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1.
海岸带是地球表层物质、能量和信息流通交换最活跃区域之一,具有动态变化的盐度、溶解氧等地球化学梯度,其界面过程体现在大气降水-河水-海水-地下水-沉积物之间的物质循环和能量交换。在人类活动与气候变化双重影响下,海岸带面临着气候灾害、海岸侵蚀、海水入侵、滨海湿地退化、水体富营养化以及重金属、新型污染物等生态环境问题,成为地球科学和环境科学领域研究的热点。本文围绕海岸带水文-生物地球化学循环、人类活动影响下的海岸带环境问题、海岸带环境对气候变化的响应、海岸带海陆交互界面观测新技术新方法4个方面,综述了国内外研究进展与发展趋势,展望了海陆交互作用及其生态环境效应研究的未来发展方向。 相似文献
2.
海南岛是我国主要的热带农作物种植基地,对海南岛种植园土壤污染物评估具有重要意义。对海南岛北部种植园土壤中的16种多环芳烃（PAHs）质量分数、来源及生态风险进行评估。使用气相色谱-质谱联用技术对咖啡、香蕉、山药、甘蔗、橙子、百香果和石榴种植园中100件表层土壤样品进行PAHs质量分数测定。结果表明,研究区种植园土壤平均∑16PAHs为37.6 ng/g,低于我国土壤背景值和荷兰无污染土壤限值（< 200 ng/g）。三环、四环和五环PAHs为主要组成成分,分别占据∑16PAHs质量分数的25.8%,26.8%和23.5%。源识别显示,种植园内PAHs主要来自机动车尾气排放,部分来自石油产品的泄露及煤和生物质的低温燃烧。生态风险评价结果显示,等效毒性当量∑16BaPeq低于国家标准,表明土壤中PAHs污染物水平处于可接受范围。 相似文献
3.
民间小规模金矿混汞冶炼活动因缺乏环保措施常常造成周围环境严重的汞污染,目前已被认定为全球最大的人为汞污染排放源。福建省德化县山区土壤汞含量异常升高和该地区民间小规模金矿冶炼活动密切相关,对当地土壤总汞、大气总汞污染分布及土壤表面汞释放的调查研究表明:金矿区周边村子稻田土壤汞平均质量分数达(5.180±7.191)mg/kg,距金矿最近民间冶炼活动最集中的邱村稻田总汞质量分数平均值达到(15.658±12.726)mg/kg,随着距离金矿点越远民间冶炼活动减少,土壤总汞含量呈下降趋势。[JP2]区域大气总汞平均质量浓度为(36.4±24.3)ng/m3,邱村大气总汞质量浓度平均值(77.2±42.4)ng/m3;工作区4个土-气界面汞通量均值分别为:华口(109.6±55.9)ng/(m2h),邱村(97.1±36.1)ng/(m2h),大安(63.5±12.6)ng/(m2h),中仙(25.9±23.5 ng/(m2h)。因地形复杂,微气象条件差异及土地利用差异等综合因素制约,土壤汞含量与大气总汞含量、释放通量间没有显著相关关系,华口测点土壤释汞通量最大。工作区民间金矿冶炼活动历史造成当地环境的汞污染及其环境影响将长期存在。 相似文献
4.
探讨壳多糖（chitosan）对虾苗的生长和抗菌防病的作用。用玻璃缸培育罗氏沼虾和斑节对虾苗,在水体中添加不同浓度的壳多糖,人为感染气单胞菌或弧菌,观测虾苗的生长和抗病情况。结果表明：（1）在培养水体中加入壳多糖（50×10-6）能净化水质,防止水质恶化,因而可进行不换水育苗;（2）壳多糖（25×10-6～100×10-6）可抑制气单胞菌和弧菌的生长繁殖,增强抗病能力,提高虾苗的成活率;（3）适宜浓度25×10－6～50×10-6）的壳多糖对虾苗的生长有促进作用。 相似文献
5.
监测地球辐射能量收支的时空变化有助于增进我们对全球气候变化的理解。地球反射的短波辐射与发射的长波辐射是地球系统与外界进行能量交换的重要组成部分,也是地球辐射收支观测的主要参量。地球辐射探测仪是探测大气层顶辐射收支能量平衡参数的专用仪器。地球目标方向订正模型（Angular Distribution Models, ADMs）专指校正大气层顶地球-大气系统目标辐射各向异性的一系列非均匀因子,它是将卫星或月基观测的地球目标反射及发射宽波段辐亮度转换为辐射通量的有效途径。ADMs模型构建和算法优化直接影响基于空间观测推算地球辐射收支的最终解算精度。本文围绕地球辐射ADMs模型展开,回顾了过去几十年来ADMs模型的发展历程,着重介绍了目前应用于Terra与Aqua卫星的云与地球辐射能量系统（Clouds and the Earth’s Radiant Energy System, CERES）的业务化ADMs模型,分析了地球静止卫星与月基对地观测在地球辐射ADMs模型中的优势、问题与潜力。基于上述综述与分析,讨论星载与月基地球辐射ADMs模型进一步优化的决定因素。 相似文献
6.
多目标区域地球化学调查是针对第四纪覆盖区开展的基础性调查工作，主要目标包括基础地质、资源潜力与生态环境等三大方面。调查工作按照1：250000采样网度和采样密度，以系统开展土壤地球化学测量（近岸海域沉积物地球化学测量和湖泊沉积物地球化学测量）为主，水地球化学测量为辅，测定其中数十种无机和有机地球化学指标，编制地球化学图件及编写相应测区调查报告。 相似文献
7.
江河湖泊等陆表水体在工农业生产、气候调节、生态系统维持等方面扮演着至关重要的角色。在气候变化与人类活动的作用下,陆表水体的空间分布始终在发生着变化,因而对其进行快速精准的时空变化监测对水资源管理与保护、未来气候变化预测等有着重要的意义。遥感技术为大范围水体动态监测提供了全新的技术手段,特别是在当前地球大数据背景下,水体提取算法不断改进,遥感数据源急剧增加,但缺乏对算法和数据演化过程的系统整理。鉴于此,本文对现有水体提取算法与遥感数据进行了综合梳理,归纳了单波段阈值法、多波段谱间关系法、水体指数与阈值法、支持向量机、随机森林、深度学习等常用算法的演变,以及遥感数据源由低（MODIS等）到中（Landsat等）和高（高分1/2号等）空间分辨率的发展过程,并在此基础上讨论了各算法与数据源在水体变化研究中的差异。此外,本文论述了数据处理平台由本地计算到高性能云计算平台（如谷歌地球引擎）的发展,云计算促进地表水变化研究由基于时间片段到基于时间序列连续过程分析的转变,以及云计算在大尺度范围的应用。最后,本文还对多源遥感数据融合与云计算平台的结合在地表水体连续变化监测中的应用进行了展望,并对不同类型水体提取的不确定性进行了讨论。 相似文献
8.
淮河流域是水体遭受营养盐污染较严重的地区,本研究选择淮河上游的淮滨流域（淮滨站以上,流域面积1.6万km2）为研究对象,首先构建了淮滨流域SWAT水文水质模型,然后利用2011—2017年淮滨站实测的月径流和月氨氮浓度对SWAT模型进行了校正与验证,最后基于全球气候模型（GCM）气象数据,预测了未来30年（2020—2029年、2030—2039年、2040—2049年）不同气候变化情境（RCP2.6、RCP4.5、RCP6.0、RCP8.5）下的径流、氨氮浓度和非点源总氮负荷。结果发现,径流在校正期和验证期的Nash-Suttcliffe系数均为0.79,氨氮在校正期和验证期的Nash-Suttcliffe系数均高于0.5,表明模型的适用性良好。研究发现本研究区施肥量与土地利用类型是非点源氮负荷空间分异的主导因素。2020—2049年,不同气候变化情景下,本研究区的降水量和气温均为增长趋势。假如保持基准期（2011—2016年）污染排放强度,仅考虑气候变化影响,流域内非点源污染总氮负荷将比基准期最多增加31.8%,流域出水口淮滨站的年均氨氮浓度将最多减小42.6%。本研究可以为气候变化下淮滨流域的水文水质管理提供科学支撑。 相似文献
9.
利用TerraSAR-X卫星2013-08~2014-08的17景雷达影像,采用小基线集（small baseline subset,SBAS）InSAR技术获取呼图壁(HTB)地下储气库（underground gas storage,UGS）运行期间的地表形变序列,并结合UGS注（采）气井口的压力数据,采用多点源Mogi模型,对HTB UGS的形变场进行模拟。结果表明,整个UGS区域的形变特征为非连续分布,形变与注（采）气压力变化具有较好的相关性;注（采）气期间沿卫星视线向(LOS)的形变峰值分别为10 mm和-8 mm;采用自适应前向搜索法,基于多点源Mogi模型初步模拟注（采）气期间的形变过程,当UGS的注（采）气平均气压为18 MPa和15 MPa时,LOS的形变可达7 mm和-4 mm,地表形变的大小与注（采）气井口密度有关;UGS的储气分布呈非均匀状态,即地下气库结构复杂多变。 相似文献
10.
城市发展对水体多方面要素产生了巨大影响,尤其是对水资源丰富的城市,迫切需要开展相关监测研究。研究以武汉市为例,通过梳理国内外相关研究以及武汉水体保护政策,提出融合水体面积、水质、水体景观、滨水区生态环境4个方面要素的分析技术路线以更为全面的反映城市尺度的水体时空演变特征,具体的,利用随机森林模型基于1979—2019年遥感影像获取武汉67个重点水体信息,并以此获取水体面积和水体景观的变化特征;同时,通过梳理多年水质监测数据分析水质变化特征;另外,基于遥感生态指数（Remote Sensing Ecological Index, RSEI）分析滨水区生态环境变化;最后,采用多尺度地理加权回归模型（Multi-scale Geographically Weighted Regression, MGWR）对重点水体面积变化的影响因素研究,希冀为政府制定差异化的水体保护政策提供科学支撑,并为其他地区水体的多要素分析提供有益借鉴。结果表明：① 武汉市水体面积呈下降趋势,水体总面积、重点水体面积分别减少10.75%及13.12%,中心城区及郊区水体变化存在显著差异;② 水体景观呈退化趋势,周长面积分维数、平均斑块面积、聚合指数及结合指数分别减少了6.43%,79.35%,1.55%及10.94%;③ 重点水体水质总体呈恶化趋势,其中江河及水库多数常年为III类及以上水体,中心城区湖泊多为V类及以下水体,郊区湖泊多为IV类及V类水体;④ 中心城区及郊区滨水区遥感生态指数（RSEI）分析表明滨水区生态环境呈恢复态势,其中中心城区滨水区平均RSEI增长了14.29%;⑤ MGWR分析表明,自然气象因素中,相对湿度的增加对江夏区湖泊恢复影响更为显著,降水对水面较小的水体恢复影响更为显著;社会经济因素中,各行政区GDP的增加有助于水体恢复,对中心城区、黄陂及新洲的水体保护影响更为显著;滨水缓冲区内不透水面占比（IS）的增加导致大多数水体面积的减少,然而,对于少数重点修复水体,IS增加是受相关保护政策影响,IS增加有助于这些水体恢复。 相似文献
11.
Based on a simulative experiment and a comparison analysis, the effect of bivalve Corbiculafluminea activity on sediment-water exchange of dissolved inorganic nitrogen （DIN） is studied. The areas included three intertidal flat sites of the Changjiang （Yangtze） River estuary in China. The interface exchange flux of ammonium, nitrate and nitrite in the short experiment （6 h） was -46.4-40, -74.8-929.1 and 2.5-14.6 μmol/（m^2·h）, respectively. It was found that the burrowing activities of C. fluminea increased NH4 and NOi release from sediments to overlying water in the short-term experiment. During long-term incubation, NH4 and NOi released in turn from the sediments. At the beginning of incubation, bioturbation by C. fluminea could accelerate NH2 release from sediments 2-17 times in different sites, resulting in stronger nitrification and increased NOi concentrations in the overlying water. Sediment profile analysis post-incubation shows that organic matter mineralization and sediment-water NH4 exchange had been stimulated by C. fluminea bioturbation and bioirrigation during the experiment. Therefore, C. fluminea activities such as excretion, burrowing, irrigation and turbation can effectively alter nitrogen dynamics and accelerate and stimulate nitrogen exchange and cycling at the sediment-water interface. 相似文献
12.
ＩＮＴＲＯＤＵＣＴＩＯＮＰｏｌｙｃｙｃｌｉｃＡｒｏｍａｔｉｃＨｙｄｒｏｃａｒｂｏｎｓ(ＰＡＨｓ)ｗｉｄｅｌｙｅｘｉｓｔｉｎｔｈｅｅｎｖｉｒｏｎｍｅｎｔ(ａｔｍｏｓｐｈｅｒｅ,ｗａｔｅｒｃｏｌｕｍｎ,ｓｏｉｌ,ｒｉｖｅｒ,ｌａｃｕｓｔｒｉｎｅａｎｄｍａｒｉｎｅｓｅｄｉｍｅｎｔｓ)ａｎｄａｒｅｐｒｅｓｅｎｔａｔｔｒａｃｅｍｉｘｔｕｒｅｓａｎｄｗｉｄｅｌｙｓｐｒｅａｄｆｒｏｍｓｅｖｅｒａｌ×10-9ｇｒａｄｅｓｉｎｒｅｍｏｔｅａｒｅａｓｔｏｓｅｖｅｒａｌ×10-6ｌｅｖｅｌｓｉｎｕｒｂａｎａｎｄｉｎｄｕｓｔｒｉａｌａ… 相似文献
13.
Xiamen Western Bay‘s water and sedimem quality were studied by detemaining thelevels of sixteen polycyclic amrrmtic hydrocarbons PAHs in water, porewater and sediment samples from nine locations in the bay. Total PAH concentrations varied from 106 to 945 ng/1 in water, below detectionto 3548 ng/1 in porewater, and 247 to 480 ng/g dry weight in surface sediments. PAHs levels in porewaterwere higher than those in surface water, due to the preference of these hydrophobic compounds for sedimentary phase instead of water. Such a concentration gradient implies a potential flux of pollutants fromsediments to overlying water. The PAils levels in sediments were one to several orders of magnitude lowerthan those in 1993, suggesting their decreased input in recent years and possible degradation with time. 相似文献
14.
土地利用和气候变化对海河流域蒸散发时空变化的影响 总被引：1，自引：0，他引：1
蒸散发（ET）是水文能量循环和气候系统的关键环节,研究ET的时空变化特征及其响应土地利用和气候变化的驱动机制对于理清流域水资源和气候变化的关系具有重要的意义。本文基于MOD16/ET数据集定量分析了海河流域2000-2014年ET的时空变化特征,并结合时序气温降水数据和土地利用数据,采用相关分析方法定量探索了ET与气候因子的驱动力关系。结果表明：① 海河流域2000-2014年ET表现为较为显著的空间分布格局,呈现出北部和南部高、西北部和中东部低的分布特性。不同土地利用类型的多年ET呈林地>草地>耕地>其他类型的特征;② 2000-2014年海河流域年均ET波动范围为371.96~441.29 mm/a,多年ET的均值为398.69 mm/a,平均相对变化率为-0.41%,整体呈下降趋势;③ 多年月ET与气温和降水均呈单峰型周期性变化趋势,年内月ET呈单峰变化趋势;④ 春秋两季的ET与降水和气温的相关性明显高于其他季节,ET与气温和降水的平均相关系数是-0.17和0.37,表明降水对于ET的响应程度强于气温;⑤ 驱动分区结果表明海河流域ET受气候因子驱动的主要类型是降水驱动型和降水、气温共同驱动型;⑥ 海河流域耕地ET变化气候因子驱动模式主要是降水、气温共同驱动型;林地、草地的驱动模式主要气温驱动型和降水驱动型,其他土地利用类型的驱动模式主要是受其他因素驱动。该研究将对海河流域水资源开发管理和区域气候调节起到科学指导作用。 相似文献
15.
《山地科学学报》2021,(8)
Rainfall infiltration on a soil slope is usually an unsaturated seepage process that can be described by a water-air two-phase flow model. The effect of pore air pressure on rainfall infiltration has been widely recognized and validated by means of numerical simulations and laboratory experiments. However, whether a slope can actually seal pore air continues to be debated by researchers. In this study, a water-air two-phase flow model is used to simulate the rainfall infiltration process on a soil slope, and a field experiment is conducted to realistically test the sealing conditions of a slope. According to the numerical simulation, the areas of water and air flow in and out on the slope surface are relatively stable and can be classified as the "inhalation zone" and "overflow zone", respectively. Intermittent rainfall on the soil slope has an amplifying effect on pore air pressure because rainfall intensity is usually at the millimeter level, and it causes pore air pressure to reach the cm level. A field experiment was performed to determine whether a slope can realistically seal pore air and subsequently verify the regularity of rainfall infiltration. Air pressure sensors were buried in the slope to monitor the pore air pressures during the rainfall process. The monitoring results show that the pore air pressure in the slope changed, which indicates that the slope can seal air. Moreover, the amplification effects of intermittent rainfall on pore air pressure were observed for natural rainfall, which agrees well with the numerical simulation results. 相似文献
16.
Alpine ecosystems in permafrost region are extremely sensitive to climate changes.To determine spatial pattern variations in alpine meadow and alpine steppe biomass dynamics in the permafrost region of the Qinghai-Tibet Plateau,China,calibrated with historical datasets of above-ground biomass production within the permafrost region's two main ecosystems,an ecosystem-biomass model was developed by employing empirical spatialdistribution models of the study region's precipitation,air temperature and soil temperature.This model was then successfully used to simulate the spatio-temporal variations in annual alpine ecosystem biomass production under climate change.For a 0.44°C decade-1 rise in air temperature,the model predicted that the biomasses of alpine meadow and alpine steppe remained roughly the same if annual precipitation increased by 8 mm per decade-1,but the biomasses were decreased by 2.7% and 2.4%,respectively if precipitation was constant.For a 2.2°C decade-1 rise in air temperature coupled with a 12 mm decade-1 rise in precipitation,the model predicted that the biomass of alpine meadow was unchanged or slightly increased,while that of alpine steppe was increased by 5.2%.However,in the absence of any rise in precipitation,the model predicted 6.8% and 4.6% declines in alpine meadow and alpine steppe biomasses,respectively.The response of alpine steppe biomass to the rising air temperatures and precipitation was significantly lesser and greater,respectively than that of alpine meadow biomass.A better understanding of the difference in alpine ecosystem biomass production under climate change is greatly significant with respect to the influence of climate change on the carbon and water cycles in the permafrost regions of the Qinghai-Tibet Plateau. 相似文献
17.
淮河流域上消化道肿瘤与环境污染的模型分析 总被引：1，自引：0，他引：1
自20世纪70年代后期以来,淮河流域不断遭受工业点源污染和其他面源污染,媒体也陆续报道了淮河流域"癌症村"的出现。本文探讨了淮河流域14个监测县5810个行政村的消化道肿瘤与环境因子之间的空间分布规律。作者从流域和行政区划等多维空间角度出发,通过全局的最小二乘法线性回归和稳健回归对环境因子进行筛选分析,以局部地理加权回归方法探测各类环境因子,在不同地区对贝叶斯调整的上消化道肿瘤死亡率的影响程度,建立了消化道肿瘤死亡的风险评估模型,其中,包括地表水水质等级、浅层地下水质量分级、河网密度、土壤多环芳烃含量分级、化肥施用量和经济密度等6类环境危险因素。根据局部回归模型中各监测点环境因子的回归系数和统计学检验结果,提取出当地主要的环境影响因素。从14个监测县区总体上看,地表水水质等级和GDP与肿瘤呈负相关,其他环境因子均与肿瘤死亡存在正相关。但从局部角度看,不同地区环境影响因子种类和影响强度有较大差别。其中淮河流域江苏段以化肥施用量、土壤多环芳烃含量、GDP和河网密度为主要影响因子,安徽段以土壤多环芳烃含量和化肥为主,河南段主要是以地下水质量分级、河网密度和化肥为主,同时河南沈丘县地表水水质等级对当地影响较大。山东段虽然也探测出来部分环境危险因子的存在,但没有发现其与肿瘤死亡的关联关系,尚需进一步深化研究。 相似文献
18.
《中国海洋湖沼学报》2018,(6)
In order to identify the effects of seasonal variation on the migration and transformation of antimony species at the sediment-water interface of the Poyang Lake, the largest fresh lake in China, a simulation study was carried out in the laboratory. Antimony species including antimonite Sb(III), antimonate Sb(V) and the fraction of organic forms(Sb-org) in overlying water at different temperatures were regularly measured during the simulation period. Different bound antimony forms in sediments were also determined along with the different antimony species in porewaters after the simulation terminated. The results indicated that temperature change during seasonal alternation plays an important role in the migration and transformation behavior of antimony at the sediment-water interface of the Poyang Lake. Antimony species both in porewaters and overlying water were sensitive to the variation of temperature, especially the Sb-org species. Antimony migrates from porewaters to the overlying water when the temperature decreases, and meanwhile the equilibrium between Sb(III) and Sb(V) in porewaters shifts toward Sb(V) when the temperature increases during seasonal alternation. Although temperature had less influence on the antimony species in sediments than in porewaters or in the overlying water, the average content of each antimony species in sediments increased with the decrease of temperature, suggesting that the decrease of temperature causes enrichment of antimony in the sediment. 相似文献
19.
Sediment-associated processes, such as sediment erosion, deposition, and pore water diffusion/advection affect sorptive contaminant transport. By considering these processes, we developed an equation to simulate contaminant transport. Erosion and deposition processes are considered as erosion and deposition fluxes of sediment, and adsorption-desorption processes of contaminants by sediment are simulated using the Langmuir Equation. Pore water diffusion is calculated based on the contaminant concentration gradient across the sediment-water interface. Pore water advection is estimated using pore water contained in the sediments of erosion flux. The equation is validated to simulate total phosphorus concentrations in Guanhe estuary in the northern Jiangsu, China. The simulated total phosphorus concentrations show better agreement with field observations compared to estimations that do consider sediment-associated processes. 相似文献
20.
Changes in the thermal and hydraulic regime within the active layer in the Qinghai-Tibet Plateau 总被引：1，自引：1，他引：0
The change trends of air temperature,precipitation and evaporation from 1999 to 2008 shows that the climate in the Qinghai-Tibet Plateau permafrost region had become warmer.The analysis of the systematic active-layer data monitoring network along the Qinghai-Tibet Highway indicated that the active-layer thickness had been increasing and the soil temperature was rising.The soil temperature was rising in winter but not at the end of spring or during the entire summer.With thickening and warming of the active layer,the liquid water content of the active layer had an obvious downward migration and liquid water content in the top horizons decreased,but in the deeper horizons it increased. 相似文献