广西综合环境质量结构与功能属性构建及其关系耦合优化

用主分量分类分析方法对广西2001—2015年各要素环境质量监测指标与自然、经济、人口、能源和污染物排放等年鉴统计指标构成的综合环境质量结构与功能属性关系进行耦合。结果表明:广西综合环境质量在省域层次上呈现明显的年、季、月等时间尺度变化规律。在市域层次上,年际时空交互变化规律分异明显;月份的时空交互变化规律在城市空间格局上有明显分异,但时间序列的分异规律不明显;季度的时空交互变化规律在空间与时间上均无明显分异。研究可为经济发展、国土空间优化、能源利用、环境保护等决策管理与判别提供参考。     

Concentration and size distribution of particulate matter in a new aviary system for laying hens in China

ABSTRACT

Particulate matter (PM) from poultry production facilities may strongly affect the health of animals and workers in the houses, and PM emitted to the ambient air is an important pollution source to the surrounding areas. Aviary system is considered as a welfare friendly production system for laying hens. However, its air quality is typically worse as compared with conventional cage systems, because of the higher PM concentration of indoor air and other airborne contaminants. Furthermore, PM’s physical property, which has a direct impact on the penetration depth into the lungs of the birds and humans, is largely unknown for the aviary system. Therefore, a systematic method was utilized to investigate the characteristics of particles in the aviary house with large cage aviary unit system (LCAU) in Beijing, China. For the field measurements, three measuring locations were selected with two inside and one outside the house with LCAU to continuously monitor PM concentrations and collect the samples for particle size distribution (PSD) analysis. Results showed that PM_2.5, PM₁₀, and total suspended particulate (TSP) concentrations averaged at 0.037 ± 0.025 mg/m³, 0.42 ± 0.10 mg/m³, and 1.92 ± 1.91 mg/m³, respectively. Particle concentrations increased from October to December due to less ventilation as the weather got colder, and were generally affected by stocking density, ventilation rate, birds’ activities, and housing system. Meanwhile, indoor PM_2.5 concentration was easily impacted by the ambient air quality. Mass median diameter (MMD) and mass geometric standard deviation (MGSD) of the TSP during the measurement were 18.92 ± 7.08 μm and 3.11 ± 0.31, respectively. Count median diameter (CMD) and count geometric standard deviation (CGSD) were 1.94 ± 0.14 μm and 1.48 ± 0.08, respectively. Results indicated that the aviary system can attain a good indoor condition by suitable system design and environment control strategy.

Implications: Indoor PM_2.5 concentration of the layer house can be significantly affected by ambient air quality when the air quality index (AQI) was larger than 100. PM_2.5 and PM₁₀ concentrations of the layer house with a LCAU system were comparable to the cage system. TSP concentration was higher, and PM size was larger than most of the cage system. System design, larger space volume, and higher ventilation rate were the main influence factors. Good indoor environment of the aviary system can be achieved through the reasonable design of the production system and appropriate environment control strategy.     

Connecting Diverse Knowledge Systems for Enhanced Ecosystem Governance: The Multiple Evidence Base Approach

Indigenous and local knowledge systems as well as practitioners’ knowledge can provide valid and useful knowledge to enhance our understanding of governance of biodiversity and ecosystems for human well-being. There is, therefore, a great need within emerging global assessment programs, such as the IPBES and other international efforts, to develop functioning mechanisms for legitimate, transparent, and constructive ways of creating synergies across knowledge systems. We present the multiple evidence base (MEB) as an approach that proposes parallels whereby indigenous, local and scientific knowledge systems are viewed to generate different manifestations of knowledge, which can generate new insights and innovations through complementarities. MEB emphasizes that evaluation of knowledge occurs primarily within rather than across knowledge systems. MEB on a particular issue creates an enriched picture of understanding, for triangulation and joint assessment of knowledge, and a starting point for further knowledge generation.     

Investigation on the influence of the Bohai Sea Geological Environment on the submarine stratum stability based on data mining: an intelligent prediction model

Environmental Science and Pollution Research - The Bohai Sea has unique characteristics of the marine geological environment, with strong water closure and weak self-purification ability....     

城镇化进程中用水量增长的门槛效应与动态作用机制分析

城镇化是发展中国家21世纪的主要发展趋势,在很大程度上主导着人口、经济和产业结构等各方面的转变,成为拉动用水量增长的关键因素。城镇化进程中城镇居民收入、人口结构、人口密度和人力资本等因素的变化,使得城镇化并非表现为线性发展规律,最终导致用水量也存在相应的门槛效应并呈现阶段性增长特征。本文首先对我国各地区城镇化水平和用水量进行统计分析,从地区层面直观描述我国城镇化水平和用水量的变化特征,然后采用面板门槛模型研究城镇化、城镇居民人均收入、人力资本、城市人口密度和人口年龄结构对于用水量的门槛效应,搜寻在城镇化进程中各人口因素对用水量影响的门槛点并分析阶段性变化特征,最后结合PVAR模型研究城镇化进程中各人口因素对用水量的动态影响和作用机制。门槛回归结果发现:城镇化对用水量的影响具有明显的阶段性特征,分别以城镇化和人均收入为门槛变量,超越门槛点后城镇化对用水量的弹性系数分别呈现先升后降的倒"U"型和先降后升的正"U"型变化趋势;以人力资本为门槛变化量,城镇化对用水量的拉动作用则不断减弱。脉冲响应结果显示:城镇化对用水量具有长期且稳定的正向冲击,而居民收入和人口年龄结构对用水量的正向冲击则逐渐收敛于零,人口密度和人力资本对用水量均具有负向冲击,且人口密度的负效应不断增强,而人力资本的负效应不断减弱。方差分解的结果表明,目前我国用水量的增长受自身的影响较大,除年龄结构外,人口密度、居民收入、人力资本和城镇化也具有小规模的贡献程度。     

基于Paircopula函数和标准化径流指数的水文干旱频率分析——以南盘江流域为例

选取南盘江流域3个水文站52 a（1961~2012年）的逐月径流资料，联合两个相邻站点，分别计算标准化径流指数（SSFI），运用游程理论识别52 a来不同站点干旱特征，并用Pair copula函数计算不同站点的联合重现期。结果表明：（1）52 a来3个站点干旱特征值的最大值都出现在2011~2012年；从单个站点看，52 a来沾益站的干旱次数、最大干旱历时、最大干旱烈度均大于高谷马站和江边街站，最大干旱峰值出现在江边街站；从联合站点看，中游以上高谷马站和沾益站的干旱特征值均大于中游以下高谷马站和江边街站，3个站点联合识别的干旱特征值大于中下游站点联合识别干旱特征值，小于中上游站点联合识别干旱特征值，上游干旱更严重；（2）Frank Pair copula函数的RMSE、AIC和BIC值最小，拟合程度最高，适合运用于南盘江流域干旱频率分析中；（3）运用Frank Pair copula函数计算得到3个水文站点2009~2012年的连续干旱重现期都在100~200 a，是52 a来最严重的一次干旱     

多溴联苯醚在河套农灌区土壤和水体中的分布特征

PBDEs作为一类全球性的新兴持久性有机污染物,因其具有疏水性,土壤和沉积物对其有很强的固着能力,被认为很难进入地下水中。文章在河套平原典型的黄河农灌区采集地下水、地表水以及表层土壤样品,利用GC-μECD和GC-MS方法测定发现,地下水和地表水中均检测到PBDEs,且主要为BDE209,其在地下水中含量高达5.3μg/L,而地表水中仅为0.03μg/L,揭示PBDEs存在污染地下水的可能性。对土壤中PBDEs的分析发现,其优势同系物为BDE47、100、183和99,主要富集在地面以下0~5 cm和10~15 cm处,该范围普遍发现农用地膜(PBDEs≤5μg/g)的残留物。此外,研究区主要农作物(玉米、番茄、瓜类、小麦和葵花)中,广泛利用地膜的玉米种植土壤中PBDEs的含量最高,达77.13 ng/g。研究显示,降雨淋滤以及灌溉水入渗作用下,地膜中PBDEs的释放可能是研究区土壤以及地下水中PBDEs不可忽略的重要污染源。     

百花湖消落带常见植物氮磷钾营养元素含量分布特征研究

于2011年9月在百花湖消落区进行随机采集,选取常见的30种百花湖消落带植物,如狗牙根(Cynodon dactylon)、牛鞭草(Hemarthria altissima)、白花三叶草(Trifolium repens)、喜旱莲子草(Alternanthera philoxeroides)、鬼针草(Bidens pilosa)、菖蒲(Acuros calamu Linn)等为研究对象,对其根、茎、叶中氮磷钾营养元素的分布进行比较研究.结果表明:大多数植物根、茎、叶中N、P、K含量表现出一致性,即K＞N＞P,并且N、P、K相互之间呈现出显著的正相关关系,这与该地区土壤中N、P、K的含量有着显著的关系.在同一植物不同器官中N、P、K的含量也表现出一致性,即叶＞茎＞根,并且根、茎、叶中的含量相互之间也呈现出现显著的正相关关系.消落区植物总体根、茎、叶的营养状况分别为低、中、高,并且地上部分的营养元素占整株植物总营养元素的平均值为80％以上.因此,收割地上部分的茎和叶,即可达到对土壤中N、P较好的处理效果.禾本科、蓼科及菊科植物中营养元素含量较低,又具有一定的耐水淹性,适宜在消落区水淹时间较长且土壤中N、P营养元素含量较低的这种特殊环境下生长.该研究揭示了百花湖消落区常见植物的营养状况,以及有助于筛选出适合消落区生长的植物,对控制水体富营养化和研究消落区生态系统的完整性有着重要的意义.     

沸石负载羟基氧化铁对铬（VI）吸附的固体浓度效应研究

本文利用沸石负载羟基氧化铁作吸附剂对六价铬进行吸附和解吸附实验。探讨了沸石负载羟基氧化铁对六价铬的吸附机制和固体浓度效应。实验结果表明：当吸附剂的用量从0.05g增加到0.2g时,在实验条件下,六价铬的吸附量从27999.493μg/g降低到8930.610μg/g,吸附剂对Cr6＋的吸附存在明显的固体浓度（Cs）效应。吸附滞后角随着Cs的增加而减小,吸附反应的可逆性增大。将实验数据分别用Languir和Freundlich吸附模型进行拟合,发现Freundlich吸附模型对实验数据拟合效果较好,表明该吸附反应以单分子层吸附为主。