Reach‐Scale Geomorphic and Biological Effects of Localized Streambank Armoring

Armoring of streambanks is a common management response to perceived threats to adjacent infrastructure from flooding or erosion. Despite their pervasiveness, effects of reach‐scale bank armoring have received less attention than those of channelization or watershed‐scale hydromodification. In this study, we explored mechanistic ecosystem responses to armoring by comparing conditions upstream, within, and downstream of six stream reaches with bank armoring in Southern California. Assessments were based on four common stream‐channel assessment methods: (1) traditional geomorphic measures, (2) the California Rapid Assessment Method for wetlands, (3) bioassessment with benthic macroinvertebrates, and (4) bioassessment with stream algae. Although physical responses varied among stream types (mountain, transitional, and lowland), armored segments generally had lower slopes, more and deeper pools and fewer riffles, and increased sediment deposition. Several armored segments exhibited channel incision and bank toe failure. All classes of biological indicators showed subtle, mechanistic responses to physical changes. However, extreme heterogeneity among sites, the presence of catchment‐scale disturbances, and low sample size made it difficult to ascribe observed patterns solely to channel armoring. The data suggest that species‐level or functional group‐level metrics may be more sensitive tools than integrative indices of biotic integrity to local‐scale effects.     

战略环境评价在内蒙古“十一五”规划中的应用——以水环境为例

实施战略环境评价（SEA）,充分考虑战略的环境影响是全面落实我国可持续发展战略的前提和重要保证。内蒙古“十一五”规划SEA实现了真正意义上的战略环评。本文以水环境为例,运用情景分析法、压力分析法探讨了战略环境评价水环境压力的变化。引进容量承压度的概念,分析了内蒙古自治区经过“十一五”5年的发展重点区域水环境容量承压度的变化。计算结果表明,与2004年水环境压力相比,内蒙古“十一五”规划重点发展区域氨氮压力增大,COD压力变化较小。根据压力变化提出了水环境影响减缓措施。     

Will progress in science and technology avert or accelerate global collapse? A critical analysis and policy recommendations

Industrial society will move towards collapse if its total environmental impact (I), expressed either in terms of energy and materials use or in terms of pollution, increases with time, i.e., dI/dt > 0. The traditional interpretation of the I = PAT equation reflects the optimistic belief that technological innovation, particularly improvements in eco-efficiency, will significantly reduce the technology (T) factor, and thereby result in a corresponding decline in impact (I). Unfortunately, this interpretation of the I = PAT equation ignores the effects of technological change on the other two factors: population (P) and per capita affluence (A). A more heuristic formulation of this equation is I = P(T)·A(T)·T in which the dependence of P and A on T is apparent. From historical evidence, it is clear that technological revolutions (tool-making, agricultural, and industrial) have been the primary driving forces behind successive population explosions, and that modern communication and transportation technologies have been employed to transform a large proportion of the world’s inhabitants into consumers of material- and energy-intensive products and services. In addition, factor analysis from neoclassical growth theory and the rebound effect provide evidence that science and technology have played a key role in contributing to rising living standards. While technological change has thus contributed to significant increases in both P and A, it has at the same time brought about considerable eco-efficiency improvements. Unfortunately, reductions in the T-factor have generally not been sufficiently rapid to compensate for the simultaneous increases in both P and A. As a result, total impact, in terms of energy production, mineral extraction, land-use and CO₂ emissions, has in most cases increased with time, indicating that industrial society is nevertheless moving towards collapse. The belief that continued and even accelerated scientific research and technological innovation will automatically result in sustainability and avert collapse is at best mistaken. Innovations in science and technology will be necessary but alone will be insufficient for sustainability. Consequently, what is most needed are specific policies designed to decrease total impact, such as (a) halting population growth via effective population stabilization plans and better access to birth control methods, (b) reducing total matter-energy throughput and pollution by removing perverse subsidies, imposing regulations that limit waste discharges and the depletion of non-renewable resources, and implementing ecological tax reform, and (c) moving towards a steady-state economy in which per-capita affluence is stabilized at lower levels by replacing wasteful conspicuous material consumption with social alternatives known to enhance subjective well-being. While science and technology must play an important role in the implementation of these policies, none will be enacted without a fundamental change in society’s dominant values of growth and exploitation. Thus, value change is the most important prerequisite for avoiding global collapse.

Integrating soil carbon cycling with that of nitrogen and phosphorus in the watershed model SWAT: Theory and model testing

In this paper we describe and test a sub-model that integrates the cycling of carbon (C), nitrogen (N) and phosphorus (P) in the Soil Water Assessment Tool (SWAT) watershed model. The core of the sub-model is a multi-layer, one-pool soil organic carbon (S_C) algorithm, in which the decomposition rate of S_C and input rate to S_C (through decomposition and humification of residues) depend on the current size of S_C. The organic N and P fluxes are coupled to that of C and depend on the available mineral N and P, and the C:N and N:P ratios of the decomposing pools. Tillage explicitly affects the soil organic matter turnover rate through tool-specific coefficients. Unlike most models, the turnover of soil organic matter does not follow first order kinetics. Each soil layer has a specific maximum capacity to accumulate C or C saturation (S_x) that depends on texture and controls the turnover rate. It is shown in an analytical solution that S_x is a parameter with major influence in the model C dynamics. Testing with a 65-yr data set from the dryland wheat growing region in Oregon shows that the model adequately simulates the S_C dynamics in the topsoil (top 0.3 m) for three different treatments. Three key model parameters, the optimal decomposition and humification rates and a factor controlling the effect of soil moisture and temperature on the decomposition rate, showed low uncertainty as determined by generalized likelihood uncertainty estimation. Nonetheless, the parameter set that provided accurate simulations in the topsoil tended to overestimate S_C in the subsoil, suggesting that a mechanism that expresses at depth might not be represented in the current sub-model structure. The explicit integration of C, N, and P fluxes allows for a more cohesive simulation of nutrient cycling in the SWAT model. The sub-model has to be tested in forestland and rangeland in addition to agricultural land, and in diverse soils with extreme properties such high or low pH, an organic horizon, or volcanic soils.     

生态市建设的战略环境影响评价初探——以淮南市为例

生态市建设是一项系统工程，是实现可持续发展的必然途径。通过对战略环境影响评价理论、方法的探讨，开发出了针对生态市建设的战略环境影响评价技术框架，并以淮南市为例，构建了一套完整的战略环境影响评价指标体系。最后分析了淮南生态市建设SEIA的主要内容：土地利用规划、产业政策结构调整以及各项战略的环境影响评价，为生态市建设SEIA提供方法和技术支持。     

环境影响评价中公众参与的机制与有效性

公众参与是环境影响评价中的重要内容。从公众参与的定义、目标和作用入手，就环境影响评价中公众参与的作用机制及其有效性进行探讨，认为：广泛的公众代表性、有效的公众参与形式以及公众意见的如实反映和客观分析，都是增进环境影响评价中公众参与的机制有效性的重要因素。     

建立我国战略环境评价理论与方法体系

战略环境评价是环境影响评价在战略层次上的应用，是具体落实可持续发展战略的重要工具。在分析其现实意义的基础上，提出我国战略环境评价理论与方法体系的主要研究内容，就建立我国战略环境评价理论与方法提出建议。     

沙漠化灾害危险度评价的初步研究

沙漠化是全球重大灾害之一,本文从我国实际出发,根据沙漠化灾害危险度评价研究的基本内容,提出了沙漠化灾害危险度评价因子系统并作出了四级量化划分,首次提出了沙漠化灾害危险度定量评价的标准与方法,并进行了实例应用和验证.     

Finding Hope in the Millennium Ecosystem Assessment

Abstract:  Over the past quarter century, a new scientific activity has emerged: collective assessments by large numbers of scientists from different disciplines combining their expertise to better understand human interrelations with nature and to inform policy. The Millennium Ecosystem Assessment exceeded all such assessments before it in both the breadth of its coverage and the depth of its analysis of socioecological system dynamics. The findings are not encouraging. Nearly all ecosystems are being degraded and will continue to be degraded for decades to come even if policy changes are initiated now. For scientists participating in the assessment, the MA had another disconcerting aspect. It clearly shows that our fragmented, disciplinary knowledges cannot simply be combined to form an understanding of a whole complex system. Counterbalancing the despair of the findings and scientific difficulties of aggregating specialized knowledges, the MA demonstrated the potential of a deliberative democratic approach to grappling with complex problems .     

Assessment of <Emphasis Type="Italic">Gmelina arborea</Emphasis> sawdust–cement-bonded rainwater storage tank

The performance of a mixture of a forest bye product and cement for the production of storage structure for harvested rainwater was assessed. Three mix ratios of Cement: Gmelina arborea sawdust 3.0:1.0 (specimen A), 2.5:1.0 (specimen B) and 2.0:1.0 (specimen C) were considered. Engineering properties and dimensional stability of the different mix-ratios were monitored from prototypes cylindrical pots and test billet specimens. Possible change in quality of stored rainwater, with time was monitored in all the three cases. Water quality parameters monitored include pH, hardness, total suspended solids, alkalinity, acidity and total dissolved CO₂. The tensile stress obtained were 110, 104, and 95 N/mm², while the compressive strength were 5,000, 3,000, and 2,000 kN for specimens A, B and C respectively. Accelerated aging test showed that sample A were more resistant to deformation, while specimen C were more susceptible to change in structure over time. Similarly, the values of tensile and compressive strength after accelerated aging test increased in the order of specimen A > B > C. Except in specimen C where significant differences in alkalinity and acidity were observed, there were no significant differences in quality of the water stored in the pots after 2 months of storage. The results indicate the suitability of the Gmelina arborea waste as an alternative in constructing water storage structures in rural communities.