基于遥感的呼伦湖水体动态监测研究

湖泊是地球重要的淡水资源,其时空动态监测对于水资源的合理利用和保护具有重要意义。呼伦湖是内蒙古第一大湖,在草原生态环境保护中举足轻重。该研究选用1975-2011年间的14景Landsat遥感影像和Aster GDEM高程数据,应用水体指数,在精确提取湖泊边界的基础上,尝试估算了呼伦湖的平均水深和蓄水量,探讨了呼伦湖面积、平均水深、水量的动态变化规律及其相关关系;并结合降水、蒸发等气候数据,揭示了呼伦湖水体变化的原因。结果表明:呼伦湖水体发生了明显的萎缩,尤其进入21世纪,萎缩速度明显加快;其水域面积、平均水深和蓄水量都表现出明显的涨落周期;蓄水量与水域面积、平均水深之间均存在较显著的正相关关系,为呼伦湖遥感动态监测和预测提供了一个简单有效的方法。     

A water quality monitoring network design methodology for the selection of critical sampling points: Part II

In order to resolve the spatial component of the design of a water quality monitoring network, a methodology has been developed to identify the critical sampling locations within a watershed. This methodology, called Critical Sampling Points (CSP), focuses on the contaminant total phosphorus (TP), and is applicable to small, predominantly agricultural-forested watersheds. The CSP methodology was translated into a model, called Water Quality Monitoring Station Analysis (WQMSA). It incorporates a geographic information system (GIS) for spatial analysis and data manipulation purposes, a hydrologic/water quality simulation model for estimating TP loads, and an artificial intelligence technology for improved input data representation. The model input data include a number of hydrologic, topographic, soils, vegetative, and land use factors. The model also includes an economic and logistics component. The validity of the CSP methodology was tested on a small experimental Pennsylvanian watershed, for which TP data from a number of single storm events were available for various sampling points within the watershed. A comparison of the ratios of observed to predicted TP loads between sampling points revealed that the model's results were promising.     

基于线性混合效应模型的河北省PM2.5浓度时空变化模型研究

京津冀地区大气PM_2.5污染严重.为揭示区域PM_2.5时空分布规律,使用2013-2014年河北省地面站点PM_2.5监测数据、MODIS AOD（气溶胶光学厚度）遥感数据、地面气象站点数据和土地利用调查数据,基于线性混合效应模型（LME）,建立了ρ（PM_2.5）时空变化与AOD因子、气象因子、土地利用因子之间的关系模型.采用十折交叉验证法对模型精度进行检验,并利用计算得到的校正因子[全部实测的ρ（PM_2.5）年均值除以参与建模的所有实测ρ（PM_2.5）年均值]纠正因AOD非随机性缺值导致的抽样偏差.结果表明:①河北省区域模拟精度R2（决定系数）为0.85,经交叉验证后R2为0.77,RMSE（均方根误差）和RPE（相对预测误差）分别为18.28 μg/m3和28.68%.②ρ（PM_2.5）年均值模拟结果的校正因子范围为1.24~2.05,校正后的研究区ρ（PM_2.5）年均值为89.84 μg/m3,与实际监测数据相近.③ρ（PM_2.5）空间分布呈平原高、山区低,平原地区西南高、东北低的趋势.④ρ（PM_2.5）与AOD、温度、相对湿度呈正相关,与风速、大气能见度呈负相关.研究显示,线性混合效应模型能有效对ρ（PM_2.5）进行时空变化模拟,并实现对非地面监测地区ρ（PM_2.5）时空变化的预测,恰当的预测因子组合和模型校正有助于模型预测精度的提升.      

China’s Total Emission Control Policy: A Critical Review

Abstract

As part of a comprehensive environmental management system, many countries establish emission control targets for mass emissions of a pollutant. Such targets are often the key objective of an environmental policy, such as an emission trading program. In China, however, it is more than just an objective of one particular policy; it has become a concept that has influenced many national environmental policies and activities. The objective of this article is to review the implementation of the total emission control policy in the past 10 years and explore emerging issues in its implementation. The article has three sections: a summary of the implementation experience, issues with the design and implementation of the policy, and policy recommendations.     

Whose Discourse Is It Anyway? Understanding Resistance through the Rise of “Barstool Biology” in Nature Conservation

This study examines what happens when contentious lay citizens harness the technical-ecological repertoire of experts as means of challenging nature conservation policy. The causes, manifestations, and implications of this phenomenon are elucidated through a critical discourse analysis. The case study is based on the wolf reintroduction project in Europe, with particular focus on Sweden, using illegal hunting discussions as a point of entry within the hunting community. It reveals the deployment of three topoi, which are defined as stock arguments situated within a discourse. Analysis shows how while some topoi often incur short-term gains in the debate because of their scientific guise, they are fundamentally relegated as folk science (or “barstool biology”) by government experts and, in some cases, contribute to the further marginalization of other knowledges. Acquiescence to this discourse is shown to greatly impede the debate. Finally, the study shows how lack of trust in the public dialog, which hunters openly recognize to be colonized by ecological expertise, results in increasingly noncommunicative forms of resistance toward policy.     

三峡大宁河水体光学特征及其对藻类生物量的影响

基于2012-04-27—2013-01-19大宁河不同水文期的监测数据,确定大宁河水体光学特性的季节变化特征,并探究其对藻类生物量的影响. 结果表明:①不同水文期大宁河的D_eu(真光层深度)差异显著(P＜0.01),最高值出现在高水位运行期,为(5.22±2.70)～(8.71±5.20)m;最低值出现在汛限期,为(3.22±0.08)～(3.81±0.14)m. ②回归分析结果表明,ρ(SS)能较好地反演真光层深度的时空变化规律,而ρ(Chla)的解释度不高,仅用ρ(SS)即可有效地反推真光层深度. ③利用局部多项式回归拟合大宁河E_t(总能量密度)和浮游生物量的回归模型,结果表明,在100t≤300时,藻类生物量随着E_t的增加而增大;E_t>300时则出现“光抑制”现象,藻类生物量随着E_t的增加而减少,基本符合藻类生物量随光辐射强度而改变的响应机制.      

青枯雷尔氏菌GMI1000菌株龙胆酸1,2-双加氧酶活性中心关键氨基酸残基的鉴定

生物信息学分析表明,位于青枯雷尔氏菌GMI1000菌株的染色体上的读码框RSc1087可能编码一个龙胆酸1,2-双加氧酶.本研究克隆、表达了该基因,并通过亲和层析对该基因表达产物进行了纯化.酶学测试结果证实,该基因编码的正是龙胆酸1,2-双加氧酶.SDS-PAGE结果表明,该酶亚基分子量约为38×103.基因的定点突变揭示105位、107位和146位组氨酸残基是该酶活性中心的关键氨基酸残基.     

SBAR反应器生物膜生长特性

采用载体吸附法的自固定化方式培养出活性良好的颗粒污泥———悬浮载体生物膜颗粒,并建立了生物膜物化特性和生化特性的系统分析方法。试验装置采用SBAR反应器,投加人工配水,裸载体为陶粒(湿视密度1 310 kg/m3、平均粒径0.55 mm)。试验运行了110 d,反应器内最大污泥浓度12.4 g/L,最大附着污泥浓度9.52 g/L。     

Evolution of soil fertility and nitrogen/phosphorus leaching risk in protected agriculture of the eastern Qinghai-Tibet Plateau北大核心CSCD

Understanding changes in soil fertility and soil environmental risks in protected agriculture with high irrigation and fertilizer inputs are of great significance for ecological protection. In this study, soil samples in the plow layer were collected from greenhouses >100 acres in the eastern Qinghai-Tibet Plateau after different durations of planting time (either ≤ 3, 3-5, 5-10, or 10-20 years) to assess the changing pattern of soil fertility indicators and the potential leaching risk of nitrogen and phosphorus. The results showed that soil organic matter (OM) and total nitrogen (TN) contents in protected agriculture were 17.1 and 1.3 g/kg, respectively, which suggests moderate content levels. Meanwhile, soil alkali-hydrolyzed nitrogen (AN), available phosphorus (Olsen-P), and available potassium (AK) contents were 160.9, 72.0, and 191.2 mg/kg, respectively, which suggests abundant content levels. As the number of planting years increased, the contents of soil OM, TN, AN, and Olsen-P increased significantly, especially after 10 years, with 41.6%, 44.2%, 26.5%, and 67.4% increases, respectively, compared to ≤ 3 years. As seen, Olsen-P had the most marked increase. In contrast, soil AK and pH decreased with planting years, and soil AK after 5 years decreased by 32% compared to ≤ 3 years. Moreover, the soil pH value in 3-5 years decreased by 2.3% compared to that of ≤ 3 years. The leaching risk of soil nitrogen and phosphorus was intensified after 10-20 years, and the probability of leaching was 0.74 and 0.84, respectively. This study indicated that, in protected agriculture, soil OM, AN, and Olsen-P contents improved, accompanied by a high risk of N and P loss, and AK and soil pH values decreased. It is recommended that the input of nitrogen and phosphorus fertilizers should be controlled, and the input of potassium fertilizer should be increased for more than 10 years of facility cultivation. This study provides a scientific basis for the rational fertilization of agricultural facilities. The findings indicate that after facility planting for 10-20 years, soil organic matter, nitrogen, and phosphorus significantly increased, yet the leaching risk of nitrogen and phosphorus increased as well, suggesting that the input of nitrogen and phosphorus fertilizer should be controlled. After 3-5 years of planting, soil AK and pH values decreased significantly, implicating that potassium and organic fertilizer should be supplemented in a timely manner. © 2022 Science Press. All rights reserved.