扎兰屯市环保工作的几点做法

扎兰屯市十分重视环境保护事业的发展,特别是"十一五"期间,环境质量有了突破性改善。环保局以科学发展观为指导思想,认真梳理工作中的经验做法,存在问题。重点在污染减排、环境监管、环保投资、环保意识提高、建设项目管理、维护群众的合法权益等方面与各基层环保交流经验,寻求在突破,积极探索美丽与发展双赢的新道路。     

Environmental Implication of Intensive Farming Practices on North China Plain

Abstract

The current pressure on production resources of North China Plain, such as land and water to feed the growing population, necessitates the assessment of the sustainability of farming practices. This study focuses on the sustainability of farming practices related to groundwater and soil fertility management. The assessment is based on selected site-specific key indicators and their established threshold limits. The current farming practices in the study area are clearly unsustainable. Only about 6% of the surveyed farm households practice sustainable farming. The study stresses that farming practice, which is economically sustainable, should not be promoted at the cost of environment. Holistic strategies need to be developed and implemented that aim at balanced use of inputs, which satisfy both productivity and environmental concerns.     

A study on the dilemmas of resource utilization and tourism in Africa

This paper explores, explains and discusses issues around the dilemma between local conservation of natural resources (often, endangered species and habitats) and tourism needs in Africa. Often and in constitutional terms, local people have a right to exploit and use resources endowed in their local area. However, tourists often are interested in viewing the vegetation and animal resources undisturbed. Inevitably, there is an undeclared animosity of values and interests between local communities and tourists and state agencies. As a result, the dilemma is thus of governance. The purpose of this paper is to demonstrate the governance dilemma of resource utilization and tourism in Africa in a bid to create an informed stewardship framework for sustainability. This is achieved by way of case studies and narratives from Africa. As such, this paper will be a review literature on how different communities perceive tourism and derive livelihoods from their immediate environment. It also explains how the external factors influence local needs and interests. A more sustainable and operational framework that reduces friction among stakeholders is suggested.     

实践与供给：面向碳中和的需求侧解决方案

碳中和目标的提出,对中国经济系统各个层面的深刻变革提出要求。社会各界对此做出积极响应,但多以行业、技术等供给侧视角为主,需求侧减排方案未得到足够重视。中产阶级崛起和人口老龄化等社会变革,推动消费结构的转型和升级,也为碳中和目标的实现带来巨大挑战,我们亟须探索需求侧的解决方案。本文将消费行为置于社会实践的框架之中,较全面地识别了不同消费实践领域中潜在的碳减排措施。从实践与供给相结合的视角,发现我国现阶段需求侧碳减排主要面临减排实践庞杂且难管理、低碳供给不足、需求难以撬动供给变革和公众环境意识薄弱等困境和问题。最后,从构建指南、实践与供给联动、政策落地和社会规范引导文化建设等方面提出建议。     

Climate change and adoption of sustainable land management practices in the Niger basin of Benin

Due to the important role that the agricultural sector plays in sustaining growth and reducing poverty in developing countries, the adoption of practices that have the potential to simultaneously improve agricultural productivity while minimizing environmental impacts is essential. This paper examines the determinants of farmers’ perceptions of climate change and subsequent adoption of sustainable land management practices in the Niger basin of Benin. Binary and multivariate probit models are applied in a two‐stage regression procedure to cross‐sectional data collected through a survey of 545 randomly selected farm households in 28 villages. The findings indicate that there are substitutabilities among three pairs of sustainable land management practices being used by the farmers. Climate change perception is positively related to land tenure, experience in farming, number of relatives, tractor use, and membership in farmers’ organizations, and negatively related to household size, remoteness, and plough use. Moreover, the findings reveal that the uptake of land management practices is related to assets, land tenure, education level of the household head, remoteness, social network, non‐irrigated land size, having a farm located near a river/lake/stream, tractor and plough use, being a subsistence farmer or not, and memberships in farmers’ organizations. The adoption of sustainable land management practices could be encouraged through improving access to markets, adequate roads, and technologies, as well as by promoting membership in farmers’ organizations.     

Costs of forestry best management practices in the south: A review

In response to federal and state clean water laws, forestry best management practices (BMPs) have been developed and implemented to prevent nonpoint source water pollution. Ellefson and Miles (1985) found that estimated BMP costs in the Midwest could amount to more than half of the net returns on national forest timber sales. Henly et al. (1988) found that government costs to implement forest practice rules ranged from as little as $100,000 per year in Idaho and Nevada to more than $4 million annually in California. A review of studies in the South indicates that estimated BMP costs have increased over time. Lickwar et al. (1992) estimated Southeast average costs of $12.45 per acre, $2.34 per MBF, or 2.87% of gross stumpage values based on 1987 BMPs and prices. Woodman and Cubbage (1994) estimated Georgia average BMP costs of $24.33 per acre or $3.02 per MBF for forest industry lands and $41.65 per acre or $5.39 per MBF for NIPF lands. For Virginia, Shaffer et al. (1998) estimated median BMP costs of $18.90 per acre. These moderate cost increases could be attributed to a higher level of standards in the revision of each state BMP guidelines manual, as well as moderate price inflation. BMPs such as better road construction, water bars, culverts, and broad-based dips have been most expensive so far. To date streamside zones have not been very expensive because the rules allow most of the valuable residual tees to be harvested as long as heavy equipment does not operate near the streams. However, this limitation may become much more difficult and costly – as indicated by Kluender et al. (2000) – as fewer chainsaw fellers and cable skidders are available. Stricter BMPs, such as those already adopted to implement forest certification standards in the South or those used to protect salmon habitat in the West, could prompt more expensive southern BMPs for landowners and state agencies in the future.     

Nitrogen Removal by Stormwater Management Structures: A Data Synthesis

A comprehensive synthesis of data from empirically based published studies and a widely used stormwater best management practice (BMP) database were used to assess the variability in nitrogen (N) removal performance of urban stormwater ponds, wetlands, and swales and to identify factors that may explain this variability. While the data suggest that BMPs were generally effective on average, removal efficiencies of ammonium (NH₄), nitrate (NO₃), and total nitrogen (TN) were highly variable ranging from negative (i.e., BMPs acting as sources of N) to 100%. For example, removal of NO₃ varied from (median ±1 SD) ?15 ± 49% for dry ponds, 32 ± 120% for wet ponds, 58 ± 210% for wetlands, and 37 ± 29% for swales. Across the same BMP types, TN removal was 27 ± 24%, 40 ± 31%, 61 ± 30%, and 50 ± 29%. NH₄ removal was 9 ± 36%, 29 ± 72%, 31 ± 24%, and 45 ± 34%. BMP size, age, and location explained some of the variability. For example, small and shallow ponds and wetlands were more effective than larger, deeper ones in removing N. Despite well‐known intra‐annual variation in N fluxes, most measurements have been made over short time periods using concentrations, not flow‐weighted N fluxes. Urban N export is increasing in some areas as large storms become more frequent. Thus, accounting for the full range of BMP performance under such conditions is crucial. A select number of long‐term flux‐based BMP studies that rigorously measure rainfall, hydrology, and site conditions could improve BMP implementation.     

Streamside Forest Buffer Width Needed to Protect Stream Water Quality,Habitat, and Organisms: A Literature Review

This literature review addresses how wide a streamside forest buffer needs to be to protect water quality, habitat, and biota for small streams (≤~100 km² or ~5th order watershed) with a focus on eight functions: (1) subsurface nitrate removal varied inversely with subsurface water flux and for sites with water flux >50 l/m/day (~40% avg base flow to Chesapeake Bay) median removal efficiency was 55% (26‐64%) for buffers <40 m wide and 89% (27‐99%) for buffers >40 m wide; (2) sediment trapping was ~65 and ~85% for a 10‐ and 30‐m buffer, respectively, based on streamside field or experimentally loaded sites; (3) stream channel width was significantly wider when bordered by ~25‐m buffer (relative to no forest) with no additional widening for buffers ≥25 m; (4) channel meandering and bank erosion were lower in forest but more studies are needed to determine the effect of buffer width; (5) temperature remained within 2°C of levels in a fully forested watershed with a buffer ≥20 m but full protection against thermal change requires buffers ≥30 m; (6) large woody debris (LWD) has been poorly studied but we infer a buffer width equal to the height of mature streamside trees (~30 m) can provide natural input levels; (7, 8) macroinvertebrate and fish communities, and their instream habitat, remain near a natural or semi‐natural state when buffered by ≥30 m of forest. Overall, buffers ≥30 m wide are needed to protect the physical, chemical, and biological integrity of small streams.     

Field test of best management practice pollutant removal efficiencies in Shenzhen, China

This paper presents a study on the use of best management practices (BMPs) for controlling nonpoint pollution in the Xikeng Reservoir watershed located in Shenzhen, China. A BMP treatment train design, including a pond, a wetland, and a buffer strip placed in series was implemented at the reservoir location. A separate grass swale was also constructed at the site. Low impact development (LID) BMPs, namely a planter box and bioboxes, were used at the parking lot of the reservoir’s Administration Building. Samples were collected during storm events and were analyzed for total suspended solids (TSS), biochemical oxygen demand (BOD₅), ammonia nitrogen (NH₃—N), and total phosphorus (TP). The removal efficiencies of both BMP systems were evaluated using the Efficiency Ratio (ER) method based on the event mean concentration (EMC) data. In summary, the pond/wetland treatment train removed 70%―90% of TSS, 20%―50% of BOD₅, and 30%―70% of TP and NH₃—N. The swale removed 50%―90% of TSS, 30%―55% of BOD₅, −10%―35% of NH₃—N, and 25%―70% of TP. For the planter box and biobox, the ranges of removal rates were 70%―90%, 20%―50%, and 30%―70% for TSS, BOD₅, and ammonia and phosphorus, respectively.     

Influence of varying nutrient and pesticide mixtures on abatement efficiency using a vegetated free water surface constructed wetland mesocosm

The nutrient and pesticide abatement efficiency of varying mixtures was examined in a vegetated free water surface constructed wetland. Three different agricultural chemical pollutant mixture conditions were assessed: nutrients only (N and P); pesticides only (atrazine, S-metolachlor and permethrin); and a mixture of nutrients and pesticides. With nutrients only, 672 h nutrient mitigation of 77–91% total phosphorous (TP) and 74–98% total nitrogen (TN) was associated with distance from the injection point and rainfall, whereas with nutrient and pesticide mixtures, 672 h nutrient mitigation of 11–71% TP and 84–98% TN were associated with distance and time. With pesticides only, 672 h pesticide mitigation of 50–99% was associated with distance and time, whereas with nutrients and pesticide mixtures, 672 h pesticide mitigation of 48–99% was associated primarily with distance. Dissipation half-lives were 2–10 times greater for P and 1.5–5 times greater for N when pesticides were present. Pesticide dissipation half-lives showed no clear differences with or without nutrients. While vegetated free water surface constructed wetlands can be effective best management practice tools to trap and abate agricultural run-off during rainfall events, efficiencies can be affected by different types of complex pollutant mixtures and wetland design and implementation should accommodate varying efficiencies.