宁夏沙湖自然保护区水生生物调查与分析

宁夏沙湖自然保护区位于平罗县，面积４２４７ｈｍ＾２，水面沼泽２７３２ｈｍ＾２。根据１９９９年７月对其进行了综合考察的统计结果，计有水生两栖类－大鲵１种，鱼类１６种，浮游植物８门２９科６１属（种）、浮游动物２９种、水生底栖无脊椎动物２９种。     

从不稳定能量触发机制探讨突发性灾害

本文通过对各种突发性灾害产生机制的分析，初步建立了不稳定能量蟹良机制模型，指出在实际存在的六种情况下，只有第一种情况下才能发生突发性灾害。     

Influence of active mitigation barriers on LNG dispersion

In recent years, particular interest has been direct to the issues of risk associated with the storage, transport and use of Liquefied Natural Gas (LNG) due to the increasing consideration that it is receiving for energy applications. Consequently, a series of experimental and modeling studies to analyze the behavior of LNG have been carried out to collect an archive of evaporation, dispersion and combustion information, and several mathematical models have been developed to represent LNG dispersion in realistic environments and to design mitigation barriers.This work uses Computational Fluid Dynamics codes to model the dispersion of a dense gas in the atmosphere after accidental release. In particular, it will study the dispersion of LNG due to accidental breakages of a pipeline and it will analyze how it is possible to mitigate the dispersing cloud through walls and curtains of water vapor and air, also providing a criterion for the design of such curtains.     

某砷污染矿区土壤清洗修复及其动力学研究

矿区不当开采导致下游土壤As污染(As含量达到194 00 mg/kg),研究了柠檬酸、氮川三乙酸三钠(NTA)、乙二胺二琥珀酸-三钠盐(EDDS)3种天然螯合剂清洗修复As污染土壤的效果以及清洗对As化学形态的影响,并探讨了清洗动力学过程。结果表明,柠檬酸、NTA和EDDS的最佳清洗条件:液土比分别为30、30和15 m L/g,浓度分别为0.2、0.05和0.1 mol/L,p H分别为2.67、13和13,震荡清洗时间分别为6、3和2 h,对应的去除率为88.70%、94.05%和89.89%。运用吸附动力学模型对As的清洗动力学数据进行拟合,准一级方程拟合决定系数达到0.982 07,是描述柠檬酸清洗过程的最佳方程;NTA和EDDS则是准二级方程,NTA分段拟合的决定系数分别为0.999 04和0.940 37,EDDS对应为0.97825和0.816 92。3种天然螯合剂对碳酸盐结合态、铁锰氧化物结合态、有机结合态和残渣态均有40%~90%的去除率,其中NTA对铁锰氧化物结合态和残渣态的去除率分别为91.24%和95.03%,显著高于柠檬酸和EDDS。     

Cyanobacterial bloom dynamics in Lake Taihu

<正>Lake Taihu is the third largest freshwater lake in China and serves as an important drinking water source for the local populace;however,decades of excessive nutrient loading fueled by anthropogenic activities have resulted in hypertrophic conditions,promoting the annual formation of nuisance phytoplankton blooms(Chen et al.,2003;Duan et al.,2009)     

Gas leakage consequence modeling for buried gas pipelines

One of conservation transfer methods for such widely-used gases as natural gas and hydrogen is buried pipelines. Safety of these pipelines is of great importance due to potential risks posed by inefficiencies of the pipelines. Therefore, an accurate understanding of release and movement characteristics of the leaked gas, i.e. distribution and speed within soil, the release to the ground surface, the movement of hydrogen gas through the ground, gas underground diffusion, gas dispersion in atmosphere, and following consequences, are very important in order to determine underground dispersion risks. In the present study, consequences of gas leakage within soil were evaluated in two sub-models, i.e. near-field and far-field, and a comprehensive model was proposed in order to ensure safety of buried gas supply pipelines. Near-field model which is related to soil and ground and its output is the gas released at different points and times from ground surface and it was adopted as input of far-field sub-model which is dispersion model in atmosphere or an open space under the surface. Validation of near-field sub-model was performed by the experimental data obtained by Okamoto et al. (2014) on full-scale hydrogen leakage and then, possible scenarios for far-field sub-model were determined.     

Understanding the patterns and characteristics of Natech events in China

With the frequent occurrence of natural disasters, natural hazard triggered technological accident (Natech) risk has attracted extensive attention from academia and industry. Natech events have the characteristics of various inducements and consequences, cascading chain reactions, and complex spatial interleaving, which leads to serious consequences. The Natech event is constantly threatening China's industrial safety production. However, the systematic analysis of Natech events in China is still lacking. The study counted 288 cases in the past 20 years and constructed Natech databases. Based on the theory of risk chain and risk system, a systematic horizontal and vertical analysis was developed for the first time. It aims to understand the characteristics of Natech events in terms of temporal and spatial, hazard factors, industry and risk material, consequences and hazard. In the results, Natech events showed a fluctuating trend. The southwest region (28.13%) and the middle Yellow River region (21.18%) belong to the critical control areas. China's industries were seriously affected by the disasters of meteorological (43.75%) and secondary, especially in the Chemical & Petrochemical and manufacturing. 64.58% of Natech events caused environmental pollution, and 13.19% of Natech events caused major or above consequences. Oil (31.25%) and hazardous chemicals (28.47%) were the main substances causing pollution, fire and explosion, which need to be controlled. The research preliminarily clarifies the risk chain and characteristics of Natech events, which provided the basis for Natech risk assessment.     

Resolving structural uncertainty in natural resources management using POMDP approaches

In recent years there has been a growing focus on the uncertainties of natural resources management, and the importance of accounting for uncertainty in assessing management effectiveness. This paper focuses on uncertainty in resource management in terms of discrete-state Markov decision processes (MDP) under structural uncertainty and partial observability. It describes the treatment of structural uncertainty with approaches developed for partially observable resource systems. In particular, I show how value iteration for partially observable MDPs (POMDP) can be extended to structurally uncertain MDPs. A key difference between these process classes is that structurally uncertain MDPs require the tracking of system state as well as a probability structure for the structure uncertainty, whereas with POMDPs require only a probability structure for the observation uncertainty. The added complexity of the optimization problem under structural uncertainty is compensated by reduced dimensionality in the search for optimal strategy. A solution algorithm for structurally uncertain processes is outlined for a simple example in conservation biology. By building on the conceptual framework developed for POMDPs, natural resource analysts and decision makers who confront structural uncertainties in natural resources can take advantage of the rapid growth in POMDP methods and approaches, and thereby produce better conservation strategies over a larger class of resource problems.     

Using Cost‐Effective Targeting to Enhance the Efficiency of Conservation Investments in Payments for Ecosystem Services

Abstract: Ecosystem services are being protected and restored worldwide through payments for ecosystem services in which participants are paid to alter their land‐management approaches to benefit the environment. The efficiency of such investments depends on the design of the payment scheme. Land features have been used to measure the environmental benefits of and amount of payment for land enrollment in payment for ecosystem services schemes. Household characteristics of program participants, however, may also be important in the targeting of land for enrollment. We used the characteristics of households participating in China's Grain‐to‐Green program, and features of enrolled land to examine the targeting of land enrollment in that program in Wolong Nature Reserve. We compared levels of environmental benefits that can be obtained through cost‐effective targeting of land enrollment for different types of benefits under different payment schemes. The efficiency of investments in a discriminative payment scheme (payments differ according to opportunity costs, i.e., landholders’ costs of forgoing alternative uses of land) was substantially higher than in a flat payment scheme (same price paid to all participants). Both optimal targeting and suboptimal targeting of land enrollment for environmental benefits achieved substantially more environmental benefits than random selection of land for enrollment. Our results suggest that cost‐effective targeting of land through the use of discriminative conservation payments can substantially improve the efficiency of investments in the Grain‐to‐Green program and other payment for ecosystem services programs.     

Marine Parks for protection and tourism in Turkey

Protected Turkish areas in the Mediterranean region are compared with those of other Mediterranean countries. Policies followed in Turkey for conservation protection of the natural and cultural environment and the use of coastal resources for tourism are discussed. The purpose and application of Turkish law is examined with respect to the interaction between the protection of coastal areas and tourism. Modifications on the administrative and management regulations in Turkey enabling a better use of coastal areas is suggested by combining coastal tourism and protection. The necessity and importance of estabilishing and managing Marine Parks in short-and long-term plans are acknowledged.