遥感反演和站点观测的地气温度分布特征差异

地表温度和近地表大气温度是地球系统、大气系统以及地—气相互作用物理过程的重要参量。在陆地—大气的相互作用过程中,水汽含量、NDVI指数、下垫面变化等因素会对地—气热量传输造成一定的影响。本文首先利用地表温度产品（MYD11A1）以及气温站点数据（GSOD）获得全国尺度下地表温度年最大值、近地面气温年最大值。在此基础上,使用趋势分析法分析2003年—2018年地、气温度年最大值时空分布特征及变化趋势,以及地—气温差气候倾向率变化趋势。最后,结合大气总水汽含量产品（MYD05）、NDVI指数（MYD13A3）、二氧化碳平均浓度增长率分析导致地表温度年最大值与近地面气温年最大值趋势发生变化的原因。研究结果表明：（1）在全国尺度下,2003年—2018年地表温度年最大值呈现北高南低的空间分布特征。近地面气温年最大值的空间分布与地表温度年最大值相反。大气总水汽含量年最大值在热带、亚热带季风气候区内总体较高。水汽含量既影响近地面气温的大小,同时也受到近地面气温的影响,因此,水汽含量年最大值与近地面气温年最大值表现出一定的空间分布一致性特征。（2）在2003年—2018年期间,地表温度年最大值的气候倾向率在空间上表现出北高南低的分布特征。近地面气温年最大值的气候倾向率在空间上也表现为北高南低,与地表温度年最大值的气候倾向率变化基本一致。但地表温度年最大值的变化幅度要大于近地面气温年最大值,并且在个别区域表现不一致。主要分布在天山地区、三江平原以及秦岭南侧地区,地—气年最大值变化趋势相反即地—气差减小。（3）大气总水汽含量年最大值的增加可造成近地面气温年最大值的增加,而植被覆盖度的上升可造成地表温度年最大值下降。但在天山地区大气总水汽含量与地—气差的响应不明显,但天山地区的近地面气温年最大值与CO₂平均浓度增长率的关系较为明显。（4）遥感数据反演的地表温度年最大值和站点观测的近地面气温年最大值空间分布表现出差异,但时间变化趋势基本一致。     

Multiple newt threats – occurrence of Paramesotriton deloustali and P. guangxiensis in differently disturbed habitats in Vietnam including new data on the parasite-host relationships with water mites

In this study we present the results from field work in northern Vietnam regarding the occurrence of the warty newt species Paramesotriton deloustali and P. guangxiensis in disturbed and undisturbed habitats and the presence of parasitic water mites of the genus Hygrobates (sg. Lurchibates) (Acari, Hydrachnidia). We report the first evidence of mite parasitism in P. guangxiensis and analyze differences in the infestation rates between both Paramesotriton species and habitat qualities. Furthermore we present the first indication of the detrimental effects of these parasite-host interactions.Our preliminary assessment seems to support the sensitivity of P. guangxiensis to habitat disturbances, as the average number of captured newts per stream was twice as high in undisturbed habitats as in disturbed ones.Until now a very specific parasite-host association was supposed between water mite and newt species. However, our results show the first evidence of a water mite species of the subgenus Lurchibates (Hygrobates forcipifer) parasitizing more than one host species, in this case not only P. deloustali (already known) but also P. guangxiensis (new record). The overall infestation rate was 27 % for P. deloustali and 71 % for P. guangxiensis, from which 100 % and 77 % of the mite-incidence occurred in undisturbed habitats, respectively. Furthermore the parasite load of the newts was clearly higher in prime quality streams: the parasite load in undisturbed habitats was very similar between P. deloustali (19.64 mites per newt) and P. guangxiensis (20.13 mites per newt), however it was significantly lower for P. guangxiensis in disturbed habitats (8.86 mites per newt). Future research should bring more detail on these parasite host associations, especially on the effect of parasitism on the newts. Warty newts are already threatened due to their shrinking natural habitat and overharvesting. We report the first concerns that mite parasitism might be a critical additional stress factor in undisturbed habitats.     

High spatial-resolution monitoring to investigate nitrate export and its drivers in a mesoscale river catchment along an anthropogenic land-cover gradient

Nitrate monitoring is commonly conducted with low-spatial resolution, only at the outlet or at a small number of selected locations. As a result, the information about spatial variations in nitrate export and its drivers is scarce. In this study, we present results of high-spatial resolution monitoring conducted between 2012 and 2017 in 65 sub-catchments in an Alpine mesoscale river catchment characterized by a land-use gradient. We combined stable isotope techniques with Bayesian mixing models and geostatistical methods to investigate nitrate export and its main drivers, namely, microbial N turnover processes, land use and hydrological conditions. In the investigated sub-catchments, mean values of NO₃⁻ concentrations and its isotope signatures (δ¹⁵N_NO3 and δ¹⁸O_NO3) varied from 2.6 to 26.7 mg L⁻¹, from −1.3‰ to 13.1‰, and from −0.4‰ to 10.1‰, respectively. In this study, land use was an important driver for nitrate export. Very strong and strong positive correlations were found between percentages of agricultural land cover and δ¹⁵N_NO3, and NO₃⁻ concentration, respectively. Mean proportional contributions of NO₃⁻ sources varied spatially and seasonally, and followed land-use patterns. The mean contribution of manure and sewage was much higher in the catchments characterized by a high percentage of agricultural and urban land cover comparing to forested sub-catchments. Specific NO₃⁻ loads were strongly correlated with specific discharge and moderately correlated with NO₃⁻ concentrations. The nitrate isotope and concentration analysis results suggest that nitrate from external sources is stored and accumulated in soil storage pools. Nitrification of reduced nitrogen species in those pools plays the most important role for the N-dynamics in the Erlauf river catchment. Consequently, nitrification of reduced N sources was the main nitrate source except for a number of sub-catchments dominated by agricultural land use. In the Erlauf catchment, denitrification plays only a minor role in controlling NO₃⁻ export on a regional scale.     

Modeling of climate change impacts on Lake Burullus,coastal lagoon (Egypt)

Coastal lagoons are particularly vulnerable to climate change, in particular, Sea Level Rise (SLR) due to their shallowness. Lake Burullus provides a variety of socio-economic services as the second largest coastal lagoon in Egypt. Recently, it has experienced significant ecological deterioration. Thus, its ecosystem is fragile in the face of anthropogenic induced changes. The main objective of the current study is to investigate the climate change impacts on characteristics of Lake Burullus. A depth averaged hydro-ecological modeling system, MIKE21, was applied to develop an eco - hydrodynamic model for the lake. The developed model was calibrated and verified for two successive years: July 2011–June 2012 and July 2012–June 2013. The model simulations exhibited good agreement with the measurements during the calibration and verification processes. Six different Regional Climate Models (RCMs) were compared, using six different statistical metrics, to determine the most accurate one for the study area. The required meteorological input, including surface air temperature, precipitation, and evaporation were derived from the selected RCM. The meteorological input was extracted for two different years in the 21 ^st century considering one Representative Concentration Pathways (RCPs) scenario, based on the Intergovernmental Panel on Climate Change (IPCC) 5th Report. Regional SLR projections for the Mediterranean Sea for the selected RCP scenario and the two studied years were obtained. These future climate change estimates were used to modify the validated model of the lake. A sensitivity analysis was applied to assess effect of future climatic conditions and SLR, separately. The results revealed that the lake water depths will increase and it will be warmer and more saline. Significant spatial variability of the studied parameters under climate change forcing is expected. Consequently, climate change is going to restrict the lake's ability to preserve the present-day species. An urgent management plan involving adaptation works, should be implemented to reduce such potential species losses in Egyptian lagoons.     

武汉市军运会期间空气质量特征及气象条件分析

利用2019年10月1—30日湖北省及邻近地区的空气质量、气象要素监测数据和再分析资料,分析了第七届世界军人运动会(以下简称军运会)期间和前后时段空气质量变化特征及气象条件的影响.军运会管控期Ⅱ(17—28日)与过去五年(2014—2018年)同期相比颗粒物浓度下降最明显,与长沙等其他城市相比也是最低,相近时间段或相似...     

黔西南部分矿集区环境背景

黔西南是金、锑、汞、砷、煤矿集中分布区,汞、砷在土壤中背景值高于一般土壤的20倍,汞高出14～5000倍,属于高砷、汞、氟环境背景区,由于矿业活动不合理,加剧了区内土壤、水体污染,存在砷、汞、氟等环境污染隐患。     

滇池水体污染和治理的特点

滇池是一个发育至老年末期的高原湖泊。滇池流域是缺水地区,水资源的供需平衡靠径流、污水和农田回归水的循环利用得以实现,重复用水率25％。随着人口的增长和工农业的发展,滇池水资源污染日益加重,水体严重富营养化。滇池是整个流域污染物唯一的汇,这也是其难以治理的原因。近年来,从中央到地方用于滇池污染治理的总投资已逾40亿元,而治理措施收效甚微,因此,对滇池这样有特殊污染机理的湖泊治理应从更宽泛的角度出发去考虑,甚至采取非常措施。     

季节性Kendall检验及其在三门峡水库水质趋势分析中的应用

选择1997—2002年三门峡库区的龙门、潼关和三门峡3个断面的水质监测资料,运用季节性Kendall检验方法分析三门峡水库水质趋势,结果显示：龙门断面,CODMn、NO2-N及Hg的变化趋势不明显,NH3-N呈显著上升趋势,As、Cd和Cu呈显著下降趋势,而Pb则呈高度显著下降趋势;潼关断面,NH3-N、NO2-N和Hg的变化趋势不明显,CODMn呈显著上升趋势,As、Cd和Pb呈显著下降趋势,而Cu则呈高度显著下降趋势;三门峡断面,CODMn、NO2-N、As及Hg的变化趋势不明显,NH3-N污染呈显著上升趋势,Cd呈显著下降趋势,而Cu和Pb则呈高度显著下降趋势。     

浅谈地质灾害治理工程项目管理及质量控制

将地质灾害治理工程项目管理及质量控制分为4个阶段：策划(可行性研究)阶段,准备阶段,施工阶段．验收审查阶段,分别阐述其管理及质量控制的重点内容。     

岩体质量对地下工程开挖效应的影响研究

以西北某大型水电站地下厂房洞室群为例．在地质调查的基础上,对洞室群围岩岩体质量进行了分析评价。而后,运用数值模拟手段研究了岩体质量不同时．洞室群开挖效应——二次应力场、位移场和破坏区的差异．较全面地讨论了岩体质量对洞室群开挖效应的影响。