长白山的台风灾区范围及植被恢复动态——基于遥感技术的研究

通过对1985年和1987年Thematic Mapper(TM)影像中提取出的归一化植被指数进行对比分析,提取了1986年长白山自然保护区内遭受台风袭击后的灾区范围,并通过比较1988年和2007年的TM影像,分析了风灾区的植被恢复过程。同时,结合该地区的地形、水文、土壤和公路数据对风灾区的植被恢复进行了驱动力分析。发现地形驱动因子与风灾区的恢复程度呈高度相关,随着高程、坡度和平地所占比例的减少,恢复程度逐渐变好;此外水文、土壤和人类活动都对风灾区的植被恢复产生一定影响,另外人工干预恢复对植被生长也起着积极的作用。研究结果可供风灾区内植被的进一步恢复和森林防火工作参考。     

Effects of reductive inorganics and NOM on the formation of chlorite in the chlorine dioxide disinfection of drinking water

Chlorine dioxide (ClO₂) disinfection usually does not produce halogenated disinfection by-products, but the formation of the inorganic by-product chlorite (ClO₂^–) is a serious consideration. In this study, the ClO₂^– formation rule in the ClO₂ disinfection of drinking water was investigated in the presence of three representative reductive inorganics and four natural organic matters (NOMs), respectively. Fe²⁺ and S^2– mainly reduced ClO₂ to ClO₂^– at low concentrations. When ClO₂ was consumed, the ClO₂^– would be further reduced by Fe²⁺ and S^2–, leading to the decrease of ClO₂^–. The reaction efficiency of Mn²⁺ with ClO₂ was lower than that of Fe²⁺ and S^2–. It might be the case that MnO₂ generated by the reaction between Mn²⁺ and ClO₂ had adsorption and catalytic oxidation on Mn²⁺. However, Mn²⁺ would not reduce ClO₂^–. Among the four NOMs, humic acid and fulvic acid reacted with ClO₂ actively, followed by bovine serum albumin, while sodium alginate had almost no reaction with ClO₂. The maximum ClO₂^– yields of reductive inorganics (70%) was higher than that of NOM (around 60%). The lower the concentration of reductive substances, the more ClO₂^– could be produced by per unit concentration of reductive substances. The results of the actual water samples showed that both reductive inorganics and NOM played an important role in the formation of ClO₂^– in disinfection.     

Application of FeIII-TAML/H2O2 system for treatment of fluoroquinolone antibiotics

Over the recent past, fluoroquinolone antibiotics (FQs) have raised extensive attention due to their potential to induce the formation of resistance genes and “superbugs”, thus various advanced oxidation techniques have been developed to eliminate their release into the environment. In the present study, the prototype tetraamido macrocyclic ligand (Fe^III-TAML)/hydrogen peroxide (H₂O₂) system is employed to degrade FQs (i.e., norfloxacin and ciprofloxacin) over a wide pH range (i.e., pH 6-10), and the reaction rate increases with the increase in pH level. The effect of dosage of Fe^III-TAML and H₂O₂ on the degradation of FQs is evaluated, and the reaction rate is linearly correlated with the added amount of chemicals. Moreover, the impact of natural organic matters (NOM) on the removal of FQs is investigated, and the degradation kinetics show that both NOM type and experimental concentration exhibit negligible influence on the oxidative degradation of selected antibiotics. Based on the results of liquid chromatography-high resolution mass spectrometry and theoretical calculations, the reaction sites and pathways of FQs by Fe^III-TAML/H₂O₂ system are further predicted and elucidated.     

江苏沿海地区的相对海平面上升及其灾害性影响研究

江苏海岸是全国潮滩最集中分布区，其面积约占全国的１／４，沿海地区地势低平，相对海平面上升幅度较大，是全国少数几个受海平面上升危害最严重的地区之一。初步估算，２１世纪前半期该地区不同岸段相对海平面上升速率将可能达到４．５～９．５ｍｍ／ａ，约为同期全球平均上升速率的２～３倍。其灾害性影响主要集中在：①造成堤外潮滩湿地资源损失，相对海平面上升５０ｃｍ，因直接淹没、侵蚀加剧和淤涨减缓造成的潮滩损失面积将超过５×１０４ｈｍ２，湿地损失面积达２．４×１０４ｈｍ２；②降低海堤防御标准、危及海堤自身和受保护地区安全，相对海平面上升５０ｃｍ，该地区现有海堤防御标准将由现状５０～１００年一遇降为２０～５０年一遇；遇５０年一遇风暴高潮位，全区受潮水漫溢的海堤长度将比现状增加１７３ｋｍ以上，占海堤总长的１／４；③阻碍低洼地的洪水排泄、加剧洪涝灾害损失，相对海平面上升４０ｃｍ，苏北里下河和苏南太湖湖东两片洼地的自然排水能力将可能分别下降约２５％和２０％，若两洼地分别重现１９９１年型和１９５４年型洪水，则因海平面上升增加的受淹面积将超过４×１０４ｈｍ２     

1994年江西省主要自然灾害综述

１９９４年江西省发生了历史上罕见的风雹灾害和洪涝灾害，受灾面积近４４万ｈａ，受灾人口１１４４万人，直接经济损失高达６３亿元，系全国重灾省份之一．本文对其中的三次主要自然灾害的灾因、灾情及减灾中的问题、经验和教训进行总结与分析。     

The resource curse revisited and revised: A tale of paradoxes and red herrings

We critically evaluate the empirical basis for the so-called resource curse and find that, despite the topic's popularity in economics and political science research, this apparent paradox may be a red herring. The most commonly used measure of “resource abundance” can be more usefully interpreted as a proxy for “resource dependence”—endogenous to underlying structural factors. In multiple estimations that combine resource abundance and dependence, institutional, and constitutional variables, we find that (i) resource abundance, constitutions, and institutions determine resource dependence, (ii) resource dependence does not affect growth, and (iii) resource abundance positively affects growth and institutional quality.     

ACCURACY AND PRECISION OF NRCS MODELS FOR SMALL WATERSHEDS1

ABSTRACT: In the last 30 years, the National Resource Conservation Service's TR‐55 and TR‐20 models have seen a dramatic increase in use for stormwater management purposes. This paper reviews some of the data that were originally used to develop these models and tests how well the models estimate annual series peak runoff rates for the same watersheds using longer historical data record lengths. The paper also explores differences between TR‐55 and TR‐20 peak runoff rate estimates and time of concentration methods. It was found that of the 37 watersheds tested, 25 were either over‐ or under‐predicting the actual historical watershed runoff rates by more than 30 percent. The results of this study indicate that these NRCS models should not be used to model small wooded watersheds less than 20 acres. This would be especially true if the watershed consisted of an area without a clearly defined outlet channel. This study also supports the need for regulators to allow educated hydrologists to alter pre‐packaged model parameters or results more easily than is currently permitted.     

Monitoring and adaptive management: resolving social and organisational issues to improve information sharing in natural resource management

Adaptive, or 'learning by doing', approaches are often advocated as a means of providing increased understanding within natural resource management. However, a number of organisational and social issues need to be resolved if these approaches are to be used successfully. A case study in the South Island high country of New Zealand is used to review what is needed to support an ongoing community-based monitoring and adaptive management programme. First, the case study is described, paying attention to the social context of the resource management problem. The results of a workshop that explored this problem are then outlined, along with a proposed information flow suggested by participants. Requirements for future steps to resolve these problems (such as information protocols and a multi-stakeholder information system) are discussed. Finally, some broad lessons are drawn from this exercise that could help others developing similar approaches.     

Quantifying Plant Population Persistence in Human-Dominated Landscapes

Abstract:  We assessed population performance of rare plants across a gradient from rural to urban landscapes and evaluated 2 hypotheses central to strategic conservation planning: (1) population performance declines with increasing human dominance and (2) small populations perform poorly relative to larger ones. Assessing these hypotheses is critical to strategic conservation planning. The current conservation paradigm adheres to the well-established ecology theory that small isolated populations, particularly those in human-dominated landscapes, are the least likely to succeed over the long term. Consequently, conservation planning has strongly favored large, remote targets for protection. This shift in conservation toward ecosystem-based programs and protection of populations within large, remote systems has been at the expense of protection of the rarest of the rare species, the dominant paradigm for conservation driven by the endangered species act. Yet, avoiding conservation of small populations appears to be based more on theoretical understanding and expert opinion than empiricism. We used Natural Heritage data from California in an assessment of population performance of rare plants across a landscape with an urban-rural gradient. Population performance did not decrease in urban settings or for populations that were initially small. Our results are consistent with a pattern of few species extinctions within these landscapes over the past several decades. We conclude that these populations within compromised landscapes can contribute to overall biodiversity conservation. We further argue that conservation planning for biodiversity preservation should allocate relatively more resources to protecting urban-associated plant taxa because they may provide conservation benefit beyond simply protecting isolated populations; they may be useful in building social interest in conservation.