鄱阳湖水功能区划细化及保护区统筹优化探讨

鄱阳湖现行水功能区划在落实最严格水资源管理制度及湖长制管理中显现出了诸多不足,如水功能区范围过宽致使无法明确地方政府责任、未统筹协调多个自然保护区范围重叠问题等。依据明确主体、分解责任、统筹兼顾、有效覆盖的原则,探讨了利于管理且切实可行的水功能区划方案。根据研究结果,建议将鄱阳湖环湖渔业用水区、鄱阳湖保留区等国划水功能区,在省划层面细化到县级行政区,构建国划与省划统一而逐层分解的水功能区划体系;通过统筹多个自然保护区划定"鄱阳湖水生生物保护区"水功能区,以促进最严格水资源管理及湖长制的推行,有效保护鄱阳湖水生态环境。     

草海湿地区域土地利用景观格局时空变化特征研究

采用3S技术和景观生态学分析方法,对草海湿地区域近20 a的景观格局动态变化进行分析,结果表明:(1) 20 a间,草海湿地区域林地、草地景观类型面积呈下降趋势,水域、建设用地景观类型面积大幅增加,耕地景观类型面积总体有所增加;(2)从景观类型转换来看,研究区景观类型转换以草地、耕地景观类型的转入转出变化最大,草地退化较为严重;(3)从景观类型斑块密度和平均斑块面积变化情况来看,研究区各类景观类型的破碎化程度越来越严重;(4)从景观斑块形状和景观多样性变化情况分析,研究区林地、草地、建设用地景观斑块形状趋于规则,景观优势度明显,在整个研究区中占绝对的优势地位。总体来看,草海自然保护区建立之后,由于人为因素的干预,对湿地区域保护力度较大,一系列湿地保护、修复和恢复工程的实施,使得草海湖区面积持续增加,湿地得以较好的保护和恢复。     

考虑太湖水质指标的流域骨干工程调度方案

通过对多年实测资料的分析,研究了太湖水环境改善需求,明确了影响太湖水质改善的关键因子,设计了考虑太湖水质指标的流域骨干工程调度方案,并对调度方案的效果进行了分析。结果表明,考虑太湖水质指标的优化调度对竺山湖水质具有较为明显的改善作用,建议在新孟河江边枢纽调度中考虑太湖水质指标,通过改善竺山湖水质促进太湖总体水质提升。     

阳澄湖地区水体重金属锑的总量控制

为确保阳澄湖饮用水源地锑浓度稳定达标,基于阳澄湖地区的水环境现状监测数据及污染源调查结果,计算了阳澄湖中锑的水环境容量,并提出了研究区域内锑的总量控制方案。结果表明:研究区域现状锑排放量约12.38 kg/d,为达到集中式生活饮用水源地特定项目标准中锑的标准限值0.005 mg/L,需削减9.38 kg/d,削减率为75.8%;纺织印染直排企业及接纳含锑废水的集中式污水处理厂尾水中锑的排放质量浓度限值为20μg/L。     

Nearshore-offshore exchanges in multi-basin coastal waters: Observations and three-dimensional modeling in Lake Erie

Nearshore-offshore exchanges through upwelling events and subsequent formation of internal Kelvin waves and coastal-jets are expected in the multi-basin coastal waters of Lake Erie; however, these phenomena have yet to be confirmed in the field or numerically modeled. Here, we demonstrate these physical processes in Lake Erie through extensive field data analysis and high-resolution three-dimensional hydrodynamic modeling. The validated model successfully reproduces dominant physical processes in the offshore and nearshore waters including surface seiches (~14?h), near-inertial waves (~17?h) and upwelling events (5–10?days). We show that upwelling events are the predominant nearshore physical processes, and are energized when winds accelerate the epilimnetic waters to the south, causing the thermocline front to move up into the north shore. After the wind subsides, the elevated thermoclines simultaneously form two separate cyclonically propagating internal Kelvin waves in the central and the eastern basins following by two coastal-jets at phase speeds of 0.22?ms^?1 and 0.37?ms^?1 within 5–15?km off the shoreline, respectively. The predominant south-west winds limit the presence of Kelvin waves only to the northern parts of each basin, where the bathymetry allows, and disappear when shoreline morphology no longer maintain these waves due to nonzero cross-shore transports at the coastal boundary layer. Intrusions of hypolimnetic waters through upwelling events contribute 10–30% to the net cross-shore transport, and are most pronounced in May and June when the offshore thermocline is shallow. The intermittent strong westward nearshore currents by Kelvin waves are in the opposite direction of seasonal eastward currents.     

浅水湖泊底栖动物栖息地模拟

为研究白洋淀水生生物栖息地适宜度,分别于2016年春、夏、秋3季进行了实地考察和采样,结合野外观测和实验室测量得到环境和生物信息。基于14个采样点的数据,通过构建广义可加模型(GAMs)模拟和预测底栖动物的分布。使用Margalef指数作为响应变量,采用向前逐步回归筛选解释环境因子,通过评价剩余偏差来判断模型的表现。水深、水温、底泥氨氮、底泥有机质和沉水植物生物量被用于建立最终优化的广义可加模型。Margalef指数对环境因子的响应曲线表明该指数与水深和底泥氨氮浓度成线性负相关,与水温和底泥有机质浓度成线性正相关,而与沉水植物生物量是单峰关系。结果表明,预测值与实测值呈现显著的强相关性(Pearson R~2=0.847,P0.001),均方误差较小(MSE=0.013),模型性能表现良好。     

Detroit River phosphorus loads: Anatomy of a binational watershed

As a result of increased harmful algal blooms and hypoxia in Lake Erie, the US and Canada revised their phosphorus loading targets under the 2012 Great Lakes Water Quality Agreement. The focus of this paper is the Detroit River and its watershed, a source of 25% of the total phosphorus (TP) load to Lake Erie. Its load declined 37% since 1998, due chiefly to improvements at the regional Great Lakes Water Authority Water Resource Recovery Facility (WRRF) in Detroit and phosphorus sequestered by zebra and quagga mussels in Lake Huron. In addition to the 54% of the load from Lake Huron, nonpoint sources contribute 57% of the TP load and 50% of the dissolved reactive phosphorus load, with the remaining balance from point sources. After Lake Huron, the largest source is the WRRF, which has already reduced its load by over 40%. Currently, loads from Lake Huron and further reductions from the WRRF are not part of the reduction strategy, therefore remaining watershed sources will need to decline by 72% to meet the Water Quality Agreement target - a daunting challenge. Because other urban sources are very small, most of the reduction would have to come from agriculturally-dominated lands. The most effective way to reduce those loads is to apply combinations of practices like cover crops, buffer strips, wetlands, and applying fertilizer below the soil surface on the lands with the highest phosphorus losses. However, our simulations suggest even extensive conservation on those lands may not be enough.     

Investigating the restoration of Lake Urmia using a numerical modelling approach

We assessed the effectiveness of multiple hydrologic restoration scenarios for Lake Urmia, as well as the variation of its salinity regime under no intervention, using a 2D shallow water model. Tested scenarios, proposed by Urmia Lake Restoration Program Committee, include: Preservation of current lake status (no intervention), complete closing of Shahid Kalantari causeway, dyke construction in the southern part of Lake Urmia, water transfer from Zarrinehrood River to Siminehrood River and reduction of agricultural water consumption by best agricultural practices. Results indicate that neither the closure of the causeway nor the construction of the southern dyke would significantly improve lake conditions when compared to preservation of current lake status. The water transfer alternative doesn’t seem to have any effect on the current lake conditions either. However, the reduction on water diversions by improving agricultural practices in the lake's basin leads to a partial restoration of the lake in terms of water level, surface area and volume. If current conditions persist, salinity in the northern part of Lake Urmia will reach supersaturation levels (340?g/L), generating further salt deposits.     

基于PSO-BP神经网络的西洞庭湖南咀站径流预测

为建立因子少、预报周期短、预报精度高的西洞庭湖控制性水文站南咀站的月平均径流量预报模型,通过对松滋-太平水系控制性水文站安乡、澧水控制性水文站石龟山站月平均水位、流量以及沙湾站月平均水位进行相关性、因子贡献率分析,确定输入因子,借助PSO-BP神经网络对南咀站1956年1月至2005年12月各月平均径流量进行训练,获取网络结构及参数进而预测2006年1月至 2008年12月各月径流量。结果表明：① 石龟山、安乡站水位对南咀站月平均径流量影响最显著;② 汛期、非汛期的划分一定程度上可提高南咀站月平均径流量预报精度;③ 以安乡、石龟山站月平均水位、流量以及沙湾站月平均水位作为输入因子,PSO-BP神经网络预报效果最好,合格率77.8 %,预报等级为乙级;④ 基于相关性、因子贡献率分析,将安乡、石龟山站作为输入因子,预报合格率降为61.1 %,预报等级降为丙级,但仍满足预报要求。     

基于改进信息熵的江苏滆湖水质分布规律研究

为得出近年来江苏滆湖水质变化趋势,基于2008~2016年近9 a的长期水质实测资料,分析了不同水质指标的年际与年内变化趋势,并发出100份问卷,根据专家经验得到主观权重,根据信息熵理论得到客观权重,最终基于综合权重构建了新型水质综合评价模型,并对滆湖不同分区的水质进行了评价。结果表明：不同水质指标近9 a均呈总体降低趋势,在2008年之后出现显著降低,原因可能是由于近年治理措施取得了良好效果,但缓冲区水质指标普遍高于其余区域,最高高出了37.2%;不同水质指标年内变化呈先减小后增加的趋势,在11月至次年2月水质普遍较差;基于新型水质综合评价模型,分析了滆湖不同分区的水质类别,发现核心区与开发控制利用区属于Ⅲ类水,而缓冲区水质属于Ⅳ类水,水质较差,需及时制定相应措施改善缓冲区水质。研究得出的结论符合实际数据观测情况与当地实际情况,表明该模型具有一定的科学性和使用价值,可为当地水质治理措施的制定提供科学依据。