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Geo-information Tupu Analysis of Land Use Change in Haihe River Basin 被引量:2
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作者 朱占永 郭伟志 张海力 《Agricultural Science & Technology》 CAS 2012年第5期1139-1144,共6页
[Objective] This study was to provide basis for the scientific management of land use in Haihe River Basin (HRB) through the quantitative exploration of the land use conversion, changes of intensity and spatial dist... [Objective] This study was to provide basis for the scientific management of land use in Haihe River Basin (HRB) through the quantitative exploration of the land use conversion, changes of intensity and spatial distribution in this region. [Method] With the support of remote sensing technology and geographic information technology, the land use maps of the study area in 40 years (1970-2010) were in- terpreted and plotted. Four kinds of tupu, namely, land use change tupu, process tupu, arising tupu and evolution mode tupu were built through the spatial overlay of the land use maps to analyze the change rules of land use patterns. [Result] The conversion of arable land to construction land was the main characteristics of land use changes in HRB for the 40 years; the area of non-stable region accounted for 35% of the total, indicating that the land use changed remarkably, thus, it was nec- essary to strengthen the scientific land management in HRB; the new conversions to all land use patterns were all the lowest in 1980-1990, indicating that land use changed slowly during this period. [Conclusion] The results indicate that, compared with conventional transfer matrix method, geo-information tupu has obvious advantage in analyzing land use changes that it can demonstrate the spatial distribution of interest region, display the multi-dimensional spatial information. 展开更多
关键词 Haihe river basin Tupu analysis Land use change Evolution mode
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X-ray diffraction analysis of cold-worked Cu-Ni-Si and Cu-Ni-Si-Cr alloys by Rietveld method 被引量:3
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作者 A.KHEREDDINE F.HADJ LARBI +3 位作者 L.DJEBALA H.AZZEDDINE B.ALILI D.BRADAI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第3期482-487,共6页
Cold worked and annealed supersaturated Cu-2.65Ni-0.6Si and Cu-2.35Ni-0.6Si-0.6Cr alloys were studied. The microstructural parameters evolution, including crystallite size, root mean square strain and dislocation dens... Cold worked and annealed supersaturated Cu-2.65Ni-0.6Si and Cu-2.35Ni-0.6Si-0.6Cr alloys were studied. The microstructural parameters evolution, including crystallite size, root mean square strain and dislocation density was analyzed using Materials Analysis Using Diffraction software (MAUD). The parameters for both alloys have typical values of cold deformed and subsequently annealed copper based alloy. A net change of the crystallite size, root mean square strain and dislocation density values of the alloys aged at 450 °C for 2.5-3 h seems corresponding to the recovery and recrystallization processes. Addition of Cr as quaternary element did not lead to any drastic changes of post deformation or ageing microstructural parameters and hence of recovery-recrystallization kinetics. 展开更多
关键词 Cu-Ni-Si alloy microstructure XRD line profile analysis Materials analysis Using Diffraction software
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Use of Intensity Analysis to Measure Land Use Changes from 1932 to 2005 in Zhenlai County, Northeast China 被引量:9
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作者 YANG Yuanyuan LIU Yansui +1 位作者 XU Di ZHANG Shuwen 《Chinese Geographical Science》 SCIE CSCD 2017年第3期441-455,共15页
Analyzing spatiotemporal dynamics of land use and land cover over time is widely recognized as important to better understand and provide solutions for social, economic, and environmental problems, especially in ecolo... Analyzing spatiotemporal dynamics of land use and land cover over time is widely recognized as important to better understand and provide solutions for social, economic, and environmental problems, especially in ecologically fragile region. In this paper, a case study was taken in Zhenlai County, which is a part of farming-pastoral ecotone of Northeast China. This study seeks to use multi-temporal satellite images and other data from various sources to analyze spatiotemporal changes from 1932 to 2005, and applied a quantitative methodology named intensity analysis in the time scale of decades at three levels: time interval, category, and transition. The findings of the case study are as follows: 1) the interval level of intensity analysis revealed that the annual rate of overall change was relatively fast in 1932–1954 and 1954–1976 time intervals. 2) The category level showed that arable land experienced less intensively gains and losses if the overall change was to have been distributed uniformly across the landscape while the gains and losses of forest land, grassland, water, settlement, wetland and other unused land were not consistent and stationary across the four time intervals. 3) The transition level illustrated that arable land expanded at the expense of grassland before 2000 while it gained intensively from wetland from 2000 to 2005. Settlement targets arable land and avoids grassland, water, wetland and other unused land. Besides, the loss of grassland was intensively targeted by arable land, forest land and wetland in the study period while the loss of wetland was targeted by water except for the time interval of 1976–2000. 4) During the early reclamation period, land use change of the study area was mainly affected by the policy, institutional and political factors, followed by the natural disasters. 展开更多
关键词 intensity analysis land use and land cover change pattern driving forces Northeast China
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Association between Macroscopic-factors and Identified HIV/AIDS Cases among Injecting Drug Users: An Analysis Using Geographically Weighted Regression Model 被引量:1
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作者 XING Jian Nan GUO Wei +5 位作者 QIAN Sha Sha DING Zheng Wei CHEN Fang Fang PENG Zhi Hang QIN Qian Qian WANG Lu 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2014年第4期311-318,共8页
Drug use (DU), particularly injecting drug use (IDU) has been the main route of transmission and spread of Human Immunodeficiency Virus (HIV)/Acquired Immune Deficiency Syndrome (AIDSJ among injecting drug use... Drug use (DU), particularly injecting drug use (IDU) has been the main route of transmission and spread of Human Immunodeficiency Virus (HIV)/Acquired Immune Deficiency Syndrome (AIDSJ among injecting drug users (IDUs)[1]. Previous studies have proven that needles or cottons sharing during drug injection were major risk factors for HIV/AIDS transmission at the personal level[z4]. Being a social behavioral issue, HIV/AIDS related risk factors should be far beyond the personal level. Therefore, studies on HIV/AIDS related risk factors should focus not only on the individual factors, but also on the association between HIV/AIDS cases and macroscopic-factors, such as economic status, transportation, health care services, etc[1]. The impact of the macroscopic-factors on HIV/AIDS status might be either positive or negative, which are potentially reflected in promoting, delaying or detecting HIV/AIDS epidemics. 展开更多
关键词 AIDS HIV An analysis Using Geographically Weighted Regression Model
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Denoising Nonlinear Time Series Using Singular Spectrum Analysis and Fuzzy Entropy 被引量:1
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作者 江剑 谢洪波 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第10期19-23,共5页
We present a hybrid singular spectrum analysis (SSA) and fuzzy entropy method to filter noisy nonlinear time series. With this approach, SSA decomposes the noisy time series into its constituent components including... We present a hybrid singular spectrum analysis (SSA) and fuzzy entropy method to filter noisy nonlinear time series. With this approach, SSA decomposes the noisy time series into its constituent components including both the deterministic behavior and noise, while fuzzy entropy automatically differentiates the optimal dominant components from the noise based on the complexity of each component. We demonstrate the effectiveness of the hybrid approach in reconstructing the Lorenz and Mackey--Class attractors, as well as improving the multi-step prediction quality of these two series in noisy environments. 展开更多
关键词 of on or in Denoising Nonlinear Time Series Using Singular Spectrum analysis and Fuzzy Entropy NLP IS
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Combination Use of PFGE and Drug-resistant Analysis in the Epidemiological Investigation of Listeria Monocytogenes 被引量:2
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作者 LV Jun ZHENG Xiang Mei +2 位作者 CHENG Shi Xiu ZHENG Hua Ying ZENG Ying Chun 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2013年第4期314-318,共5页
Listeria monocytogenes is the pathogen of listeriosis and it causes severe infections like septicemia, encephalitis, and meningitis, especially in immunocompromised individuals, newborns, and pregnant women. Its wide ... Listeria monocytogenes is the pathogen of listeriosis and it causes severe infections like septicemia, encephalitis, and meningitis, especially in immunocompromised individuals, newborns, and pregnant women. Its wide distribution in the environment and ability to survive or even grow under adverse conditions has made L. monocytogenes an important public health concern and in food industry. 展开更多
关键词 PFGE Combination Use of PFGE and Drug-resistant analysis in the Epidemiological Investigation of Listeria Monocytogenes
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Risk Analysis of Sulfites Used as Food Additives in China 被引量:7
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作者 ZHANG Jian Bo ZHANG Hong +4 位作者 WANG Hua Li ZHANG Ji Yue LUO Peng Jie ZHU Lei WANG Zhu Tian 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2014年第2期147-154,共8页
This study was to analyze the risk of sulfites in food consumed by the Chinese people and assess the health protection capability of maximum-permitted level (MPL) of sulfites in GB 2760-2011. Sulfites as food additi... This study was to analyze the risk of sulfites in food consumed by the Chinese people and assess the health protection capability of maximum-permitted level (MPL) of sulfites in GB 2760-2011. Sulfites as food additives are overused or abused in many food categories. When the MPL in GB 2760-2011 was used as sulfites content in food, the intake of sulfites in most surveyed populations was lower than the acceptable daily intake (ADI). Excess intake of sulfites was found in all the surveyed groups when a high percentile of sulfites in food was intaken. Moreover, children aged 1-6 years are at a high risk to intake excess sulfites. The primary cause for the excess intake of sulfites in Chinese people is the overuse and abuse of sulfites by the food industry. The current MPL of sulfites in GB 2760-2011 protects the health of most populations. 展开更多
关键词 Risk analysis of Sulfites Used as Food Additives in China
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Carbon Emission of Regional Land Use and Its Decomposition Analysis: Case Study of Nanjing City, China 被引量:11
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作者 ZHAO Rongqin HUANG Xianjin +3 位作者 LIU Ying ZHONG Taiyang DING Minglei CHUAI Xiaowei 《Chinese Geographical Science》 SCIE CSCD 2015年第2期198-212,共15页
Through the matching relationship between land use types and carbon emission items, this paper estimated carbon emissions of different land use types in Nanjing City, China and analyzed the influencing factors of carb... Through the matching relationship between land use types and carbon emission items, this paper estimated carbon emissions of different land use types in Nanjing City, China and analyzed the influencing factors of carbon emissions by Logarithmic Mean Divisia Index(LMDI) model. The main conclusions are as follows: 1) Total anthropogenic carbon emission of Nanjing increased from 1.22928 ×10^7 t in 2000 to 3.06939 × 10^7 t in 2009, in which the carbon emission of Inhabitation, mining & manufacturing land accounted for 93% of the total. 2) The average land use carbon emission intensity of Nanjing in 2009 was 46.63 t/ha, in which carbon emission intensity of Inhabitation, mining & manufacturing land was the highest(200.52 t/ha), which was much higher than that of other land use types. 3) The average carbon source intensity in Nanjing was 16 times of the average carbon sink intensity(2.83 t/ha) in 2009, indicating that Nanjing was confronted with serious carbon deficit and huge carbon cycle pressure. 4) Land use area per unit GDP was an inhibitory factor for the increase of carbon emissions, while the other factors were all contributing factors. 5) Carbon emission effect evaluation should be introduced into land use activities to formulate low-carbon land use strategies in regional development. 展开更多
关键词 carbon emission land use intensity Logarithmic Mean Divisia Index(LMDI) model decomposition analysis Nanjing City
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An Analysis of Mutual Interference in Radar Systems Using Dual-Band (Ka / X) Antennas
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作者 DU Shimin, Beijing Institute of Radio Measurement, P.O.Box 3923-2, Beijing 100854, China WANG Baofa, Beijing University of Aeronautics and Astronautics, Beijing, China WU Yi, No.2 Radio Instrument Factory of Beijing, Beijing, China 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1992年第4期84-87,共4页
An analysis of mutual interfering sources on RF systems using dual-band (Ka / X) radar is presented. The purpose of this paper is to improve operational performance of the system from the point of view of EMC design. ... An analysis of mutual interfering sources on RF systems using dual-band (Ka / X) radar is presented. The purpose of this paper is to improve operational performance of the system from the point of view of EMC design. The experimental dual-band antenna system have decreased the disturbing effects of most mutual interfering sources. 展开更多
关键词 ANTENNAS KA An analysis of Mutual Interference in Radar Systems Using Dual-Band
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Assessment of glaucoma using extreme learning machine and fractal feature analysis
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作者 Subramaniam Kavitha Karuppusamy Duraiswamy Sakthivel Karthikeyan 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2015年第6期1255-1257,共3页
Dear Sir,Iam Dr.Kavitha S,from the Department of Electronics and Communication Engineering,Nandha Engineering College,Erode,Tamil Nadu,India.I write to present the detection of glaucoma using extreme learning machine(... Dear Sir,Iam Dr.Kavitha S,from the Department of Electronics and Communication Engineering,Nandha Engineering College,Erode,Tamil Nadu,India.I write to present the detection of glaucoma using extreme learning machine(ELM)and fractal feature analysis.Glaucoma is the second most frequent cause of permanent blindness in industrial 展开更多
关键词 In Assessment of glaucoma using extreme learning machine and fractal feature analysis ELM FIGURE
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Cases analysis of rational use of medicine (31) Nongonococcal urethritis(NGU)
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《天津药学》 2008年第5期77-78,共2页
1.Patient's conditionsA 29-year-old man,was infected with nongonococcal urethritis(NGU).He complained that he had dysuria and discomfort in the urethra and mucopurulent discharge,which appeared one week after inte... 1.Patient's conditionsA 29-year-old man,was infected with nongonococcal urethritis(NGU).He complained that he had dysuria and discomfort in the urethra and mucopurulent discharge,which appeared one week after intercourse. 展开更多
关键词 NGU Nongonococcal urethritis Cases analysis of rational use of medicine
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Analysis of Household Use of Traditional Fuels and Possible Contribution to Deforestation in Kisii County, Kenya
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作者 Ondiek Renish Awuor Olorunnisola Abel Olajide Basweti Evans 《Open Journal of Ecology》 2022年第11期756-772,共17页
A large majority of Kenyans still rely on traditional fuels to meet their domestic cooking needs. The demand for traditional biomass is therefore likely to increase in the coming decades as long as they remain the mos... A large majority of Kenyans still rely on traditional fuels to meet their domestic cooking needs. The demand for traditional biomass is therefore likely to increase in the coming decades as long as they remain the most readily available and affordable in comparison to modern energy options. This research sought to analyze the household use of traditional fuels and its possible contribution to deforestation in Kisii County. The willingness of respondents to adopt alternative biofuels and energy efficient stoves and barriers encountered were also assessed. Two structured questionnaires that contained both open and close-ended questions were administered to 436 households and 40 wood fuel sellers respectively. Analysis of variance and regression analysis were used to analyze the alternative hypotheses of the study. It was established that the use of charcoal was the most prevalent compared to other fuels. Household consumption of traditional fuels contributed to an estimated loss of 39 ha of forest cover per annum. However, since 89.7% of the wood fuel used was sourced from other counties, the loss of biomass did not occur in Kisii County. Given a chance, about 63% of the respondents were willing to adopt alternative biofuels and energy efficient stoves. However, the greatest barrier to the adoption of these alternatives was the high cost of purchase. Other barriers identified included lack of government support and unwillingness to let go of traditional cooking practices. It was recommended that the Kenyan government and other stakeholders should promote local technologies for producing energy efficient stoves to make them more affordable to the populace. 展开更多
关键词 analysis of Household Use of Traditional Fuels and Possible Contribution to Deforestation in Kisii County Kenya
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Some Experiments with Multivariate Objective Analysis Scheme of Heights and Winds Using Optimum Interpolation
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作者 S.K.Sinha S.G.Narkhedkar +1 位作者 D.R.Talwalkar S.Rajamani 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1992年第4期431-440,共10页
A two-dimensional, multitvariate objective analysis scheme for simultaneous analysis of geopotential height and wind fields has been developed over Indian and adjoining region for use in numerical weather prediction. ... A two-dimensional, multitvariate objective analysis scheme for simultaneous analysis of geopotential height and wind fields has been developed over Indian and adjoining region for use in numerical weather prediction. The height-height correlations calculated using daily data of four July months (1976-1979), are used to derive the other autocorrelations and cross-correlations assuming geostropic relationship. A Gaussian function is used to model the autocorrelation function. Since the scheme is multivariate the regression coefficients (weights) are matrix.Near the equator, the geostrophic approximation relating mass and wind is decoupled in a way similar to Bergman (1979). The objective analyses were made over Indian and adjoining region for 850, 700, 500, 300 and 200 hPa levels for the period from 4 July to 8 July 1979, 12 GMT. The analyses obtained using multivariate optimum interpolation scheme depict the synoptic situations satisfactorily. The analyses were also compared with the FGGE analyses (from ECMWF) and also with the station observations by computing the root mean square (RMS) errors and the RMS errors are comparable with those obtained in other similar studies. 展开更多
关键词 In Some Experiments with Multivariate Objective analysis Scheme of Heights and Winds Using Optimum Interpolation
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Prioritization of Sub-Watersheds in Ruparel Watershed, Rajasthan Based on Morphometric and Land Use/Land Cover Analysis Using Remote Sensing and GIS
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作者 Munahzah Meraj Akram Javed 《International Journal of Geosciences》 2022年第2期138-154,共17页
Watershed prioritization is considered as the most significant aspect in watershed resource management and development program. The present work attempts to prioritize seventeen sub-watersheds in Ruparel watershed of ... Watershed prioritization is considered as the most significant aspect in watershed resource management and development program. The present work attempts to prioritize seventeen sub-watersheds in Ruparel watershed of Alwar district of Rajasthan, India. For prioritization of sub-watersheds, morphometric and land use/land cover (LULC) analysis were performed using remote sensing and GIS. Base map of the study area has been derived from SOI toposheet on 1:50,000 scale whereas LULC mapping was done using IRS P6 LISS III data. Standard methods for drainage morphometry have been followed for computing morphometric parameters such as linear and shape for seventeen sub-watersheds and allotted ranks based on their relationship with erodibility and a compound value has been calculated for final ranking. Five main LULC categories were computed and were assigned priority ranks and subsequently a compound parameter was determined for final ranking. Integration of both morphometric and LULC results reveal that SBW5, SBW7, SBW12 and SBW16 are the common sub-watersheds that fall under high priority, SBW3 falls under Medium category and SBW11 comes under low priority. The results of the analysis can be used to identify the sub-watersheds which need immediate restoration and will eventually help in watershed resource management for sustainable development. 展开更多
关键词 PRIORITIZATION Watershed Resource Management MORPHOMETRY Land Use/Land Cover analysis
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Gene targeted and immune therapies for nodal and gastrointestinal follicular lymphomas
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作者 Takuya Watanabe 《World Journal of Gastroenterology》 SCIE CAS 2023年第48期6179-6197,共19页
Follicular lymphoma(FL)is the most common indolent B-cell lymphoma(BCL)globally.Recently,its incidence has increased in Europe,the United States,and Asia,with the number of gastrointestinal FL cases expected to increa... Follicular lymphoma(FL)is the most common indolent B-cell lymphoma(BCL)globally.Recently,its incidence has increased in Europe,the United States,and Asia,with the number of gastrointestinal FL cases expected to increase.Genetic abnormalities related to t(14;18)translocation,BCL2 overexpression,NF-κB pathway-related factors,histone acetylases,and histone methyltransferases cause FL and enhance its proliferation.Meanwhile,microRNAs are commonly used in diagnosing FL and predicting patient prognosis.Many clinical trials on novel therapeutics targeting these genetic abnormalities and immunomodulatory mechanisms have been conducted,resulting in a marked improvement in therapeutic outcomes for FL.Although developing these innovative therapeutic agents targeting specific genetic mutations and immune pathways has provided hope for curative options,FL treatment has become more complex,requiring combinatorial therapeutic regimens.However,optimal treatment combinations have not yet been achieved,highlighting the importance of a complete understanding regarding the pathogenesis of gastrointestinal FL.Accordingly,this article reviews key research on the molecular pathogenesis of nodal FL and novel therapies targeting the causative genetic mutations.Moreover,the results of clinical trials are summarized,with a particular focus on treating nodal and gastrointestinal FLs. 展开更多
关键词 Gastrointestinal follicular lymphoma Genetic mutation analysis using nextgeneration sequencing MicroRNA Gene targeted therapy Immune therapy
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Arc-length technique for nonlinear finite element analysis 被引量:9
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作者 MEMONBashir-Ahmed 苏小卒 《Journal of Zhejiang University Science》 EI CSCD 2004年第5期618-628,共11页
Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ... Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ordinary solution techniques lead to instability near the limit points and also have problems in case of snap-through and snap-back. Thus they fail to predict the complete load-displacement response. The arc-length method serves the purpose well in principle, received wide acceptance in finite element analysis, and has been used extensively. However modifications to the basic idea are vital to meet the particular needs of the analysis. This paper reviews some of the recent developments of the method in the last two decades, with particular emphasis on nonlinear finite element analysis of reinforced concrete structures. 展开更多
关键词 Arc-length method Nonlinear analysis Finite element method Reinforced concrete Load-deflection path Document code: A CLC number: TU31 Arc-length technique for nonlinear finite element analysis* MEMON Bashir-Ahmed# SU Xiao-zu (苏小卒) (Department of Structural Engineering Tongji University Shanghai 200092 China) E-mail: bashirmemon@sohu.com xiaozub@online.sh.cn Received July 30 2003 revision accepted Sept. 11 2003 Abstract: Nonlinear solution of reinforced concrete structures particularly complete load-deflection response requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard ordinary solution techniques lead to instability near the limit points and also have problems in case of snap-through and snap-back. Thus they fail to predict the complete load-displacement response. The arc-length method serves the purpose well in principle received wide acceptance in finite element analysis and has been used extensively. However modifications to the basic idea are vital to meet the particular needs of the analysis. This paper reviews some of the recent developments of the method in the last two decades with particular emphasis on nonlinear finite element analysis of reinforced concrete structures. Key words: Arc-length method Nonlinear analysis Finite element method Reinforced concrete Load-deflection path
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A New Method Based on Association Rules Mining and Geo-filter for Mining Spatial Association Knowledge 被引量:6
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作者 LIU Yaolin XIE Peng +3 位作者 HE Qingsong ZHAO Xiang WEI Xiaojian TAN Ronghui 《Chinese Geographical Science》 SCIE CSCD 2017年第3期389-401,共13页
Association rule mining methods, as a set of important data mining tools, could be used for mining spatial association rules of spatial data. However, applications of these methods are limited for mining results conta... Association rule mining methods, as a set of important data mining tools, could be used for mining spatial association rules of spatial data. However, applications of these methods are limited for mining results containing large number of redundant rules. In this paper, a new method named Geo-Filtered Association Rules Mining(GFARM) is proposed to effectively eliminate the redundant rules. An application of GFARM is performed as a case study in which association rules are discovered between building land distribution and potential driving factors in Wuhan, China from 1995 to 2015. Ten sets of regular sampling grids with different sizes are used for detecting the influence of multi-scales on GFARM. Results show that the proposed method can filter 50%–70% of redundant rules. GFARM is also successful in discovering spatial association pattern between building land distribution and driving factors. 展开更多
关键词 data mining association rules rules spatial visualization driving factors analysis land use change
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Relationships Between River Water Quality and Landscape Factors in Haihe River Basin, China: Implications for Environmental Management 被引量:4
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作者 XU Huashan ZHENG Hua +2 位作者 CHEN Xiaoshu REN Yufen OUYANG Zhiyun 《Chinese Geographical Science》 SCIE CSCD 2016年第2期197-207,共11页
River water plays a key role in human health, and in social and economic development, and is often affected by both natural factors and human activities. An in-depth understanding of the role of these factors can help... River water plays a key role in human health, and in social and economic development, and is often affected by both natural factors and human activities. An in-depth understanding of the role of these factors can help in developing an effective catchment management strategy to protect precious water resources. This study analyzed river water quality, patterns of terrestrial and riparian ecosystems, intensity of agricultural activities, industrial structure, and spatial distribution of pollutant emissions in the Haihe River Basin in China for the year of 2010, identifying the variables that have the greatest impact on river water quality. The area percentage of farmland in study area, the percentage of natural vegetation cover in the 1000-m riparian zone, rural population density, industrial Gross Domestic Product(GDP)/km^2, and industrial amino nitrogen emissions were all significantly correlated with river water quality(P < 0.05). Farming had the largest impact on river water quality, explaining 43.0% of the water quality variance, followed by the coverage of natural vegetation in the 1000-m riparian zone, which explained 36.2% of the water quality variance. Industrial amino nitrogen emissions intensity and rural population density explained 31.6% and 31.4% of the water quality variance, respectively, while industrial GDP/km^2 explained 26.6%. Together, these five indicators explained 67.3% of the total variance in water quality. Consequently, water environmental management of the Haihe River Basin should focus on adjusting agricultural activities, conserving riparian vegetation, and reducing industrial pollutant emissions by optimizing industrial structure. The results demonstrate how human activities drive the spatial pattern changes of river water quality, and they can provide reference for developing land use guidelines and for prioritizing management practices to maintain stream water quality in a large river basin. 展开更多
关键词 land use watershed management river water quality gradient analysis
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Impacts of precipitation variation and soil and water conservation measures on runoff and sediment yield in the Loess Plateau Gully Region, China 被引量:8
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作者 XIA Lu SONG Xiao-yu +3 位作者 FU Na MENG Chun-fang LI Huai-you LI Yao-lin 《Journal of Mountain Science》 SCIE CSCD 2017年第10期2028-2041,共14页
The Loess Plateau of China has experienced a lengthy drought and severe soil erosion.Changes in precipitation and land use largely determine the dynamics of runoff and sediment yield in this region. Trend and mutation... The Loess Plateau of China has experienced a lengthy drought and severe soil erosion.Changes in precipitation and land use largely determine the dynamics of runoff and sediment yield in this region. Trend and mutation analyses were performed on hydrological data(1981–2012) from the Yanwachuan watershed in the Loess Plateau Gully Region to study the evolution characteristics of runoff and sediment yield. A time-series contrasting method also was used to evaluate the effects of precipitation and soil and water conservation(SWC) on runoff and sediment yield. Annual sediment yield declined markedly from 1981 to 2012 although there was no significant change in annual precipitation and annual runoff. Change points of annual runoff and annual sediment yield occurred in 1996 and 1997,respectively. Compared with that in the baseline period(1981–1996), annual runoff and annual sediment yield in the change period(1997–2012)decreased by 17.0% and 76.0%, respectively, but annual precipitation increased by 6.3%. Runoff decreased in the flood season and normal season, but increased in the dry season, while sediment yield significantly declined in the whole study period. The SWC measures contributed significantly to the reduction of annual runoff(137.9%) and annual sediment yield(135%) and were more important than precipitation. Biological measures(forestland and grassland) accounted for 61.04% of total runoff reduction, while engineering measures(terraces and dams) accounted for 102.84% of total sediment yield reduction. Furthermore, SWC measures had positive ecological effects. This study provides a scientific basis for soil erosion control on the Loess Plateau. 展开更多
关键词 Quantitative impact Trend analysis Evolution characteristics Runoff and sediment yield Rainfall Land use change
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Effects of Topography and Land use on Woody Plant Species Composition and Beta Diversity in an Arid Trans-Himalayan Landscape, Nepal 被引量:5
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作者 Shishir PAUDEL Ole R VETAAS 《Journal of Mountain Science》 SCIE CSCD 2014年第5期1112-1122,共11页
Distribution patterns of plant species are believed to be impacted by small-scale habitat heterogeneity. However, there have been few comparative studies examining how woody vegetation composition and diversity varies... Distribution patterns of plant species are believed to be impacted by small-scale habitat heterogeneity. However, there have been few comparative studies examining how woody vegetation composition and diversity varies with aspects of different orientations in the Trans-Himalayan region at a local scale. Here, we examined the effects of incoming solar radiation on variation in woody species composition and compared the diversity between the northeast- and southwest-facing slopes in a Trans-Himalayan valley of Nepal. We also examined the implicit interactions between slope orientation and land use in determining the compositional variations between the slopes. We selected two pairs of northeast- and southwest-facing slopes where the first pair has a similar land use and differs in exposure only(Pisang site) while the other pair has clear differences in land use in addition to slope exposure(Braka site). In each site, we sampled 72 plots(36 on each slope) in which the presence and absence of woody species, environmental variables, and disturbance were recorded. Correspondence Analysis(CA) results suggested that the woody species composition significantly varied between northeast- and southwest-facing slopes at both sites, and was significantly correlated with measured environmental variables such as radiation index, altitude, and canopy openness. In the Braka site,mean alpha diversity was significantly higher on southwest-facing slopes. In contrast, beta diversity and gamma diversity were greater on northeast-facing slopes at both sites. Our results suggest that topographic variables(e.g., radiation index) affect species composition between the slopes, likely due to their influence on small scale abiotic environmental variables. However, the effects of land use, such as livestock browsing/grazing may interact with the effects of slope exposure, effectively reducing differences in species composition within slopes but enhancing the differences in beta diversity between contrasting slopes in the Braka. We conclude that slope orientation and land use are important factors in structuring the woody species composition and diversity in the arid Trans-Himalayan region. We suggest that both environmental and land use variables should be taken into consideration in future studies on plant community structure along the cultural landscapes. 展开更多
关键词 Correspondence analysis Diversity Environmental gradients Himalaya Land use Topographic aspect Woody vegetation
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