本文選題：彌河沖洪積扇 + 咸水入侵��； 參考：《濟南大學(xué)》2015年碩士論文

【摘要】：咸水入侵是目前世界上濱海平原地區(qū)普遍存在地下水環(huán)境問題。其主要原因是由于人為超量開采地下淡水,引起地下水位大幅度下降,咸水與淡水之間的水動力平衡遭到破壞,導(dǎo)致海水或古咸水以各種方式向內(nèi)陸淡水含水層入侵。咸水入侵的發(fā)生具有動態(tài)變化快、潛在危害大,難以治理等特點。研究區(qū)位于彌河下游沖洪積平原,屬于農(nóng)業(yè)集約化、專業(yè)化、規(guī)�；氖卟舜笈锓N植區(qū)。據(jù)了解,該區(qū)域北部曾經(jīng)歷了三次海水入侵現(xiàn)象,賦存了大量鹵水。研究區(qū)由于彌河多次改道形成了不同時期的古沖洪積扇、古河道帶,為北部咸鹵水向內(nèi)陸淡水含水層的入侵提供了良好的通道。過量的地下水開采加之良好的地層條件導(dǎo)致研究區(qū)北部咸水入侵現(xiàn)象愈發(fā)嚴(yán)重。本文依托國家海洋局公益性行業(yè)科研專項項目“環(huán)渤海區(qū)域海水入侵、土壤鹽漬化預(yù)警與防控關(guān)鍵技術(shù)研究示范”(201105020),在對彌河下游沖洪積扇地下水開發(fā)利用狀況、水文地質(zhì)條件以及咸水入侵程度調(diào)查的基礎(chǔ)上,深入分析了研究區(qū)地下含水層分布特征以及咸水入侵的動態(tài)變化規(guī)律,構(gòu)建了三維地下水流水質(zhì)耦合數(shù)值模型,預(yù)測未來不同方案下的咸水入侵變化趨勢,為咸水入侵防治提供科學(xué)依據(jù)。本論文主要研究內(nèi)容及工作量如下:(1)本文通過對彌河下游沖洪積扇地區(qū)的氣象、水文、地形地貌及水文地質(zhì)等資料的收集整理,根據(jù)研究區(qū)域地質(zhì)結(jié)構(gòu)和水文地質(zhì)條件資料,明確了地下含水層的分布特征和地下水水動態(tài)變化特征。(2)通過對彌河下游沖洪積扇地區(qū)咸水入侵歷史情況的調(diào)查,在咸淡水分界線附近布設(shè)了16個水質(zhì)監(jiān)測剖面,對79個井點的水質(zhì)情況進(jìn)行取樣化驗分析。以1981年250mg/L氯離子濃度等值線為彌河下游沖洪積扇地區(qū)咸水入侵的初始分界線,確定了彌河下游沖洪積扇2014年咸淡水分界線的位置。(3)建立了三維非穩(wěn)定流和變密度溶質(zhì)運移模型,利用Visual ModFlow4.6軟件中的SEAWAT模塊對研究區(qū)域進(jìn)行數(shù)值模擬。模擬過程中選取2008年10月1日至2010年12月31日作為本次模型的識別時段,2011年1月1日至2011年12月31日作為模型的驗證時段,模擬時間1187天,共計39個應(yīng)力期,時間步長設(shè)為6。通過模型反復(fù)的驗證求解,選取了合適的水文地質(zhì)參數(shù)。(4)利用建立好的地下水?dāng)?shù)值模型對彌河下游沖洪積扇地區(qū)進(jìn)行不同地下水開采方案下未來咸水入侵變化趨勢進(jìn)行預(yù)測。結(jié)果表明,在未來氣候條件變化下和局部壓采地下水條件下,咸水入侵現(xiàn)象都得到了一定程度上的緩解,但局部壓采地下水的方案對咸水入侵的緩解較為明顯。(5)根據(jù)上述預(yù)測結(jié)果,從水利工程建設(shè)方面和相關(guān)管理部門角度出發(fā),提出了彌河下游沖洪積扇地區(qū)相應(yīng)的咸水入侵防治措施。
[Abstract]:Salt water intrusion is a common problem of groundwater environment in coastal plain area of the world at present. The main reason is that the groundwater level is greatly decreased and the hydrodynamic balance between salt water and fresh water is destroyed, which leads to the invasion of seawater or paleo-salt water into inland freshwater aquifers in various ways. The occurrence of salt water intrusion has the characteristics of fast dynamic change, great potential harm and difficult to control. The research area is located in the alluvial plain of the lower reaches of Mihe River, which belongs to the intensive, specialized and large-scale vegetable greenhouse planting area. It is understood that the northern part of the region has experienced three sea-water intrusions and a large amount of brine. In the study area the ancient alluvial fan and the paleo-channel belt were formed in different periods due to the multiple diversion of Mihe River which provided a good channel for the intrusion of the brine from the northern brine to the inland fresh water aquifer. Excessive groundwater exploitation and good stratigraphic conditions lead to more and more salt water intrusion in the northern part of the study area. This paper relies on the special project of the public welfare industry of the State Oceanic Administration, "study and demonstration of key techniques of seawater intrusion, soil salinization early warning and prevention and control" in the area around Bohai Sea, in order to develop and utilize the groundwater of alluvial fan in the lower reaches of Mihe River. Based on the investigation of hydrogeological conditions and the degree of salt water intrusion, the distribution characteristics of groundwater aquifers and the dynamic variation of salt water intrusion in the study area are analyzed in depth, and a three-dimensional numerical model of groundwater quality coupling is constructed. The trend of salt water intrusion in the future is predicted, which provides scientific basis for the prevention and treatment of salt water invasion. The main contents and workload of this paper are as follows: 1) by collecting and arranging the data of meteorology, hydrology, topography and hydrogeology in the alluvial fan area of the lower reaches of Mihe River, the paper studies the regional geological structure and hydrogeological conditions. By investigating the history of salt water intrusion in the alluvial fan area of the lower reaches of Mihe River, 16 water quality monitoring sections have been set up near the dividing line of salt and fresh water. The water quality of 79 well sites was analyzed. Taking the 1981 250mg/L chloride concentration isoline as the initial dividing line of salt water intrusion in the alluvial fan area of the lower reaches of Mihe River, the location of the salt and fresh water boundary of the alluvial fan in the lower reaches of Mihe River in 2014 is determined. The SEAWAT module in Visual ModFlow4.6 software is used to simulate the research area. During the simulation process, the model was identified from October 1, 2008 to December 31, 2010, and from January 1, 2011 to December 31, 2011, as the verification period. The simulation time was 1187 days, with a total of 39 stress periods and a time step of 6. Through the repeated verification and solution of the model, the suitable hydrogeological parameters are selected. The established groundwater numerical model is used to predict the future trend of salt water intrusion in the alluvial fan area of the lower reaches of Mihe River under different plans of groundwater exploitation. The results show that the salt water intrusion has been alleviated to some extent under the future climatic conditions and local pressure groundwater conditions. However, the scheme of local pressure extraction of groundwater can obviously alleviate the invasion of salt water. (5) according to the above forecast results, from the point of view of water conservancy engineering construction and relevant management departments, The corresponding saline water intrusion prevention measures in the alluvial fan area of the lower reaches of Mihe River are put forward.
【學(xué)位授予單位】：濟南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：P641.8

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 陳鴻漢,王新民,張永祥,任仲宇;濰河下游地區(qū)海咸水入侵動態(tài)三維數(shù)值模擬分析[J];地學(xué)前緣;2000年S2期

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本文編號：1887707