Continental‐Scale River Flow Modeling of the Mississippi River Basin Using High‐Resolution NHDPlus Dataset

As a key component of the National Flood Interoperability Experiment (NFIE), this article presents the continental scale river flow modeling of the Mississippi River Basin (MRB), using high‐resolution river data from NHDPlus. The Routing Application for Parallel computatIon of Discharge (RAPID) was applied to the MRB with more than 1.2 million river reaches for a 10‐year study (2005‐2014). Runoff data from the Variable Infiltration Capacity (VIC) model was used as input to RAPID. This article investigates the effect of topography on RAPID performance, the differences between the VIC‐RAPID streamflow simulations in the HUC‐2 regions of the MRB, and the impact of major dams on the streamflow simulations. The model performance improved when initial parameter values, especially the Muskingum K parameter, were estimated by taking topography into account. The statistical summary indicates the RAPID model performs better in the Ohio and Tennessee Regions and the Upper and Lower Mississippi River Regions in comparison to the western part of the MRB, due to the better performance of the VIC model. The model accuracy also increases when lakes and reservoirs are considered in the modeling framework. In general, results show the VIC‐RAPID streamflow simulation is satisfactory at the continental scale of the MRB.     

三峡库区药用植物资源特征及其保护对策

三峡库区共有药用植物１１２９种,隶属于６０３属,１７４科。菊科、百合科、蝶形花科等１９个大科的种数达总种数的４９４％,蓼属、铁线莲属等２６个大属的种数达１８５％。中国特有种类占３７２％,显示出其在库区的丰富性。根茎类药用植物占４２１％,提示我们应适度采挖,做到永续利用。以林地为生境的药用植物占４８９％,表明森林是库区药用植物的资源库。三峡水库对库区药用植物资源的淹没损失不大,但其间接影响巨大。保护天然林是保护库区药用植物资源的重要途径。     

运城市乡村企业发展中的若干环境问题及控制对策

快速、蓬勃发展的乡村企业对繁荣乡村经济,改变乡村产业结构,促进与增加农村居民收入及提高农村居民生活质量发挥着十分重要的作用.但是,由于缺乏正确的引导和规划,许多已经发展起来的乡村企业在创造社会财富,促进农村经济发展的同时,对当地自然生态环境带来了很大的压力并且严重影响和制约着当地居民的生活质量与乡村企业及乡村经济的进一步发展与壮大.本文通过运城市乡村企业的污染调查,论述了运城市发展乡村企业所带来的环境污染与危害,分析了乡村企业污染产生的主要原因与症结,提出了加强和改进乡村企业环境污染控制的对策与措施,喻示了乡村企业与自然生态环境相协调共发展之必然.     

Effects of copper concentration on methane emission from rice soils

Outdoor pot experiments with various paddy soils representing five soil types were conducted at Nanjing Agricultural University during the 2000 and 2001 rice-growing seasons. Eighteen soils and ten out of the eighteen soils were involved in the 2000 and the 2001 experiment, respectively. Two treatments were designed as mineral fertilization (MF) and mineral fertilizer + wheat straw incorporation (MF + WS) for the 2001 experiment. Seasonal average rate of CH4 emission from different soils ranged from 1.96 to 11.06 mg m(-2) h(-1) in the 2000 experiment, and from 0.89 to 5.92 mg m(-2) h(-1) for the MF treatment in the 2001 experiment, respectively. Incorporation of wheat straw enhanced considerably CH4 emission with an average increment of 7.09 mg m(-2) h(-1). CH4 emissions from the two-year experiment were negatively correlated to soil available and total copper concentration. A further investigation showed that CH4 emission from the MF treatment was positively related to the dissolved organic carbon (DOC) in the soil (r = 0.904, p < 0.001), and that the DOC was negatively correlated to the concentrations of available copper (r = -0.844, p < 0.01) and total copper (r = -0.833, p < 0.01), respectively. Nevertheless, the incorporation of wheat straw did not enhance the soil DOC, and the relationship between CH4 emission and soil DOC was not statistically significant (r = 0.470, p < 0.20). It was concluded that higher concentration of copper in the soils resulted in lower soil DOC and thus reduced CH4 emission when there was no additional organic matter input. Incorporation of wheat straw did not affect soil DOC and available copper concentration but enhanced CH4 emission.     

浊度与微生物指标在污水再生处理系统中的去除特性及相关性

本研究考察了污水再生处理系统对颗粒物(包括浊度和粒径分布)和微生物指标(包括隐孢子虫、贾第鞭毛虫、粪大肠菌群和SC噬菌体)的去除特性以及不同指标间的相关关系。研究结果表明,污水再生处理系统对浊度的平均去除率为3.53-log,其中二级生化处理及砂滤对浊度的去除率较高,分别为1.52-log和1.35-log。粒径分析结果表明,絮凝沉淀后粒径均值达到最大值223.2μm;而再生水中粒径均值最小,仅为5.8μm。污水再生处理系统对各微生物指标的去除率为2.96-log~4.11-log。各处理单元中,二级生化处理单元对粪大肠菌群和SC噬菌体的去除率较高,分别为2.81-log及2.14-log;而砂滤对SC噬菌体去除效果较差,仅为0.18-log。从再生处理工艺整体上看,水样浊度、粪大肠菌群、SC噬菌体和两虫浓度具有显著相关性。而对于单个取样点,除污水厂进水中SC噬菌体和两虫浓度表现出一定相关性外,其他情况下各指标与两虫浓度间均无显著相关关系。     

百年来东海内陆架沉积物中重金属的累积过程及生态风险变化

研究了东海内陆架两个沉积岩芯DH33和KP04中重金属的含量，分析了重金属的累积过程及影响因素，并对不同重金属间的相关性进行了比较，最后利用潜在生态危害指数表征了百年来的生态风险变化。结果表明:东海内陆架沉积物中重金属主要来源于长江的入海携带，因地理位置差异，两岩芯重金属含量变化与长江径流量变化响应程度不同，DH33靠近长江口，响应较好，径流量大的年份重金属含量高；KP04远离长江口，响应较差，浙闽沿岸流和台湾暖流均会对KP04有物源供应。重金属V与Cr、Cr与Ni间相关性良好；As、Hg、Cd 3者与其它金属相关性较差，KP04重金属的含量总体大于DH33，与“粒度律”相矛盾，初步推测KP04站位重金属含量的变化受物源供应和沉积速率共同作用的影响，台湾暖流可能是重要的物源供应途径。生态风险评价结果显示，仅岩芯KP04在1990s和1930s处于“中度污染”级别，且主要是由Hg、Cd、As引起     

A GIS Framework for Regional Modeling of Riverine Nitrogen Transport: Case Study,San Antonio and Guadalupe Basins

This article presents a framework for integrating a regional geographic information system (GIS)‐based nitrogen dataset (Texas Anthropogenic Nitrogen Dataset, TX‐ANB) and a GIS‐based river routing model (Routing Application for Parallel computation of Discharge) to simulate steady‐state riverine total nitrogen (TN) transport in river networks containing thousands of reaches. A two‐year case study was conducted in the San Antonio and Guadalupe basins during dry and wet years (2008 and 2009, respectively). This article investigates TN export in urbanized (San Antonio) vs. rural (Guadalupe) drainage basins and considers the effect of reservoirs on TN transport. Simulated TN export values are within 10 percent of measured export values for selected stations in 2008 and 2009. Results show that in both years the San Antonio basin contributed a larger quantity than the Guadalupe basin of delivered TN to the coastal ocean. The San Antonio basin is affected by urban activities including point sources, associated with the city of San Antonio, in addition to greater agricultural activities. The Guadalupe basin lacks major metropolitan areas and is dominated by rangeland, rather than fertilized agricultural fields. Both basins delivered more TN to coastal waters in 2009 than in 2008. Furthermore, TN removal in the San Antonio and Guadalupe basins is inversely related to stream orders: the higher the order the more TN delivery (or the less TN removal).     

城市景观生态价值的边际效用分析法

本文从城市景观价值量的测定出发，引入经济学的效用和边际效用概念．提出城市景观价值量边际效用分析法，在理想状态下，以城市景观结构边际效用递减率为依据。通过面积-效益损益比，揭示城市景观经济效益与环境效益之间的内在联系．结果表明：在城市自然景观面积按比例递减的条件下，不但使环境效益损失趋于无穷大，而且使增加人工景观面积带来的城市经济效益锐减。     

大伙房水库的指示生物水蚯蚓和摇蚊幼虫

大伙房水库底栖动物历年监测,水蚯蚓Microdrili、摇蚊幼虫Chironomdae是优势种群。根据其分布特点和种类变化情况,确定了7种水蚯蚓、15种摇蚊幼虫为判定该水体是否安全的指示生物。     

肝素提取废水的GC-MS分析和处理研究

肝素钠废水含有高浓度无机盐和大量有机污染物，对环境具有潜在的毒性且难以处理，已经受到环境工作者的关注。为了了解废水的主要成分和处理此类废水，本实验用GC-MS对废水进行了分析，并且利用芬顿试剂对其进行了处理，结果发现废水中有机物有26种，其中脂肪酸和芳香衍生物占有较大比例，处理后，有机成分只有3种；讨论了影响处理效果的因素和最佳的工艺条件，发现当pH 值为6.66，硫酸亚铁和过氧化氢的量分别为2.5 g/L和2.8‰ (v/v)，搅拌速度为2 000 r/min, 搅拌时间为15 min时，COD的去除率可达到94.50%。