Compensatory Mitigation for Streams Under the Clean Water Act: Reassessing Science and Redirecting Policy1

Doyle, Martin W. and F. Douglas Shields, 2012. Compensatory Mitigation for Streams Under the Clean Water Act: Reassessing Science and Redirecting Policy. Journal of the American Water Resources Association (JAWRA) 48(3): 494-509. DOI: 10.1111/j.1752-1688.2011.00631.x Abstract: Current stream restoration science is not adequate to assume high rates of success in recovering ecosystem functional integrity. The physical scale of most stream restoration projects is insufficient because watershed land use controls ambient water quality and hydrology, and land use surrounding many restoration projects at the time of their construction, or in the future, do not provide sufficient conditions for functional integrity recovery. Reach scale channel restoration or modification has limited benefits within the broader landscape context. Physical habitat variables are often the basis for indicating success, but are now increasingly seen as poor surrogates for actual biological function; the assumption “if you build it they will come” lacks support of empirical studies. If stream restoration is to play a continued role in compensatory mitigation under the United States Clean Water Act, then significant policy changes are needed to adapt to the limitations of restoration science and the social environment under which most projects are constructed. When used for compensatory mitigation, stream restoration should be held to effectiveness standards for actual and measurable physical, chemical, or biological functional improvement. To achieve improved mitigation results, greater flexibility may be required for the location and funding of restoration projects, the size of projects, and the restoration process itself.     

Economic Development,Rural livelihoods,and Ecological Restoration: Evidence from China

This article uses a case study in Southeast China to demonstrate how the substantial changes in rural livelihoods have been driven by a combination of “pull” forces from external economic development, and “push” forces from local areas, leading to a shift in rural household economic activities: household outmigration and de-population of the countryside, changes in energy consumption, and most importantly, changes in land uses and eventually, ecological restoration. Such dramatic changes are becoming common across the Chinese countryside. It is pointed out that economic development has generally caused a deterioration of the environment at least at the early period of economic growth, but the positive impacts, especially in some ecosystem in rural areas, have become more apparent.     

丙溴磷在稻田环境中的残留动态研究

确立了气相色谱法测定丙溴磷残留量的检测方法.采用该方法,丙溴磷在土壤、植株、糙米、稻壳和田水中的平均添加回收率为87.2％～103.6％,变异系数为3.20％～11.50％,最低检测质量浓度:田水为0.005 mg/kg;土壤、植株、糙米和稻壳为0.050 mg/kg.残留动态研究表明,丙溴磷在田水、植株和土壤中的半衰...     

镇江滨江带湿地修复对浮游生物群落结构的影响

在镇江滨江带50 m×50 m的开放性湿地内进行实验,通过构建高位湿地、架设植物浮巢来改善滨江带湿地生境梯度和生境异质性,营造适宜各类士著动植物生长发育的湿地环境,从而达到增强生态系统延展性及增加生物多样性的目的.结果表明,高位湿地的构建、植物浮巢的架设等生态修复措施对提高研究区浮游植物、浮游动物群落的生物多样性有着显...     

Constructing an Interdisciplinary Flow Regime Recommendation1

Bartholow, John M., 2010. Constructing an Interdisciplinary Flow Regime Recommendation. Journal of the American Water Resources Association (JAWRA) 1-15. DOI: 10.1111/j.1752-1688.2010.00461.x Abstract: It is generally agreed that river rehabilitation most often relies on restoring a more natural flow regime, but credibly defining the desired regime can be problematic. I combined four distinct methods to develop and refine month-by-month and event-based flow recommendations to protect and partially restore the ecological integrity of the Cache la Poudre River through Fort Collins, Colorado. A statistical hydrologic approach was used to summarize the river’s natural flow regime and set provisional monthly flow targets at levels that were historically exceeded 75% of the time. These preliminary monthly targets were supplemented using results from three Poudre-specific disciplinary studies. A substrate maintenance flow model was used to better define the high flows needed to flush accumulated sediment from the river’s channel and help sustain the riparian zone in this snowmelt-dominated river. A hydraulic/habitat model and a water temperature model were both used to better define the minimum flows necessary to maintain a thriving cool water fishery. The result is a range of recommended monthly flows and daily flow guidance illustrating the advantage of combining a wide range of available disciplinary information, supplemented by judgment based on ecological principles and a general understanding of river ecosystems, in a highly altered, working river.     

Hydrological regime and salinity alter the bioavailability of Cu and Zn in wetlands

In the context of the European Water Framework Directive, controlled flooding of lowlands is considered as a potential water management strategy to minimise the risk of flooding of inhabited areas. However, due to historical pollution and overbank sedimentation, metal levels are elevated in most wetlands, which can cause adverse effects on the ecosystem's dynamics. Additionally, salinity affects the bioavailability of metals present or imported into these systems. The effect of different flooding regimes and salinity exposure scenarios (fresh- and brackish water conditions) on Cu and Zn accumulation in the oligochaete Tubifex tubifex (Müller, 1774) was examined. Metal mobility was closely linked to redox potential, which is directly related to the prevalent hydrological regime. Flooded, and thus more reduced, conditions minimized the availability of metals, while oxidation of the substrates during a drier period was associated with a rapid increase of metal availability and accumulation in the oligochaetes.     

Environmental restoration of invaded ecosystems: How much versus how often?

This paper derives the optimal level of restorative efforts required to restore environments degraded by invasive species invasion. Specific attention is focused on a case when restoration faces the risk of failure through relapse of the restored environment caused by repeat invasions. The level of restored environment may also play a role in its future improvement or susceptibility to failure. The tradeoff between the optimal level of environmental quality and number of restorative efforts required to attain that given environmental quality is highlighted.     

Generating sustainable towns from Chinese villages: a system modeling approach

The great majority of China's developing towns will be extensions of already existing villages. With the prospect of hundreds of millions of Chinese farmers projected to leave their villages to become industrial workers in new and expanded towns within the next few years, new challenges will be faced. As expansion and modernization progress, this development moves from the traditional village model that operates not far from resource sustainability to increasingly unsustainable patterns of commerce, urban development, and modern life. With such an unprecedented mass migration and transformation, how can Chinese culture survive? What is to become of the existing million plus agricultural villages? How can these massively unsustainable new industrial towns survive? In the European Commission sponsored research program SUCCESS, researchers worked from the scale of the Chinese village to find viable answers to these questions.     

磐石市矿山生态环境现状与恢复治理对策

磐石市矿山生态环境问题日益突出,主要是矿山"三废"排放污染生态环境,侵占土地和农田,严重影响了矿山经济的可持续发展.矿山生态环境恢复治理要坚持"在开发中保护,在保护中开发"和"谁开发,谁保护;谁污染,谁治理;谁破坏,谁恢复"的原则,多渠道增加复垦资金,建立监督管理新机制,依靠科技进步提高环境保护水平.     

电缆隧道火灾数值仿真及分析

电缆隧道灭火以及人员疏散的关键,在于对灾变条件下隧道火灾参数变化的正确预测,特别是火焰、烟气蔓延范围,烟气浓度变化以及有毒气体的扩散范围等参数的预测。为了获得电缆隧道火灾参数,应用美国国家标准和技术研究院(NIST)开发的FDS(Fire Dynam ics Simulator)软件,建立电缆隧道模型,对隧道火灾进行全尺寸模拟,通过对模拟实验数据处理和分析,给出电缆隧道火灾时烟气浓度和氧气浓度,纵向温度的变化规律,火焰蔓延情况以及高温烟气在隧道中水平蔓延规律,为有效救援和紧急疏散以及消防决策提供一定依据。