Ecology of the River Dolphin (Platanista gangetica) in the Upper Brahmaputra

There are nearly 200 species of aquatic vertebrates, almost exclusively fishes, in the Brahmaputra River System. This faunal composition includes not only a wide variety of food-fishes, but also about 50 varieties of aquarium fishes. The most spectacular animal in the Brahmaputra is undoubtedly the river dolphin, Platanista gangetica. The population of many species, particularly of the dolphin, is in steady decline. River dolphins, mostly juveniles, often entangle themselves in gill and drift nets, while feeding on trapped fishes. Proper implementation of Indian Fisheries Act, especially a total ban on destructive nets and on killing of brooders and juveniles by explosives and poisoning should be strictly implemented. Poor communication facilities in remote riverbank areas and lack of funds are two important reasons for the slow progress of the conservation of river dolphin and this endangered species is now on the verge of extinction. The anthropogenic activities and their impact on the habitat of river dolphin are discussed.     

A comprehensive analysis of blue water scarcity from the production,consumption, and water transfer perspectives

The issue of growing water scarcity has been increasingly perceived as a global systemic risk. To solve it, an integrated approach considering different perspectives of water scarcity is at a premise. In this study, we developed an approach to calculate the blue water scarcity (BWS) and integrated the production, consumption, and water transfer perspectives into a single framework. The results are as follows: The average BWS in the Hetao irrigation district was 0.491 during the 2001–2010 year period, which was much larger than the threshold of 0.30, indicating a high water stress level. From the production perspective, the agricultural sector was the largest contributor to regional water scarcity and the average BWS was as high as 0.479. From the consumption perspective, BWS related to virtual water export was much larger than that related to water consumption for making products to be consumed locally and the values were 0.422 and 0.069, respectively. Under the influence of physical and virtual water transfer, BWS changed from 0.242 (medium to high water stress level) to 0.491 (high water stress level). Strategies for reducing agricultural water consumption, such as increasing crop water productivity, improving irrigation efficiency, and promoting more reasonable irrigation water price, could be adopted in the Hetao irrigation district to alleviate regional BWS. Compared with physical and virtual water import, the virtual water export played a more important role in influencing the regional water scarcity, and the increase in crop water productivity, decrease in crop export volume, or adjustment of trade pattern from water-intensive crops to water-extensive ones could be feasible measures to decrease virtual water export for lower water stress, while the trade-offs in the product-consuming regions should be considered.     

南滚河流域土地利用变化对亚洲象生境的影响

土地利用变化对亚洲象生境影响显著,明晰其影响机制是有效保护亚洲象的前提。为探明土地利用变化对亚洲象生境影响的时空过程及机制,以亚洲象残存的中-缅跨境流域-南滚河流域为例,在1988和2018年两期Landsat土地利用/土地覆被遥感分类图的基础上,采用LandTrendr算法检测30年间流域土地利用变化引起的天然林扰动,结合生态位因子分析（ENFA）模型评定的亚洲象生境适宜性分布,探究以天然林扰动为主的土地利用变化对亚洲象生境的影响。结果表明：（1）1988-2018年间,南滚河流域土地利用变化主要为天然林转化为其他地类,且天然林扰动强度在中、缅境内差异明显;（2）以橡胶种植扩张导致毁林为主的土地利用变化造成南滚河流域亚洲象生境萎缩,生境斑块间连通性降低,破碎化程度较高;（3）该流域亚洲象生境丧失过程表现为由边缘向内部逐渐被蚕食,适宜生境最终被分割为上、下游两个相互孤立的子区域。因此,抑制以橡胶林为主的热作种植扩张,恢复上、下游生境连通性,建立流域尺度的跨境保护区,是实现南滚河流域亚洲象种群保护和缓解人象冲突的重要途径。     

An indicator framework for assessing the technology aspect of Integrated Lake Basin Management for Lake Malawi Basin

Lake Malawi is one of the African Great Lakes and is well known for its fish biodiversity which is the greatest in the world for freshwaters. The lake basin is a valuable resource to the riparian countries. Activities associated with the derivation of the values offered by the lake basin, however, result in the generation of wastes and pollutants that also impact on the lake basin. Such anthropogenic activities within the lake basin place considerable strain on the lake system and may lead to the degradation of the lake basin. Proper application of technology can effectively supplement command-and-control measures and economic instruments for better lake basin management. Currently, no comprehensive framework exists to assess the management of the lake basin. Such a framework is necessary to guide managers and policy-makers in the formulation of management plans and strategies for the sustainable management and utilization of the lake basin. We propose an indicator framework for assessing the technology aspect of Integrated Lake Basin Management (ILBM) in the context of the Lake Malawi Basin. We further demonstrate applicability of the proposed framework through a study conducted in the Malawian side of the basin. We applied a five point Likert-type scale in our indicator assessment. Overall, our results show that the technology aspect of the management of the lake basin is weak to moderate. This threatens the sustainability of the lake especially in the areas of solid waste management, sanitation services, pollution control and protection of wetlands and lagoons which performed from very low to moderate. The major challenges are weak institutional capacity, weak regulation enforcement, and insufficient resources.     

A critique on the water-scarcity weighted water footprint in LCA

The water footprint (WF) has been developed within the water resources research community as a volumetric measure of freshwater appropriation. The concept is used to assess water use along supply chains, sustainability of water use within river basins, efficiency of water use, equitability of water allocation and dependency on water in the supply chain. With the purpose of integrating the WF in life cycle assessment of products, LCA scholars have proposed to weight the original volumetric WF by the water scarcity in the catchment where the WF is located, thus obtaining a water-scarcity weighted WF that reflects the potential local environmental impact of water consumption. This paper provides an elaborate critique on this proposal. The main points are: (1) counting litres of water use differently based on the level of local water scarcity obscures the actual debate about water scarcity, which is about allocating water resources to competing uses and depletion at a global scale; (2) the neglect of green water consumption ignores the fact that green water is scarce as well; (3) since water scarcity in a catchment increases with growing overall water consumption in the catchment, multiplication of the consumptive water use of a specific process or activity with water scarcity implies that the resultant weighted WF of a process or activity will be affected by the WFs of other processes or activities, which cannot be the purpose of an environmental performance indicator; (4) the LCA treatment of the WF is inconsistent with how other environmental footprints are defined; and (5) the Water Stress Index, the most cited water scarcity metric in the LCA community, lacks meaningful physical interpretation. It is proposed to incorporate the topic of freshwater scarcity in LCA as a “natural resource depletion” category, considering depletion from a global perspective. Since global freshwater demand is growing while global freshwater availability is limited, it is key to measure the comparative claim of different products on the globe's limited accessible and usable freshwater flows.     

Distribution and risk assessment of heavy metals in river surface sediments of middle reach of Xijiang River basin,China

Xijiang River is the main surface water source in Guangxi province, South China. This study was carried out to investigate the distribution and potential ecological risks of seven heavy metals (Cu, Pb, Zn, As, Cd, Ni, and Cr) in surface sediments in Xijiang River basin. The results illustrated that the average concentrations of Zn, Pb, Cd, Cu, As, Ni, and Cr were 483.9, 207.5, 13.35, 23.50, 312.1, 28.75, and 50.62 mg/kg, respectively. Among them, Zn, Pb, Cd, and As were the major heave metals with concentration exceeding Class 3 threshold value of Chinese national standard. The result also showed samples with high ecological risk were mainly located in the upstream of Xijiang River basin as Diaojiang River, Hongshui River, Jincheng River, and Dahuan River. Based on the pollution risk assessment, the area manifested composite pollution of heavy metals in the sediments, signifying As, Pb, and Cd as the dominant heavy metals, and there were high ecological risk in sediments for these metals. According to correlation matrix and factor analysis (FA), the seven heavy metals were divided into three types/classes, Cd, as and Zn attributed by anthropogenic sources, natural sources corresponds for Ni and Cr while both natural and anthropogenic sources were attributed to Cu.     

Quantitative risk assessment of Listeria monocytogenes in ready-to-eat foods: the FAO/WHO approach

Quantitative microbiological risk assessment is a very new and unique scientific approach able to link, for the first time, data from food (in the farm-to-fork continuum) and the various data on human disease to provide a clear estimation of the impact of contaminated food on human public health. The Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO) have recently launched risk assessment studies of a number of pathogen-food commodity combinations (Salmonella in eggs and in broiler chickens, Listeria monocytogenes in ready-to-eat foods, Campylobacter in broiler chickens, Vibrio in seafood) to be used to lower the risk associated with these food-borne diseases and ensure fair practices in the international trade of food. The FAO/WHO Listeria risk assessment was undertaken in part to determine how previously developed risk assessments done at the national level could be adapted or expanded to address concerns related to L. monocytogenes in ready-to-eat foods at an international level. In addition, after initiation of the risk assessment, the risk assessors were asked by the Codex Committee on Food to consider three specific questions related to ready-to-eat foods in general, which are: (1). estimate the risk for consumers in different susceptible populations groups (elderly, infants, pregnant women and immunocompromised patients) relative to the general population; (2). estimate the risk for L. monocytogenes in foods that support growth and foods that do not support growth under specific storage and shelf-life conditions; (3). estimate the risk from L. monocytogenes in food when the number of organisms ranges from absence in 25 g to 1000 colonies forming units per gram or milliliter, or does not exceed specified levels at the point of consumption. To achieve these goals, new dose-response relationships and exposure assessments for ready-to-eat foods were developed. Preliminary data indicate that eliminating the higher dose levels at the time of consumption has a large impact on the number of predicted cases.     

基于SWAT模型的图们江流域蓝绿水资源供需平衡分析

随着经济快速发展和工农业各类用水量大幅增加,对河流的开发程度随之加强,流域水资源可持续利用受到不利影响。从蓝绿水视角出发,基于SWAT模型量化了图们江流域2015—2020年不同时间尺度下的蓝绿水资源并探讨了研究区水资源供需平衡情况。结果表明：研究时段内流域蓝绿水资源均具有明显的季节特征,年均蓝绿水资源量为117.16亿m³,其中蓝水资源量30.14亿m³,绿水资源量87.02亿m³,绿水占水资源量的74.27%。以年为尺度,蓝水资源供需评估指数>1,可利用蓝水资源量基本不能满足其需求量,降水少的年份蓝水资源供需矛盾突出,而绿水资源可以达到供需平衡,其供需评估指数集中在0.1—0.2之间。在月尺度分析中研究区蓝水供需评估指数出现极端值的频率较高,表明该地区蓝水供需不平衡,尤其是可利用蓝水资源一般在每年的7—8月才较为丰富,而蓝水需求用水集中分布于作物生长期,导致蓝水供应与蓝水需求在时间分配上不均衡,且在实际水资源分配中忽略了生态用水;月尺度绿水供需评估指数集中在0.1—0.4之间,有明显的季节变化特征,整体上绿水资...     

Occurrence and risk assessment of polycyclic aromatic hydrocarbons in the Hanjiang River Basin and the Danjiangkou Reservoir,China

This study was conducted to investigate the occurrence, distribution, and source of 16 polycyclic aromatic hydrocarbons (PAHs) in the Hanjiang River Basin and the Danjiangkou (DJK) Reservoir. The concentrations of total PAHs in surface water, sediments, and bank soils ranged from 9.42 to 137.94 ng/l, 86.23 to 2514.93 ng/g, and 133.17 to 671.93 ng/g dry weight, respectively. The composition pattern of PAHs showed that 3-ring PAHs were dominated in all of the samples, while the proportion of high molecular weight PAHs (5- to 6-ring PAHs) in sediments and bank soil samples was almost three times higher than water. The source apportionment analysis showed that most of the PAHs in water were derived from sources of petroleum and combustion, while combustion was the predominant source of PAHs in sediments and bank soils. The methods based on toxic equivalency factors, risk quotient, and incremental lifetime cancer risk were used to assess the ecosystem risk and potential health risk of PAHs. The risk assessments showed that PAHs in the DJK Reservoir were out of potential health risk, but the ecological risk for majority of 16 PAHs was in the moderate level.     

Climate-induced land health risk in farmland systems: A case study of Qarasou sub-basin in Karkheh River Basin

The present study was carried out to investigate the impact of climate change on land suitability for agricultural development in a sub-basin of Karkheh River Basin, Iran. For this, land suitability of the sub-basin was evaluated twice; once regardless of the climate change impact, and again by involving the impact of climate change. Simple Limitation Approach was used to evaluate the suitability of the sub-basin for cultivation of winter wheat. According to the results, around 22.57% (124121.16 ha) of the study area is suitable for cropping while the capability of 39.29% (216086.13 ha) of the sub-basin was evaluated to be poor/moderate for this purpose. In this research, in order to investigate the impact of climate change on farmlands, the changing trend of the four variables of maximum and minimum temperature, precipitation, and radiation were stimulated by the year 2039 using downscaled interpolation of IPCM general circulation model under three emission scenarios of A1B, A2, and B1. The stimulation was done by LARS-WG Software. The overlaying was done once more, but this time using the stimulated values. Comparing the current and stimulated land suitability maps revealed the fact that, in the most pessimistic future under A1B scenario, approximately 15.51% (85288.95 ha) of the study area will lose its capability for farming as a result of an increase of 1.3?C in temperature, and a decrease of 20.43% mm in total precipitation. The research finding emphasizes the risk of climate change on land health for farming purposes.     

海河流域森林生态系统服务功能评估

森林生态系统在流域中发挥着极其重要的生态作用,为流域发展提供着巨大的服务功能。本研究根据生态系统服务功能的内涵,建立了流域森林生态系统服务功能评价指标体系,利用市场价值法、影子工程法和生产成本法等,定量评价了海河流域森林生态系统服务功能的经济价值。结果表明：海河流域森林生态系统总价值2349.4亿元,其中直接价值358.7亿元,间接价值1990.7亿元。从不同的服务功能类型来看,其价值量大小依次为：涵养水源>固碳释氧>环境净化>提供产品>土壤保持>营养元素循环;从不同的森林类型来看,其价值量大小依次为：松柏类>灌丛>栎类>桦木类>混交林>杨树类>松杉类。但是从各种森林类型单位面积价值量来看,大小依次是：松杉类>松柏类>桦木类>混交林>栎类>杨树类>灌丛。从研究结果来看,海河流域森林生态系统服务功能价值巨大,该结果有利于加强人们对森林生态系统的认识,可以为流域生态系统管理、生态保护和生态补偿提供依据。     

Ecological risk assessment of metals in roadside agricultural soils: A modified approach

The threat of metal contamination of roadside agricultural soils poses severe ecological risks throughout the globe due to dual contamination by intensive agriculture and traffic-related activities. Therefore, the present study was conducted to assess ecological risks posed by metals (Cd, Co, Cr, Cu, Fe, Mn, Pb, and Zn) in intensively cultivated roadside agricultural soils of Punjab, India. The results of the contamination assessment factors i.e. Contamination Factor (CF) and Enrichment Factor (EF) indicated that the studied soils were moderately to highly contaminated with metals. It was observed that the Modified Risk Index (MRI), which is based upon EF, indicated the ecological risks of metals more efficiently than the traditional Ecological Risk Index (RI), which is based upon CF in the present study. The MRI values indicated that the metals posed considerable to high risk in 67.86% samples as compared to only 7.14% samples based upon RI values. Thus, MRI can be considered as a more efficient risk indicator in comparison to RI. Spatial distribution maps of MRI indicated to higher metal contamination in inner urban parts of study area due to higher traffic and industrial activities.     

基于CLUE-S模型的湟水流域土地利用空间分布模拟

基于CLUE-S模型,以青海湟水流域为研究区,分别利用1987年和1996年两期土地利用数据,运用逻辑斯蒂逐步回归方法选择自然和社会经济等18种驱动因子,对湟水流域2007年土地利用空间分布格局进行模拟.在此基础上,构建流域2008-2027年土地利用变化的4种不同情景,并模拟了4种情景下2027年土地利用空间分布格局.研究结果表明:(1)两期模拟总体精度分别达到了88.31％和89.96％,4种Kappa指数均大于0.82,表明CLUE-S模型在湟水流域具有良好的土地利用模拟能力.(2)流域2008-2027年不同情景下,城乡居住建设用地在4种情景下均表现为明显增加,主要沿湟水河谷区域扩展,而3种退耕情景下的坡耕地空间格局模拟结果存在着明显的空间差异,从情景二、情景三到情景四,流域内坡耕地范围逐步减小,林地、草地面积范围增大,退耕部分主要分布在流域东部、西部和北部:东部地区退耕的范围主要是集中在乐都县和民和县;北部地区退耕的范围主要是集中在大通县县城北部;西部地区退耕范围则主要在湟源县县城西北部的湟水河两岸.研究结论可为湟水流域未来土地利用管理、规划及政策的制定等提供参考依据和决策支持.     

An integrated risk assessment for climate change: analysing the vulnerability of sharks and rays on Australia's Great Barrier Reef

An Integrated Risk Assessment for Climate Change (IRACC) is developed and applied to assess the vulnerability of sharks and rays on Australia's Great Barrier Reef (GBR) to climate change. The IRACC merges a traditional climate change vulnerability framework with approaches from fisheries ecological risk assessments. This semi‐quantitative assessment accommodates uncertainty and can be applied at different spatial and temporal scales to identify exposure factors, at‐risk species and their key biological and ecological attributes, critical habitats a`nd ecological processes, and major knowledge gaps. Consequently, the IRACC can provide a foundation upon which to develop climate change response strategies. Here, we describe the assessment process, demonstrate its application to GBR shark and ray species, and explore the issues affecting their vulnerability to climate change. The assessment indicates that for the GBR, freshwater/estuarine and reef associated sharks and rays are most vulnerable to climate change, and that vulnerability is driven by case‐specific interactions of multiple factors and species attributes. Changes in temperature, freshwater input and ocean circulation will have the most widespread effects on these species. Although relatively few GBR sharks and rays were assessed as highly vulnerable, their vulnerability increases when synergies with other factors are considered. This is especially true for freshwater/estuarine and coastal/inshore sharks and rays. Reducing the impacts of climate change on the GBR's sharks and rays requires a range of approaches including mitigating climate change and addressing habitat degradation and sustainability issues. Species‐specific conservation actions may be required for higher risk species (e.g. the freshwater whipray, porcupine ray, speartooth shark and sawfishes) including reducing mortality, preserving coastal catchments and estuarine habitats, and addressing fisheries sustainability. The assessment identified many knowledge gaps concerning GBR habitats and processes, and highlights the need for improved understanding of the biology and ecology of the sharks and rays of the GBR.     

Coastal and estuarine ecological risk assessment: the need for a more formal approach to stressor identification

Application of ecological risk assessment to coastal and estuarine systems is accelerating although it initially lagged behind applications to land and freshwaters. Broader spatial and temporal scales, and multiple stressor integration are appropriately being considered more frequently in all risk assessment activities. This expansion and integration is essential for coastal risk assessment. Because coastal assessments must deal with co-occurrence of several candidate stressors manifesting within broad spatial and temporal scales, wider use of formal methods for assessing causal linkages is needed. Simple Bayesian inference techniques are discussed here to demonstrate their utility in quantifying the belief warranted by available information. The applicability of Bayesian techniques is illustrated with two examples, possible causes of fish kills on the Mid-Atlantic US coast and possible causes of hepatic lesions in fish of Puget Sound (Washington, US).     

Study on the Carbon Cycle of Leymus chinensis Steppe in the Xilin River Basin

Based on the past researches, an initial study on the carbon cycle of Leymus chinensis (Trin.) Tzvel. steppe in the Xilin river basin of Neimenggu (Inner Mongolia) was conducted by combining field surveys and the CENTURY model simulation. The major results were summarized as follows: 1) Observed annual amount of carbon fixation via primary production for a L. chinensis community on a fenced site in the basin averaged (231.25 + 74.41 ) g C·m-2·a-1, average annual carbon input into soil was about 220.75 g C· m- 2· a- 1, while carbon output from the community via soil respiration was estimated to be (181.03 + 46.32) g C· m-2· a-1 by CENTURY model simulation; 2) The community had a simulated net carbon gain of about 19.88 g C·m-2·a-1 and an observed carbon gain of 39.72 g C·m-2·a-1; 3) About 12.4% of carbon originally stored in soil had been lost due to over-grazing over the recent 40-year period in Leymus chinensis steppe in the Xilin river basin.     

基于生态保护目标的疏勒河中游绿洲生态环境需水研究

以疏勒河中游绿洲为研究对象,基于RS和GIS技术,选择1990年、2000年和2013年Landsat TM/ETM影像解译成果作为中游绿洲生态演变研究的基础资料,并确定了中游绿洲2020年和2030年生态保护目标。根据疏勒河中游绿洲生态环境需水特征,建立了基于天然植被、河流、湿地和防治耕地盐碱化的疏勒河中游绿洲生态环境需水定量化模型,并估算了现状和保护目标下流域中游绿洲生态需水量,从而为区域水资源合理配置和生态系统的协调发展提供参考依据。通过计算得出了疏勒河中游绿洲2013、2020和2030年天然植被、河流基本生态、河流输沙、河流渗漏补给、水面蒸发、湿地生态和防治耕地盐碱化生态环境需水量。同时得出疏勒河中游绿洲2013、2020和2030年疏勒河中游绿洲最大、最小和最适生态环境需水量分别为7.42×10~8、7.09×10~8、7.29×10~8,8.24×10~8、7.91×10~8、8.11×10~8m~3和9.12×10~8、8.79×10~8、8.99×10~8m~3。2013、2020和2030年疏勒河中游绿洲生态环境需水量年内变化主要集中于5—8月,累积生态环境需水量占全年的比例分别为58.01%、58.08%和58.13%;疏勒河中游绿洲生态环境需水量瓜州所占比例相对较大,玉门相对最小,敦煌介于二者之间。     

伊洛河流域草本植物群落物种多样性

生物多样性沿环境梯度的变化是生物多样性研究的重要内容,环境梯度包含了多种环境因子(海拔高度、水热条件、人类扰动等)的综合。以伊洛河流域草本植物群落为对象,沿河从入黄河口到河源地选取典型样地调查研究伊洛河流域草本植物群落物种多样性及其分布格局。结果表明:物种丰富度和Shannon-Wiener多样性指数沿河均稍呈"S"型曲线变化,不同群落类型中分布格局差别不大,各群落类型中的物种丰富度和多样性均呈现出中游丘陵山地交界区最高,上游河源区次之,下游平原地区最低的趋势;β多样性指数的变化趋势与α多样性较一致,总体上呈现出中游丘陵山地区物种更替速率较快,平原区更替较慢;在流域内上游河源地属于自然植被区,人为干扰较轻,具有较高的物种多样性,物种替代主要受物种的竞争扩散能力和生境条件的制约;在下游平原农业区,人类活动强烈,区域内以人工生态系统为主,物种组成简单,物种替代具有跳跃性的特征,主要受人类活动的制约;在中游从自然生态系统向农业生态系统的过渡区域,人类活动的扰动有一定的强度,导致该区域内自然分布种和伴人种混合生长,具有较高的物种多样性和较快的物种替代速率。总体上伊洛河流域草本植物群落物种多样性分布格局强烈的受到人类活动的影响,物种替代速率较高。     

A HIVE model for regional integrated environmental risk assessment: A case study in China

Regional environmental risk assessment has been a significant means of environmental management and decision-making. To assess the regional integrated environmental risk at a nationwide scale, a new index system named the Hazard, Intensity, Vulnerability, and Effectiveness (HIVE) model was designed and evolved from previous researches. The HIVE model consisted of a relatively complete framework with accessible indexes related to environment and social economy, and it considered different risk sources, pathways, and receptors as well as the influence of the risk control. As an important segment of the assessment process, a simple gridding information diffusion method was also proposed to assess the diffusion effect of risk factors in nationwide rivers. Taking China as a case study, this study calculated the environmental risk value of every sub-unit. Through the clustering function of Statistical Package for Social Sciences and the visual representation of a geographic information system, the study area was divided into nine zones that were visualized on maps according to their different risk levels and risk characteristics. This study also identified the dominant factors of each zone, which could provide the foundation for regional environmental management. Moreover, the results implied some significant correlations between risk system components and the regional social economy in China.