系统响应气候变化脆弱性定量评价国内研究综述

定量评价气候变化脆弱性是人类采取适应性措施应对全球气候变化,以减少其不利影响的关键和基础。在对气候变化脆弱性有关概念进行讨论,及对国际、国内系统响应气候变化脆弱性评价研究回顾的基础上,对中国近十几来有关气候变化脆弱性定量评价研究的成果从三个方面进行了较为系统的总结：气候情景的模拟预测、系统变化过程的模拟、脆弱性指标的选取及脆弱性层次的划分。最后,从评价对象、技术手段、指标体系、时间尺度等方面探讨了该领域研究的不足及发展方向。     

Experimental study of the transport properties of rough self-affine fractures

An experimental study of the transport properties of fluid-saturated joints composed of two complementary rough fracture surfaces, translated with respect to each other and brought in contact, is reported. Quantitative roughness measurements on different fractured granite samples show that the surfaces have a self-affine geometry from which the dependence of the mean aperture on the relative displacement of fracture surfaces kept in contact can be predicted. Variations of the hydraulic and electrical conductances of the joint are measured as functions of its mean aperture. A simple parallel plane model accounts for the global trend of the measurements, but significant deviations are observed when a relative lateral displacement of the surfaces is introduced. A theoretical analysis of their origin shows that they are due both to the randomness of the aperture field and to a nonzero local slope of the surface near the injection hole; the corresponding conductivity fluctuation amplitudes have power law and linear variations with the lateral displacement, and are enhanced by the radial injection geometry.     

河西走廊水资源供需平衡及其对农业发展的承载潜力

河西走廊是甘肃省主要经济地区之一,河西走廊未来的经济发展规模在很大程度上取决于本地区水资源的承载能力。本文在水量平衡原理的基础上,对河西走廊水资源的供需平衡和水土资源平衡状况以及水资源对农业发展的承载潜力进行了分析计算,并建立了相应的数学模型,指出了河西走廊水资源的潜力巨大,只有在发展节水型农业和水资源合理、高效利用的条件下才能提高农业用水的承载潜力。     

固定床厌氧反应器处理高浓度禽畜粪尿

为开展高效厌氧生物技术处理家禽粪便的应用研究,试验依据固定床厌氧反应器(anaerobic pecked bed reac-tor)的特点,设计了一个有效容积为20 L的高效厌氧反应器,以猪粪尿为发酵原料,进水COD浓度范围在4 820~54 000mg/L,实验过程为55 d。按进料的水力停留时间可将实验划分为2个阶段:前期(44 d)和后期(11 d),前期通过提高进料浓度直接提高反应器处理浓度,水力停留时间保持为2 d,每7~8 d为一个周期;后期通过缩短水力停留时间间接提高反应器处理浓度,进料浓度保持不变,每2~3 d为一个周期。通过对厌氧处理系统运行过程中COD、pH、挥发性成分、TN、TP和NH3-N含量的测定,分析了该系统运行特点。结果表明:在发酵的第1~55 d,整个厌氧处理系统能够稳定运行,COD去除率稳定在67%~88%之间;对TN、TP、NH3-N都有很好的去除能力。     

Characterization of fracture aperture field heterogeneity by electrical resistance measurement

We use electrical resistance measurements to characterize the aperture field in a rough fracture. This is done by performing displacement experiments using two miscible fluids of different electrical resistivity and monitoring the time variation of the overall fracture resistance. Two fractures have been used: their complementary rough walls are identical but have different relative shear displacements which create "channel" or "barrier" structures in the aperture field, respectively parallel or perpendicular to the mean flow velocity U(→). In the "channel" geometry, the resistance displays an initial linear variation followed by a tail part which reflects the velocity contrast between slow and fast flow channels. In the "barrier" geometry, a change in the slope between two linear zones suggests the existence of domains of different characteristic aperture along the fracture. These variations are well reproduced analytically and numerically using simple flow models. For each geometry, we present then a data inversion procedure that allows one to extract the key features of the heterogeneity from the resistance measurement.     

Prosulfocarb at center stage!

Environmental Science and Pollution Research - Prosulfocarb is a thiocarbamate herbicide that is rapidly growing in use due to the progressive bioresistance of weeds to certain pesticides and the...     

西藏年楚河流域水化学特征分析

年楚河流域是西藏发达的农业区,有"西藏粮仓"之称,对区域经济发展起着决定性的作用。然而对该流域水体水化学的系统研究鲜见报道。为揭示年楚河流域水化学特征及其控制因素,本研究于2018年11月(平水期)对年楚河主干流及其主要支流的水体理化参数、主要离子和微量元素进行分析研究。结果表明,年楚河流域水体总体呈弱碱性,总溶解性固体、电导率和矿化度均值分别为275.64 mg/L、389.06μS/cm和172.71 mg/L,且空间上均表现为自上游至下游递增的趋势。主干流及其主要支流阳离子以Ca~(2+)为主,占阳离子总量的71.45%,阴离子则以HCO_3~-为主,占阴离子总量的63.21%。河水主要离子浓度在空间上表现出一定的差异性,整体上主干流自上游至下游有逐渐递增趋势,河口段则相对平稳。年楚河三个主要源头湖泊区域中,错嘎布和冲巴雍错及下游出水口附近水体水化学类型主要为HCO_3-Ca型,桑旺湖及主干流上中游和雅鲁藏布江汇入口附近河段水化学类型为HCO_3·SO_4-Ca·Mg型,而下游区域,包括支流冲巴涌曲下游和龙马河的水化学类型主要为HCO_3·SO_4-Ca型。流域内碳酸盐岩和硅酸盐岩的风化作用是控制整个流域水化学特征的主要因素,且自源头区到下游河段其主导控制风化作用由碳酸盐岩逐渐过渡为硅酸盐岩。流域内以农业为主的人类活动对河流水环境造成的潜在影响不可忽视。     

生态环境对我国居民幸福感的影响机制与实证研究

深入揭示生态环境与居民幸福感的内在关系对创造人民美好生活具有重要的理论与现实意义。本研究基于幸福感产生机制对生态环境影响居民幸福感的机制进行了深入的理论探讨,利用2013-2014年我国居民大样本调查数据,定量分析了水、大气,绿化三个关键生态环境要素对我国居民幸福感的影响。研究认为,生态环境对居民幸福感的影响受制于经济发展与居民收入水平及居民对环境价值的认知与重视程度;尽管研究期居民对生态环境质量满意度不高,但生态环境对我国居民幸福感的并没造成显著影响;比较而言,水环境对居民幸福感的影响小于空气环境,而空气环境的影响又小于绿化环境。为提升我国居民生态幸福感并激励居民亲环境行为,应通过科普教育切实提高居民对环境及其价值的认知度,努力营建人地和谐的文化氛围;应在普遍提高居民收入和物质生活水平的基础上,引导和促进居民向环境审美消费需求的升级;当前应重视生态补偿等经济手段的运用,通过影响居民经济利益激发居民环保行为;应优先解决居民直观感知明显且反映强烈的环境问题。     

基于IWRM视角的污水治理绩效综合评价研究——以浙江省为例

绩效评价是地方政府污水治理工作的重要但仍很薄弱的环节。本研究基于综合水资源管理(IWRM)目标原则开发了污水治理绩效综合评价指标体系,确定了指标权重,并对浙江省污水治理绩效进行了实证研究。结果表明,污水治理关键是改善自然水体功能。当前浙江省污水治理绩效总体良好,但存在污水处理投资项目运转效率差、农田污灌比重高、东部沿海市污水治理效果不理想等问题。建议今后浙江省污水治理工作应在继续提高自然水体功能的基础上,提高污水处理设施运转效率,加强农田水污染防治,并强化对东部沿海市区污水治理支持力度。     

Modelling the distribution of plant species using the autologistic regression model

For modeling the distribution of plant species in terms of climate covariates, we consider an autologistic regression model for spatial binary data on a regularly spaced lattice. This model belongs to the class of autologistic models introduced by Besag (1974). Three estimation methods, the coding method, maximum pseudolikelihood method and Markov chain Monte Carlo method are studied and comparedvia simulation and real data examples. As examples, we use the proposed methodology to model the distributions of two plant species in the state of Florida.