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题名	塔里木河中下游地下水化学特征变化及其生态效应研究
作者	陈永金
学位类别	博士
答辩日期	2008
授予单位	中国科学院．新疆生态与地理研究所
导师	陈亚宁，中国科学院新疆生态与地理研究所
关键词	地下水化学特征
其他题名	Study on the Variations in Groundwater Chemistry and Ecological response in the Middle and Lower reaches of the Tarim River
中文摘要	塔里木河下游间歇性生态输水对河道两侧地下水化学特征有明显的影响：处在下游上段的监测断面和近河道处的地下水化学组分在间歇性输水的影响下表现出明显的升降升阶段性变化规律，处在中段地下水化学组分则呈逐渐降低的态势，处在下段的断面和距河道远处的监测井，其地下水化学组分一直呈增加变化。在输水间歇地下水中各离子的变化方向却不相同：Cl-、Na+ 等离子的含量表现为上升变化，而SO42-含量则呈下降变化的趋势。地下水化学组分的变化与河道径流量、河道水质、地下水埋深、土壤剖面盐分含量等因素紧密相关。地下水质的变化也深刻影响着植被：胡杨的覆盖度与地下水pH值成正相关，与地下水矿化度和各主要离子含量成负相关；柽柳覆盖度随地下水中各主要离子含量和矿化度的增加而增加。根据水质变化与相关因子以及植被覆盖度关系的数理统计分析，确定了在输水条件下，利于植被复壮，同时保证水分得到有效利用的合理生态水位是埋深5 m。塔里木河中游地区输水堤防修建后，地下水化学特征在丰枯期变化规律被打乱，而且地下水矿化度和主要离子含量随时间的变化而上升，尤其在距离堤防800 m以外的区域更为明显。在输水堤防修建之初的2001年，距堤防2000 m以内各监测井地下水化学组分相关性都非常高。而到2006－2007年，只有距堤防800 m以内的地下水化学组分的相关性较显著，说明由于堤防的修建河水对800 m以外区域的水力联系被隔断。在堤防修建初期植被覆盖度变化较小，随着时间的推移，植被覆盖度的下降幅度越来越大。植被覆盖度的下降主要表现为胡杨为代表的乔本植物和草本植物，以柽柳为主的灌木覆盖度却呈一定的上升变化。分析表明：胡杨覆盖度的变化与地下水盐分含量的上升有关，草本植物覆盖度的下降是地下水埋深增加的结果，而盐生植物柽柳覆盖度的增加则说明了中游地区河道两侧湿地生态环境的劣变。从中游湿地保护和全流域生态恢复与保护的角度考虑，中游输水堤防的修建弊大于利.Groundwater chemistry along the river underwent great changes influenced by the intermittent water deliveries from the year 2000 to 2007: the chemical compositions in the transects near to Daxihaizi Reservoir and the monitoring wells near to watercourse exhibited an up-down and up trend thanks to the arrival of most water. However, the concentrations of major ions and dissolved solids (TDS) of groundwater in the monitoring wells farthest away from the water source disclosed an increasing regulation, for the reason of little water they receipted. And the groundwater chemistry of the transects neither too near to nor too far way from Daxihaizi Reservoir gave a decreased change, it may be explained as they acted as channel only in the process of water deliveries, the salts in the soil and ground water were carried away and few salt was brought. At the interval of water deliveries, the ions in groundwater revealed complex changes: Cl- and Na+ increased a lot, SO42-, however, decreased much. Many environmental factors controlled the variations in groundwater chemistry, such as runoff, water quality in river, depth of groundwater, salinity in soil profile , temperature and so on. The change of plants along river were related to the groundwater chemistry: the coverage of Populus euphratica-the only arbor in study area increased along with increasing pH in ground water, and decreased when the TDS and major ions increase; the coverage of Tamarix spp. showed the same direct to the major ions and TDS in groundwater. Based on the analysis above, the rational depth in the lower Tarim River is 5 m. The regulation of the variations in groundwater chemistry between flooding and wilt periods were reversed since the dikes were built in the middle reaches of the Tarim River, and the concentration of major cations and anions as well as TDS in ground water increased directly. It is found that at the initial of the dikes building, the salt in different distance to dikes showed close relations, and the groundwater chemistry within 800m had less relations to that beyond 800m from the dike, which means that the dikes prohibited the water connect between watercourse and ground water far away from the dikes. Furthermore, the vegetation coverage outside the dikes decreased due to the increase of groundwater depth and the salt in groundwater.
语种	中文
学科主题	恢复生态
公开日期	2010-11-12
页码	共161页
内容类型	学位论文
源URL	[http://ir.xjlas.org/handle/365004/8000]
专题	新疆生态与地理研究所_中国科学院新疆生态与地理研究所(2010年以前数据)
推荐引用方式 GB/T 7714	陈永金. 塔里木河中下游地下水化学特征变化及其生态效应研究[D]. 中国科学院．新疆生态与地理研究所. 2008.

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