流域面源污染研究进展与展望

面源污染已成为影响流域水环境和水安全的重要来源,是当前国内外学者关注的热点之一,同时也是最具挑战性的研究领域之一。科学高效地治理面源污染问题已经纳入国家战略计划。因此,在新形势和政策背景下如何推进面源污染研究工作,以保障流域水环境可持续发展已成为紧迫任务。本文较为全面地回顾和总结了我国面源污染研究现状,归纳了主要研究方法和典型治理措施,并基于研究中存在的主要问题,结合我国水污染治理现状给出相应建议,指出未来发展趋势。本文可为面源污染的全过程监管、评估及治理提供重要参考,有助于完善我国水污染治理体系。     

Changes in hydrology,sediment loss and microtopography of a vegetated mine waste rock dump impacted by fire

Dry season burning to control wildfire is conducted in Kakadu National Park in the Northern Territory. The ERA Ranger Mine is adjacent to the park, and it is likely that at some stage the post-mining landform will be affected by fire. Rainfall simulations were conducted on a vegetated site on the mine waste rock dump. The site was then burnt and the rainfall simulation series repeated. Initially, there was little difference between sediment loss and runoff from the vegetated condition and sediment loss and runoff from the burnt condition. As simulations continued, total sediment loss from the burnt condition increased as a result of increasing runoff compared to the vegetated condition. Burning of vegetation affected the surface hydrology of the site, resulting in increased erosion under saturating rainfall similar to rainfall expected at the commencement of a wet season. Litter dams formed during runoff from the burnt condition providing areas of localized deposition. The distribution of the dams was non-random. If fire is used as a management tool to control wildfire, placement of artificial microdams on steep slopes may provide areas of sediment deposition and seedbank storage to reduce the effects of elevated runoff and sediment loss and facilitate vegetation regeneration. Copyright © 1999 John Wiley & Sons, Ltd.     

黄土丘陵沟壑区小叶杨林生长的空间差异分析--以吴旗县为例

对延河流域降水、径流和泥沙等水文要素从20世纪中叶到21世纪初的年内分配及年际变化进行了时变过程分析。以探求区域植被重建对流域水文过程的影响情况。结果表明,三个水文基本要素都有不同程度的年内分布趋于均匀和年际变化趋缓的趋势。20世纪70-90年代比60年代流域平均面雨量分别减少了10．5％,11．7％和14．0％,年径流量分别减少了19．0％,12．9％和22．6％,年输沙量分别减少了21．1％．46．2％和41．7％。     

考虑灌排运行特点的南方平原圩区分布式水文模拟

为探究适合中国南方平原圩区的水文模型及平原圩区建模与参数率定方法，把握平原圩区内部水循环规律，该研究以巢湖流域庐北大圩为研究区，基于改进SWAT(soil and water assessment tool)模型，提出了一种基于“burn-in”算法与模型河网及子流域人工修正手段的空间离散方法，考虑圩区灌排运行特点后，通过添加虚拟水库，构建了平原圩区多水源灌溉系统，通过对不同大小及特征圩区进行分类，提出了以月尺度为主的多目标参数率定方法。模拟结果表明，大部分圩区出口月径流的相对误差在±15%以内，决定系数大于0.65，纳什效率系数大于0.6，模拟效果处于中等或良好水平，表明改进SWAT模型及该研究提出的平原圩区建模与参数率定方法适用于庐北大圩的水文模拟。水量平衡与灌溉用水模拟分析结果表明，研究区的降水与外河引水主要转化为径流和蒸散发，外河引水量近似等于泵站抽排量，径流系数相对较小，大圩外河是主要灌溉水源，不同时间段内不同水源的可供水量差异明显。考虑灌排运行特点的分布式水文模型为中国南方平原圩区水管理提供了一种有效的手段。