茅洲河地表水—地下水交互关系研究

RESEARCH ON INTERACTIVE RELATIONSHIP BETWEEN SURFACE WATER AND GROUNDWATER OF MAOZHOU RIVER

吴广祥

11649176

硕士

环境工程

易树平

2018-05-29

2018-07-09

哈尔滨工业大学

深圳

随着《水污染防治行动计划》的逐步推进，水环境污染防治特别是黑臭水体的治理越来越受到国家、社会和公众的重视。监测数据表明，深圳市茅洲河河水水质长期处于劣Ⅴ类，存在严重的水污染问题，是深圳市“治水提质”工作的重中之重。受气候、潮汐和人类活动的影响，茅洲河地表水和地下水交互关系复杂，受污染的地表水和地下水存在交互污染的风险，给流域水环境污染的长效治理带来极大的挑战。鉴于此，本论文开展茅洲河地表水和地下水交互关系研究，通过水动力、水化学、同位素以及数值模拟方法，综合分析和查明地表水和地下水之间的水量和水质转换关系，为流域水污染治理和水环境质量的进一步提升提供依据。茅洲河流域位于亚热带海洋性季风气候区，降水丰沛，流域河网密集，中下游受潮水影响，生态、水文条件较为复杂。流域区域地壳稳定，断裂构造不发育，下伏地层主要由震旦系大绀山组、三叠系小坪组、侏罗纪桥源组和金鸡组、第四系桂洲组和大湾镇组等地质单元组成。流域含水岩组主要分为松散岩类孔隙水和基岩裂隙水两大类，含水岩组富水性较差，地下水埋深较浅，易受到来自地表和河流水体的污染。本研究在茅洲河干流燕川河段及支流新桥河设置了 4 个典型研究断面，共建设了 13 口地下水监测井。水文地质钻探结果表明茅洲河潜流带区域第四系孔隙含水层厚约 8.24-19.0 m，岩性以砂质粘土和细砂、粗砂为主。抽水试验结果表明砂质粘土含水层平均渗透系数为 0.185 m/d，细砂和粗砂含水层平均渗透系数分别为 4.93 m/d 和 12.94 m/d。典型研究断面的地表水、地下水水位、温度联合监测结果表明，监测时间段（2018 年 1 月至 5 月）内流域地表水和地下水的补给关系主要为地下水泄流补给河水。燕川河段地表水—地下水交互带的单侧宽度约 67.5m。依托地下水监测井和流域部分民用水井，沿河流上游到下游采集地表水和浅层地下水样品，进行水化学和氢氧稳定同位素组成测定，分析地表水和地下水水化学和氢氧稳定同位素组成的空间分布规律和演化趋势，以进一步揭示地表水和地下水交互关系的空间分布特征。地表水和地下水的电导率、TDS、氯离子、氢氧同位素分析结果均证明茅洲河地表水和地下水之间的交互关系主要为地下水泄流补给地表水。茅洲河上游经过河道整治，河水和地下水之间水力联系较好，河水接受地下水的补给；茅洲河中下游是感潮河段，海水涨潮、落潮导致河水水位周期性波动，对茅洲河河水和地下水的交互关系产生较大影响，出现河水水位上升后补给地下水的现象；茅洲河下游随着河流进入冲积平原，水力梯度减小，河道底泥大量淤积，地表水和地下水水力联系减弱，但仍以地下水补给河水为主。依托流域气象水文、土地利用类型、土壤类型和数字高程模型等数据建立并校正了茅洲河流域 SWAT 模型，并进一步建立了 SWAT-LUD 模型，定量计算了茅洲河地表水和地下水之间的交互量。模型计算结果显示 2017 年茅洲河流域地下水通过排泄转化为河水的水量约为 1.6×108m3，地下水接收地表水侧向补给的量为 1.0×106m3，洪水泛滥区河水入渗补给地下水的水量为 6.7×106m3。基于以上研究，提出了河道底泥清淤、12、13 号子流域建设渗透式反应墙、茅洲河河口建闸等水环境治理措施，以进一步改善地表水和地下水水环境质量，为茅洲河地表水和地下水污染联合防治提供依据。

With the advance of < Water pollution controlaction plan >, the prevention and control of water pollution, especially the disposal of black and odorous water body, has been paid more and more attention by the state, society and the public.Monitoring data shows that water quality of Maozhou river has kept bad Ⅴ class chronically, and has been the key of ‘water quality improvement’ work of Shenzhen city. Affected by climate, tidal and human activities, the interactive relationship of surface water and groundwater for Maozhou river is complex, and the contaminated surface water and groundwater has the risk of being sources of contamination, it brings great challenge to the long-term management of water pollution in the watershed. In view of this, this paper carries out research on the interactive relationship between surface water and groundwater, four methods, such as, hydrodynamics, water chemistry, isotopes and numerical simulation were used in this research, and the relationship between surface water and groundwater was analyzed to provide a basis for further improvement of water pollution control and water environment quality.Maozhou river basin locates in the subtropical maritime monsoon climate zone, with abundant rainfall and dense river networks, affected by the tides, the ecological and hydrological conditions of middle and lower reaches are complex. The crust of the basin is stable and the fault structure is not developed, and the basin is mainly composed of Sinian Daganshan Formation, Triassic Xiaoping Formation, Jurassic Qianyuan Formation and Jinji Formation, the quaternary Guizhou Formation and Dawanzhen Formation, etc. Groundwater aquifer group of Maozhou river basin consists loose rock pore water and bedrock fissure water, and poor water were found in both of them, groundwater depth is shallow and vulnerable to the contamination from surface water bodies.In this study, four typical research sections were selected in the Yanchuan river section and Xinqiao tributary, and 13 groundwater monitoring wells were constructed. The results of hydrogeological drilling show that the thickness ofquaternary pore aquifer is about 8.24-19.0 m, and the lithology is mainly composed of sandy clay and fine sand and coarse sand. The results of pumping test shows that the average hydraulic conductivity of sand clay aquifer was 0.185 m/d, and the average hydraulic conductivity of fine sand and coarse sand aquifer was 4.93 m/d and 12.94 m/d respectively. The water level and temperature monitoring results show that groundwater discharge to river is the mainly interactive relationship between surface water and groundwater in the monitoring period (January to May, 2018). The unilateral width of surface water - groundwater interaction zone in Yanchuan river section is about 67.5m.Relying on the constructed groundwater monitoring wells and some civilian Wells, surface water and groundwater samples were collected, water chemistry and hydrogen and oxygen stable isotopic composition of the samples were analytically tested to analyze its spatial distribution trend, in order to further reveal the interactive relationship between surface water and groundwater. Conductivity, TDS, chloride ion, hydrogen and oxygen isotope evidences all proved that groundwater discharge to river is the mainly interactive relationship between surface water and groundwater. In the upstream of the Maozhou river, the surface water and groundwater has a great hydraulic connection, and the river receives the recharge from groundwater; the midstream and downstream of Maozhou river is tidal river, affected by the rising tide and falling tide of sea water, periodic fluctuation happens in this stream, and it has a great influence to the interaction between groundwater and surface water; the downstream of maozhou river flows into the alluvial plain, with the reduce of hydraulic gradient and the silted up of channel sediment, the hydraulic connection between surface water and the groundwater are weakened, but groundwater discharge to river is still the main intercative relationship.On the basis of meteorological hydrology, land use type, soil type and digital elevation model, a SWAT model were constructed and calibrated, and further more the SWAT-LUD model were constructed to calculate the water transformation quantity between surface water and groundwater of Maozhou river basin. After calibrated, the model reveals that the amount of groundwater discharge to river is 1.6×108 m3 in the year of 2017; the amount of surface water infiltrate to groundwater is 1.0×106m3; during flood perid, the amount of surface water infiltrate to groundwater through the bank is 6.7×106m3. Based on the above research, three strategies, such as, river sediment dredging, Permeable Reactive Barrier construction, brake construction in the Maozhou river estuary, were put forward to further improve the water environment quality.

地表水—地下水交互关系 水文地质 水文地球化学 氢氧稳定同位素 SWAT-LUD 茅洲河

surface water - groundwater interactions hydrogeology hydrochemistry hydrogen and oxygen isotopes SWAT-LUD Maozhou River

中文

联合培养

哈尔滨工业大学

吴广祥. 茅洲河地表水—地下水交互关系研究[D]. 深圳. 哈尔滨工业大学,2018.