Improvement of Glacial Lakes Detection under Shadow Environment Using ASTER Data in Himalayas, Nepal

The detection of glacial lake change in the Himalayas, Nepal is extremely significant since the glacial lake change is one of the crucial indicators of global climate change in this area, where is the most sensitive area of the global climate changes. In the Hima- layas, some of glacial lakes are covered by the dark mountains＇ shadow because of their location. Therefore, these lakes can not be de- tected by conventional method such as Normalized Difference Water Index （NDWI）, because the reflectance feature of shadowed glacial lake is different comparing to the ones which are located in the open flat area. The shadow causes two major problems： 1） glacial lakes which are covered by shadow completely result in underestimation of the number of glacial lakes; 2） glacial lakes which are partly iden- tified are considered to undervalue the area of glacial lakes. The aim of this study is to develop a new model, named Detection of Shadowed Glacial Lakes （DSGL） model, to identify glacial lakes under the shadow environment by using Advanced Space-borne Ther- mal Emission and Reflection Radiometer （ASTER） data in the Himalayas, Nepal. The DSGL model is based on integration of two dif- ferent modifications of NDWI, namely NDWls model and NDWIshe model. NDWI~ is defined as integration of the NDWI and slope analysis and used for detecting non-shadowed lake in the mountain area. The NDWIshe is proposed as a new methodology to overcome the weakness of NDWI~ on identifying shadowed lakes in highly elevated mountainous area such as the Himalayas. The first step of the NDWIshe is to enhance the data from ASTER 1B using the histogram equalization （HE） method, and its outcome product is named AS- TERho. We used the ASTERhe for calculating the NDWIhc and the NDWIshe. Integrated with terrain analysis using Digital Elevation Model （DEM） data, the NDWIshe can be used to identify the shadowed glacial lakes in the Himalayas. NDWIs value of 0.41 is used to identify the glacier lake （NDWI~ 〉 0.41）, and 0.3 of NDWIshe is used to identify the shadowed glacier lake （NDWIsho 〈 0.3）. The DSGL model was proved to be able to classify the glacial lakes more accurately, while the NDWI model had tendency to underestimate the presence of actual glacial lakes. Correct classification rate regarding the products from NDWI model and DSGL model were 57% and 99%, respectively. The results of this paper demonstrated that the DSGL model is promising to detect glacial lakes in the shadowed en- vironment at high mountains.

Effects of Nitrobenzene on Liver Antioxidant Defense System of Carassius auratus

With superoxidedismutase（SOD）, catalase（CAT）, glutathione S-transferase（GST） and malondialdehyde （MDA） as characteristic indexes, the effects of nitrobenzene（NB） on the liver antioxidant defense system of Carassius auratus were studied under the indoors stimulant conditions, and the toxic mechanisms were discussed. The exposure concentrations of NB were 0.5, 1.0, 5.0 and 10.0 mg/L, and the exposure time was 5, 10 and 15 days, respectively. The results show that the stress responses of four antioxidant indexes in the fish liver to nitrobenzene were different. The SOD activity was firstly inhibited and then induced. The CAT and GST activities were mainly induced. The MDA content in the high concentration group showed a significant time-effect relationship. In addition, the changes of CAT and SOD activities were not synchronous, and GST played an important part in the detoxification process of nitrobenzene.

Changes in Imja Lake and Karda Lake in the Everest Region of Himalaya

The Himalaya is a region sensitive to climate change. Changes in the glacial regime are one indicator of global climate changes. There are several studies focusing on analysis of temporal changes of these glacial lakes in the Himalaya region. However, the researches on addressing these trends in relation with surrounding topographical conditions are quite limited. In this study, we analyzed spatio-temporal changes in Imja Lake, located on the southern slope, and Karda Lake, located on the northern slope of the Mt. Everest region, in 1976, 1992, 2000, and 2008. Moreover, we examined whether the topographic conditions differ between the two slopes. Landsat and ASTER GDEM (advanced space borne thermal emission and reflection radiometer, global digital elevation model) data were used to identify boundaries of target glacial lakes and to calculate three indices of growth rate compared to year of 1976 (%, GRa), growth rate compared to preceding year (%, GRb), and growth speed (m2/year, GS) of the two lakes. The topographic conditions in circular buffer zones from the centroid of the two lakes were analyzed. Although the area of two lakes demonstrated linear increase from 1976 to 2008, growth rate compared to year of 1976 (GRa) differed significantly (Kruskal-Wallis test, p squared test for independence on m × n contingency table between 1976, 1992, 2000, and 2008 on growth speed (GS)). The two slopes differed in terms of three topographical variables: altitude, aspect, and angle of inclination (Kruskal-Wallis test,

Characterizing conservative and protective needs of the aridland forests of Sudan

Forests in the aridlands of Sudan are distinctive in nature and require special attention due to the great role they play as a first and last line of defense against southward desertification.Thus,to determine their conservative and protective needs based on current conditions in the Wad Al-Bashir Forest(WF),toward ensuring sustainable forest resources in these areas,we used a systematic field survey,existing and available documents review and key informant interviews(KII),to collect data from 08 December 2017 to 15 May 2018.A severe depletion and changes in the forest tree cover and composition were found during the field survey,where species such as Balanitis aegyptiaca is threatened and invasive species(e.g.,Acacia nubica)have started to dominate.Reviewed documents have credited illegal cutting and agricultural activities for the changes in the forest status,whereas the KII indicated that past and current forest conservative and protective practices(CPPs),where forest clearance for agricultural,grazing,pests and disease control,were not given a deserved consideration as they relate to tree cutting and reforestation practices.Likewise,negligence of the needs of those who depend on the forest and inadequate funds have constrained implementation of some CPPs.Accordingly,on the basis of the results of this study,we recommend that CPPs associated with agriculture,grazing,forest fire,pest and disease control should be a top priority concern of forest authorities.Better financial support,which could be enriched by involving governmental and non-governmental organizations,is also needed to boost CPPs in the WF.Invasive species also need to be cleared and replaced by trees such as A.senegal and B.aegyptiaca that are of economic and environmental value.

Study on Aerobic Composting of Mixed Municipal Sludge, Kitchen Waste and Water Hyacinth

In this study, a in vessel aerobic composting method is adopted to investigate the variation rules of various evaluation parameters （temperature, moisture content, pH, organic matter, water soluble ammonia nitrogen, water soluble nitrate nitrogen and germination index） in cocomposting of municipal sludge, kitchen waste and water hyacinth at different proportions. The results show that, in composting, the parameters of moisture content, pH, water soluble ammonia nitrogen and water soluble nitrate nitrogen demonstrate marked dynamic change rules during composting process; the temperature of three groups of compost materials rapidly rise to above 55 ~C within 96h, and last for 3 - 7d, meeting the harmless requirements, and their organic matter degradation rate excess 30%, the GI index is higher than 83%, in line with the requirements on maturity, which proves that the co-composting of municipal sludge, kitchen waste and water hyacinth can realize harmlessness and resource reutilization after composting.

One-year observation of the mixing states of oxygenated organics-containing single particles in Guangzhou,China

Oxygenated organic molecules(OOMs)play an important role in the formation of secondary organic aerosols(SOAs),but the mixing states of OOMs are still unclear.This study investigates the mixing states of OOM-containing single particles from the measurements taken using a single particle aerosol mass spectrometer in Guangzhou,China in 2022.Generally,the particle counts of OOM particles and the mass concentration of secondary organic carbon(SOC)exhibited similar temporal trends throughout the entire year.The OOM particles were consistently enriched in secondary ions,including ^(16)O^(−),^(26)CN^(−),^(46)NO_(2)^(−),^(62)NO_(3)^(−),and ^(97)HSO_(4)^(−).In contrast,the number fractions and diurnal patterns of OOM particles among the total detected particles showed similar distributions in August and October;however,the SOC ratios in fine particulate matter were quite different,suggesting that there were different mixing states of single-particle oxygenated organics.In addition,further classification results indicated that the OOM particles were more aged in October than August,even though the SOC ratios were higher in August.Furthermore,the distribution of hydrocarbon fragments exhibited a notable decrease from January to October,emphasizing the more aged state of the organics in October.In addition,the sharp increase in elemental carbon(EC)-OOM particles in the afternoon in October suggests the potential role of EC in the aging process of organics.Overall,in contrast to the bulk analysis of SOC mass concentration,the mixing states of the OOM particles provide insights into the formation process of SOAs in field studies.

Case study of high waves in the South Pacific generated by Tropical Cyclone Harold in 2020

This study highlighted a high wave case by severe tropical cyclone Harold and conducted a simulation with a newly developed wave forecasting system for the South Pacific based on the Japan Meteorological Agency third generation wave model(JMA MRI-III)using the National Center for Environment Prediction Global Forecast System(GFS)winds.Harold was a very intense tropical cyclone(TC)and very high waves up to 10 m affected parts of Vanuatu and Fiji.The model results were reasonable and verified against observations of orbital satellites and a wave buoy at Komave in Fiji.The statistical verifications were carefully analysed.The Root Mean Squared Error(RSME),Scatter Index(SI),Bias and R2 are all showing very impressive results.The new wave forecasting system is the first high resolution operational model at Fiji Meteorological Service(FMS),which covers the whole Fiji area.The system will provide guidance to FMS in preparing marine alerts and warning better and more confidence in providing the marine forecast accurately.

气候变化对水生生物区系,生态系统结构和功能的影响

气候变化将引起水生生物地球化学过程(包括碳动力变化)、水生食物网结构、动态和生物多样性以及初级和次级生产力的显著变化,影响水生哺乳动物和水禽的分布范围、分布型、栖息地质量和数量。未来永久冻土融化的增加将使营养物、沉积物和水生系统的碳负荷增加,对淡水的化学成分产生正负作用。营养物和碳富集将促进营养物循环和生产力提高,改变含碳痕量气体的形成和消耗。因此,作为碳汇或源的水生生态系统的状态将发生改变。气候变化对北极大部分地区淡水生态系统的生物多样性也具有显著影响,影响和响应的大小、程度和持续时间将随系统和位点而异。对水生哺乳动物和水禽的影响包括迁徙路径和时间改变,由于疾病和寄生虫感染而可能使死亡率升高、生长和生产力下降,以及或许发生栖息地适合性和可获得时间变化。

气候变化对北极地区鱼类和鱼类种群的总体影响

一些气候驱动变量(如气温和降水量)的预期变化与北极的淡水生态系统和生物区系有很大的相关性。这些将对那里当前的生态系统和鱼类产生许多直接和间接的影响。预期鱼种群的变化总体上是从正面到负面,随鱼种而不同,相同鱼种不同种群也有差异,取决于鱼种的生物学特性和耐受力。在当地水域内,鱼种群的变化是综合的。这会对未来北极的淡水鱼和河海洄游性鱼类带来大范围的可能性。由于缺乏北方地区鱼类生物学与生境相互作用方面的基本知识,加上未来气候预测的尺度问题和不确定性,大多数案例研究只能给出那些定性情景。这限制了在北极应对气候变化对鱼类和渔业影响所做的一些准备。

气候变化对北极淡水生态系统的水文生态学影响

北极淡水-陆地系统变暖的速度通常大于全球平均速度,特别是在秋季和冬季。许多低温层组分的减少或消失,以及从多雪到多雨气候类型的转变将对淡水生态系统产生多种影响,其中最显著的是春汛优势地位的下降和河冰融解强度的变化。无冰期的延长、气温和水温的升高、高蒸腾植物的增加,以及永久冻土融化引起的渗透性增加将使植物蒸腾作用或土壤水分蒸发蒸腾损失总量增加,从而造成地表水位和面积下降。冰盖和永久冻土的减少、水温升高和植被类型变化对水化学的影响通常是使激流和静水群落生产力增加。冰盖和淡水流量或水位的变化导致北极圈动物栖息地可获得性和质量的某些方面的变化。

气候变化和紫外线辐射对北极淡水鱼类及溯河产卵鱼类渔业的影响

北极淡水鱼类和洄游鱼类渔业为北方经济做出了重大贡献。但是,对于淡水水体,气候变化和增长的紫外线辐射对渔业产生的巨大影响有3个方面:可获鱼的数量、质量和捕捞成功率。因此,在这些影响发生作用之际,可能需要实质有效的适应行为以引导北极未来的渔业走向可持续性。当务之急是为商业渔业选择灵活和快速反应的"适宜管理"方式;改变生计渔业的当地土地和资源利用模式;改变很多休闲渔业的特性、管理方式和地点。总的来说,在气候变化及其对北极淡水水域和生物区影响的复杂性和不确定性情况下,为保证生态系统和主导鱼种有足够的恢复力和应对将来变化的能力,需要对渔业的各个方面实施更保守的管理办法。

气候变化对北极淡水生态系统及渔业的影响:北极气候影响评估(ACIA)的背景,基本原理及做法

北极的气候变化和紫外辐射水平的变化将具有深远的影响,会影响各营养级的水生物种、构成其生境的物理和化学环境以及作用于淡水生态系统和其内部的过程。诸如温度和降水之类的气候变量与淡水生态系统的相互作用高度复杂并能够以难以预测的方式在生态系统中蔓延。这部分是由于对北极淡水生态系统及其与气候和其他环境变量的相互关系缺乏了解,同时也由于北极地区缺乏长期的淡水监测点和综合的水文—生态学研究计划。本专刊中的文章是25名国际专家和他们各自的网络关于北极淡水水文学和相关的水生生态系统进行的分析的摘要,该摘要最初在2005年作为北极气候影响评估(ACIA)的"第8章——淡水生态系统和渔业"发表。这些文章广泛地概述了北极各种淡水系统的一般水文学和生态学特征,包括对每一个ACIA地区的描述,后面回顾了全新世期间淡水系统的历史变化。接着是气候变化对大尺度水文生态学、水生生物和生态系统结构和功能,以及北极鱼类和渔业影响的评估。还讨论了潜在的增效效应和累积效应以及紫外辐射和污染物的作用。文章利用环北极地区的案例研究结果说明了许多影响的性质和复杂性,以及重要的临界响应(即:那些产生分阶段影响和/或非线性影响的响应)。本期最后总结了关键的发现,并列举了科学认识方面的空白,以及与政策有关的建议。

气候变化对部分北极淡水鱼类和溯河产卵鱼类的影响概述

北极淡水鱼类和洄游鱼类会以不同方式回应气候变化的各种影响。对于分布广泛的鱼类(其中有很多是北极水生生态系统及渔业的重要组成部分),由于种内和种间的差异、ACIA区域内气候驱动力影响的不同、地区之间驱动力的差异,它们的可能的反应是形形色色的。这种多样性,加上对鱼类的气候反应方面的了解普遍很有限,使得我们通过所选的重要的鱼类,仅列举出一些可能的反应。因此,ACIA区域内鱼种之间可能影响的深入检验,以及跨区域的对比研究很有必要。这里以两种特别重要的鱼类(北极红点鲑和大西洋鲑)为例进行讨论,以为此类研究提供背景资料。

与气候变化相关的北极淡水生态系统的一般特征

在北极附近存在的两大类淡水生态系统,即:激流(流水;如:河流、溪流、三角洲及河口)和死水(静水;如湖泊、池塘及湿地)生态系统,它们在大小、丰度及生物群方面存在着巨大的差异。北极的气候,其许多的组分沿纬度梯度呈现出强烈的变化,直接影响这些水生系统中的各种物理、化学及生物学过程。此外,北极气候通过控制陆地水文系统和过程,特别是那些与诸如永久冻土、淡水冰和雪聚积/融化等低温层组分有关的,而产生其它间接的生态影响。北极淡水系统的生态结构和功能也受外部过程和条件的控制,特别是在主要北极河流源头和毗邻海洋环境中的那些。物理、化学及生物组分穿过互连的死水和激流淡水生态系统的运动是北极淡水生态的主要决定因素。

北极淡水生态系统的历史变化

各类基于生态系统的气候替代数据一直用于评估北极过去的变化。虽然由于河流物质的持续性重新建构使流水生态系统的记录相对缺乏,但可通过高质量静水生态系统数据的组合,回溯到环北极地区的更新世末期和冰川消失时期。总之,可以部分地归因于冰川覆盖收缩效应的变化引起的全新世的气候变化,使北极的水文和淡水生态系统产生了重要的时空变化。特别值得注意的是,在长期的润湿时期,北部泥炭地得到了大规模扩展。较近期的湖泊生物区和沉积学数据揭示了在过去1～2个世纪期间出现的一般性气候变暖趋势,并且表明了淡水特征,譬如冰盖持续时间和热量层化的主要变化。这些数据为预测和量测气候变化对未来的影响提供了一个极好的依据基线。

Photon-Ion Catalysis Synergy Material and Its Application

The co-operation action mechanism and model of photon-ion catalysis synergy material composed of thallium and valency-variable rare earth elements and semiconductor oxide were proposed. The radiation catalysis reactions of water and oxygen assisted by the synergy material that could largely increase electron, free radical and negative ion products were discussed. The applications of photon-ion catalysis synergy material in areas of air cleaning material, antibacterial material , healthy material and energy resource material were suggested.

日本有害废物的现状及其存在的问题

1.引言自从日本制定废物处理法以来,已有18年的时间,对于现代多样化的垃圾处理,该法律早已不能适应。按该法律规定一般废物是不舍有害物质的。

紫外线辐射和污染相关胁迫因子对北极淡水生态系统的影响

气候变化很可能作为一种多重胁迫因子,对水生生态系统造成累积的和/或协同的影响。预测的温度上升以及由此带来的降水季节性特征的改变将会增加污染物流入水生生态系统的量,并且会独自提高水生生物体对污染物暴露和影响的易感性。对生物区系造成的结果在多数情况下是加和的(累积的)或倍增的(协同的),其总的结果必然是污染物负荷加重,生物放大作用(指有毒化学物质在食物链各环节中的毒性渐进)加强。同温层中臭氧和紫外线辐射季节性特征的变化也会对水生生态系统的结构和功能产生累加或协同的影响。与预测的同温层臭氧量减少这一原因相比,冰层覆盖度的降低可能对水下紫外线暴露产生更为重大的影响。紫外线辐射水平的大幅升高会导致对生物体的损伤增强(生物分子学、细胞学和生理学上的损害,以及物种组成的变化),而生物区系分配用于抵抗紫外线伤害的能量和资源也会增加,有可能使营养水平上的生产力降低。通过光化学途径,元素的通量将会增加。

关键发现及科学认识的空白和政策建议

引言 总的来讲，北极地区气候和紫外辐射的变化将会产生深远的影响，其影响主要作用于不同营养级的水生物种，作为水生生物生境的自然环境及其化学性质，对水生生态系统起作用的进程和水生生态系统自身的进程。气候变量，例如气温和降水，与淡水生态系统的交互作用非常复杂，而且这种作用可以通过生态系统以某些不易察觉的方式扩散。系统的复杂性使准确预测气候和紫外辐射变化对淡水系统的影响增加了难度，尤其是那些跳跃式或非线形的临界反应，更难把握。由于缺乏对北极淡水系统与气候及其他环境变量之间的相互影响关系的了解，加上北极地区非常稀少的长期淡水监测站点和综合水文生态研究项目，我们的预测能力受到进一步的限制。

极端干旱与食草昆虫对草原群落的交互作用受干旱模式的影响

极端干旱和食草昆虫可以共同影响植物群落,并且它们的交互作用可能受到干旱模式的影响。然而,目前尚缺乏相关的观测证据。本研究以半干旱草原为研究对象,通过控制实验探讨了不同极端干旱模式与食草昆虫的交互作用对植物群落的影响。实验设置了3种干旱处理,分别为对照(自然降雨量)、慢性干旱(生长季5–8月减少66%降雨量)和急性干旱(6–7月完全无降雨)。在各小区设置了两种食草昆虫处理,分别是有食草昆虫和无食草昆虫。结果表明,食草昆虫和极端干旱及二者的交互作用对物种丰富度无显著影响。食草昆虫缓解了慢性干旱对总盖度的负面影响,而这种缓解作用在急性干旱下较低。食草昆虫对慢性干旱带来的负面效应具有更强的缓解作用,这主要是因为食草昆虫导致慢性干旱下适口性较高的杂类草(具有较低叶片碳含量、叶片干物质含量,以及较低叶片淀粉、钙、镁、锰含量)的大幅降低,进而降低了禾草的负面效应。上述结果表明,干旱和食草昆虫的交互作用受干旱模式的影响。通过调节植物的适口性来控制食草昆虫的采食行为,可以减轻极端干旱对草原生态系统的影响。