How the DPSIR framework can be used for structuring problems and facilitating empirical research in coastal systems

As pressures on coastal zones mount, there is a growing need for frameworks that can be used to conceptualize complex sustainability challenges and help organize research that increases understand about interacting ecological and societal processes, predicts change, and supports the management, persistence, and resilience of coastal systems. The Driver–Pressure–State–Impact–Response (DPSIR) framework is one such approach that has been adopted in some coastal zones around the world. Although the application of the DPSIR framework has considerable potential to bridge the gap between scientific disciplines and link science to coastal policy and management, current applications of DPSIR in coastal environments have been limited and new innovations in the application of the DPSIR model are needed. We conducted a structured review of literature on the DPSIR framework as applied to the function, process and components of complex coastal systems. Our specific focus was on how the DPSIR framework has been used as a tool to organize sophisticated empirical scientific research, support transdisciplinary knowledge at a level appropriate for building understanding about coastal systems, and how adopting a DPSIR approach can help stakeholders to articulate and structure challenges in coastal systems and use the framework to support policy and management outcomes. The review revealed that DPSIR models of coastal systems have been largely used to support and develop conceptual understanding of coastal social–ecological systems and to identify drivers and pressures in the coastal realm. A limited number of studies have used DPSIR as a starting point for semi-quantitative or quantitative analyses, although our review highlights the continued need for, and potential of, transformative quantitative analyses and transdisciplinary applications of the DPSIR framework. The DPSIR models we reviewed were predominantly single sector, encompassing ecological or biophysical factors or focusing primarily on socio-cultural dimensions rather than full integration of both types of information. Only in eight of 24 shortlisted articles did researchers actively engage decision-makers or citizens in their research: given the potential opportunity for using DPSIR as a tool to successfully engage policy-makers and stakeholders, it appears that the DPSIR framework has been under-utilized in this regard.     

Determination of pendimethalin (PROWL®480 EC) spray drift from ground applications

Abstract

Pendimethalin herbicide (PROWL^®480 EC) spray drift was determined from ground applications representing the highest rate applied to corn in eastern Canada. A novel drift collector pattern was laid out on the ground immediately before herbicide application. Most of the drift collectors were located downwind of the application target area. The maximum labelled rate of 1.68 kg ai/Ha was applied on 2 occasions on separate sites. In both applications, drift collector cards indicated that concentrations of pendimethalin were not detectable outside the target zone (<0.01 μg/cm²) at or beyond the 10 metre drift collector stations. Risk assessment calculations indicated that non‐target organisms would not be at significant risk from off‐site movement of pendimethalin.     

Evaluating long-term urban resilience through an examination of the history of green spaces in Tokyo

Long-term urban resilience requires urban systems with the capacity to respond to change and disturbance and to enhance the conditions for lasting wellbeing. Over the past century Tokyo has demonstrated impressive resilience, especially a capacity to reorganise and rebuild in response to successive major disturbances. Throughout these recoveries, the city-region maintained a focus on re-establishing, improving and maintaining international competitiveness through industrial development. Green spaces in Tokyo provided a flexible, but gradually disappearing resource. Today, to meet the needs of its ageing and minimally expanding population for enhanced wellbeing, Tokyo requires active transition planning covering many intertwined factors, but the adaptive capacity provided by the green space resource is no longer available. The Tokyo case underscores the risk inherent in the depletion of non-renewable resources (in this instance, green space) to secure immediate recovery and accommodate growth and short-term resilience at the expense of long-term resilience.     

采空区瓦斯涌出源位置对瓦斯浓度及自燃带分布的影响

利用Fluent软件,对采空区瓦斯为采空区整个区域涌出和上、下临近层及底板遗煤处同时涌出两种情况下的流场进行了数值模拟,并分析了采空区瓦斯体积分数及自燃带分布规律。结果表明:当采空区整个区域瓦斯涌出时,采空区瓦斯体积分数由底板到顶板垂直方向上呈逐渐升高的趋势;当上、下临近层及底板遗煤处瓦斯同时涌出时,采空区瓦斯体积分数在靠近底板和顶板位置处较高,中间区域处较低。与采空区整个区域瓦斯涌出相比,当上、下临近层及底板遗煤处瓦斯同时涌出时,在采空区底板处,自燃带更靠近工作面;在采空区底板和顶板中间位置处,自燃带远离工作面;在采空区顶板处,自燃带位置几乎没有变化。     

Geomorphic and Ecological Consequences of Riprap Placement in River Systems

Riprap, consisting of large boulders or concrete blocks, is extensively used to stabilize streambanks and to inhibit lateral erosion of rivers, yet its effect on river morphology and its ecological consequences have been relatively little studied. In this paper, we review the available information, most of it culled from the “grey” literature. We use a simple one‐dimensional morphodynamic model as a conceptual tool to illustrate potential morphological effects of riprap placement in a gravel‐bed river, which include inhibition of local sediment supply to the channel and consequent channel bed scour and substrate coarsening, and downstream erosion. Riprap placement also tends to sever organic material input from the riparian zone, with loss of shade, wood input, and input of finer organic material. Available information on the consequences for the aquatic ecosystem mainly concerns effects on commercially and recreationally important fishes. The preponderance of studies report unfavorable effects on local numbers, but habitat niches created by openings in riprap can favorably affect invertebrates and some small fishes. There is a need for much more research on both morphological and ecosystem effects of riprap placement.     

春季沙尘过程对华东高山背景区域颗粒物中水溶性无机离子的影响

于2014年3—5月在国家大气背景监测福建武夷山站采集了PM2.5及PM2.5~10样品,利用离子色谱对其中的水溶性组分进行分析,并同步收集气象因子及污染物质量浓度数据,结合后向气流轨迹,分离出受沙尘影响的样品,探讨了春季沙尘过程华东高山背景区域颗粒物中水溶性组分的特征.结果表明,春季武夷山背景点沙尘影响期间颗粒物质量浓度及各水溶性离子浓度均比非沙尘期高,在粗粒子中表现更为明显;沙尘期间NO-3在粗粒子中明显富集,NO-3浓度显著升高;受沙尘影响,粗粒子中阳离子与阴离子的当量浓度比及NO2的二次转化率均明显升高.     

柠檬酸对三峡水库消落区土壤中汞活化及甲基化的影响

利用室内模拟实验,用不同浓度柠檬酸溶液分别浸提和培养土壤,探讨了植被根系分泌物的主要成分柠檬酸对三峡库区消落带土壤中汞活化及甲基化的影响.结果表明,添加柠檬酸后浸提液中汞含量在达到最高值之前均高于对照组(0 mmol·L~(-1)),且随柠檬酸浓度的增加而增大.0、1、2、4、5、6、8 mmol·L~(-1)浓度下最大汞溶出量随柠檬酸浓度的增加先增大而后保持稳定,分别占供试土壤总汞的1.03%、1.67%、1.99%、2.47%、2.68%、2.73%、2.73%.培养实验中,土壤甲基汞(Me Hg)含量在前3 h内基本维持稳定,随后除对照组增加缓慢外,其余组均开始上升,且上升速率随柠檬酸浓度的升高而增大.在同一培养时段内,土壤Me Hg含量及增加量随柠檬酸浓度的升高而增大.表明柠檬酸对土壤中无机汞向甲基汞的转化过程有一定的促进作用,且促进作用随着柠檬酸浓度的增加而愈加显著.     

季节性温度升高对落干期消落带土壤氮矿化影响

为揭示季节性温度升高对消落带落干期土壤氮矿化的影响,分别采集三峡支流澎溪河消落带上游和下游两个水文断面,155 m(低)、165 m(中)和175 m(高)这3个水位高程表层土壤,结合落干期气温变化特点,在25℃和35℃两个温度下进行恒温培养.结果表明,消落带土壤总氮和硝态氮在上游断面和高水位高程含量更高,而下游和低水位高程含量更低,铵态氮分布与其相反.硝态氮是无机氮的主要存在形式,占无机氮的57.4%~84.7%.相同培养温度下,氨化、硝化、净氮矿化速率均表现为随水位高程增加,随流域断面由下至上而显著增加(P0.05);总体上,在水位高程和流域断面上均表现为:温度升高使硝化速率和净氮矿化速率显著增加(P0.05),而对土壤氨化速率无显著影响(P0.05).     

含油污水海洋处置的混合区范围界定探讨

本文建立深度平均二维对流扩散模型进行含油污水排海的浓度场数值模拟,根据各时刻的最高瞬时浓度,得出了远区混合区的范围.利用验证良好的水动力模型的计算结果,Cormix模型选择最小的潮流流速,计算了近区混合区范围,并在计算机控制的潮汐流动水槽中进行了系统的排污试验,计算结果与试验值符合性良好.结合远区和近区模型的模拟结果,最终确定了混合区的位置、范围,为含油污水排海工程的混合区范围确定提供了一种较为高效、实用的解决途径.     

三峡库区香溪河消落带及库岸土壤重金属迁移特征及来源分析

在测定香溪河消落带(海拔145~175 m)和库岸(海拔175~185 m)土壤重金属含量的基础上,分析重金属的迁移特征,运用地累积指数进行污染评价,同时采用因子分析-多元线性回归(FA-MLR)分析重金属的来源和各来源的贡献比率.结果表明,2012年落干时段内(6~9月),香溪河库岸上层和下层土壤重金属含量都在减少,消落带重金属含量上层土壤减少,下层土壤增多;库岸重金属向消落带迁移,消落带重金属向下层积累.重金属污染级别是Cd>Pb>Cu>Cr,主要风险元素为Cd,各重金属污染程度评价等级都在中等以下.FA-MLR分析表明,消落带75.60%的Pb来源于交通运输,62.03%的Cd来源于农业,64.71%的Cu和75.36%的Cr来源于天然矿石.在库岸,82.26%的Pb来源于交通运输,68.63%的Cd来源于农业,65.72%的Cu和69.33%的Cr来源于天然矿石.FA-MLR成功地模拟了香溪河消落带和库岸土壤重金属的来源,并给出各来源的贡献率;同时揭示了重金属的迁移特征,能为香溪河流域重金属污染防治提供有益参考.