method. The main pollution load of Longjing Lake comes from upstream water and non-point source pollution. The water quality is in class 鈪，

本文編號：2327555