Comparative Analysis of Inundation Mapping Approaches for the 2016 Flood in the Brazos River,Texas

Accurate and timely flood inundation maps serve as crucial information for hydrologists, first‐responders, and decision makers of natural disaster management agencies. In this study, two modeling approaches are applied to estimate the inundation area for a large flooding event that occurred in May 2016 in the Brazos River: (1) Height Above the Nearest Drainage combined with National Hydrograph Dataset Plus (NHDPlus‐HAND) and (2) International River Interface Cooperative — Flow and Sediment Transport with Morphological Evolution of Channels (iRIC‐FaSTMECH). The inundation extents simulated from these two modeling approaches are then compared against the observed inundation extents derived from a Landsat 8 satellite image. The simulated results from NHDPlus‐HAND and iRIC‐FaSTMECH show 56% and 70% of overlaps with the observed flood extents, respectively. A modified version of the NHDPlus‐HAND model, considering networked catchment behaviors, is also tested with an improved fitness of 67%. This study suggests that NHDPlus‐HAND has the potential for real‐time continental inundation forecast due to its low computational cost and ease to couple with the National Water Model. Better performance of NHDPlus‐HAND can be achieved by considering the inter‐catchment flows during extreme riverine flood events. Overall, this study presents a comprehensive examination made of remote sensing compared with HAND‐based inundation mapping in a region of complex topography.     

不同覆被下红壤坡地地表径流及其养分流失特征

通过对南方红壤坡地农作区、茶园、柑橘园、退化区和恢复区5种不同利用方式所产生的地表径流量的全年连续观测及其径流水中养分含量分析,结果表明:覆被植物群落类型单一化和农事耕作都能增加地表径流量、次数和增加养分流失,5种类型地表径流量不论是月平均径流量还是年总径流量,其大小关系为农作区*>茶园*>柑橘园>退化区>恢复区*,产流次数也是恢复区最少,其余4种类型基本一致;径流水中总P、K 、Ca2 、Mg2和SO42-流失量以农作区达到最大,茶园和柑橘园次之,然后是退化区和,恢复区的径流各养分流失量量少,耕作区的总P、K 、Ca2 、Mg2 和SO42-流失量大于非耕作区,覆被植物群落类型少的总P、K 、Ca2 、Mg2 和SO42-流失量大于覆被植物群落类型复杂.综合考虑,红壤坡地用来耕作可以加剧水土和土壤养分流失,自然植被对红壤坡地保持水土和养分效果最佳,如果种植经济价值较高的果林和药、茶、草等需采用复种方式,避免单一种植和减少人工扰动,以便维持坡地土壤利用的可持续性.     

Anoxic phosphorus removal in a pilot scale anaerobic-anoxic oxidation ditch process

The anaerobic-anoxic oxidation ditch (A²/O OD) process is popularly used to eliminate nutrients from domestic wastewater. In order to identify the existence of denitrifying phosphorus removing bacteria (DPB), evaluate the contribution of DPB to biological nutrient removal, and enhance the denitrifying phosphorus removal in the A²/O OD process, a pilot-scale A²/O OD plant (375 L) was conducted. At the same time batch tests using sequence batch reactors (12 L and 4 L) were operated to reveal the significance of anoxic phosphorus removal. The results indicated that: The average removal efficiency of COD, NH4+, PO43-, and TN were 88.2%, 92.6%, 87.8%, and 73.1%, respectively, when the steady state of the pilot-scale A²/O OD plant was reached during 31-73 d, demonstrating a good denitrifying phosphorus removal performance. Phosphorus uptake took place in the anoxic zone by poly-phosphorus accumulating organisms NO2- could be used as electron receptors in denitrifying phosphorus removal, and the phosphorus uptake rate with NO2- as the electron receptor was higher than that with NO3- when the initial concentration of either NO2- or NO3- was 40 mg/L.     

培养基种类和培养条件对白腐真菌生长和产酶特性的影响

以白腐真菌(Phanerochaete chrysosporium)为研究对象,比较了该菌种在人工合成培养基和天然培养基中的生长和产酶特性,考察了竹子浸出液,pH,载体和抗生素等对白腐真菌在天然培养基中生长和产酶特性的影响.结果表明,天然培养基中白腐真菌的生物量、菌丝小球直径和木质素过氧化物酶(LiP)活性均大于人工培养基.以天然培养基为基础培养基,加入竹子浸出液可以促进白腐真菌的生长和提高木质素过氧化物酶活性;较低pH(4.5)条件下菌丝小球直径较小;载体的加入使得菌体以附着形式生长;抗生素两性霉素B对白腐真菌的生长和产酶的影响存在阈值,当ρ(两性霉素B)超过50　mg/L时,白腐真菌的生长和产酶受到明显的抑制.      

水解酸化-SBR工艺处理饮料生产废水

介绍了水解酸化+SBR工艺处理饮料生产废水的工艺设计和运行效果。该工艺具有处理效果好、低能耗、易管理等特点。在进水CODCr为2000～4000mg/L,BOD5为1000～2000mg/L的条件下,经过该系统处理,出水CODCr保持在130mg/L以下,BOD5保持在25mg/L以下,出水水质达到(GB8978-1996)《中华人民共和国国家标准污水综合排放标准》的Ⅱ级标准。     

螯合剂在重金属污染土壤修复中应用研究进展

螯合剂在重金属污染土壤修复中具有重要的作用.文章结合国内外的研究成果和最新研究进展,从螫合剂对重金属的活化效率及其影响因素、螯合剂在土壤中风险评价、生物可降解性螯合剂S,S-EDDS在化学淋洗修复和植物修复中的应用等几个方面论述了国内外螯合剂的研究现状,总结了在螯合剂应用研究中存在的问题,同时指出必须对螯合剂对重金属在土壤中的存在形态的影响以及螯合剂对矿物元素的作用,螯合剂与污染土壤组分作用的微观机理等进行深入的研究.     

Modelling tritrophic interactions mediated by induced defence volatiles

Many plant species defend themselves against herbivorous insects indirectly by producing and releasing induced volatiles to attract natural enemies of the herbivores. In this paper, we consider the recruitment of natural enemies attracted by plant-induced volatiles and introduce the An–Liu–Johnson–Lovett model into the Lotka–Volterra model in an attempt to add this missing vital link in tritrophic interaction. Increase in attraction strength of plant-induced volatiles to the natural enemy leads to high fluctuation amplitude of plant biomass and herbivore population. When the attack strength of natural enemies reaches a certain level, fluctuation amplitude of plant biomass and herbivore population will decrease and plant biomass will approach to its environmental carrying capacity. The simulation demonstrates that plant volatile compounds induced by insects have led to the introduction of a third tritrophic level, e.g., natural enemies, into the plant–herbivore system, resulting in the coexistence of plants, insects, and natural enemies during the evolution process.     

A fuzzy analytic hierarchy process (FAHP) approach to eco-environmental vulnerability assessment for the danjiangkou reservoir area,China

The Danjiangkou reservoir lies in the upper Hanjiang basin and is the source of water for the Middle Route Project (MRP) under the South-to-North Water Transfer Scheme (SNWT) in China. The eco-environment of water resource areas plays an important role in water conservation and purification and would have significant implications for the economic prosperity in Hanjiang basin as well as for the SNWT. Focusing on the Danjiangkou Reservoir Area (DRA), this study established an environmental information system database. Based on the database, an eco-environmental vulnerability assessment method using integrated fuzzy AHP (FAHP) and GIS was developed for the DRA. According to eco-environmental conditions and anthropic effects, vulnerability was classified into five levels: potential, light, medium, heavy and very heavy. The eco-environmental vulnerability distribution and major problems of the eco-environment were analysed and discussed. The results indicated that eco-environmental vulnerability in the DRA was moderate overall. Regions with lower eco-environmental vulnerability were located in Qinling Mountain area in the northwest, Daba Mountain area in the south and the area immediately surrounding Danjiangkou Reservoir in the east. Two regions with very high eco-environmental vulnerability were located in the north of Danjiangkou Reservoir in Henan province and in the western part of Shanxi province. On the basis of analysis of distribution of the different factors of eco-environmental vulnerability, different environmental protection measures were proposed for different areas. This study demonstrated that the proposed method was an effective approach for the assessment of environmental vulnerability. The results gained closely reflected the reality of the eco-environmental vulnerability of the DRA.     

煤中As赋存状态的逐级化学提取研究

应用５步法逐级化学提取研究了２个烟煤和３个无烟煤样品中微量Ａｓ（０．６６μｇ－５．２６μｇ／ｇ）的赋存状态,研究表明应用逐级化学提取方法可以有效地定量研究煤中微量Ａｓ的赋存状态;煤中Ａｓ含量较低时,Ａｓ仍然有多种赋存状态,当煤灰分（主要是粘土矿物）较低时主要是进入有机质中,当灰分较高时主要进入粘土的晶格。     

氯代芳香化合物的KOW与对数拓扑指数和路径指数的相关性

本文用１ｇＫｏｗ表征氯代芳香化合物的生物降解能力,并分别以对数拓扑指数（ＬＴＩ）和路径指数（ＰＩ）为自变量,建立了新的预测模型。结果表明,回归方程的预测值与实验值十分吻合,相关系数接近于１,平均标准偏差小于０．１。