磁法在煤火探测中的应用

对采自宁夏汝箕沟煤田上覆盖层的原岩样品在温度作用下的磁性变化进行了系统研究.通过分析煤火区不同燃烧阶段围岩的温度变化情况,对原岩样品进行了模拟“燃烧”试验,试验结果表明,岩石磁性在不同温度作用条件下存在明显差异,从而从岩石磁性的角度讨论了磁法勘探圈定煤田火烧区的可行性.最后,采用人机交互法对地面实测磁异常剖面进行反演,有效地圈定了煤火区着火点的位置及范围.     

地下城市综合管廊的抗火构造与消防设计

综合管廊作为现代化城市的基础设施,能够从根本上解决管线埋设或架立引起的挖掘道路、影响交通、破坏景观等问题。提高道路和公用管线的管理水平,有效利用地下空间,提高防灾能力,是现代化都市的必然要求。本文从管廊的构造、抗火设计要求、管线布置、消防系统等方面出发,对地下城市综合管廊的设计提出了一些具体的建议。     

The pitfalls and potential of debt-for-nature swaps: A US-Indonesian case study

The vital role of forests in limiting the likelihood of dangerous climate change has precipitated renewed interest in debt-for-nature swaps. This article uses evidence on past debt-for-nature deals and similar debt mechanisms to assess a recent second wave of such swaps. It outlines five typical shortcomings of this form of financial transaction: that they often fail to deliver additional resources to the debtor country and/or debtor government budget; often fail to deliver more resources for conservation/climate purposes; often have a negligible effect on overall debt burdens (and, as such, do not generate more ‘indirect’ benefits); and are often in conflict with principles of alignment with government policy and alignment with government systems (these two last shortcomings being important elements within the new aid delivery paradigm). Our analysis is applied to a recent debt-for-nature swap between the United States and Indonesia. We show that this case, which we consider a litmus test for current swap practice, performs unevenly across the five shortcomings. First, although the US-Indonesian swap does increase available resources to Indonesia at the country level, it does not generate extra budgetary room for the Indonesian government. Second, the extent to which the resources provided by the swap are additional to other donor support and reserved domestic budget lines for conservation goals is unclear. Third, the swap is too insignificant to create indirect (positive) economic effects. Regarding alignment issues, fourth, the swap is very much in line with current national policy, but, fifth, appears at odds with the new aid delivery paradigm's insistence on system alignment. We argue that if a second generation of debt-for-nature swaps is to be pursued then they need to avoid the common pitfalls associated with this form of finance. Moreover, there is a need to debate broader ways of linking debt service repayments to climate mitigation and adaptation.     

东营市森林火险天气等级预报系统

利用9210传输的气象资料，选用国家气象中心T106和HLAFS数值预报产品中的要素作为火险天气因子，根据森林火险原因，建立了东营市森林火险天气等级预报系统。     

Biomass burning in the tropical savannas of Ivory Coast: An overview of the field experiment Fire of Savannas (FOS/DECAFE 91)

FOS/DECAFE 91 (Fire of Savannas/Dynamique et Chimie Atmosphérique en Forêt Equatoriale) was the first multidisciplinary experiment organized in Africa to determine gas and aerosol emissions by prescribed savanna fires. The humid savanna of Lamto in Ivory Coast was chosen for its ecological characteristics representative of savannas with a high biomass density (900 g m^–2 dry matter). Moreover the vegetation and the climate of Lamto have been studied for more than twenty years. The emission ratios (X/CO₂) of the carbon compounds (CO₂, CO, NMHC, CH₄, PAH, organic acids and aerosols), nitrogen compounds (NO_x, N₂O, NH₃ and soluble aerosols) and sulfur compounds (SO₂, COS and aerosols) were experimentally determined by ground and aircraft measurements. To perform this experiment, 4 small plots (100×100 m) and 2 large areas (10×10 km) were prepared and burnt in January 1991 during the period of maximum occurrence of fires in this type of savanna. The detailed ecological study shows that the carbon content of the vegetation is constant within 1% (42 g C for 100 g of vegetal dry matter), the nitrogen content (0.29 g N for 100 g of dry matter) may vary by 10% and the sulfur content (0.05 g S/100 d.m.) by 20%. These variations of the biomass chemical content do not constitute an important factor in the variation of the gas and particle emission levels. With the emission ratios characteristic of humid savanna and flaming conditions (CO/CO₂ of 6.1% at the ground and 8% for airborne measurements), we propose a set of new emission factors, taking into account the burning efficiency which is about 80%: 74.4% of the carbon content of the savanna biomass is released to the atmosphere in the form of CO₂, 4.6% as CO, 0.2% as CH₄, 0.5% as NMHC and 0.7% as aerosols. 17.2% of the nitrogen content of the biomass is released as NO_x, 3.5% as N₂O, 0.6% as NH₃ and 0.5% as soluble aerosols.     

Inequalities, institutions, and forest commons

This paper contributes to a growing literature on the commons that examines the relationship between inequality and commons outcomes. Our analysis of evidence on forest commons outcomes in 228 cases from South Asia (India and Nepal), East Africa (Kenya and Uganda) and Latin America (Mexico and Bolivia) suggests that local governance and collective action matter in shaping how socioeconomic inequalities affect forest conditions. In particular, we find that both inter-group and intra-group economic inequalities have consistently negative effects on forest outcomes, but that effectively functioning local institutions for collective action dampen the negative effect of inter-group inequality on forest outcomes.     

Turbulence Statistics Inside and Over Forest: Influence on Footprint Prediction

Observations of wind statistics within and above a Scots pine forest are comparedwith those predicted from an analytical second-order closure model. The roughnesssublayer (RSL) effects, and the influence of stability on similarity functions, arestudied using observations. The commonly accepted forms of similarity functionsdescribe the influence of diabatic effects above the RSL well. According to earlierstudies they are expected also to apply within the RSL. As an exception, the averagewind speed normalised with friction velocity was found to be invariant with stabilityclose to the canopy top under unstable conditions. Lagrangian stochastic trajectorysimulations were used to evaluate the influence of canopy turbulence profiles onfootprint prediction. The main uncertainty was found to arise from parameterisationof the random forcing term in the Lagrangian velocity equation. The influence ofdiabatic conditions was studied, and it was found that thermal stability affectssignificantly the footprint function above the forest canopy, but significantuncertainty exists because of uncertainties in the formulation of stability functions.     

Observation of gravity waves in a boreal forest

In this paper we report the results of the analysis of two 60-min wave events that occurred in a boreal aspen forest during the 1994 BOREAS (Boreal Ecosystems-Atmosphere Study) field experiment. High frequency wind and temperature data were provided by three 3-D sonic anemometer/thermometers and fourteen fine-wire thermocouples positioned within and above the forest. Wave phase speeds, estimated from information revealed by spectral analysis and linear plane wave equations, are 2.2 and 1.3 m s^-1 for the two events. The wavelengths are 130 m and 65 m respectively and are much larger than the vertical wave displacements. There is strong evidence from the present analysis and from the literature supporting our postulate that these waves are generated by shear instability. We propose that wind shear near the top of the stand is often large enough to reduce the gradient Richardson number below the critical value of 0.25 and thus is able to trigger the instability. When external conditions are favorable, the instability will grow into waves.     

Assessing protected area’s carbon stocks and ecological structure at regional-scale using GEDI lidar

Protected areas (PAs) serve as a critical strategy for protecting natural resources, conserving biodiversity, and mitigating climate change. While there is a critical need to guide area-based conservation efforts, a systematic assessment of PA effectiveness for storing carbon stocks has not been possible due to the lack of globally consistent forest biomass data. In this study, we present a new methodology utilizing forest structural information and aboveground biomass density (AGBD) obtained from the Global Ecosystem Dynamics Investigation (GEDI) mission. We compare PAs with similar, unprotected forests obtained through statistical matching to assess differences in carbon storage and forest structure. We also assess matching outcomes for a robust and minimally biased way to quantify PA efficacy. We find that all analyzed PAs in Tanzania possess higher biomass densities than their unprotected counterfactuals (24.4% higher on average). This is also true for other forest structure metrics, including tree height, canopy cover, and plant area index (PAI). We also find that community-governed PAs are the most effective category of PAs at preserving forest structure and AGBD – often outperforming those managed by international or national entities. In addition, PAs designated under more than one entity perform better than the PAs with a single designation, especially those with multiple international designations. Finally, our findings suggest that smaller PAs may be more effective for conservation, depending on levels of connectivity. Taken together, these findings support the designation of PAs as an effective means for forest management with considerable potential to protect forest ecosystems and achieve long-term climate goals.