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Comprehending drivers of land use land cover change from 1999 to 2021 in the Pithoragarh District,Kumaon Himalaya,Uttarakhand,India
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作者 Mahika PHARTIYAL Sanjeev SHARMA 《Journal of Mountain Science》 SCIE CSCD 2024年第7期2394-2407,共14页
The Himalayan region has been experiencing stark impacts of climate change,demographic and livelihood pattern changes.The analysis of land use and land cover(LULC)change provides insights into the shifts in spatial an... The Himalayan region has been experiencing stark impacts of climate change,demographic and livelihood pattern changes.The analysis of land use and land cover(LULC)change provides insights into the shifts in spatial and temporal patterns of landscape.These changes are the combined effects of anthropogenic and natural/climatic factors.The present study attempts to monitor and comprehend the main drivers behind LULC changes(1999-2021)in the Himalayan region of Pithoragarh district,Uttarakhand.Pithoragarh district is a border district,remotely located in the north-east region of Uttarakhand,India.The study draws upon primary and secondary data sources.A total of 400 household surveys and five group discussions from 38 villages were conducted randomly to understand the climate perception of the local community and the drivers of change.Satellite imagery,CRU(Climatic Research Unit)climate data and climate perception data from the field have been used to comprehensively comprehend,analyze,and discuss the trends and reasons for LULC change.GIS and remote sensing techniques were used to construct LULC maps.This multifaceted approach ensures comprehensive and corroborated information.Five classes were identified and formed viz-cultivation,barren,settlement,snow,and vegetation.Results show that vegetation and builtup have increased whereas cultivation,barren land,and snow cover have decreased.The study further aims to elucidate the causes behind LULC changes in the spatially heterogeneous region,distinguishing between those attributed to human activities,climate shifts,and the interconnected impacts of both.The study provides a comprehensive picture of the study area and delivers a targeted understanding of local drivers and their potential remedies by offering a foundation for formulating sustainable adaptation policies in the region. 展开更多
关键词 Himalayan region Land use/land cover change Anthropogenic factors Climate change Socioecological system
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Changes in snow cover extent in the Central Taurus Mountains from 1981 to 2021 in relation to temperature, precipitation, and atmospheric teleconnections
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作者 Ecmel ERLAT Fulya AYDIN-KANDEMİR 《Journal of Mountain Science》 SCIE CSCD 2024年第1期49-67,共19页
The snow cover over the Taurus Mountains affects water supply, agriculture, and hydropower generation in the region. In this study, we analyzed the monthly Snow Cover Extent(SCE) from November to April in the Central ... The snow cover over the Taurus Mountains affects water supply, agriculture, and hydropower generation in the region. In this study, we analyzed the monthly Snow Cover Extent(SCE) from November to April in the Central Taurus Mountains(Bolkar, Aladaglar, Tahtali and Binboga Mountains) from 1981 to 2021. Linear trends of snow cover season(November to April) over the last 41 years showed decreases in SCE primarily at lower elevations. The downward trend in SCE was found to be more pronounced and statistically significant for only November and March. SCE in the Central Taurus Mountains has declined about-6.3% per decade for 2500-3000 m in November and about-6.0% per decade for 1000-1500 m and 3000+ m in March over the last 41 years. The loss of SCE has become evident since the 2000s, and the lowest negative anomalies in SCE have been observed in 2014, 2001, and 2007 in the last 41 years, which are consistent with an increase in air temperature and decreased precipitation. SCE was correlated with both mean temperature and precipitation, with temperature having a greater relative importance at all elevated gradients. Results showed that there is a strong linear relationship between SCE and the mean air temperature(r =-0.80) and precipitation(r = 0.44) for all elevated gradients during the snow season. The Arctic Oscillation(AO), the North Atlantic Oscillation(NAO), and the Mediterranean Oscillation(MO) winter indices were used to explain the year-to-year variability in SCE over the Central Taurus Mountains. The results showed that the inter-annual variability observed in the winter SCE on the Central Taurus Mountains was positively correlated with the phases of the winter AO, NAO and MO, especially below 2000 m elevation. 展开更多
关键词 Snow cover extent Atmospheric teleconnection Central Taurus Mountains Air temperature and precipitation Geographic Information Systems Türkiye
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妊娠合并慢性乙型肝炎血清HBV pgRNA、PreS1抗原表达与肝内胆汁淤积症的相关性分析
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作者 李佳 何霞 李玲 《安徽医药》 CAS 2024年第4期709-713,共5页
目的 探究妊娠合并慢性乙型肝炎病人血清乙型肝炎病毒(HBV)前基因组RNA(HBV pgRNA)、前S1抗原(PreS1Ag)水平变化及与妊娠期肝内胆汁淤积症(ICP)发生的相关性。方法 选取2017年6月至2020年6月在雅安市人民医院进行孕期检查的慢性乙型肝... 目的 探究妊娠合并慢性乙型肝炎病人血清乙型肝炎病毒(HBV)前基因组RNA(HBV pgRNA)、前S1抗原(PreS1Ag)水平变化及与妊娠期肝内胆汁淤积症(ICP)发生的相关性。方法 选取2017年6月至2020年6月在雅安市人民医院进行孕期检查的慢性乙型肝炎孕妇279例作为研究对象,根据入组病人是否患有ICP分为合并ICP组43例、未合并ICP组236例。比较两组病人血清中HBV pgRNA、PreS1 Ag水平,并分析两组血清HBV pgRNA、PreS1 Ag表达与HBV DNA表达水平相关性;比较两组病人妊娠结局,并分析合并ICP组病人血清HBV pgRNA表达水平及PreS1 Ag阳性表达率与妊娠结局的关系。受试者操作特征(ROC)曲线分析血清HBV pgRNA、PreS1 Ag光密度[D(λ)]值诊断慢性乙型肝炎孕妇合并ICP的效能。结果 合并ICP组慢性乙型肝炎病人血清HBV表面抗原(HbsAg)水平[(3.71±0.92)log IU/mL]、HBV e抗原(HbeAg)阳性率[65.12%(28/43)]、HBV DNA含量[(8.03±1.69)log copies/mL]、天冬氨酸转氨酶(AST)[(79.68±15.73)U/L]、丙氨酸转氨酶(ALT)[(72.08±16.95)U/L]、PreS1 Ag阳性表达率[88.37%(38/43)]、PreS1 Ag D(λ)值水平(1.24±0.25)及HBV pgRNA表达水平[(5.17±1.25)log copies/mL]明显高于未合并ICP组[(2.26±0.74)log IU/mL、24.15%(57/236)、(5.19±1.07)logcopies/mL、(23.01±12.47)U/L、(21.76±10.51)U/L、67.80%(160/236)、(0.92±0.23)、(3.02±0.98)logcopies/mL](P<0.05)。血清HBV pgRNA诊断慢性乙型肝炎孕妇合并ICP的曲线下面积(AUC)为0.89,灵敏度为81.40%,特异度为80.50%。PreS1 Ag D(λ)值诊断慢性乙型肝炎孕妇合并ICP的AUC为0.83,灵敏度为76.70%,特异度为79.20%。二者联合诊断的AUC为0.91,灵敏度为93.00%,特异度为78.40%。合并ICP组、未合并ICP组血清PreS1 Ag阳性的慢性乙型肝炎病人血清HBV DNA、HBV pgRNA表达水平均明显高于PreS1 Ag阴性表达病人(P<0.05)。合并ICP组、未合并ICP组血清HBV pgRNA、PreS1 Ag D(λ)值均与HBV DNA表达水平呈正相关(P<0.05)。合并ICP组产后出血、早产的发生率明显高于未合并ICP组(P<0.05)。发生不良妊娠结局的慢性乙型肝炎合并ICP病人血清PreS1 Ag阳性表达率、PreS1 Ag D(λ)值、HBV pgRNA表达水平均明显高于未发生不良妊娠结局病人(P<0.05)。结论 合并ICP的慢性乙型肝炎病人血清HBV pgRNA表达水平、PreS1 Ag阳性表达率及D(λ)值水平均明显升高,对ICP有一定诊断价值,且两者水平变化均与HBV DNA含量有关,并可能预示病人不良妊娠结局的发生。 展开更多
关键词 妊娠并发症 乙型肝炎 慢性 HBV前基因组RNA 前S1抗原 妊娠期肝内胆汁淤积症 相关性
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血清preS1水平与慢性乙型肝炎患者肝纤维化的关系及对癌变的诊断价值
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作者 高兴娟 程磊 +5 位作者 马秀清 刘守珠 王宝英 刘海燕 才德吉 杨兴唐 《传染病信息》 2024年第2期132-136,共5页
目的分析血清乙型肝炎病毒(hepatitis B virus,HBV)前S1蛋白(precursor S1 protein,preS1)与慢性乙型肝炎(chronic hepatitis B,CHB)肝纤维化及癌变进展的相关性。方法对2019年10月—2021年10月期间在青海红十字医院接受检查的228例乙... 目的分析血清乙型肝炎病毒(hepatitis B virus,HBV)前S1蛋白(precursor S1 protein,preS1)与慢性乙型肝炎(chronic hepatitis B,CHB)肝纤维化及癌变进展的相关性。方法对2019年10月—2021年10月期间在青海红十字医院接受检查的228例乙肝表面抗原(hepatitis B surface antigen,HBsAg)阳性慢性HBV感染者进行回顾性分析,其中CHB患者75例、肝硬化(liver cirrhosis,LC)患者93例(LC组)、肝细胞癌(hepatocellular carcinoma,HCC)患者60例(HCC组)。根据LC和HCC组肝组织活检分析肝脏炎症活动及肝纤维化程度。结果HCC组血清preS1水平[496.32(457.63,988.0)ng/mL]和LC组[338.72(247.93,554.61)ng/mL]血清preS1水平均显著高于CHB组[113.69(87.09,177.40)ng/mL],且差异具有统计学意义(P均<0.05)。HCC组血清preS1水平亦高于LC组(P=0.002)。经受试者工作特征曲线分析,血清preS1水平鉴别诊断CHB与LC的曲线下面积(area under the curve,AUC)是0.881(95%CI:0.830~0.932),鉴别诊断CHB/LC与HCC的AUC是0.861(95%CI:0.815~0.908)。3组患者的血清preS1水平与HBsAg(rs=0.799,P<0.001)呈强正相关和Log HBV DNA(rs=0.262,P<0.001)呈弱正相关。此外LC组和HCC组血清preS1水平与肝脏炎症活动分级(rs=0.201,P=0.009)及肝纤维化分期也呈弱正相关性(rs=0.295,P<0.001)。结论血清preS1水平与血清HBsAg、HBV DNA水平和肝脏炎症和纤维化进展呈正相关,有可能成为鉴别诊断HBV相关慢性肝病肝硬化或癌变的候选标志物。 展开更多
关键词 乙型肝炎病毒 HBV前S1蛋白 慢性乙型肝炎 肝纤维化 肝硬化 肝细胞癌
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植物PRE类转录因子基因的研究进展
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作者 路文婧 沙伟 马天意 《高师理科学刊》 2024年第2期64-68,共5页
多效唑是一种赤霉素合成抑制剂,抗多效唑(paclobutrazol-resistance,PRE)基因家族编码的蛋白质可与多效唑发生拮抗作用,这些蛋白质具有螺旋-环-螺旋(basic Helix-Loop-Helix,bHLH)结构,在高等植物中参与转录调控从而在植物发育的许多方... 多效唑是一种赤霉素合成抑制剂,抗多效唑(paclobutrazol-resistance,PRE)基因家族编码的蛋白质可与多效唑发生拮抗作用,这些蛋白质具有螺旋-环-螺旋(basic Helix-Loop-Helix,bHLH)结构,在高等植物中参与转录调控从而在植物发育的许多方面发挥关键作用.PRE基因通过参与各种激素(如赤霉素,油菜素内酯,生长素等)、温度和光响应信号通路来调节植物的生长和发育,对植物生长发育具有重要意义.综述PRE基因在植物中的研究进展,主要包括PRE基因的基本性质、分类、功能以及所参与的植物生理过程等方面,为进一步研究植物PRE类转录因子基因提供理论基础. 展开更多
关键词 pre 植物生长 植物发育
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Adding Value to Crop Production Systems by Integrating Forage Cover Crop Grazing
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作者 Robert B. Mitchell Daren D. Redfearn +9 位作者 Kenneth P. Vogel Terry J. Klopfenstein Galen Erickson P. Stephen Baenziger Bruce E. Anderson Mary E. Drewnoski Jay Parsons Steven D. Masterson Marty R. Schmer Virginia L. Jin 《American Journal of Plant Sciences》 CAS 2024年第3期180-192,共13页
In addition to their value as cereal grains, wheat (Triticum aestivum L.) and triticale (× Triticosecale Wittmack) are important cool-season annual forages and cover crops. Yearling steer (Bos taurus) performance... In addition to their value as cereal grains, wheat (Triticum aestivum L.) and triticale (× Triticosecale Wittmack) are important cool-season annual forages and cover crops. Yearling steer (Bos taurus) performance was compared in the spring following autumn establishment as for age cover crops after soybean [Glycine max (L.) Merr.] grain harvest. Replicated pastures (0.4 ha) were no-till seeded in three consecutive years into soybean stubble in autumn, fertilized, and grazed the following spring near Ithaca, NE, USA. Each pasture (n = 3) was continuously stocked in spring with four yearling steers (380 ± 38 kg) for 17, 32, and 28 d in 2005, 2006, and 2007, respectively. In 2005, average daily gain (ADG) for steers grazing triticale exceeded the ADG for wheat by 0.31 kghd<sup>-1</sup>d<sup>-1</sup>. In 2006, wheat ADG exceeded that for triticale by 0.12 kghd<sup>-1</sup>d<sup>-1</sup>. In 2007, steers grazing wheat lost weight, while steers grazing triticale gained 0.20 kghd<sup>-1</sup>d<sup>-1</sup>. Based on the 3-year average animal gains valued at $1.32 kg<sup>-1</sup>, mean net return ($ ha<sup>-1</sup> yr<sup>-1</sup>) was $62.15 for triticale and $22.55 for wheat. Since these grazed cover crops provide ecosystem services in addition to forage, grazing could be viewed as a mechanism for recovering costs and adds additional value to the system. Based on this 3-year grazing trial, triticale was superior to wheat and likely will provide the most stable beef yearling performance across years with variable weather for the western Cornbelt USA. 展开更多
关键词 cover crops SOYBEAN TRITICALE WHEAT
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Modelling Land Use/Land Cover Change of River Rwizi Catchment, South-Western Uganda Using GIS and Markov Chain Model
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作者 Lauben Muhangane Morgan Andama 《Journal of Water Resource and Protection》 CAS 2024年第2期181-206,共26页
Analysis of catchment Land use/Land cover (LULC) change is a vital tool in ensuring sustainable catchment management. The study analyzed land use/land cover changes in the Rwizi catchment, south western Uganda from 19... Analysis of catchment Land use/Land cover (LULC) change is a vital tool in ensuring sustainable catchment management. The study analyzed land use/land cover changes in the Rwizi catchment, south western Uganda from 1989-2019 and projected the trend by 2040. Landsat images, field observations, key informant interviews and focus group discussions were used to collect data. Changes in cropland, forestland, built up area, grazing land, wetland and open water bodies were analyzed in ArcGIS version 10.2.2 and ERDAS IMAGINE 14 software and a Markov chain model. All the LULC classes increased in area except grazing land. Forest land and builtup area between 2009-2019 increased by 370.03% and 229.53% respectively. Projections revealed an increase in forest land and builtup area by 2030 and only built up area by 2040. LULCC in the catchment results from population pressure, reduced soil fertility and high value of agricultural products. 展开更多
关键词 Land cover River Catchment Geographic Information System Markov Model Sustainable Land Management
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Changes in Spring Snow Cover over the Eastern and Western Tibetan Plateau and Their Associated Mechanism
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作者 Fangchi LIU Xiaojing JIA Wei DONG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第5期959-973,共15页
The spring snow cover(SC)over the western Tibetan Plateau(TP)(TPSC)(W_TPSC)and eastern TPSC(E_TPSC)have displayed remarkable decreasing and increasing trends,respectively,during 1985–2020.The current work investigate... The spring snow cover(SC)over the western Tibetan Plateau(TP)(TPSC)(W_TPSC)and eastern TPSC(E_TPSC)have displayed remarkable decreasing and increasing trends,respectively,during 1985–2020.The current work investigates the possible mechanisms accounting for these distinct TPSC changes.Our results indicate that the decrease in W_TPSC is primarily attributed to rising temperatures,while the increase in E_TPSC is closely linked to enhanced precipitation.Local circulation analysis shows that the essential system responsible for the TPSC changes is a significant anticyclonic system centered over the northwestern TP.The anomalous descending motion and adiabatic heating linked to this anticyclone leads to warmer temperatures and consequent snowmelt over the western TP.Conversely,anomalous easterly winds along the southern flank of this anticyclone serve to transport additional moisture from the North Pacific,leading to an increase in snowfall over the eastern TP.Further analysis reveals that the anomalous anticyclone is associated with an atmospheric wave pattern that originates from upstream regions.Springtime warming of the subtropical North Atlantic(NA)sea surface temperature(SST)induces an atmospheric pattern resembling a wave train that travels eastward across the Eurasian continent before reaching the TP.Furthermore,the decline in winter sea ice(SIC)over the Barents Sea exerts a persistent warming influence on the atmosphere,inducing an anomalous atmospheric circulation that propagates southeastward and strengthens the northwest TP anticyclone in spring.Additionally,an enhancement of subtropical stationary waves has resulted in significant increases in easterly moisture fluxes over the coastal areas of East Asia,which further promotes more snowfall over eastern TP. 展开更多
关键词 snow cover Tibetan Plateau long-term changes SPRING
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Assessing Spatio-Temporal Land Cover Changes in Dhund River Basin, Eastern Rajasthan (India), Using Multi-Temporal Landsat Data
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作者 Sadia Mazahir Akram Javed Mohd Yusuf Khanday 《Journal of Geographic Information System》 2024年第4期244-258,共15页
Land cover is an impression of natural cover on surface of earth such as bare soil, river, grass etc. and utilization of these natural covers for various human needs and purposes by mankind is defined as land use. Lan... Land cover is an impression of natural cover on surface of earth such as bare soil, river, grass etc. and utilization of these natural covers for various human needs and purposes by mankind is defined as land use. Land cover identification, delineation and mapping is important for planning activities, resource management and global monitoring studies while baseline mapping and subsequent monitoring is done by application of land use to get timely information about quantity of land that has been used. The present study has been carried out in Dhund river watershed of Jaipur, Rajasthan which covers an area of about 1828 sq∙km. The minimum and maximum elevation of the area is found to be 214 m and 603 m respectively. Land use and land cover changes of three decades from 1991 to 2021 have been interpreted by using remotes sensing and GIS techniques. ArcGIS software (Arc map 10.2), SOI topographic map, Cartosat-1 DEM and satellite data of Landsat 5 and Landsat 8 have been used for interpretation of eleven classes. The study shows an increase in cultivated land, settlement, waterbody, open forest, plantation and mining due to urbanization because of increasing demands of food, shelter and water while a decrease in dense forest, river, open scrub, wasteland and uncultivated land has also been marked due to destruction of aforementioned by anthropogenic activities such as industrialization resulting in environmental degradation that leads to air, soil and water pollution. 展开更多
关键词 Dhund River LANDSAT Land Use/Land cover Change Detection Analysis RAJASTHAN
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Glacier area change (1993-2019) and its relationship to debris cover, proglacial lakes, and morphological parameters in the Chandra-Bhaga Basin, Western Himalaya, India
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作者 VATSAL Sarvagya AZAM Mohd Farooq +5 位作者 BHARDWAJ Anshuman MANDAL Arindan BAHUGUNA Ishmohan RAMANATHAN Alagappan RAJU N.Janardhana TOMAR Sangita Singh 《Journal of Mountain Science》 SCIE CSCD 2024年第4期1287-1306,共20页
Glacier inventories serve as critical baseline data for understanding the impacts of climate change on glaciers.The present study maps the outlines of glaciers in the Chandra-Bhaga Basin(western Himalaya)for the years... Glacier inventories serve as critical baseline data for understanding the impacts of climate change on glaciers.The present study maps the outlines of glaciers in the Chandra-Bhaga Basin(western Himalaya)for the years 1993,2000,2010,and 2019 using Landsat Thematic Mapper(TM),Enhanced Thematic Mapper(ETM),and Operational Land Imager(OLI)datasets.A total of 251 glaciers,each having an area above 0.5 km^(2),were identified,which include 216 clean-ice and 35 debris-covered glaciers.Area changes are estimated for three periods:1993-2000,2000-2010,and 2010-2019.The total glacierized area was 996±62 km^(2) in 1993,which decreased to 973±70 km^(2) in 2019.The mean rate of glacier area loss was higher in the recent decade(2010-2019),at 0.036 km^(2),compared to previous decades(0.029 km^(2) in 2000-2010 and 0.025 km^(2) in 1993-2000).Supraglacial debris cover changes are also mapped over the period of 1993 and 2019.It is found that the supraglacial debris cover increased by 14.12±2.54 km^(2)(15.2%)during 1993-2019.Extensive field surveys on Chhota Shigri,Panchi II,Patsio,Hamtah,Mulkila,and Yoche Lungpa glaciers were carried out to validate the glacier outlines and supraglacial debris cover estimated using satellite datasets.Controls of various morphological parameters on retreat were also analyzed.It is observed that small,clean ice,south oriented glaciers,and glaciers with proglacial lakes are losing area at faster rates than other glaciers in the basin. 展开更多
关键词 GLACIER Area change Debris cover MORPHOLOGY Proglacial lake
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Land use and cover change and influencing factor analysis in the Shiyang River Basin,China
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作者 ZHAO Yaxuan CAO Bo +4 位作者 SHA Linwei CHENG Jinquan ZHAO Xuanru GUAN Weijin PAN Baotian 《Journal of Arid Land》 SCIE CSCD 2024年第2期246-265,共20页
Land use and cover change(LUCC)is the most direct manifestation of the interaction between anthropological activities and the natural environment on Earth's surface,with significant impacts on the environment and ... Land use and cover change(LUCC)is the most direct manifestation of the interaction between anthropological activities and the natural environment on Earth's surface,with significant impacts on the environment and social economy.Rapid economic development and climate change have resulted in significant changes in land use and cover.The Shiyang River Basin,located in the eastern part of the Hexi Corridor in China,has undergone significant climate change and LUCC over the past few decades.In this study,we used the random forest classification to obtain the land use and cover datasets of the Shiyang River Basin in 1991,1995,2000,2005,2010,2015,and 2020 based on Landsat images.We validated the land use and cover data in 2015 from the random forest classification results(this study),the high-resolution dataset of annual global land cover from 2000 to 2015(AGLC-2000-2015),the global 30 m land cover classification with a fine classification system(GLC_FCS30),and the first Landsat-derived annual China Land Cover Dataset(CLCD)against ground-truth classification results to evaluate the accuracy of the classification results in this study.Furthermore,we explored and compared the spatiotemporal patterns of LUCC in the upper,middle,and lower reaches of the Shiyang River Basin over the past 30 years,and employed the random forest importance ranking method to analyze the influencing factors of LUCC based on natural(evapotranspiration,precipitation,temperature,and surface soil moisture)and anthropogenic(nighttime light,gross domestic product(GDP),and population)factors.The results indicated that the random forest classification results for land use and cover in the Shiyang River Basin in 2015 outperformed the AGLC-2000-2015,GLC_FCS30,and CLCD datasets in both overall and partial validations.Moreover,the classification results in this study exhibited a high level of agreement with the ground truth features.From 1991 to 2020,the area of bare land exhibited a decreasing trend,with changes primarily occurring in the middle and lower reaches of the basin.The area of grassland initially decreased and then increased,with changes occurring mainly in the upper and middle reaches of the basin.In contrast,the area of cropland initially increased and then decreased,with changes occurring in the middle and lower reaches.The LUCC was influenced by both natural and anthropogenic factors.Climatic factors and population contributed significantly to LUCC,and the importance values of evapotranspiration,precipitation,temperature,and population were 22.12%,32.41%,21.89%,and 19.65%,respectively.Moreover,policy interventions also played an important role.Land use and cover in the Shiyang River Basin exhibited fluctuating changes over the past 30 years,with the ecological environment improving in the last 10 years.This suggests that governance efforts in the study area have had some effects,and the government can continue to move in this direction in the future.The findings can provide crucial insights for related research and regional sustainable development in the Shiyang River Basin and other similar arid and semi-arid areas. 展开更多
关键词 land use and cover classification land use and cover change(LUCC) climate change random forest accuracy assessment three-dimensional sampling method Shiyang River Basin
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Land Use and Land Cover Dynamics in the Eseka Alluvial Gold Mining District, Centre Region, Cameroon
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作者 Shu Vejiline Lum-Ndob Fonge Beatrice Ambo +3 位作者 Ambe Godlove Neba Ateh Kevin Ijunghi Enerst Tata Cheo Emmanuel Suh 《Journal of Geographic Information System》 2024年第4期289-305,共17页
Local populations in Cameroon thrive on forest resources and the flow of ecosystem services they provide are pivotal in sustaining national economy, improving people’s lives, safeguarding biodiversity, and mitigating... Local populations in Cameroon thrive on forest resources and the flow of ecosystem services they provide are pivotal in sustaining national economy, improving people’s lives, safeguarding biodiversity, and mitigating the impacts of environmental changes. The exploitation of these resources invariably leads to deforestation and forest degradation. This study was designed to evaluate land use land cover change (LULCC) in the Eseka alluvial gold mining district with the aid of Landsat images. In the investigation of forest cover change, four Landsat satellite images for (1990, 2002, 2015 and 2022) were used. Ground-truthing also helped to identify the activities carried out by the local population and to determine agents, drivers and pressures of land use and land cover change. Four main land cover classes namely: forest, agricultural land, settlement/mining camps and water bodies were selected. Between 1990 and 2022, the proportion of forest decreased from 98% to 34% while those of agricultural land and settlement/mining camps increased from 2% to 60% and 0.54% to 6% respectively. Analysis showed ongoing deforestation with forest cover loss of ~98,263 ha in 32 years giving a cover change percentage of 63.94%. Kappa coefficient for the study period ranged from 0.92 to 0.99. Forest cover loss could be attributed to farming activities, wood extraction and alluvial gold mining activities. Economic motives notably the need to increase household income from a frequent demand for farm and wood products in neighbouring towns and the quest for gold were the main drivers of these activities. Hence, this study assesses the impact of human activities from the mining sector on the forest ecosystem in a bid to inform mitigation policies. 展开更多
关键词 Land Use and Land cover Changes BIODIVERSITY Alluvial Gold Mining DRIVERS Landsat Images Ground-Truthing MITIGATION
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Characteristics of the microbial communities regulate soil multi-functionality under different cover crop amendments in Ultisol
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作者 Guilong Li Xiaofen Chen +8 位作者 Wenjing Qin Jingrui Chen Ke Leng Luyuan Sun Ming Liu Meng Wu Jianbo Fan Changxu Xu Jia Liu 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第6期2099-2111,共13页
The use of cover crops is a promising strategy for influencing the soil microbial consortium,which is essential for the delivery of multiple soil functions(i.e.,soil multifunctionality).Nonetheless,relatively little i... The use of cover crops is a promising strategy for influencing the soil microbial consortium,which is essential for the delivery of multiple soil functions(i.e.,soil multifunctionality).Nonetheless,relatively little is known about the role of the soil microbial consortium in mediating soil multifunctionality under different cover crop amendments in dryland Ultisols.Here,we assessed the multifunctionality of soils subjected to four cover crop amendments(control,non-amended treatment;RD,radish monoculture;HV,hairy vetch monoculture;and RDHV,radish-hairy vetch mixture),and we investigated the contributions of soil microbial richness,network complexity,and ecological clusters to soil multifunctionality.Our results demonstrated that cover crops whose chemical composition differed from that of the main plant crop promoted higher multifunctionality,and the radish-hairy vetch mixture rendered the highest enhancement.We obtained evidence that changes in soil microbial richness and network complexity triggered by the cover crops were associated with higher soil multifunctionality.Specifically,specialized microbes in a key ecological cluster(ecological cluster 2)of the soil microbial network were particularly important for maintaining soil multifunctionality.Our results highlight the importance of cover crop-induced variations in functionally important taxa for promoting the soil multifunctionality of dryland Ultisols. 展开更多
关键词 cover crops soil multifunctionality microbial richness network complexity ecological cluster
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Modelling the water diversion of a sustainable cover system under humid climates
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作者 Haowen Guo Charles Wang Wai Ng +2 位作者 Qi Zhang Chuanxiang Qu Liwen Hu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第7期2429-2440,共12页
Extreme rainfall significantly threatens the safety of the landfill cover system,especially under humid climates.This study aims to provide design recommendations for a sustainable landfill cover system consisting of ... Extreme rainfall significantly threatens the safety of the landfill cover system,especially under humid climates.This study aims to provide design recommendations for a sustainable landfill cover system consisting of a low-permeability soil layer underlying a two-layer capillary barrier for humid climates.First,the numerical back-analysis was conducted for verification against a series of flume model tests.Then,a parametric study was performed to investigate the effects of inclination angle,particle size and layer thickness on the lateral diversion length(DL)of the three-layer cover system under the 100-year return period rainfall of humid climates.The results show that the water lateral DL of the cover system can be greatly enhanced by increasing the inclination angle from 3°to 18°.Moreover,the bottom layer of the cover system with a coarser d10 was more susceptible to the impact of the heavy rainfall,while this can be alleviated by increasing the thickness of the bottom layer.A dimensionless number,defined as the ratio of thickness and d_(10) of the bottom layer,is proposed for designing lateral diversion of the three-layer cover system under humid climates.To preserve the maximum DL,it is suggested that the proposed dimensionless number should be larger than 95 and 110 for the design of rainfall events with 50-year and 100-year return periods for humid climates,respectively. 展开更多
关键词 Unsaturated soil RECYCLING Construction waste Three-layer landfill cover Water infiltration
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Near-Surface Soil Chemical Properties as Affected by Cover Crops Over Time in the Lower Mississippi River Valley
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作者 Cooper Fanning Kristofor R. Brye +3 位作者 Michael B. Daniels Trenton L. Roberts Samuel Fernandes Lisa S. Wood 《Agricultural Sciences》 2024年第9期1035-1056,共22页
Typical row-crop agricultural practices can potentially be harmful to soil health and future sustainability. The use of cover crops (CC) as a mechanism to improve soil health on a wide scale remains underutilized. Soi... Typical row-crop agricultural practices can potentially be harmful to soil health and future sustainability. The use of cover crops (CC) as a mechanism to improve soil health on a wide scale remains underutilized. Soil health remains a major concern for the sustainability of agricultural productivity, therefore, research into CC implementation as a mean to preserve or improve soil health is warranted. The objective of this study was to evaluate the effects of CC on the soils in the eastern Arkansas portion of the Lower Mississippi River Valley (LMRV) over time for various chemical soil parameters, including pH, soil organic matter (SOM), soil elemental contents (i.e., P, K, Ca, Mg, S, Na, Fe, Mn, Zn, Cu, and B), soil respiration, and a generalized soil health score index. Soil pH decreased over time under both CC and no-cover-crop (NCC) treatments, by −0.3 and −0.2, respectively. Soil OM decreased over time under NCC by −0.1%, but did not differ between CC treatments. Soil N availability decreased over time under NCC (−22.6 kg·ha−1), but did not change over time under CC. Soil respiration decreased over time under both CC and NCC, by −76.1 mg·L−1 and −77.3 mg·L−1, respectively, though there was no effect of CC treatment. The Haney soil health score index decreased under CC (−7.0) and NCC (−6.8) without an effect from CC treatment. Results of the study place emphasis on the temporal nature of soil health as influenced by cover crops and their potential to improve soil health. 展开更多
关键词 ARKANSAS cover Crops Soil Properties Soil Organic Matter Soil Health Score
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Assessment of vegetation cover changes and the contributing factors in the Al-Ahsa Oasis using Normalized Difference Vegetation Index(NDVI)
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作者 Walid CHOUARI 《Regional Sustainability》 2024年第1期42-53,共12页
The abandonment of date palm grove of the former Al-Ahsa Oasis in the eastern region of Saudi Arabia has resulted in the conversion of delicate agricultural area into urban area.The current state of the oasis is influ... The abandonment of date palm grove of the former Al-Ahsa Oasis in the eastern region of Saudi Arabia has resulted in the conversion of delicate agricultural area into urban area.The current state of the oasis is influenced by both expansion and degradation factors.Therefore,it is important to study the spatiotemporal variation of vegetation cover for the sustainable management of oasis resources.This study used Landsat satellite images in 1987,2002,and 2021 to monitor the spatiotemporal variation of vegetation cover in the Al-Ahsa Oasis,applied multi-temporal Normalized Difference Vegetation Index(NDVI)data spanning from 1987 to 2021 to assess environmental and spatiotemporal variations that have occurred in the Al-Ahsa Oasis,and investigated the factors influencing these variation.This study reveals that there is a significant improvement in the ecological environment of the oasis during 1987–2021,with increase of NDVI values being higher than 0.10.In 2021,the highest NDVI value is generally above 0.70,while the lowest value remains largely unchanged.However,there is a remarkable increase in NDVI values between 0.20 and 0.30.The area of low NDVI values(0.00–0.20)has remained almost stable,but the region with high NDVI values(above 0.70)expands during 1987–2021.Furthermore,this study finds that in 1987–2002,the increase of vegetation cover is most notable in the northern region of the study area,whereas from 2002 to 2021,the increase of vegetation cover is mainly concentrated in the northern and southern regions of the study area.From 1987 to 2021,NDVI values exhibit the most pronounced variation,with a significant increase in the“green”zone(characterized by NDVI values exceeding 0.40),indicating a substantial enhancement in the ecological environment of the oasis.The NDVI classification is validated through 50 ground validation points in the study area,demonstrating a mean accuracy of 92.00%in the detection of vegetation cover.In general,both the user’s and producer’s accuracies of NDVI classification are extremely high in 1987,2002,and 2021.Finally,this study suggests that environmental authorities should strengthen their overall forestry project arrangements to combat sand encroachment and enhance the ecological environment of the Al-Ahsa Oasis. 展开更多
关键词 Normalized Difference Vegetation Index(NDVI) Vegetation cover Ecological environment Land use and land cover(LULC) Urban expansion Al-Ahsa Oasis
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Dynamics of Land Use/Land Cover Considering Ecosystem Services for a Dense-Population Watershed Based on a Hybrid Dual-Subject Agent and Cellular Automaton Modeling Approach
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作者 Yutong Li Yanpeng Cai +3 位作者 Qiang Fu Xiaodong Zhang Hang Wan Zhifeng Yang 《Engineering》 SCIE EI CAS CSCD 2024年第6期182-195,共14页
Land use/land cover represents the interactive and comprehensive influences between human activities and natural conditions,leading to potential conflicts among natural and human-related issues as well as among stakeh... Land use/land cover represents the interactive and comprehensive influences between human activities and natural conditions,leading to potential conflicts among natural and human-related issues as well as among stakeholders.This study introduced economic standards for farmers.A hybrid approach(CA-ABM)of cellular automaton(CA)and an agent-based model(ABM)was developed to effectively deal with social and land-use synergic issues to examine human–environment interactions and projections of land-use conversions for a humid basin in south China.Natural attributes and socioeconomic data were used to analyze land use/land cover and its drivers of change.The major modules of the CA-ABM are initialization,migration,assets,land suitability,and land-use change decisions.Empirical estimates of the factors influencing the urban land-use conversion probability were captured using parameters based on a spatial logistic regression(SLR)model.Simultaneously,multicriteria evaluation(MCE)and Markov models were introduced to obtain empirical estimates of the factors affecting the probability of ecological land conversion.An agent-based CA-SLR-MCE-Markov(ABCSMM)land-use conversion model was proposed to explore the impacts of policies on land-use conversion.This model can reproduce observed land-use patterns and provide links for forest transition and urban expansion to land-use decisions and ecosystem services.The results demonstrated land-use simulations under multi-policy scenarios,revealing the usefulness of the model for normative research on land-use management. 展开更多
关键词 Land use/land cover Human-environment interactions Agent-based model Cellular automaton
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An Analysis of Land Use and Land Cover Changes, and Implications for Conservation in Mukumbura (Ward 2), Mt Darwin, Zimbabwe, 2002-2022
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作者 Musekiwa Innocent Maruza Edson Gandiwa +3 位作者 Never Muboko Ishmael Sango Tawanda Tarakini Nobert Tafadzwa Mukomberanwa 《Open Journal of Ecology》 2024年第9期706-730,共25页
Understanding trends of land use land cover (LULC) changes is important for biodiversity monitoring and conservation planning, and identifying the areas affected by change and designing sustainable solutions to reduce... Understanding trends of land use land cover (LULC) changes is important for biodiversity monitoring and conservation planning, and identifying the areas affected by change and designing sustainable solutions to reduce the changes. The study aims to evaluate and quantify the historical changes in land use and land cover in Mukumbura (Ward 2), Mt Darwin, Zimbabwe, from 2002 to 2022. The objective of the study was to analyse the LULC changes in Ward 2 (Mukumbura), Mt Darwin, Northern Zimbabwe, for a period of 20 years using geospatial techniques. Landsat satellite images were processed using Google Earth Engine (GEE) and the supervised classification with maximum likelihood algorithm was employed to generate LULC maps between 2002 and 2022 with a five (5) year interval, investigating the following variables, forest cover, barren land, water cover and the fields. Findings revealed a substantial reduction in forest cover by 38.8%, water bodies (wetlands, ponds, and rivers) declined by 55.6%, whilst fields (crop/agricultural fields) increased by 93.3% and the barren land cover increased by 26.3% from 2002 to 2022. These findings point to substantial changes in LULC over the observed years. LULC changes have resulted in habitat fragmentation, reduced biodiversity, and the disruption of ecosystem functions. The study concludes that if these deforestation trends, cultivation, and settlement land expansion continue, the ward will have limited indigenous fruit trees. Therefore, the causes for LULC changes must be controlled, sustainable forest resources use practiced, hence the need to domesticate the indigenous fruit trees in arborloo toilets. 展开更多
关键词 Anthropogenic Activities DEFORESTATION Geospatial Analysis Land Use/Land cover Supervised Classification
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Land Use Land Cover Analysis for Godavari Basin in Maharashtra Using Geographical Information System and Remote Sensing
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作者 Pallavi Saraf Dattatray G. Regulwar 《Journal of Geographic Information System》 2024年第1期21-31,共11页
The dynamic transformation of land use and land cover has emerged as a crucial aspect in the effective management of natural resources and the continual monitoring of environmental shifts. This study focused on the la... The dynamic transformation of land use and land cover has emerged as a crucial aspect in the effective management of natural resources and the continual monitoring of environmental shifts. This study focused on the land use and land cover (LULC) changes within the catchment area of the Godavari River, assessing the repercussions of land and water resource exploitation. Utilizing LANDSAT satellite images from 2009, 2014, and 2019, this research employed supervised classification through the Quantum Geographic Information System (QGIS) software’s SCP plugin. Maximum likelihood classification algorithm was used for the assessment of supervised land use classification. Seven distinct LULC classes—forest, irrigated cropland, agricultural land (fallow), barren land, shrub land, water, and urban land—are delineated for classification purposes. The study revealed substantial changes in the Godavari basin’s land use patterns over the ten-year period from 2009 to 2019. Spatial and temporal dynamics of land use/cover changes (2009-2019) were quantified using three Satellite/Landsat images, a supervised classification algorithm and the post classification change detection technique in GIS. The total study area of the Godavari basin in Maharashtra encompasses 5138175.48 hectares. Notably, the built-up area increased from 0.14% in 2009 to 1.94% in 2019. The proportion of irrigated cropland, which was 62.32% in 2009, declined to 41.52% in 2019. Shrub land witnessed a noteworthy increase from 0.05% to 2.05% over the last decade. The key findings underscored significant declines in barren land, agricultural land, and irrigated cropland, juxtaposed with an expansion in forest land, shrub land, and urban land. The classification methodology achieved an overall accuracy of 80%, with a Kappa Statistic of 71.9% for the satellite images. The overall classification accuracy along with the Kappa value for 2009, 2014 and 2019 supervised land use land cover classification was good enough to detect the changing scenarios of Godavari River basin under study. These findings provide valuable insights for discerning land utilization across various categories, facilitating the adoption of appropriate strategies for sustainable land use in the region. 展开更多
关键词 GIS Remote Sensing Land Use Land cover Change Change Detection Supervised Classification
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Exploring factors of disaster preparedness in UNESCO-designated heritage sites
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作者 Emmanuel Eze Alexander Siegmund 《Geography and Sustainability》 CSCD 2024年第3期392-404,共13页
Increased hazards threatening the United Nations Educational,Scientific and Cultural Organization(UNESCO)-designated sites and endangering cultural heritage and community well-being require attention and action.Con-si... Increased hazards threatening the United Nations Educational,Scientific and Cultural Organization(UNESCO)-designated sites and endangering cultural heritage and community well-being require attention and action.Con-sidering the pivotal role of UNESCO sites in conservation and development,this study assessed their levels of disaster preparedness.The absence of studies assessing disaster awareness,risk perception,and preparedness among UNESCO site actors,as well as the pivotal place of preparedness within the Disaster Risk Management(DRM)cycle justifies this research.Applying the tenets of the Person-Relative-to-Event framework,we hypothe-sized that a strong positive correlation exists between perceived risks,resources,and disaster preparedness.To collect pertinent data,we employed an embedded mixed-method design and conducted an online questionnaire survey yielding 141 responses from 59 countries.From the results of relevant analyses,wildfires,floods,and droughts are top hazards occurring frequently in UNESCO sites,with significant concerns about pollution and habitat loss during future events.Smartphones emerged as the most available crucial DRM resource,with higher availability of DRM resources correlating positively and significantly with sites’preparedness.Our findings con-tribute valuable insights to address missing links for disaster-ready and resilient UNESCO sites,promoting their preservation for future generations. 展开更多
关键词 Biosphere reserves Disaster risk management(DRM) Global geoparks Person-relative-to-event(pre)framework SUSTAINABILITY World heritage sites
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