测定天文大气折射和建立电磁波折射延迟实测模型(Ⅵ)-瞬时大气折射值和折射率差的取得

根据测定天文大气折射的原理,叙述了利用相应的观测值获得瞬时大气折射测定值和建立大气折射实测模型的途径,并从各种测定值与最后结果之间的关系,指出了这里对数据处理的要求;文章介绍了对测定值进行波长改正和建立折射延迟实测模型的处理方法,分析了改正模型对天文大气折射测定值的分布要求,给出了观测数据随天顶距的增大而加密的分布模型。     

嵌入式软件覆盖测试的研究

在实际应用中覆盖测试分析采用测量方法的多样性决定了代码插装需要识别程序结构特征的复杂性。结合编译原理的中间代码优化理论，针对汇编语言开发的嵌入式软件，提出了划分基本块，构造程序流图来分析汇编源程序的结构的算法模型，并讨论了覆盖测试的方法及原理。     

Streamflow response to Pinus plantation harvesting: Canobolas State forest,southeastern Australia

Streamflows were measured in two Pinus radiata plantation catchments and one native eucalypt forest catchment in Canobolas State forest from 1999 to 2007. In 2002/2003, clearfall harvesting of 43·2 and 40·3% of two plantation catchments occurred, respectively. Water yields increased by 54 mm (52%), 71 mm (35%) and 50 mm (19%) in the first three years post‐harvest in treated catchment A and by 103 mm (118%), 157 mm (82%) and 119 mm (48%) in treated catchment B relative to the native forest control catchment. In the fourth post‐harvest water year annual rainfall was only 488 mm, which resulted in negligible run‐off in all catchments, regardless of forest cover. In both plantation catchments, monthly streamflows increased significantly (p = 0·01, p < 0·001) due to a significant increase in baseflows (p < 0·001) after harvesting. Monthly stormflows were not significantly affected by harvesting. Flow duration curve analyses indicated a variable response between the two plantation catchments. Treated catchment A was converted from an ephemeral stream flowing 42% of the time pre‐harvest to a temporary stream flowing 82% of the time post‐harvest. These changes occurred throughout all seasons of the year but were most pronounced during summer and autumn when baseflows were maintained post‐harvest but were not observed under native forest or mature pine plantations. By contrast, flow duration increased in treated catchment B from 12% of the time pre‐harvest to 38% of the time post‐harvest with the greatest changes measured during the winter and spring months when streamflow would normally occur under native forest conditions. These observations have important implications for the development of models of plantation water use to be utilized in water resource planning in Australia. Copyright © 2009 John Wiley & Sons, Ltd.     

Integrating national forestry initiatives in India with international climate change policy

Policy initiatives in India, such as the Social Forestry Program and later the Joint Forest Management, were introduced for their co-benefits, including forest protection, employment opportunities, and added income for communities living in and around the forests. The evolution of these forest policies is critically reviewed. It is argued that India is perfectly positioned to benefit from climate change mitigation efforts, due to a rich, albeit chequered, history in forest management. National forestry policies are examined to assess how they can complement international climate change mitigation instruments, such as the Clean Development Mechanism (CDM) and the more recent Reduced Emissions from Deforestation and Forest Degradation (REDD or REDD+ with conservation, sustainable management of forests, and enhancement of forest carbon stocks) and aid national sustainable development objectives. There is a need to heed the experiences from India's evolving forest policies, particularly those concerning land tenure and resource rights, which lack specificity within international mechanisms. The active engagement of rural communities must be integral to any programmes that make any claim to development and to environmental integrity as a whole.

Policy relevance

India's forestry programmes are examined for their effectiveness in informing international initiatives such as the CDM and REDD+. Forestry policies in India can evolve to complement international climate mitigation tools. By examining current and historical forest legislation, and their subsequent impacts, it is shown how communities can sustain their system of forest management and retain/obtain rights to land and resources under the CDM and REDD+. Looking for such synergies within existing national policies to implement newer international initiatives can greatly facilitate and increase the momentum of global environmental change.     

Finding a path for REDD+ between ODA and the CDM

Abstract

Strategies to mitigate anthropogenic climate change recognize that carbon sequestration in the terrestrial biosphere can reduce the build-up of carbon dioxide in the Earth's atmosphere. However, climate mitigation policies do not generally incorporate the effects of these changes in the land surface on the surface albedo, the fluxes of sensible and latent heat to the atmosphere, and the distribution of energy within the climate system. Changes in these components of the surface energy budget can affect the local, regional, and global climate. Given the goal of mitigating climate change, it is important to consider all of the effects of changes in terrestrial vegetation and to work toward a better understanding of the full climate system. Acknowledging the importance of land surface change as a component of climate change makes it more challenging to create a system of credits and debits wherein emission or sequestration of carbon in the biosphere is equated with emission of carbon from fossil fuels. Recognition of the complexity of human-caused changes in climate does not, however, weaken the importance of actions that would seek to minimize our disturbance of the Earth's environmental system and that would reduce societal and ecological vulnerability to environmental change and variability.

© 2003 Elsevier Science Ltd. All rights reserved.     

Piecemeal or combined? Assessing greenhouse gas mitigation spillovers in US forest and agriculture policy portfolios

ABSTRACT

Forest and agricultural sector response to comprehensive climate policy is well represented in the literature. Less analysis has been devoted to piecemeal solutions. We use the Forest and Agriculture Sector Optimization Model with Greenhouse Gases (FASOMGHG) to project the individual and combined effect of three existing U.S. Department of Agriculture programmes with potential to increase greenhouse gas (GHG) mitigation. We find that a combined policy scenario may achieve greater mitigation than individual constituent programmes, suggesting the possibility of complementary spillover effects in some periods. Mitigation varies over time, however, and some periods experience net emissions as markets and management practices respond to initial policy shocks. The regional distribution of GHG mitigation also varies between policy scenario. Differences in the magnitude and imputed cost of mitigation under each scenario, generating negative values for some programmes and time periods, reinforces the need to evaluate portfolio design to cost-effectively achieve near-term GHG mitigation.

Key policy insights

• Increased near-term GHG mitigation in the forest and agriculture sectors in the US may be possible by expanding or refocusing the emphasis of existing programmes.

• Implementing several such forest and agricultural programmes simultaneously may lead to greater GHG mitigation than when implemented separately, indicating the possibility of positive spillover effects.

• Programmes targeted to agricultural management may hold outsized potential to achieve near-term GHG mitigation; Policies aimed at influencing land use conversion appear to be more vulnerable to reversion and subject to larger inter-annual swings.

• The staged implementation of programmes could also be useful, helping to encourage increased mitigation (or the retention of already achieved mitigation) over time as markets re-equilibrate to initial shocks.

• Though the particular scenarios assessed here are unique to the US, our findings may be applicable to other locations outside the US where land management is influenced by individual market actors and there is competition between forest and agricultural land uses.

     

Analysis of suspended sediment yields after low impact forest harvesting

Disturbances to forest catchments have profound effects on the environment of headwater streams and have an impact on suspended sediment (SS) management. Forest harvesting is a dominant factor in increasing SS yields. Road construction, skidder activity and ploughing associated with harvesting cause serious soil disturbance that results in SS increases. However, few studies have shown whether harvesting itself increases SS yields. This study examined how harvesting influenced SS yields in a steep forested area. During harvesting, soil surface disturbance was prevented as much as possible by using skyline logging treatments and piling branches and leaves at selected locations in the watershed. Using these methods, the representative SS rating curve did not change significantly after harvesting. The results also show that the characteristics of SS transport were related to the SS source area, and reveal that the riparian zone/stream bank was a dominant SS source area at the study site. Annual SS yields did not increase despite increasing annual water yields after harvesting. The limited water capacity of the soil at the study site likely led to only slight differences in pre‐ and post‐harvest water discharge from heavy rainfall events. Most SS was transported during heavy rainfall events, and increases in SS yields were not detected after harvesting. We concluded that it is possible to prevent post‐harvest SS increases by performing careful, low‐impact harvesting procedures. Copyright © 2007 John Wiley & Sons, Ltd.     

兰州西固区TSP污染的预测及烟尘排放总量控制研究

以复杂地形上的平流扩散模式和高斯扩散模式相结合，首先预测了由于污染源排放量的变化所引起的２０００年兰州西固区ＴＳＰ污染状况的变化。然后提出了以Ａ－Ｐ限制为基础的区域总体优化的总量控制方案，计算了兰州西固区烟尘的基础、平权、优化三种允许排放量及相应的削减量。其结果可为兰州西固区ＴＳＰ污染的控制和治理提供理论上的依据和参考     

我国水管仪倾斜固体潮观测长系列调和分析结果

本文扼要介绍了我国水管仪倾斜固体潮观测台站的台址条件和仪器设备状况,公布其资料利用率及借ICET通用程序所作长系列调和分析结果,同时公布了国外同类优质台站的计算结果,以资对比。     

BERNESE 5.0软件及其在高精度GPS数据处理中的应用

介绍了BERNESEGPS软件的研发过程、程序设计和主要功能及其在高精度GPS数据处理中的应用特点,并通过应用实例,与GAMIT/GLOBK软件解算结果进行比较,验证了BERNESE 5.0软件解算精度的可靠性。