Analyses of Urban Drainage Network Structure and its Impact on Hydrologic Response1

Meierdiercks, Katherine L., James A. Smith, Mary Lynn Baeck, and Andrew J. Miller, 2010. Analyses of Urban Drainage Network Structure and Its Impact on Hydrologic Response. Journal of the American Water Resources Association (JAWRA) 1-12. DOI: 10.1111/j.1752-1688.2010.00465.x Abstract: Urban flood studies have linked the severity of flooding to the percent imperviousness or land use classifications of a watershed, but relatively little attention has been given to the impact of urban drainage networks on hydrologic response. The drainage network, which can include storm pipes, surface channels, street gutters, and stormwater management ponds, is examined in the Dead Run watershed (14.3 km²). Comprehensive digital representations of the urban drainage network in Dead Run were developed and provide a key observational resource for analyses of urban drainage networks and their impact on hydrologic response. Analyses in this study focus on three headwater subbasins with drainage areas ranging from 1.3 to 1.9 km² and that exhibit striking contrasts in their patterns and history of development. It is shown that the drainage networks of the three subbasins, like natural river networks, exhibit characteristic structures and that these features play critical roles in determining urban hydrologic response. Hydrologic modeling analyses utilize the Environmental Protection Agency’s Stormwater Management Model (SWMM), which provides a flexible platform for examining the impacts of drainage network structure on hydrologic response. Results of SWMM modeling analyses suggest that drainage density and presence of stormwater ponds impact peak discharge more significantly in the Dead Run subbasins than the percent impervious or land use type of the subbasins.     

由不可逆过程热力学线性关系推导的传质方程

本文用不可逆过程势力学线性关系式，推导出了在不同盐平均浓度下的一系列线性关系式，这些关系式与采用不同高聚物膜，不同盐浓度所做的反渗透实验结果符合得很好。     

西南地区公路洪灾孕灾环境分区

以西南地区公路洪灾为研究对象,在孕灾因子分析基础上构建由6个因子组成的孕灾环境分区指标体系,利用层次分析和专家效度相耦合方法确定各指标权重,采用综合指数法建立孕灾环境综合指数评价模型。在ArcGIS软件平台支持下获取各评价指标数据,并计算得到各网格孕灾环境综合指数值,以县级行政区为单位进行公路洪灾孕灾等级区的划分。研究表明：西南地区孕育公路洪灾发生的环境条件较充分,孕灾环境综合指数值在3313~7746,孕灾分区主要集中在中易发区和高易发区,其中高易发区占整个研究区面积的5718%,中易发区占4039%,低易发区占243%,公路管理部门在汛期防治洪灾的任务较繁重     

水分条件对生物炭钝化水稻土铅镉复合污染的影响

采用培养试验,探究30％ WHC、淹水和干湿交替等3种水分条件下,向Pb和Cd污染水稻土以1％添加量施入水稻秸秆生物炭后重金属的形态变化,为生物炭修复重金属复合污染稻田的水分管理提供科学依据.结果表明,添加生物炭后,淹水和干湿交替可显著提高土壤pH值、可溶性有机碳(DOC)和无定形氧化铁含量(Fe.).培养结束后,在添...     

新中国成立至改革开放前我国应对海洋灾害的实践及启示

梳理和总结新中国初期我国应对海洋灾害的实践,有助于我们了解海洋灾害的应对措施并为当今提供借鉴。通过对我国海洋灾害史料的分析和总结,得知从新中国成立至改革开放前这一时期内,"防重于救"是我国应对海洋灾害的的主要指导思想,在海洋灾害预测预警、建设防护性工程、群众自救和政府辅以必要救济等方面发挥了重要作用,并为之后我国应对海洋灾害打下了一定基础。     

PDMDAAC阳离子膨润土处理染料废水的研究

采用聚二甲基二烯丙基氯化铵均聚物(PDMDAAC)对膨润土进行改性,制得阳离子膨润土,研究其电动特性及对染料废水的脱色效果．结果表明,与膨润土相比,阳离子膨润土的表面电性发生了变化;处理染料废水的效果明显提高,而且在强酸性和强碱性条件下对染料废水的脱色效果最好．     

阳离子高分子絮凝剂的合成及其在油田的应用

利用ASP以及其他助剂组成的复合引发体系,研究了在50℃下采用水溶液自由基聚合方式,得到了溶解性能好的阳离子均聚物PDMDAAC。考察了pH值、引发剂用量和单体浓度对阳离子均聚物黏度和阳离子度的影响。研究了PDMDAAC作为絮凝荆在油田污水处理中的应用。     

Extraction of 17p-estradiol in water using non-imprinted polymer submicron particles in membrane filters

17β-Estradiol (E2) is an endocrine disrupting chemical of harm to both animals and human beings at a low concentration level (ng/L).It cannot be completely removed by wastewater treatments,and is often detected in both environment and drinking waters.The purpose of this feasibility study,towards environmental engineering in the field of water analysis and treatment,was to remove E2 by extraction using non-imprinted polymer (NIP) submicron particles.Experimental results showed that 0.5 mg/L of E2 could be completely extracted by adding 10 mg of NIP particles directly into 10 mL of water.However,the extraction efficiency decreased to 64% for 100 mL of water.prefilling the NIP particles inside a membrane filter showed a potential for water treatment of a large volume,requiring no effort to distribute the particles uniformly in the water.High extraction efficiency (80±10)% for E2 was achieved for 100 mL of water.A total mass of 0.29 mg E2 was extracted from 1000 mL of water containing 0.8 mg/L E2 (by using only 10 mg of NIP particles).Both efficiency and mass capacity can be increased,by scaling up the amount of NIP particles,towards environmental engineering applications.     

多核无机高分子絮凝剂研究进展

多核无机高分子絮凝剂因其具有其他絮凝剂不具备的优点,近年来得到国内外广泛关注。综述了多核无机高分子絮凝剂的种类,分别阐述了不同种絮凝剂的特点、研究与应用概况,并对无机多核高分子絮凝剂的发展趋势做了分析和展望。     

Influence of flooding and vegetation on carbon, nitrogen, and phosphorus dynamics in the pore water of a Spartina alterniflora salt marsh

Four sites were selected in a salt marsh in the Bah′?a Blanca Estuary (Argentina): (1) low marsh (flooded by the tide twice daily) vegetated by S. alterniflora; (2) non-vegetated low marsh; (3) high marsh (flooded only in spring tides) vegetated by S. alterniflora; (4) non-vegetated high marsh. The pH and Eh were measured in sediments, while dissolved nutrients (ammonium, nitrate, nitrite and phosphate) and particulate organic matter (POM) were determined in pore water. pH (6.2–8.7) was only a ected by vegetation in low areas. Eh (from –300 to 250 mV) was lower at low sites than at high ones; in the latter, the values were higher in the non-vegetated sediments. The POM concentration was greater in the high marsh than in the low marsh, with no e ect of vegetation. Ammonium was the most abundant nitrogen nutrient species in pore water, except in the non-vegetated high marsh where nitrate concentration was higher. All nitrogen nutrients were a ected by both flooding and vegetation. Phosphate was always present in pore water at all sites throughout the year and its concentration varied within narrow limits, with no e ect of flooding and greater values always at non-vegetated sites. Our results showed that the variability of the pore water composition within the marsh is greater than the temporal variation, meaning that both tidal flooding and vegetation are important in the dynamics of nutrients and organic matter in the sediment pore water.