期刊文献+
共找到590篇文章
< 1 2 30 >
每页显示 20 50 100
Anthropogenic Direct Radiative Forcing of Tropospheric Ozone and Aerosols in 1850 and 2000 Estimated with IPCC AR5 Emissions Inventories 被引量:6
1
作者 CHANG Wen-Yuan LIAO Hong 《Atmospheric and Oceanic Science Letters》 2009年第4期201-207,共7页
This study estimates direct radiative forcing by tropospheric ozone and all aerosols between the years 1850 and 2000, using the new IPCC AR5 (the Intergovernmental Panel on Climate Change Fifth Assessment Report) em... This study estimates direct radiative forcing by tropospheric ozone and all aerosols between the years 1850 and 2000, using the new IPCC AR5 (the Intergovernmental Panel on Climate Change Fifth Assessment Report) emissions inventories and a fully coupled chemistry-aerosol general circulation model. As compared to the previous Global Emissions Inventory Activity (GEIA) data, that have been commonly used for forcing estimates since 1990, the IPCC AR5 emissions inventories report lower anthropogenic emissions of organic carbon and black carbon aerosols and higher sulfur and NOx emissions. The simulated global and annual mean burdens of sulfate, nitrate, black carbon (BC), primary organic aerosol (POA), secondary organic aerosol (SOA), and ozone were 0.79, 0.35, 0.05, 0.49, 0.34, and 269 Tg, respectively, in the year 1850, and 1.90, 0.90, 0.11, 0.71, 0.32, and 377 Tg, respectively, in the year 2000. The estimated annual mean top of the atmosphere (TOA) direct radiative forcing of all anthropogenic aerosols based on the AR5 emissions inventories is -0.60 W m^-2 on a global mean basis from 1850 to 2000. However, this is -2.40 W m-2 when forcing values are averaged over eastern China (18-45°N and 95-125°E). The value for tropospheric ozone is 0.17 W m^-1 on a global mean basis and 0.24 W m^-2 over eastern China. Forcing values indicate that the climatic effect of aerosols over eastern China is much more significant than the globally averaged effect. 展开更多
关键词 IPCC AR5 emissions inventories AEROSOLS tropospheric ozone direct radiative forcing
下载PDF
The role of net ecosystem productivity and of inventories in climate change research:the need for “net ecosystem productivity with harvest”,NEPH 被引量:3
2
作者 E.D.Schulze R.Valentini O.Bouriaud 《Forest Ecosystems》 SCIE CSCD 2021年第1期199-206,共8页
Background:There is an urgent need for quantifying the terrestrial carbon sink in the context of global carbon emissions.However,neither the flux measurements,nor the national wood balances fulfil this purpose.In this... Background:There is an urgent need for quantifying the terrestrial carbon sink in the context of global carbon emissions.However,neither the flux measurements,nor the national wood balances fulfil this purpose.In this discussion article we point at various shortcomings and necessary improvements of these approaches in order to achieve a true quantification of the carbon exchange of land surfaces.Results:We discuss the necessity of incorporating all lateral fluxes,but mainly the export of biomass by harvest,into the flux balance and to recognize feedbacks between management and fluxes to make flux measurements compatible with inventories.At the same time,we discuss the necessity that national reports of wood use need to fully recognize the use of wood for energy use.Both approaches of establishing an ecosystem carbon balance,fluxes and inventories,have shortcomings.Conclusions:Including harvest and feedbacks by management appears to be the main requirement for the flux approach.A better quantification of wood use for bioenergy seems a real need for integrating the national wood balances into the global carbon cycle. 展开更多
关键词 Terrestrial carbon sink Flux measurements Carbon inventories National wood balances
下载PDF
Gridded inventories of historical usage for selected organochlorine pesticides in Heilongjiang River Basin, China 被引量:2
3
作者 LIU Li-yan JIANG An-xi +2 位作者 REN Nan-qi JIANG Gui-bin LI Yi-fan 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2006年第4期822-826,共5页
The use of technical HCH (1, 2, 3, 4, 5, 6-hexachlorocyclohexane), DDT (dichlorodiphenyltrichloroethane) and lindane in Heilongjiang River Basin (HRB) of China was studied. Between 1952 and 1984 the total usage ... The use of technical HCH (1, 2, 3, 4, 5, 6-hexachlorocyclohexane), DDT (dichlorodiphenyltrichloroethane) and lindane in Heilongjiang River Basin (HRB) of China was studied. Between 1952 and 1984 the total usage in the HRB was 108900 t for technical HCH, and 4900 t for DDT, respectively, and the use of DDT due to dicofol application in the HRB was 220 t from 1984 to 2003. The usage of lindane in HRB was 109 t from 1991 to 2000. The results show that the highest technical HCH use (41800 t) in HRB was on maize, accounting for 38.3% of the total usage on all crops, followed by the use on wheat (28000 t, 25.7%) and on soybean (26600 t, 24.4%). The highest DDT use (2300 t) was on soybean, accounting for 46.8% of the total usage on all crops, followed by the use on maize (1500 t, 31.3%) and on sorghum (600 t, 13.2%). The major use of lindane was mainly on wheat. Gridded usage inventories of these three OCPs (organochlorine pesticides), in HRB with a 1/6° latitude by 1/4° longitude resolution have been created by using different gridded cropland as surrogates. Some soil samples have also been collected in HRB. Data of usage and soil concentrations of 5: HCH in HRB match quite well to those in Shanghai region, and much higher soil concentration of 5: DDT in Shanghai region could be due to much heavier dicofol use in this region. 展开更多
关键词 persistent organic pollutants (POPs) organochlorine pesticides (OCPs) DDT HCH LINDANE inventories Heilongjiang River Basin
下载PDF
Carbon storage dynamics of subtropical forests estimated with multi-period forest inventories at a regional scale:the case of Jiangxi forests 被引量:1
4
作者 Qiugen Zhang Hao Ye +3 位作者 Yuan Ding Qun Cao Yangjian Zhang Ke Huang 《Journal of Forestry Research》 SCIE CAS CSCD 2020年第4期1247-1254,共8页
Temperate and high-latitude forests are carbon sinks and play pivotal roles in offsetting greenhouse gas emissions of CO2.However,uncertainty still exists for subtropical forests,especially in monsoon-prevalent easter... Temperate and high-latitude forests are carbon sinks and play pivotal roles in offsetting greenhouse gas emissions of CO2.However,uncertainty still exists for subtropical forests,especially in monsoon-prevalent eastern Asia.Earlier studies have depended on remote sensing,ecosystem modeling,carbon fluxes,or single period forest surveys to estimate carbon sequestration capacities,and the results vary significantly.This study was designed to utilize multi-period forest survey data to explore spatial-dynamics of biomass storage in subtropical forests of China.Jiangxi province,a region with over 60%subtropical forest cover,was selected as the case study site and is located in central east China.Based on forest inventory data 1984-2013,and the stock-difference and biomass expansion factor methods,the carbon storage and density,of arboreal forests,economic forests,bamboo forests,woodlands and shrubberies were estimated.The results show that carbon storage increased from 159.1 Tg C in 1988 to 276.1 TgC in 2013,making up 3.1-3.8%of carbon stored throughout China.Among the four types of forests,the amount of carbon stored was as follows:arboreal forest>economic forest>bamboo forest>woodland and shrubbery.Arboreal forests accounted for 64.0-79.4%of the total.Forest carbon density increased from 21.2 Mg C ha-1 in 1984 to26.2 Mg C ha-1 in 2013,equal to 61.2-70.2%of the average carbon density of China’s forests in the same period.Forest carbon storage in Jiangxi will reach 355.5 Tg C and 535.8 Tg C in 2020 and 2030,respectively,and forest carbon density is predicted to be 31.9 Mg C ha-1and 46.4 Mg C ha-1,respectively.As one of the few studies using multi-period data tracking biomass dynamics in Jiangxi province,the findings of this study may be used as a reference for other research.Using Jiangxi as a case study underlies the fact that subtropical forests in China have great carbon sequestration potential and have fundamental significance to offset global environmental change effects. 展开更多
关键词 Subtropical forests Carbon storage/carbon density Multi-period inventories Prediction Jiangxi Province
下载PDF
Price Dynamics of the World Gold Market: A Model Incorporating Inventories
5
作者 Lyman Mlambo 《Chinese Business Review》 2012年第5期425-433,共9页
Gold is regarded as a strategic mineral in many countries and its price is a key indicator of global business confidence. There is need for dynamic modelling of the world gold market, which would enhance understanding... Gold is regarded as a strategic mineral in many countries and its price is a key indicator of global business confidence. There is need for dynamic modelling of the world gold market, which would enhance understanding of the world market conditions, especially the long-term tendency of world gold prices, and hence facilitate long-term planning. This study incorporates inventories into the world market model and uses simultaneous equation approaches to estimate the model. From this estimation, the paper derives the time-path for the world annual price of gold. Results show that the price time-path converges without oscillations, from below, towards an intertemporal equilibrium. This equilibrium is estimated at about US$105,000.00 per kilogram based on a projected average world income. If the assumption of average income is relaxed, the intertemporal equilibrium price becomes variable dependent on the actual values of world income at a given time, which however, does not alter its dynamic characteristics. The results, therefore, show that gold price is dynamically stable. Short-term fluctuations, which are sometimes extreme, have no long-term effect on gold attractiveness. 展开更多
关键词 world gold prices inventories dynamic stability
下载PDF
Forest biomass carbon storage from multiple inventories over the past 30 years in Gansu Province, China: implications from the age structure of major forest types 被引量:5
6
作者 Jinhong Guan Huanshui Zhou +2 位作者 Lei Deng Jianguo Zhang Sheng Du 《Journal of Forestry Research》 SCIE CAS CSCD 2015年第4期887-896,共10页
We used the forest inventory data of Gansu Province, China to quantify carbon storage and carbon density changes by regional forest cover and by typical forest types in 1979-2006. Total forest area increased from 1.77... We used the forest inventory data of Gansu Province, China to quantify carbon storage and carbon density changes by regional forest cover and by typical forest types in 1979-2006. Total forest area increased from 1.77 x 106 ha in 1979 to 2.32 x 106 ha in 2006, and the forest carbon storage, estimated by the continuous biomass expansion factor method, increased from 83.14 to 100.66 Tg, equivalent to a carbon accumulation rate of 0.0071 Tg per year during the period. Mean carbon densities were 44.83-48.50 t ha-1 and the values decreased slightly over the time period. Natural forests generated greater car- bon storage and density than did plantations. By regression analysis, forest stand age was an important parameter incarbon density studies. We developed various regression equations between carbon density and stand age for major types of natural forests and plantations in the region. Our results can be used for proper selection of re-forestation species and efficient management of young and middle-aged forests, offering great potential for future carbon sequestra- tion, especially in arid and semi-arid regions. 展开更多
关键词 Age class Carbon density Forest carbonstorage Forest inventory data Gansu Province REFORESTATION
下载PDF
Review and suggestions for estimating particulate organic carbon and dissolved organic carbon inventories in the ocean using remote sensing data 被引量:2
7
作者 PAN Delu LIU Qiong BAI Yan 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第1期1-10,共10页
Dissolved organic carbon(DOC) and particulate organic carbon(POC) are basic variables for the ocean carbon cycle.Knowledge of the distribution and inventory of these variables is important for a better estimation ... Dissolved organic carbon(DOC) and particulate organic carbon(POC) are basic variables for the ocean carbon cycle.Knowledge of the distribution and inventory of these variables is important for a better estimation and understanding of the global carbon cycle.Owing to its considerable advantages in spatial and temporal coverage,remote sensing data provide estimates of DOC and POC inventories,which are able to give a synthetic view for the distribution and transportation of carbon pools.To estimate organic carbon inventories using remote sensing involves integration of the surface concentration and vertical profile models,and the development of these models is critical to the accuracy of estimates.Hence,the distribution and control factors of DOC and POC in the ocean first are briefly summarized,and then studies of DOC and POC inventories and flux estimations are reviewed,most of which are based on field data and few of which consider the vertical distributions of POC or DOC.There is some research on the estimation of POC inventory by remote sensing,mainly in the open ocean,in which three kinds of vertical profile models have been proposed:the uniform,exponential decay,and Gauss models.However,research on remote-sensing estimation of the DOC inventory remains lacking.A synthetic review of approaches used to estimate the organic carbon inventories is offered and the future development of methods is discussed for such estimates using remote sensing data in coastal waters. 展开更多
关键词 ocean carbon inventory dissolved organic carbon particulate organic carbon remote sensing
下载PDF
Development of National Greenhouse Gas Emissions Inventories in the Context of International Climate Negotiations 被引量:5
8
作者 ZHU Song-Li WANG Wen-Tao 《Advances in Climate Change Research》 SCIE 2013年第1期60-68,共9页
Based on the principle of common but differentiated responsibilities, the UNFCCC has different requirements on national GHG inventories submitted by Annex I and non-Annex I parties. Since 2007, the transparency of mit... Based on the principle of common but differentiated responsibilities, the UNFCCC has different requirements on national GHG inventories submitted by Annex I and non-Annex I parties. Since 2007, the transparency of mitigation actions by developing countries, the submission frequency of national communications cored on national inventory and the relevant international consultation and analysis have become the key issues in climate negotiations. Relevant responsibilities of developing countries showed an increasing trend. Through the analysis of these different requirements, particularly on technical review system of national inventories on developed countries and of the current situation of China's inventory development, the challenges faced by China are identified and the corresponding countermeasures are also put forward, including improving institutional arrangements and statistic system, building country-specific and comprehensive database and preparing for time-series inventory development. 展开更多
关键词 climate negotiation greenhouse gas national emissions inventory transparency
下载PDF
Emission Inventories of Carbon-containing Greenhouse Gases in China and Technological Measures for Their Abatement
9
作者 Zhuang Yahui, Zhang Hongxun, Wang Xiaoke & Li Changsheng Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, PO Box 2871, Beijing 700085, China Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, 03824 U.S.A. 《Chinese Journal of Population,Resources and Environment》 2004年第3期7-13,共7页
The report summarizes surveys on carbon inventories and initiatives on sustainable carbon cycling taken by the Research Center for Eco-Environmental Sciences, where the authors work/worked. The first part of the repor... The report summarizes surveys on carbon inventories and initiatives on sustainable carbon cycling taken by the Research Center for Eco-Environmental Sciences, where the authors work/worked. The first part of the report, which appeared in the preceding issue of this journal, deals with the concept of sustainable carbon cycling, the historic evolution of carbon cycling processes in China, carbon pool enhancement, value addition, carbon sequestration and carbon balance. This very paper, as the second part of the report, covers the results of carbon dynamics modeling, emission inventories of various carbon-containing greenhouse gases and their potential abatement measures. 展开更多
关键词 sustainable development carbon cycle carbon dynamics modeling emission inventory
下载PDF
Comparison of the local pivotal method and systematic sampling for national forest inventories
10
作者 Minna Räty Mikko Kuronen +3 位作者 Mari Myllymäki Annika Kangas Kai Mäkisara Juha Heikkinen 《Forest Ecosystems》 SCIE CSCD 2020年第4期716-732,共17页
Background:The local pivotal method(LPM)utilizing auxiliary data in sample selection has recently been proposed as a sampling method for national forest inventories(NFIs).Its performance compared to simple random samp... Background:The local pivotal method(LPM)utilizing auxiliary data in sample selection has recently been proposed as a sampling method for national forest inventories(NFIs).Its performance compared to simple random sampling(SRS)and LPM with geographical coordinates has produced promising results in simulation studies.In this simulation study we compared all these sampling methods to systematic sampling.The LPM samples were selected solely using the coordinates(LPMxy)or,in addition to that,auxiliary remote sensing-based forest variables(RS variables).We utilized field measurement data(NFI-field)and Multi-Source NFI(MS-NFI)maps as target data,and independent MS-NFI maps as auxiliary data.The designs were compared using relative efficiency(RE);a ratio of mean squared errors of the reference sampling design against the studied design.Applying a method in NFI also requires a proven estimator for the variance.Therefore,three different variance estimators were evaluated against the empirical variance of replications:1)an estimator corresponding to SRS;2)a Grafström-Schelin estimator repurposed for LPM;and 3)a Matérn estimator applied in the Finnish NFI for systematic sampling design.Results:The LPMxy was nearly comparable with the systematic design for the most target variables.The REs of the LPM designs utilizing auxiliary data compared to the systematic design varied between 0.74–1.18,according to the studied target variable.The SRS estimator for variance was expectedly the most biased and conservative estimator.Similarly,the Grafström-Schelin estimator gave overestimates in the case of LPMxy.When the RS variables were utilized as auxiliary data,the Grafström-Schelin estimates tended to underestimate the empirical variance.In systematic sampling the Matérn and Grafström-Schelin estimators performed for practical purposes equally.Conclusions:LPM optimized for a specific variable tended to be more efficient than systematic sampling,but all of the considered LPM designs were less efficient than the systematic sampling design for some target variables.The Grafström-Schelin estimator could be used as such with LPMxy or instead of the Matérn estimator in systematic sampling.Further studies of the variance estimators are needed if other auxiliary variables are to be used in LPM. 展开更多
关键词 Auxiliary data Bias Local pivotal method Matérn estimator National forest inventory Sampling efficiency Simple random sampling Spatially balanced sampling Systematic sampling Variance
下载PDF
Comparison of Radionuclide’s Inventories and Activities With Slightly Enriched Uranium and Plutonium Fuel in CANDU Reactors
11
作者 Zafar Yasin Javaid Iqbal M. Ikram Shahzad 《World Journal of Nuclear Science and Technology》 2011年第2期31-36,共6页
In these studies the isotopic inventories and corresponding activities of important nuclides for different fuel cycles of a CANDU reactor have been compared. The calculations have been performed using the computer cod... In these studies the isotopic inventories and corresponding activities of important nuclides for different fuel cycles of a CANDU reactor have been compared. The calculations have been performed using the computer code WIMSD4. The isotopic inventories and activities have been calculated versus the fuel burn-up for the natural UO2 fuel, 1.2% enriched UO2 fuel and for the 0.45% PuO2-UO2 fuel. It is found that 1.2% enriched uranium fuel has the lowest activity as compared to other two fuel cycles and vice versa for the 0.45% PuO2-UO2 fuel. 展开更多
关键词 Actinide and FISSION Product INVENTORY CANDU Natural URANIUM PLUTONIUM
下载PDF
iεepa kai Oσia:The Polis Life in the Parthenon Inventories of 5th Century BC
12
作者 张朵朵 《World History Studies》 2023年第1期46-56,共11页
"iεepa"and"Oσia"are two core concepts in research related to religion,which also play important roles in social life.The traditional view is that the dichotomy between"iεepa"and"O... "iεepa"and"Oσia"are two core concepts in research related to religion,which also play important roles in social life.The traditional view is that the dichotomy between"iεepa"and"Oσia"is an important method of research related to religion and that the border between"iεepa"and"Oσia"is clear.However,through reassessing the relationship between"iεepa"and"Oσia"on a case study of the Parthenon inventory,this article will demonstrate that the relationship between"iεepa"and"Oσia"is not one of complete opposition,but that it is in fact a unity of opposites.This relationship is primarily reflected in the three aspects of the Parthenon inventory:invocation,treasurers system and treasures type,aspects which also highlight the Athenian propensity to blend the sacred and secular spheres.These reassessed views shed new light on polis life,especially as regards public finance. 展开更多
关键词 iεepa kai Oσia Parthenon inventories Polis Life Public Finance
原文传递
Recent advances and perspectives towards emission inventories of mobile sources:Compilation approaches,data acquisition methods,and case studies 被引量:1
13
作者 Han Jiang Hefeng Zhang +4 位作者 Mingliang Fu Zhihui Huang Hong Ni Hang Yin Yan Ding 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2023年第1期460-475,共16页
In recent years,great efforts have been devoted to reducing emissions from mobile sources with the dramatic growth of motor vehicle and nonroad mobile source populations.Compilation of a mobile source emission invento... In recent years,great efforts have been devoted to reducing emissions from mobile sources with the dramatic growth of motor vehicle and nonroad mobile source populations.Compilation of a mobile source emission inventory is conducive to the analysis of pollution emission characteristics and the formulation of emission reduction policies.This study summarizes the latest compilation approaches and data acquisition methods for mobile source emission inventories.For motor vehicles,a high-resolution emission inventory can be developed based on a bottom-up approach with a refined traffic flow model and real-world speed-coupled emission factors.The top-down approach has advantages when dealing with macroscale vehicle emission estimation without substantial traffic flow infrastructure.For nonroad mobile sources,nonroad machinery,inland river ships,locomotives,and civil aviation aircraft,a top-down approach based on fuel consumption or power is adopted.For ocean-going ships,a bottom-up approach based on automatic identification system(AIS)data is adopted.Three typical cases are studied,including emission reduction potential,a cost-benefit model,and marine shipping emission control.Outlooks and suggestions are given on future research directions for emission inventories for mobile sources:building localized emission models and factor databases,improving the dynamic updating capability of emission inventories,establishing a database of emission factors of unconventional pollutants and greenhouse gas from mobile sources,and establishing an urban high temporalspatial resolution volatile organic compound(VOC)evaporation emission inventory. 展开更多
关键词 Emission inventory Mobile source Emission factor Emission control policy
原文传递
Generalized Height-Diameter Models for Pinus montezumae Lamb. and Pinus pseudostrobus Lindl. Plantations in Michoacan, Mexico
14
作者 Jonathan Hernández-Ramos Valentín José Reyes-Hernández +3 位作者 Héctor Manuel De los Santos-Posadas Aurelio Manuel Fierros-González Enrique Buendía-Rodríguez Gerónimo Quiñonez-Barraza 《Open Journal of Forestry》 2024年第3期214-232,共19页
Tree height (H) in a natural stand or forest plantation is a fundamental variable in management, and the use of mathematical expressions that estimate H as a function of diameter at breast height (d) or variables at t... Tree height (H) in a natural stand or forest plantation is a fundamental variable in management, and the use of mathematical expressions that estimate H as a function of diameter at breast height (d) or variables at the stand level is a valuable support tool in forest inventories. The objective was to fit and propose a generalized H-d model for Pinus montezumae and Pinus pseudostrobus established in forest plantations of Nuevo San Juan Parangaricutiro, Michoacan, Mexico. Using nonlinear least squares (NLS), 10 generalized H-d models were fitted to 883 and 1226 pairs of H-d data from Pinus montezumae and Pinus pseudostrobus, respectively. The best model was refitted with the maximum likelihood mixed effects model (MEM) approach by including the site as a classification variable and a known variance structure. The Wang and Tang equation was selected as the best model with NLS;the MEM with an additive effect on two of its parameters and an exponential variance function improved the fit statistics for Pinus montezumae and Pinus pseudostrobus, respectively. The model validation showed equality of means among the estimates for both species and an independent subsample. The calibration of the MEM at the plot level was efficient and might increase the applicability of these results. The inclusion of dominant height in the MEM approach helped to reduce bias in the estimates and also to better explain the variability among plots. 展开更多
关键词 Random Covariate Random Effects Variance Structure Forest inventories Forest Management Mixed Models
下载PDF
Analysis of China's Production- and Consumption-Based CO_2 Emission Inventories 被引量:1
15
作者 FU Jiafeng A Rouna +7 位作者 WANG Meng KONG Shanshan GAO Qingxian 付加锋 阿柔娜 王蒙 孔珊珊 高庆先 《Journal of Resources and Ecology》 CSCD 2013年第4期293-303,共11页
China, as the biggest GHG emitter and the largest developing country, has been urged by international society to take responsibilities for reducing GHG, especially in the post-Kyoto commitment period. Currently, the U... China, as the biggest GHG emitter and the largest developing country, has been urged by international society to take responsibilities for reducing GHG, especially in the post-Kyoto commitment period. Currently, the United Nations Framework Convention on Climate Change (UNFCCC) assigns the responsibility to parties who produce the pollution, using the production-based GHG emissions inventories. In this article, we analyze the difference between China's production- and consumption- based emission inventories and conclude that consumption-based GHG emission inventories are preferred; as it is fair that whoever consumes the emission should pay for their consumption. In addition, in order to consider environmental justice, policy-makers should take both economic and administrative measures to support poor provinces for reducing C02 emissions. 展开更多
关键词 CO2 emissions inventories China economic input-output analysis carbon tax
原文传递
An updated inventory of marine opisthobranch(Mollusca,Gastropoda)from the territorial waters of the Republic of Mauritius
16
作者 Lisa AH SHEE TEE Chandani APPADOO +1 位作者 Daneshwar PUCHOOA Vishwakalyan BHOYROO 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第1期226-243,共18页
Island ecosystems support diverse aquatic invertebrate communities comprising endemic taxa.Documentation of existing species is important for conservation.In this study,a checklist of marine opisthobranch from the Rep... Island ecosystems support diverse aquatic invertebrate communities comprising endemic taxa.Documentation of existing species is important for conservation.In this study,a checklist of marine opisthobranch from the Republic of Mauritius is presented.A combination of benthic surveys(50 m×5 m in triplicates),rover diving techniques and photo documentation were used over two years(2018–2020)within 35 sheltered and unsheltered lagoons.Morphological and molecular analysis were used for identification.Species composition within sheltered and unsheltered areas in Mauritius was estimated using the Bray-Curtis similarity.The checklist featured 117 species belonging to 61 genera and 28families,of which 13 are new records.The findings increased the knowledge of opisthobranch diversity from the Mauritius by 15.4%.Among the listed species,the distribution range of Cyerce nigra,Actinocyclus papillatus,and Phyllidia picta extended from the Western Pacific to the South Western Indian Ocean.Molecular analysis of the undescribed Gymnodoris sp.showed it resembled Gymnodoris sp.from Hawaii and were different by a genetic distance value of 10.6%.The species richness and evenness were higher within the sheltered regions of Mauritius which harboured the food resource of opisthobranch.These areas as compared to unsheltered regions were heavily populated,suggesting the probable influence of wave actions on opisthobranch diversity and abundance.The order Nudibranchia was reported as most speciose,with 86 species.The Sacoglossa and Nudibranchia were observed only on macroalgae and sponges respectively.High abundance was also recorded on shipwrecks which are the most common form of artificial reefs.With the inclusion of observations from previous studies,201species belonging to 94 genera and 36 families are now known from the Mauritius. 展开更多
关键词 marine opisthobranch INVENTORY new record occurrence Republic of Mauritius Indian Ocean
下载PDF
Developing kNN forest data imputation for Catalonia
17
作者 Timo Pukkala Núria Aquilué +2 位作者 Ariadna Just Jordi Corbera Antoni Trasobares 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第4期142-155,共14页
The combined use of LiDAR(Light Detection And Ranging)scanning and field inventories can provide spatially continuous wall-to-wall information on forest characteristics.This information can be used in many ways in for... The combined use of LiDAR(Light Detection And Ranging)scanning and field inventories can provide spatially continuous wall-to-wall information on forest characteristics.This information can be used in many ways in forest mapping,scenario analyses,and forest manage-ment planning.This study aimed to find the optimal way to obtain continuous forest data for Catalonia when using kNN imputation(kNN stands for“k nearest neighbors”).In this method,data are imputed to a certain location from k field-measured sample plots,which are the most similar to the location in terms of LiDAR metrics and topographic variables.Weighted multidimensional Euclidean distance was used as the similarity measure.The study tested two different methods to optimize the distance measure.The first method optimized,in the first step,the set of LiDAR and topographic variables used in the measure,as well as the transformations of these variables.The weights of the selected variables were optimized in the second step.The other method optimized the variable set as well as their transformations and weights in one single step.The two-step method that first finds the variables and their transfor-mations and subsequently optimizes their weights resulted in the best imputation results.In the study area,the use of three to five nearest neighbors was recommended.Altitude and latitude turned out to be the most important variables when assessing the similarity of two locations of Catalan forests in the context of kNN data imputation.The optimal distance measure always included both LiDAR metrics and topographic variables.The study showed that the optimal similarity measure may be different for different regions.Therefore,it was suggested that kNN data imputation should always be started with the optimization of the measure that is used to select the k nearest neighbors. 展开更多
关键词 Forest inventory Differential evolution Simulated annealing LIDAR
下载PDF
Accuracy of tree mapping based on hand-held laser scanning comparing leaf-on and leaf-off conditions in mixed forests
18
作者 Frederico Tupinambá-Simões Adrián Pascual +3 位作者 Juan Guerra-Hernández Cristóbal Ordóñez Tiago de Conto Felipe Bravo 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第5期14-25,共12页
The use of mobile laser scanning to survey forest ecosystems is a promising,scalable technology to describe forest 3D structures at high resolution.To confirm the con-sistency in the retrieval of forest structural par... The use of mobile laser scanning to survey forest ecosystems is a promising,scalable technology to describe forest 3D structures at high resolution.To confirm the con-sistency in the retrieval of forest structural parameters using hand-held laser scanning(HLS),before operationalizing the method,confirming the data is crucial.We analyzed the per-formance of tree-level mapping based on HLS under differ-ent phenology conditions on a mixed forest in western Spain comprising Pinus pinaster and two deciduous species,Alnus glutinosa and Quercus pyrenaica.The area was surveyed twice during the growing season(July 2022)and once in the deciduous season(February 2022)using several scan-ning paths.Ground reference data(418 trees,15 snags)was used to calibrate the HLS data and to assess the influence of phenology when converting 3D data into tree-level attrib-utes(DBH,height and volume).The HLS-based workflow was robust at isolating tree positions and recognizing stems despite changes in phenology.Ninety-six percent of all pairs matched below 65 cm.For DBH,phenology barely altered estimates.We observed a strong agreement when comparing HLS-based tree height distributions.The values exceeded 2 m when comparing height measurements,confirming height data should be carefully used as reference in remote sensing-based inventories,especially for deciduous species.Tree volume was more precise for pines(r=0.95,and rela-tive RMSE=21.3–23.8%)compared to deciduous species(r=0.91–0.96,and relative RMSE=27.3–30.5%).HLS data and the forest structural complexity tool performed remark-ably,especially in tree positioning considering mixed forests and mixed phenology conditions. 展开更多
关键词 Precision forestry Forest monitoring Mobile laser scanning Forest inventory
下载PDF
Modelling of debris-flow susceptibility and propagation: a case study from Northwest Himalaya
19
作者 Hamza DAUD Javed Iqbal TANOLI +5 位作者 Sardar Muhammad ASIF Muhammad QASIM Muhammad ALI Junaid KHAN Zahid Imran BHATTI Ishtiaq Ahmad Khan JADOON 《Journal of Mountain Science》 SCIE CSCD 2024年第1期200-217,共18页
The geological and geographical position of the Northwest Himalayas makes it a vulnerable area for mass movements particularly landslides and debris flows. Mass movements have had a substantial impact on the study are... The geological and geographical position of the Northwest Himalayas makes it a vulnerable area for mass movements particularly landslides and debris flows. Mass movements have had a substantial impact on the study area which is extending along Karakorum Highway(KKH) from Besham to Chilas. Intense seismicity, deep gorges, steep terrain and extreme climatic events trigger multiple mountain hazards along the KKH, among which debris flow is recognized as the most destructive geohazard. This study aims to prepare a field-based debris flow inventory map at a regional scale along a 200 km stretch from Besham to Chilas. A total of 117 debris flows were identified in the field, and subsequently, a point-based debris-flow inventory and catchment delineation were performed through Arc GIS analysis. Regional scale debris flow susceptibility and propagation maps were prepared using Weighted Overlay Method(WOM) and Flow-R technique sequentially. Predisposing factors include slope, slope aspect, elevation, Topographic Roughness Index(TRI), Topographic Wetness Index(TWI), stream buffer, distance to faults, lithology rainfall, curvature, and collapsed material layer. The dataset was randomly divided into training data(75%) and validation data(25%). Results were validated through the Receiver Operator Characteristics(ROC) curve. Results show that Area Under the Curve(AUC) using WOM model is 79.2%. Flow-R propagation of debris flow shows that the 13.15%, 22.94%, and 63.91% areas are very high, high, and low susceptible to debris flow respectively. The propagation predicated by Flow-R validates the naturally occurring debris flow propagation as observed in the field surveys. The output of this research will provide valuable input to the decision makers for the site selection, designing of the prevention system, and for the protection of current infrastructure. 展开更多
关键词 North Pakistan Debris flow Flow-R Propagation Susceptibility mapping Debris-flow inventory Weighted Overlay Method
下载PDF
Spatial distribution characteristics of climate-induced landslides in the Eastern Himalayas
20
作者 UWIZEYIMANA David LIU Weiming +3 位作者 HUANG Yu HABUMUGISHA Jules Maurice ZHOU Yanlian YANG Zewen 《Journal of Mountain Science》 SCIE CSCD 2024年第10期3396-3412,共17页
Climate warming is constantly causing hydro-meteorological perturbations,especially in high-altitude mountainous regions,which lead to the occurrences of landslides.The impact of climatic variables(i.e.,precipitation ... Climate warming is constantly causing hydro-meteorological perturbations,especially in high-altitude mountainous regions,which lead to the occurrences of landslides.The impact of climatic variables(i.e.,precipitation and temperature)on the distribution of landslides in the eastern regions of the Himalayas is poorly understood.To address this,the current study analyzes the relationship between the spatial distribution of landslide characteristics and climatic variables from 2013 to 2021.Google Earth Engine(GEE)was employed to make landslide inventories using satellite data.The results show that 2163,6927,and 9601 landslides were heterogeneously distributed across the study area in 2013,2017,and 2021,respectively.The maximum annual temperature was positively correlated with the distribution of landslides,whereas precipitation was found to have a non-significant impact on the landslide distribution.Spatially,most of the landslides occurred in areas with maximum annual precipitation ranging from 800 to 1600 mm and maximum annual temperature above 15℃.However,in certain regions,earthquake disruptions marginally affected the occurrence of landslides.Landslides were highly distributed in areas with elevations ranging between 3000 and 5000 m above sea level,and many landslides occurred near the lower permafrost limit and close to glaciers.The latter indicates that temperature change-induced freeze-thaw action influences landslides in the region.Temperature changes have shown a positive correlation with the number of landslides within elevations,indicating that temperature affects their spatial distribution.Various climate projections suggest that the region will experience further warming,which will increase the likelihood of landslides in the future.Thus,it is crucial to enhance ground observation capabilities and climate datasets to effectively monitor and mitigate landslide risks. 展开更多
关键词 Landslide inventory Climate variables Normalized difference vegetation index CRYOSPHERE Eastern Himalaya
下载PDF
上一页 1 2 30 下一页 到第
使用帮助 返回顶部