本文選題：沂沭河下游沿海平原 + 地下水　； 參考：《吉林大學(xué)》2017年碩士論文

【摘要】：地下淡水資源是我國沿海地區(qū)重要的供水水源?隨著社會經(jīng)濟(jì)的快速發(fā)展,水資源需求量劇增,許多沿海地區(qū)由于過量開采地下水而引發(fā)了一系列環(huán)境地質(zhì)問題?沂沭河下游沿海平原地處江蘇沿海地區(qū)北部,發(fā)育有基巖裂隙水?孔隙潛水、第I?II?III?IV承壓水,其中承壓水為主要開采對象?多年的過量開采使II?III承壓水位持續(xù)下降,形成了區(qū)域性水位降落漏斗,導(dǎo)致水質(zhì)咸化,地面沉降等問題?為了合理的開發(fā)利用地下水,控制II、III承壓地下淡水的咸化,需要明確研究區(qū)各層地下水的補(bǔ)徑排條件,咸淡水的空間分布特征,識別出控制地下水水化學(xué)組分形成的主要水文地球化學(xué)作用?本文在充分分析沂沭河下游沿海平原地質(zhì)?水文地質(zhì)條件的基礎(chǔ)上,綜合分析水位?水化學(xué)及同位素數(shù)據(jù),對研究區(qū)地下水補(bǔ)徑排條件和水化學(xué)的形成演化機(jī)理進(jìn)行了研究并應(yīng)用水文地球化學(xué)模擬技術(shù)識別控制水化學(xué)行程演化的主要水文地球化學(xué)作用。主要取得了如下認(rèn)識:1、裂隙水的徑流方向受導(dǎo)水裂隙控制,TDS含量為400~600mg/L,多為HCO3-Na·Ca型水。裂隙水水化學(xué)的形成主要與基巖中長石礦物的溶解作用?2、在北部孤山丘陵區(qū),潛水和I承壓水呈放射狀由山區(qū)向海徑流。水力坡度達(dá)1.5‰,水循環(huán)交替較為強(qiáng)烈。潛水TDS含量在0.5g/L~2g/L之間,I承壓水TDS含量略高于潛水。兩者水化學(xué)類型多為HCO3-Na·Ca、Cl·HCO3-Na·Ca型。主要水巖作用為斜長石和黑云母的溶解作用,方解石的沉淀和陽離子交換作用,生成高嶺石和伊利石?潛水還受蒸發(fā)濃縮作用和人類活動影響?3、在濱海平原區(qū)潛水和I承壓水徑流方向總體為由陸向海,I承壓水在灌河口和濱�？h一帶向下越流補(bǔ)給II承壓水。潛水受降水淡化,水質(zhì)優(yōu)于I承壓水?I承壓水TDS含量自西部400mg/L左右增加到濱海20g/L以上,水化學(xué)類型由內(nèi)陸的HCO3-Ca型水逐漸演變至濱海的Cl-Na型水?控制濱海平原區(qū)潛水和I承壓水水化學(xué)演化的作用主要為與海水的混合作用,廣泛存在斜長石的溶解作用、方解石的沉淀作用和陽離子交替吸附作用?潛水受蒸發(fā)濃縮作用和人類活動影響。4、在濱海平原區(qū),II承壓水在陳家港?燕尾港一帶接受了上覆I承壓水越流補(bǔ)給,TDS含量高達(dá)20g/L以上,其他地區(qū)水質(zhì)與III承壓水相似,為淡水和微咸水。II?III承壓水水化學(xué)類型空間分布類似,由內(nèi)陸HCO3-Ca·Na型水至濱海的Cl·HCO3-Na·Ca型水�？刂扑瘜W(xué)演化的主要作用為斜長石?黑云母的溶解作用,方解石的沉淀作用,陽離子交換作用以及脫硫酸作用,伴隨沉淀形成高嶺石和伊利石?5、通過定量模擬識別出控制各水化學(xué)作用對地下水化學(xué)形成的貢獻(xiàn)比例。以Na+濃度的變化為例,在非越流區(qū),對深層承壓水水化學(xué)形成貢獻(xiàn)較大的作用為陽離子交替吸附或斜長石礦物溶解作用;在越流區(qū)貢獻(xiàn)較大的作用為混合作用,其次為陽離子交替吸附作用或斜長石礦物的溶解作用。
[Abstract]:Groundwater resource is an important source of water supply in coastal areas of China. With the rapid development of social economy, the demand for water resources has increased dramatically. Many coastal areas have caused a series of environmental geological problems due to excessive exploitation of groundwater. The coastal plain of the lower reaches of the Yi-Shuhe River is located in the northern part of Jiangsu coastal area, where is there a bedrock fissure water? Pore diving, I?II?III?IV confined water, in which confined water is the main mining object? After years of excessive mining, the pressure level of II?III has continued to decline, forming a regional water level drop funnel, leading to water salinization, land subsidence and other problems. In order to develop and utilize groundwater reasonably and control the salinization of IIHIII confined groundwater, it is necessary to make clear the recharge and discharge conditions of groundwater in each layer of the study area and the spatial distribution characteristics of salty fresh water. Identify the main hydrogeochemical processes that control the formation of chemical components in groundwater? This paper fully analyzes the geology of the coastal plain in the lower reaches of the Yishu River. On the basis of hydrogeological conditions, comprehensive analysis of water level? The hydrochemistry and isotopic data were used to study the recharge and discharge conditions of groundwater and the formation and evolution mechanism of hydrochemistry in the study area. The hydrogeochemical simulation technique was applied to identify the main hydrogeochemical effects controlling the evolution of hydrochemical stroke. The main results are as follows: (1) the runoff direction of fissure water is controlled by water conductivity fissures, TDs content is 400 ~ 600mg / L, mostly HCO3-Na Ca type water. The formation of fissure water chemistry is mainly related to the dissolution of feldspar minerals in the bedrock. In the northern Gushan hilly area, the phreatic and I confined water flow radially from the mountains to the sea. The hydraulic slope reaches 1.5 鈥，

本文編號：1991565