The impact of climate change and human activities on streamflow and sediment load in the Pearl River basin

This paper uses monthly streamflow, suspended sediment concentration, and meteorological data to examine the impact of human activity and climate change on streamflow and sediment load in the Pearl River basin from the 1950s to the 2000s. The influences of climate change and human activities on hydrological processes were quantitatively evaluated using the Mann–Kendall abrupt change test and power rating curves. The results showed that:(1) abrupt changes and turning points in streamflow occurred in 1963, 1983, and 1991 which were found to be consistent with global ENSO events and volcanic eruptions. However, abrupt changes in sediment load showed significant spatial differences across the Pearl River basin. For the Xijiang River, an abrupt change in sediment load occurred in 2002, and after 2007 the change becomes significant at the 95% confidence level. At Beijiang and Dongjiang, abrupt changes in sediment load occurred in 1998 and 1988, respectively.(2) The time series of sediment load data was divided into four periods according to abrupt changes. The contribution of climate change and human activities is different in the different rivers. For the Xijiang River, compared with the first period, climate change and human activities contributed 83% and 17%, respectively, to the increasing sediment load during the second period. In the third period, the variation of sediment load followed a decreasing trend. The contribution from climate change and human activities also changed to t236% and -136%, respectively. In the fourth period, climate change and human activities contributed -32% and t132%, respectively. Meanwhile, For the Beijiang River, climate change and human activities contributed 90% and 10% in the second period, the contribution of climate change increased to t115% and human activities decreased to -15% in the third period. In the fourth period, the value for climate change decreased to t36% and human activities increased to t64%. For the Dongjiang River, the contribution of human activities was from 74.5% to 90%, and the values for climate change were from 11% to 25%. Therefore, the effect of human activity showed both spatial and temporal differences, and it seems likely that the decreased sediment load will continue to be controlled mainly by human activities in the future.     

Solar and geomagnetic activity, extremely low frequency magnetic and electric fields and human health at the Earth’s surface

The possibility that conditions on the Sun and in the Earth’s magnetosphere can affect human health at the Earth’s surface has been debated for many decades. This work reviews the research undertaken in the field of heliobiology, focusing on the effect of variations of geomagnetic activity on human cardiovascular health. Data from previous research are analysed for their statistical significance, resulting in support for some studies and the undermining of others. Three conclusions are that geomagnetic effects are more pronounced at higher magnetic latitudes, that extremely high as well as extremely low values of geomagnetic activity seem to have adverse health effects and that a subset of the population (10–15%) is predisposed to adverse health due to geomagnetic variations. The reported health effects of anthropogenic sources of electric and magnetic fields are also briefly discussed, as research performed in this area could help to explain the results from studies into natural electric and magnetic field interactions with the human body.Possible mechanisms by which variations in solar and geophysical parameters could affect human health are discussed and the most likely candidates investigated further. Direct effects of natural ELF electric and magnetic fields appear implausible; a mechanism involving some form of resonant absorption is more likely. The idea that the Schumann resonance signals could be the global environmental signal absorbed by the human body, thereby linking geomagnetic activity and human health is investigated. Suppression of melatonin secreted by the pineal gland, possibly via desynchronised biological rhythms, appears to be a promising contender linking geomagnetic activity and human health. There are indications that calcium ions in cells could play a role in one or more mechanisms. It is found to be unlikely that a single mechanism can explain all of the reported phenomena.     

Climate and human health: synthesizing environmental complexity and uncertainty

Broad relationships between weather and human health have long been recognized, and there is currently a large body of research examining the impacts of climate change on human health. Much of the literature in this area examines climate–health relationships at global or regional levels, incorporating mostly generalized responses of pathogens and vectors to broad changes in climate. Far less research has been done to understand the direct and indirect climate-mediated processes involved at finer scales. Thus, some studies simplify the role of climate and may over- or under-estimate the potential response, while others have begun to highlight the subtle and complex role for climate that is contingent on other relevant processes occurring in natural and social environments. These fundamental processes need to be understood to determine the effects of past, current and future climate variation and change on human health. We summarize the principal climate variables and climate-dependent processes that are believed to impact human health across a representative set of diseases, along with key uncertainties in these relationships.     

气候变化和人类活动对鄱阳湖流域径流过程影响的定量分析

量化气候变化和人类活动对流域水文影响及其对流域水资源规划和管理具有重要的理论与现实意义.采用水文模型和多元回归法定量分析气候变化和人类活动对鄱阳湖"五河"径流的影响,并通过与灵敏度分析法对比来进一步验证分析结果 .研究表明,1970-2009年,气候变化和人类活动对鄱阳湖流域径流增加的贡献率分别为73%和27%.气候变化是饶河、信江和赣江径流增加的主导因素,而人类活动是修水径流增加的主要因素,是抚河径流减少的主要原因.另外,不同季节影响径流变化的主导因素又有不同,人类活动为干季(11月到次年2月)径流增加和湿季(4-6月)径流减小的主导因素,其贡献率分别为78.9%和82.7%.本研究可为鄱阳湖流域防洪抗旱及水资源优化配置提供重要科学依据.     

Biomarkers in environmental and human health risk assessment

Marine pollution is a major threat to human and environmental health. Given the complexity of function of marine and coastal ecosystems, it is unlikely that a balanced view of the nature and extent of risk will easily be achieved if human and environmental risk assessments continue to be conducted in isolation. Here, the integration of assessment protocols is advocated as a holistic means of improving risk management. Biomarkers can provide the common conceptual framework and measurable endpoints necessary for successful integration. Examples are given of the ways in which suites of biomarkers encompassing molecular change, cellular pathology and physiological impairment can be developed and adapted for human and ecological scenarios. By placing a greater emphasis on the health status of impacted biota, it is more likely that risk assessment will develop the efficiency, reliability and predictive power to adapt to the unforeseen environmental threats that are an inevitable consequence of human development and global change.     

Evaluation of impacts of climate change and human activities on streamflow in the Poyang Lake basin,China

Variations in streamflows of five tributaries of the Poyang Lake basin, China, because of the influence of human activities and climate change were evaluated using the Australia Water Balance Model and multivariate regression. Results indicated that multiple regression models were appropriate with precipitation, potential evapotranspiration of the current month, and precipitation of the last month as explanatory variables. The NASH coefficient for the Australia Water Balance Model was larger than 0.842, indicating satisfactory simulation of streamflow of the Poyang Lake basin. Comparison indicated that the sensitivity method could not exclude the benchmark‐period human influence, and the human influence on streamflow changes was overestimated. Generally, contributions of human activities and climate change to streamflow changes were 73.2% and 26.8% respectively. However, human‐induced and climate‐induced influences on streamflow were different in different river basins. Specifically, climate change was found to be the major driving factor for the increase of streamflow within the Rao, Xin, and Gan River basins; however, human activity was the principal driving factor for the increase of streamflow of the Xiu River basin and also for the decrease of streamflow of the Fu River basin. Meanwhile, impacts of human activities and climate change on streamflow variations were distinctly different at different temporal scales. At the annual time scale, the increase of streamflow was largely because of climate change and human activities during the 1970s–1990s and the decrease of streamflow during the 2000s. At the seasonal scale, climate change was the main factor behind the increase of streamflow in the spring and summer season. Human activities increase the streamflow in autumn and winter, but decrease the streamflow in spring. At the monthly scale, different influences of climate change and human activities were detected. Climate change was the main factor behind the decrease of streamflow during May to June and human activities behind the decrease of streamflow during February to May. Results of this study can provide a theoretical basis for basin‐scale water resources management under the influence of climate change and human activities. Copyright © 2016 John Wiley & Sons, Ltd.     

POPs in edible clams from different Italian and European markets and possible human health risk

Human intake of persistent organic pollutants (POPs) occurs primarily through diet and fish and other seafood represent the principal means of contamination. Despite this, few legal limits have been established to protect human health from the various chemicals that are alleged to be carcinogenic or endocrine disruptor compounds.Several pools of edible clams (Tapes philippinarum and Venus gallina) bought in different Italian and European markets were examined in order to perform a risk assessment of some of these contaminants and also to identify possible health issues. POP concentrations in the soft tissues of mollusks varied considerably among source farming sites, particularly in the Venice Lagoon. Some POPs (DDTs, HCB and HCHs) showed very low concentrations and no risk for human health, in line with the limits established by European law. In contrast, PAHs could represent a potential hazard for human health and PCB levels in the most contaminated sites reached or even exceed the Minimal Risk Level as set by the ATSDR for human consumption, even if all the samples did not exceed the PCB limits in edible seafood as set by the FDA.     

The geomorphology of the Anthropocene: emergence,status and implications

The Anthropocene is proposed as a new interval of geological time in which human influence on Earth and its geological record dominates over natural processes. A major challenge in demarcating the Anthropocene is that the balance between human‐influenced and natural processes varies over spatial and temporal scales owing to the inherent variability of both human activities (as associated with culture and modes of development) and natural drivers (e.g. tectonic activity and sea level variation). Against this backdrop, we consider how geomorphology might contribute towards the Anthropocene debate by focusing on human impact on aeolian, fluvial, cryospheric and coastal process domains, and how evidence of this impact is preserved in landforms and sedimentary records. We also consider the evidence for an explicitly anthropogenic geomorphology that includes artificial slopes and other human‐created landforms. This provides the basis for discussing the theoretical and practical contributions that geomorphology can make to defining an Anthropocene stratigraphy. It is clear that the relevance of the Anthropocene concept varies considerably amongst different branches of geomorphology, depending on the history of human actions in different process domains. For example, evidence of human dominance is more widespread in fluvial and coastal records than in aeolian and cryospheric records, so geomorphologically the Anthropocene would inevitably comprise a highly diachronous lower boundary. Even to identify this lower boundary, research would need to focus on the disambiguation of human effects on geomorphological and sedimentological signatures. This would require robust data, derived from a combination of modelling and new empirical work rather than an arbitrary ‘war of possible boundaries' associated with convenient, but disputed, ‘golden’ spikes. Rather than being drawn into stratigraphical debates, the primary concern of geomorphology should be with the investigation of processes and landform development, so providing the underpinning science for the study of this time of critical geological transition. Copyright © 2016 John Wiley & Sons, Ltd.     

Separating climate change and human contributions to variations in streamflow and its components using eight time‐trend methods

Separating impacts of human activities and climate change on hydrology is essential for watershed and ecosystem management. Many previous studies have focused on the impacts on total streamflow, however, with little attentions paid to its components (i.e., baseflow and surface run‐off). This study distinguished the contributions of climate change and human activities to the variations in streamflow, baseflow, and surface run‐off in the upstream area of the Heihe River Basin, a typical inland river basin in northwest China, by using eight different forms of time‐trend methods. The isolated contributions to streamflow variation were also compared with those obtained by two Budyko‐based approaches. Our results showed that the time‐trend methods consistently estimated positive contributions of climate variability and human activities to the increases in streamflow and its components but with obviously varying magnitudes. With regard to streamflow, the time‐trend method double‐mass‐curve–Wei, with a physical basis, produced a reasonable smaller contribution of human activities than climate changes, inconsistent with the Budyko‐based approaches. However, all the other time‐trend methods led to contrary results. The contributions to baseflow variation diverged more significantly than those to streamflow and surface run‐off, ranging from 24% to 92% for human activities and from 8% to 76% for climate variability. In terms of surface run‐off, most of the time‐trend approaches produced smaller contributions of human activities (ranging from 21% to 49%) than climate change. The uncertainties associated with the various time‐trend approaches and the baseflow separation algorithm were revealed and discussed, along with some recommendations for future work.     

The relative roles of climate variations and human activities in vegetation change in North China

Using SPOT-VEGETATION Normal Difference Vegetation Index (SPOT/NDVI) data from 1998 to 2011 and climate data obtained from 223 weather stations in or near North China, vegetation variation characteristics within North China were analyzed. Vegetation variation characteristics under the influence of climate variations and human activities were distinguished through a residual analysis. Based on the results of that analysis, the relative roles of climate variations and human activities in vegetation variation were calculated. The results showed that NDVI observed by remote sensing (SPOT/NDVI) increased from 1998 to 2011. The relative roles of climate variations and human activities in vegetation increase were 30.82% and 69.18%, respectively, indicating that human activities played a major role. And observed NDVI showed an increasing trend for different land cover types overall. While NDVI increase in shrub was mainly caused by climate variations, NDVI increases in forest, grassland, farmland, deserts and urban were all primarily caused by human activities. For areas with increasing vegetation, as identified by remote sensing observations in North China, the relative roles of climate variations and human activities in vegetation change were calculated at 14.85% and 85.15% respectively, again indicating that human activities played an important role in vegetation increase. For areas of decreasing vegetation, as identified by remote sensing observations in North China, the relative roles of climate variations and human activities in vegetation change were calculated at 87.72% and 12.28% respectively, indicating that climate variations had large negative effects on vegetation condition. In addition, the relative roles of climate variations and human activities on vegetation variation have obvious spatial differences in North China. Human activities played a positive role in vegetation growth in North China. However, we cannot ignore the function of human destruction on vegetation variation in some areas.     

围垦对鄱阳湖洪水位的影响及防治对策

１９９２年１０月,在江汉平原沔城钻探,取得总长５６．１８ｍ的柱状岩芯。根据Ｍ１孔湖泊沉积岩性及所含文化遗物,＾１４Ｃ年代测定,以及深受人类活动影响的气候与环境指标如孢粉,频率磁化率,化学元素Ｐ等分析,结合该区文化遗址的时空分布,揭示了沔城地区中晚全新世人类活动的时间序列及与古气候,古环境的关系：６．７－３．５ｋａＢＰ该区气候温暖湿润,为河间洼地和浅湖环境;２．５－１．７ｋａＢＰ湖泊稳定,均无人类居     

基于超宽带雷达及支持向量机的灾后人体呼吸信号识别方法与试验研究

与常规雷达相比,超宽带雷达具有距离分辨力高、近距离盲区小、穿透性强、目标识别率高等特点,已被广泛应用于灾后搜寻、救援工作中,以对受困生命体征目标进行生命探测。为实现使用超宽带雷达对受困生命体征目标的识别定位,本研究提出基于信号多特征提取技术及支持向量机模型的人体呼吸信号识别方法。首先,使用经验模态分解、变分模态分解及希尔伯特变换提取雷达探测信号的微多普勒特征,使用傅里叶变换提取宏观频谱特征,使用相关分析获取相关性特征;然后,以提取的信号特征为输入,使用支持向量机模型对信号进行分类,进而对人体呼吸信号进行识别,对人体位置进行定位。不同障碍物场景下的试验结果表明,本方法可有效识别砖墙、建筑楼板等遮挡物下的受困生命体征目标,并提供其位置信息。     

The role of long‐term human impact on avulsion and fan development

This study aims to understand (mainly qualitatively) the long‐term role of human impact on avulsion processes and the development of fluvial (mega‐) fans in semi‐arid environments. In this paper we refer to human impact as the direct influences of actions on the river's hydraulics (i.e. flow regulation, flow diversion and channel engineering). In five case‐studies drawn from the Khuzestan plains in southwest Iran we have analysed the setup and triggering conditions of specific avulsions that occurred in the past (timescale of millennia) and identified the role of human interference in their causation. Our analysis is based on the integration of historical, archaeological, geomorphological and geological data. Through this study we demonstrate that avulsions in the Khuzestan plains are the result of long‐term and complex interplay between multiple human‐induced and natural causes. In similar ways human‐induced actions may play important roles during different phases of avulsion development. The ‘success‘ of an avulsion in the post‐triggering phase may be defined by human‐induced setup causes as well as morphodynamic processes. We suggest that present‐day flood events may be partly inherited from long‐term human alterations of the natural processes. These finding could have implications for any fluvial system (e.g. distributive fluvial systems, deltas) where avulsion plays a major role in their development and research tends to emphasize on natural mechanisms. Copyright © 2016 John Wiley & Sons, Ltd.     

Evaluation of sewage source and fate on southeast Florida coastal reefs

Water, sponge and coral samples were collected from stations impacted by a variety of pollution sources and screened for human enteric viruses as conservative markers for human sewage. While human enteroviruses and adenoviruses were not detected, noroviruses (NoV; human genogroups I and II) were detected in 31% of samples (especially in sponge tissue). Stations near inlets were the only ones to show multiple sample types positive for NoV. Fecal indicator bacteria and enteric viruses were further evaluated at multiple inlet stations on an outgoing tide. Greatest indicator concentrations and highest prevalence of viruses were found at the mouth of the inlet and offshore in the inlet plume. Results suggest that inlets moving large volumes of water into the coastal zone with tides may be an important source of fecal contaminants. Efforts to reduce run-off or unintended release of water into the Intracoastal Waterway may lower contaminants entering sensitive coastal areas.     

Hydrological change driven by human activities and climate variation and its spatial variability in Huaihe Basin,China

ABSTRACT

This study investigated the impacts of human activities, especially water resources development, and climate variation on the runoff reduction and its spatial variability in the Huaihe Basin, the sixth largest river basin in China, which is also an important agricultural area in Eastern China. The annual runoff had statistically negative trends at all hydrological stations located on the main river and the major tributaries, which ranges from ?0.13 to ?1.99 mm year^-1. The Budyko-based approach was employed to quantitatively differentiate the runoff reduction driven by human activities and climate variation. Results showed that the precipitation decrease contributed to the runoff reduction in all study sub-catchments. However, significant reductions of the annual runoff in some sub-catchments were mainly caused by the human activities rather than the precipitation decrease. Spatial variability of hydrological changes were closely related to different types of human activities especially irrigation and water diversion. In the southern sub-catchments, water diversion played a significant role in runoff reduction, while agriculture irrigation was the relatively dominant driving factor in the northern sub-catchments. The results show the complexity in the catchment hydrological response to the changes in climate forcing and human water resources development and the effectiveness of the Budyko-based approach for attribution analysis.

Editor D. Koutsoyiannis; Associate editor C. Cudennec     

Quantitative assessment of the contribution of climate variability and human activity to streamflow alteration in Dongting Lake,China

Climate variability and human activity were regarded as two contributors to streamflow alteration. However, the contributions of the two factors were still unclear in Dongting Lake. Therefore, it was crucial to quantify the relative impact of climate variability and human activity on streamflow alteration. The time series (1961–2010) was divided into three periods, namely, natural period (1961–1980), change period I (1981–2002) and change period II (2003–2010). Sensitivity analysis based on Budyko‐type equations was applied to reveal the contributions of climate variability and human activity in those two change periods, respectively. The results showed that during the change period I, climate variability was the main factor responsible for streamflow alteration in most parts of Dongting Lake, accounting for 60.07–67.27%. However, the impact of climate variability was slightly smaller than that of human activity in West Dongting Lake (the former accounting for 43.20% while the latter accounting for 56.80%). For the change period II, human activity was the dominate factor for streamflow alteration, accounting for 58.89–78.33%. The impact of climate variability gradually decreased while the impact of human activity gradually increased. Along with the intensification of the human activity, the impact of it became more dominant. The results could provide a reference for water resources planning and management decisions. Under the condition of uncontrollable climatic factor, effective measures should be put forward in controlling human activity, such as reservoir/dam operation, closed management of protected area and so on. Besides, it is essential to study the impact of climate variability on future water resources and water resource management under different climate change scenarios. Copyright © 2016 John Wiley & Sons, Ltd.     

Volcanoes and human history

The study of volcanic hazards leads inevitably to questions of how past cultures have lived in volcanically active regions of the world. Here we summarize linkages between volcanological, archaeological and anthropological studies of historic and prehistoric volcanic eruptions, with the goal of evaluating the impact of past eruptions on human populations to better prepare for future events. We use examples from papers collected in this volume to illustrate ways in which volcanological studies aid archaeological investigations by providing basic stratigraphic markers and information about the nature and timing of specific volcanic events. We then turn to archaeological perspectives, which provide physical evidence of the direct impacts of volcanic eruptions, such as site abandonment and human migration, as well as indirect impacts on local cultures as reflected in human artifacts. Finally we review anthropological studies of societal responses to past and recent volcanic eruptions. We pay particular attention to both the psychological impact of catastrophic events and records of these impacts encoded within oral traditions. Taken together these studies record drastic short-term eruption impacts but adaptation to volcanic activity over the longer term, largely through strategies of adaptive land use.     

Relative effects of human activities and climate change on the river runoff in an arid basin in northwest China

Understanding the mechanisms of river runoff variation is important for the effective management of water resources in arid and semi‐arid regions. This study uses long‐term observational data as a basis for examining the effects of human activities and climate change on the runoff variation of Jinghe River Basin, a typical arid inland basin in northwest China. A distributed hydrological model called the Soil and Water Assessment Tool, combined with a sequential cluster method and a separation approach, was used to quantify and distinguish the effects of human activities and climate change on runoff. The hydrological sequence before 1981 can be considered natural. However, human activities have significantly affected runoff since 1981. The runoff reduction caused by human activities between 1981 and 2008 accounted for 85.7% of the total reduction in the downstream of Jinghe River, whereas that caused by climatic variation was only 14.3%. This observation suggests that human activities are the major driver of runoff variation in the basin. Although the role of climate change in driving runoff variation has been identified to be prevalent and dominant in arid regions, this study highlights the importance of human activities. Copyright © 2013 John Wiley & Sons, Ltd.     

Understanding the relative impacts of natural processes and human activities on the hydrology of the Central Rift Valley lakes,East Africa

Significant changes have been observed in the hydrology of Central Rift Valley (CRV) lakes in Ethiopia, East Africa as a result of both natural processes and human activities during the past three decades. This study applied an integrated approach (remote sensing, hydrologic modelling, and statistical analysis) to understand the relative effects of natural processes and human activities over a sparsely gauged CRV basin. Lake storage estimates were calculated from a hydrologic model constructed without inputs from human impacts such as water abstraction and compared with satellite‐based (observed) lake storage measurements to characterize the magnitude of human‐induced impacts. A non‐parametric Mann–Kendall test was used to detect the presence of climatic trends (e.g. a decreasing or increasing trends in precipitation), while the Standard Precipitation Index (SPI) analysis was used to assess the long‐term, inter‐annual climate variability within the basin. Results indicate human activities (e.g. abstraction) significantly contributed to the changes in the hydrology of the lakes, while no statistically significant climatic trend was seen in the basin, however inter‐annual natural climate variability, extreme dryness, and prolonged drought has negatively affected the lakes. The relative contributions of natural and human‐induced impacts on the lakes were quantified and evaluated by comparing hydrographs of the CRV lakes. Lake Abiyata has lost ~6.5 m in total lake height between 1985 and 2006, 70% (~4.5 m) of the loss has been attributed to human‐induced causes, whereas the remaining 30% is related to natural climate variability. The relative impact analysis utilized in this study could potentially be used to better plan and create effective water‐management practices in the basin and demonstrates the utility of this integrated methodology for similar studies assessing the relative natural and human‐induced impacts on lakes in data sparse areas. Copyright © 2015 John Wiley & Sons, Ltd.     

Assessing the relative role of climate change and human activities in sandy desertification of Ordos region,China

Climate change and human activities are driving forces of sandy desertification and the relative role of them in sandy desertification is the hot point in related researches. A study was carried to assess the relative role of climate change and human activities in sandy desertification of Ordos region in China. Potential NPP and the difference between potential and actual NPP were selected as indicators to assess the relative role of climate change and human activities in sandy desertification, respectively. Assessing methods were built based on some scenarios for the reversion and expansion of sandy desertification and the relative role of climate change and human activities in sandy desertification of Ordos region were assessed from 1981 to 2000. The results showed that although some local places experienced an expansion of sandy desertification, the change of sandy desertification of Ordos region from 1981 to 2000 showed a stably reversing trend. The relative role of climate change and human activities in sandy desertification of Ordos region varied at different temporal and spatial scales in the reversion and expansion processes. In the reversion of sandy desertification, climate change was the dominant factor in the period of 1981 to 1990 and the reversed areas mainly induced by climate change including Mu Us sandy land and the transition zone between temperate steppe and temperate deciduous scrubs in north east of Ordos region; however, human activities controlled the reversed process during the period from 1991 to 2000 and the areas mainly induced by human activities distributed in all banners of Ordos region. In the expansion of sandy desertification, human activities were the dominant factor in the period of 1981 to 1990 and the expanded areas mainly included the regions around common boundary of Hanggin, Dalad Banners and Dongsheng City; however, climate change dominated the expansion of sandy desertification from 1991 to 2000, the expanded areas equably distributed in the whole of Ordos region except the south east of Otog Qian, Uxin and Jungar Banners. Supported by Chinese National Academic Institutional Commonweal Research Programs (Grant No. 2005DIA3J006)