Excess seawater nutrients,enlarged algal symbiont densities and bleaching sensitive reef locations: 2. A regional-scale predictive model for the Great Barrier Reef,Australia

A spatial risk assessment model is developed for the Great Barrier Reef (GBR, Australia) that helps identify reef locations at higher or lower risk of coral bleaching in summer heat-wave conditions. The model confirms the considerable benefit of discriminating nutrient-enriched areas that contain corals with enlarged (suboptimal) symbiont densities for the purpose of identifying bleaching-sensitive reef locations. The benefit of the new system-level understanding is showcased in terms of: (i) improving early-warning forecasts of summer bleaching risk, (ii) explaining historical bleaching patterns, (iii) testing the bleaching-resistant quality of the current marine protected area (MPA) network (iv) identifying routinely monitored coral health attributes, such as the tissue energy reserves and skeletal growth characteristics (viz. density and extension rates) that correlate with bleaching resistant reef locations, and (v) targeting region-specific water quality improvement strategies that may increase reef-scale coral health and bleaching resistance.     

Linking human-biophysical interactions with the trophic status of Dal Lake,Kashmir Himalaya,India

The study analyses the long-term biophysical and demographic changes in Dal lake, located in the heart of Srinagar city, Kashmir India, using a repository of historical, remote sensing, socio-economic and water quality data supported by the extensive field observations. The lake faces multiple pressures from the unplanned urbanization, high population growth, nutrient load from intensive agriculture and tourism. The data showed that the lake has shrunk from 31 km² in 1859–24 km² in 2013. Significant changes were observed in the land use and land cover (LULC) within the lake (1859–2013) and in the vicinity of the lake (1962–2013). Analysis of the demographic data indicates that the human population within the lake has shown more than double the national growth rate. Additionally, 7 important water quality parameters from 82 well distributed sites across the lake were analyzed and compared with the past data to determine the historical changes in the water quality from 1971 to 2014. The changes in the LULC and demography have adversely affected the pollution status of this pristine lake. Ortho-phosphate phosphorous concentration has increased from 16.75 μg L⁻¹ in 1977–45.78 μg L⁻¹ in 2014 and that of the nitrate-nitrogen from 365 μg L⁻¹ to 557 μg L⁻¹, indicating nutrient enrichment of the lake over the years. Built-up area within the lake has increased 40 times since 1859, which, together with the changes in the population and settlements, have led to the high discharge of untreated nutrient-rich sewage into the lake. Similarly the expansion of floating gardens within the lake and agriculture lands in the catchment has contributed to the increased nutrient load into the lake due to the increasing use of fertilizers. The information about the existing land cover, demography and water quality was integrated and analyzed in GIS environment to identify the trophic status of the lake. The analysis indicated that 32% of the lake falls under sever degradation, 48% under medium degradation while as 20% of the lake waters are relatively clean. It is believed that the results provide improved knowledge and insights about the lake health and causal factors of its degradation necessary for effectively restoring its ecological and hydrological functionality.     

基于生态系统的海洋综合管理研究 ——以美国大沼泽湿地项目为例

基于生态系统的海洋综合管理是海洋管理的新理念和新模式,其倡导从海洋生态系统角度开展环境资源保护,并以促进海洋生态系统与人类开发活动的协调可持续发展为终极目标。美国大沼泽湿地项目是基于生态系统的海洋综合管理的经典范例。基于生态系统的海洋综合管理的核心理念是将整个生态系统纳入海洋综合管理范畴,颠覆传统的单一对象保护理念,实现海洋生态保护与人类生存发展协调可持续。美国大沼泽湿地项目采用了基于生态系统的海洋综合管理理念,将整个大沼泽湿地视为一个整体生态系统,实现联邦政府、州政府和社会组织协作,合力促进大沼泽湿地的绿色生态可持续发展。美国大沼泽湿地项目全面贯彻基于生态系统的海洋综合管理理念,采用联合管理模式,重视水资源环境治理取得一定成效,但也暴露出管理模式有待改进、公众宣传参与不到位、区域间联系不紧密等问题。     

A method for non-parametric damage detection through the use of neural networks

A neural network-based approach is presented for the detection of changes in the characteristics of structure-unknown systems. The approach relies on the use of vibration measurements from a ‘healthy’ system to train a neural network for identification purposes. Subsequently, the trained network is fed comparable vibration measurements from the same structure under different episodes of response in order to monitor the health of the structure. The methodology is applied to actual data obtained from ambient vibration measurements on a steel building structure that was damaged under strong seismic motion during the Hyogo-Ken Nanbu Earthquake of 17 January 1995. The measurements were done before and after repairs to the damaged frame were made. A neural network is trained with data after the repairs, which represents ‘healthy’ condition of the building. The trained network, which is subsequently fed data before the repairs, successfully identified the difference between the damaged storey and the undamaged storey. Through this study, it is shown that the proposed approach has the potential of being a practical tool for a damage detection methodology applied to smart civil structures. © 1998 John Wiley & Sons, Ltd.     

我国霾研究进展与公共安全影响应对*

在给出霾的定义、特征及空间分布的基础上,介绍了霾的物理学特性、化学特性及气象学研究的最新进展,分析了霾对公共卫生健康、交通安全的影响, 提出了科学编制防御规划、统筹建立协调机制、有效推进减霾行动、提供相应科技支撑、完善相关政策法规等对策建议,对于政府相关部门制定霾天气应对和防治措施具有积极的决策参考作用,减少或减轻霾对经济社会发展和人体健康带来的损害威胁。     

中国城市公共健康水平的时空演化及其影响因素

采用定基极差熵权法与定基等权赋值法相结合的综合评价方法、核密度估计、探索性空间数据分析等方法,分析2003—2018年中国284个地级以上城市公共健康水平的时空演化特征,并运用广义空间两阶段最小二乘法考察其影响因素。结果发现：① 研究期内中国城市公共健康水平整体呈上升趋势,但各城市间公共健康水平差异有所扩大,且始终存在多级分化现象;② 四大板块核密度曲线在重心位置、主峰高度、波峰数量、拖尾长度、拖尾厚度上均有各自演化形态,是一种时段特征与地区特色相互耦合叠加的结果;③ 中国城市公共健康水平存在正向空间溢出效应和空间“同群效应”,空间集聚类型实现了由LL型为主体向HH型为主体的转化;④ 收入水平、人口密度、科技进步、工业化程度、卫生体制改革对城市公共健康具有影响,但各因素对不同区域的影响存在异质性。     

杭州城市人口密度对人居环境感知的影响

研究人口密度与人居环境感知的非线性关系对于合理控制大城市规模、制定适宜的人口密度控制标准以及寻求城镇化科学发展具有重要的现实意义。以杭州为案例城市,基于2020年住建部“城市体检”社会满意度问卷调查结果和杭州城市建成环境空间数据,利用三阶段逐步回归模型和中介效应检验重点分析了人口密度与居民生态宜居感知、健康舒适感知和交通便捷感知的非线性关系,并分析了人口密度对不同维度人居环境感知的影响路径。研究发现：人口密度与居民生态宜居感知、健康舒适感知和交通便捷感知具有显著的倒U型关联,当人口密度在（1.5~2.0）万人/km²时,居民对这3个维度的感知情况最好;在影响路径方面,人口密度对居民生态宜居感知的影响路径为部分中介,对居民健康舒适感知以及交通便捷感知的影响路径为完全中介。研究不仅可以加深对于紧凑城市理论的理解,还可以为城市体检工作中指标参照值的设置提供科学的参考依据,促进新型城镇化健康有序地发展。     

淮河流域平原区高铁锰地下水环境健康风险评估

基于近期获得的水文地球化学分析数据,应用指示克立格法开展了淮河流域平原区高铁、锰地下水环境健康风险评估,并分析了高铁、锰地下水的形成原因。结果表明:铁、锰是影响研究区地下水质量的主要化学组分,铁、锰在地下水中的空间分布上表现出明显的变异性。铁、锰超标概率峰值具有相似的空间分布格局,铁、锰高风险地区呈岛状分布,深层地下水的环境健康风险明显降低。含铁浅层地下水高风险地区面积为1 257.15 km2,面积占比0.07％;含铁深层地下水高风险地区面积为476.93 km2,面积占比0.03％。含锰浅层地下水高风险地区面积为35 883.16 km2,面积占比19.19％;含锰深层地下水高风险地区面积为1 269.30 km2,面积占比0.07％。淮河流域高铁锰地下水是原生成因,铁、锰离子主要来源于含水层中含铁、锰矿物的还原性溶解。高铁锰地下水的风险评价结果,可为区域供水区划提供指导。     

我国古食谱稳定同位素分析的影响因素及其蕴含的考古学信息

根据"我即我食"原理,生物体组织的稳定同位素组成与其食物来源密切相关。多样化食物资源与复杂的新陈代谢暗示着生物体组织的稳定同位素组成可能受到自然环境、人类活动以及自身生理健康等多因素的影响。对这些影响因素的综合评估不仅为更全面准确的重建古代人（或动物）的食谱提供重要依据,同时,结合考古学文化发展脉络,判断引起考古遗址出土生物体稳定同位素组成时空变化的主导因素,又可为揭示古代人地关系、人类活动以及社会经济发展等提供新的视角。为此,以我国古代独具特色的饮食文化为背景,在多因素影响机理论述基础之上,探讨可能影响我国古代人（或动物）稳定同位素食谱分析的各方面因素;同时,通过对不同影响因素的诠释,揭秘其背后隐藏的考古学信息。