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Improving the accuracy of precipitation estimates in a typical inland arid area of China using a dynamic Bayesian model averaging approach

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Journal of Arid Land 2024年第3期16卷 331-354页

作者： XU Wenjie ding jianli BAO Qingling WANG Jinjie XU Kun College of Geography and Remote Sensing Sciences Xinjiang UniversityUrumqi 830017China Key Laboratory of Smart City and Environment Modelling of Higher Education Institute Xinjiang UniversityUrumqi 830017China

Xinjiang Uygur Autonomous Region is a typical inland arid area in China with a sparse and uneven distribution of meteorological stations,limited access to precipitation data,and significant water *** and integrating precipitation datasets from different sources to accurately characterize precipitation patterns has become a challenge to provide more accurate and alternative precipitation information for the region,which can even improve the performance of hydrological *** study evaluated the applicability of widely used five satellite-based precipitation products(Climate Hazards Group InfraRed Precipitation with Station(CHIRPS),China Meteorological Forcing Dataset(CMFD),Climate Prediction Center morphing method(CMORPH),Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Record(PERSIANN-CDR),and Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis(TMPA))and a reanalysis precipitation dataset(ECMWF Reanalysis v5-Land Dataset(ERA5-Land))in Xinjiang using ground-based observational precipitation data from a limited number of meteorological *** on this assessment,we proposed a framework that integrated different precipitation datasets with varying spatial resolutions using a dynamic Bayesian model averaging(DBMA)approach,the expectation-maximization method,and the ordinary Kriging interpolation *** daily precipitation data merged using the DBMA approach exhibited distinct spatiotemporal variability,with an outstanding performance,as indicated by low root mean square error(RMSE=1.40 mm/d)and high Person's correlation coefficient(CC=0.67).Compared with the traditional simple model averaging(SMA)and individual product data,although the DBMA-fused precipitation data were slightly lower than the best precipitation product(CMFD),the overall performance of DBMA was more *** error analysis between DBMA-fused precipitation dataset and the more advanced Inte

关键词： precipitation estimates satellite-based and reanalysis precipitation dynamic Bayesian model averaging streamflow simulation Ebinur Lake Basin Xinjiang

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Straw mulching alters the composition and loss of dissolved organic matter in farmland surface runoff by inhibiting the fragmentation of soil small macroaggregates

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Journal of Integrative Agriculture 2024年第5期23卷 1703-1717页

作者： Shanshan Cai Lei Sun Wei Wang Yan Li jianli ding Liang Jin Yumei Li Jiuming Zhang Jingkuan Wang Dan Wei College of Land and Environment Shenyang Agricultural UniversityShenyang 110866China Heilongjiang Academy of Black Soil Conservation and Utilization Harbin 150086China Institute of Plant Nutrition Resources and EnvironmentBeijing Academy of Agricultural and Forestry SciencesBeijing 100097China

Straw mulching is a widespread practice for reducing the soil carbon loss caused by ***,the effects of straw mulching on dissolved organic matter(DOM)runoff loss from black soil are not well *** straw mulching affects the composition and loss of runoff DOM by changing soil aggregates remains largely ***,a straw mulching treatment was compared to a no mulching treatment(as a control)on sloping farmland with black soil erosion in Northeast *** divided the soil into large macroaggregates(>2 mm),small macroaggregates(0.25-2 mm),and microaggregates(ding the hydrological paths of rain events by capturing the dynamic changes of runoff and soil DOM characteristics.A variation partitioning analysis(VPA)indicated that the DOM concentration and composition of microaggregates explained 68.2%of the change in runoff DOM from no mulching plots,while the change in runoff DOM from straw mulching plots was dominated by small macroaggregates at a rate of 55.1%.Taken together,our results demonstrated that straw mulching reduces the fragmentation of small macroaggregates and the loss of microaggregates,thus effecting DOM compositions in soil and reducing the DOM loss in *** results provi

关键词： dissolved organic matter black soil surface runoff aggregates fluorescence spectrum

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面向多维时间序列异常检测的时空图卷积网络

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西安电子科技大学学报 2024年第3期51卷 170-181页

作者：王静何苗苗丁建立李永华中国民航大学安全科学与工程学院天津300300 中国民航大学信息安全测评中心天津300300 中国民航大学计算机科学与技术学院天津300300

针对现有多维时间序列异常检测模型对局部和全局时空依赖性捕获能力不足的问题,提出一种基于时空图卷积网络的多维时间序列异常检测模型。首先,在时间维度上利用扩张因果卷积和多头自注意力机制,分别捕获短期和长期时间依赖性,并且引入... 详细信息

针对现有多维时间序列异常检测模型对局部和全局时空依赖性捕获能力不足的问题,提出一种基于时空图卷积网络的多维时间序列异常检测模型。首先,在时间维度上利用扩张因果卷积和多头自注意力机制,分别捕获短期和长期时间依赖性,并且引入通道注意力来学习不同通道的重要性权重;其次,在空间维度上利用静态图学习层根据节点嵌入构建静态图邻接矩阵,旨在捕获多维时间序列数据的全局空间依赖性,同时利用动态图学习层构建一系列演化的图邻接矩阵,旨在建模局部动态的空间依赖性;最后,联合优化重构模型和预测模型,通过重构误差和预测误差计算异常分数,然后比较阈值和异常分数的关系,进而检测异常。在MSL、SMAP和SWaT三个公开数据集上的实验结果表明,该模型在异常检测性能指标F1分数方面优于OmniAnomaly、MTAD-GAT和GDN等相关的基线模型。

关键词：图卷积网络时空依赖多维时间序列异常检测

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南疆地区不同类型沙尘天气及相关因素对气溶胶光学厚度影响研究

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环境科学学报 2024年第6期44卷 259-269页

作者：古丽斯坦·阿卜杜克热木丁建丽马雯新疆大学地理与遥感科学学院乌鲁木齐830017 新疆大学新疆绿洲生态自治区重点实验室乌鲁木齐830017 新疆大学智慧城市与环境建模自治区普通高校重点实验室乌鲁木齐830017

为探究南疆地区沙尘气溶胶光学厚度(Dust aerosol optical depth,DOD)的时空分布特征及影响因素,基于遥感数据与气象站观测资料探讨了南疆地区2003—2019年期间DOD的时空分布特征,并分析了不同类型沙尘天气与非沙尘天气及其他相关因素对... 详细信息

为探究南疆地区沙尘气溶胶光学厚度(Dust aerosol optical depth,DOD)的时空分布特征及影响因素,基于遥感数据与气象站观测资料探讨了南疆地区2003—2019年期间DOD的时空分布特征,并分析了不同类型沙尘天气与非沙尘天气及其他相关因素对DOD的影响.结果表明:①南疆地区DOD值与沙尘天气日数分布呈显著的空间差异,塔克拉玛干沙漠东部的DOD峰值达0.21,塔克拉玛干沙漠南缘年均沙尘天气日数高达90 d以上.②不同类型沙尘天气与非沙尘天气的DOD值大小排序依次为:沙尘暴(0.10~0.71)>浮尘(0.24~0.44)>扬沙(0.13~0.47)>非沙尘日(0.08~0.11).③从年际变化来看,非沙尘天气、浮尘天气及扬沙天气的DOD值有减小趋势,而沙尘暴天气的DOD值有增大趋势,各沙尘天气日数也有增多的趋势;DOD最高值出现在3—5月,浮尘天气3月最多,扬沙与沙尘暴天气5月最多.④相关性结果表明,土壤体积含水量、相对湿度、最大风速对DOD值的影响最为显著;DOD与影响因素之间的拟合关系表明:DOD与土壤体积含水量、水汽压、相对湿度的拟合关系呈线性负相关,DOD与平均气温、最大风速的拟合关系呈“抛物线”型曲线.

关键词： MODIS 沙尘气溶胶光学厚度(DOD) 沙尘天气影响因素南疆地区

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基于视频关键帧提取的快速T3D动作识别模型

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计算机应用与软件 2024年第8期41卷 182-188页

作者：丁建立袁梓瑞王怀超中国民航大学计算机科学与技术学院天津300300 中国民航信息科研基地天津300300

视频级动作识别存在着数据量大、识别速度慢的问题,主要原因是需要提取空间维度上人体姿态,还需要考虑时间维度上动作关联。提出一种基于视频关键帧提取的快速T3D动作识别模型,通过改进的Superpoint网络提取视频关键帧,缩减数据量。以T3... 详细信息

视频级动作识别存在着数据量大、识别速度慢的问题,主要原因是需要提取空间维度上人体姿态,还需要考虑时间维度上动作关联。提出一种基于视频关键帧提取的快速T3D动作识别模型,通过改进的Superpoint网络提取视频关键帧,缩减数据量。以T3D网络为基础,时空分解其关键模块可变时序卷积层,显著提升了其计算效率。在公共数据集UCF-101和HMDB-51数据集进行了实验验证,准确率和原T3D网络近似,但其识别速度为原T3D网络的2倍,更适合于实际的应用场景。

关键词：快速动作识别视频关键帧提取 T3D网络 Superpoint网络快速识别

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Assessment of ecological quality in Northwest China(2000-2020)using the Google Earth Engine platform:Climate factors and land use/land cover contribute to ecological quality

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Journal of Arid Land 2022年第11期14卷 1196-1211页

作者： WANG Jinjie ding jianli GE Xiangyu QIN Shaofeng ZHANG Zhe College of Geography and Remote Sensing Science Xinjiang UniversityUrumqi 800046China Xinjiang Key Laboratory of Oasis Ecology Xinjiang UniversityUrumqi 830046China Key Laboratory of Smart City and Environment Modelling of Higher Education Institute Xinjiang UniversityUrumqi 830046China

The ecological quality of inland areas is an important aspect of the United Nations Sustainable Development Goals(UN SDGs).The ecological environment of Northwest China is vulnerable to changes in climate and land use/land cover,and the changes in ecological quality in this arid region over the last two decades are not well *** makes it more difficult to advance the UN SDGs and develop appropriate measures at the regional *** this study,we used the Moderate Resolution Imaging Spectroradiometer(MODIS)products to generate remote sensing ecological index(RSEI)on the Google Earth Engine(GEE)platform to examine the relationship between ecological quality and environment in Xinjiang during the last two decades(from 2000 to 2020).We analyzed a 21-year time series of the trends and spatial characteristics of ecological *** further assessed the importance of different environmental factors affecting ecological quality through the random forest algorithm using data from statistical yearbooks and land use *** results show that the RSEI constructed using the GEE platform can accurately reflect the ecological quality information in Xinjiang because the contribution of the first principal component was higher than 90.00%.The ecological quality in Xinjiang has increased significantly over the last two decades,with the northern part of this region having a better ecological quality than the southern *** areas with slightly improved ecological quality accounted for 31.26%of the total land area of Xinjiang,whereas only 3.55%of the land area was classified as having a slightly worsen(3.16%)or worsen(0.39%)ecological *** vast majority of the deterioration in ecological quality mainly occurred in the barren areas Temperature,precipitation,closed shrublands,grasslands and savannas were the top five environmental factors affecting the changes in *** factors were allocated different weights for different RSEI *** genera

关键词： ecological quality land use/land cover spatiotemporal change remote sensing ecological index(RSEI) Google Earth Engine Xinjiang

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Estimation of soil organic matter in the Ogan-Kuqa River Oasis, Northwest China, based on visible and near-infrared spectroscopy and machine learning

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Journal of Arid Land 2023年第2期15卷 191-204页

作者： ZHOU Qian ding jianli GE Xiangyu LI Ke ZHANG Zipeng GU Yongsheng College of Geography and Remote Sensing Science Xinjiang UniversityUrumqi 830046China Xinjiang Key Laboratory of Oasis Ecology Xinjiang UniversityUrumqi 830046China Key Laboratory of Smart City and Environment Modelling of Higher Education Institute Xinjiang UniversityUrumqi 830046China

Visible and near-infrared(vis-NIR)spectroscopy technique allows for fast and efficient determination of soil organic matter(SOM).However,a prior requirement for the vis-NIR spectroscopy technique to predict SOM is the effective removal of redundant ***,this study aims to select three wavelength selection strategies for obtaining the spectral response characteristics of *** SOM content and spectral information of 110 soil samples from the Ogan-Kuqa River Oasis were measured under laboratory conditions in July *** correlation analysis was introduced to preselect spectral wavelengths from the preprocessed spectra that passed the 0.01 level significance *** successive projection algorithm(SPA),competitive adaptive reweighted sampling(CARS),and Boruta algorithm were used to detect the optimal variables from the preselected ***,partial least squares regression(PLSR)and random forest(RF)models combined with the optimal wavelengths were applied to develop a quantitative estimation model of the SOM *** results demonstrate that the optimal variables selected were mainly located near the range of spectral absorption features(i.e.,1400.0,1900.0,and 2200.0 nm),and the CARS and Boruta algorithm also selected a few visible wavelengths located in the range of 480.0–510.0 *** models can achieve a more satisfactory prediction of the SOM content,and the RF model had better accuracy than the PLSR *** SOM content prediction model established by Boruta algorithm combined with the RF model performed best with 23 variables and the model achieved the coefficient of determination(R2)of 0.78 and the residual prediction deviation(RPD)of *** Boruta algorithm effectively removed redundant information and optimized the optimal wavelengths to improve the prediction accuracy of the estimated SOM ***,combining vis-NIR spectroscopy with machine learning to estimate SOM content is an important method to improve th

关键词： soil organic matter content vis-NIR spectroscopy random forest Boruta algorithm machine learning

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Vertical Distribution and Transport of Aerosols during a Dust Event in Xinjiang,Northwest China

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Journal of Meteorological Research 2023年第3期37卷 387-403页

作者： Mengzhu XU jianli ding Jie LIU Fangqing LIU Xiaoye JIN Yi QU College of Geography and Remote Sensing Sciences Xinjiang UniversityUrumqi 800046 Xinjiang Key Laboratory of Oasis Ecology Xinjiang UniversityUrumqi 830046 Key Laboratory of Smart City and Environment Modeling of Higher Education Institutes Xinjiang UniversityUrumqi 830046 MNR Technology Innovation Center for Central Asia Geo-Information Exploitation and Utilization Urumqi 830046 College of Ecology and Environment Xinjiang UniversityUrumqi 830046

Dust aerosols profoundly influence the radiative balance of the earth–atmosphere system and hence the global and regional *** this study,using multi-source satellite and ground-level observations combined with meteorological data,we investigated the three-dimensional evolution and transport characteristics of aerosols during a dust event that occurred in Xinjiang,China from 19 to 21 March *** of the meteorological data reveals that the dust air mass initially appeared in the northwest of Xinjiang and was subsequently transported to the Hami and Turpan areas due to the prevailing northwesterly winds,after which the direction of the airflow shifted due to topography,and the dust air masses were transported into southern *** air quality in the affected areas decreased rapidly,accompanied by a significant increase in aerosol optical depth (AOD),with the maximum value exceeding 3.5 in some *** addition,the Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations(CALIPSO) data reveal that the aerosol particles in the dust-affected areas were mainly dust aerosols,with small amounts of pollutant dust aerosols.A reduction in the attenuated backscatter coefficient (β532||) was found with increasing altitude,with the dust aerosol pollution mainly distributed in the lower *** size of dust particles in the lower troposphere was relatively small and *** depolarization ratio (PDR) values at altitudes of 8–10 km were relatively lower than those recorded in the lower troposphere,whereas the color ratio (CR)values were higher,which may have been influenced by the sparse vegetation coverage and poor subsurface conditions in Xinjiang,and attributable to the fact that regular large particles of dust are more likely to be dispersed to altitudes between 8 and 10 km within a short period of *** a consequence of the meteorological conditions and topography,the dusting process in Xinjiang persisted for a relatively long peri

关键词： dust event CALIPSO atmospheric aerosol vertical distribution Xinjiang Northwest China

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Dielectric properties of saline soil based on a modified Dobson dielectric model

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Journal of Arid Land 2015年第5期7卷 696-705页

作者： Nigara TASHPOLAT ding jianli YU Danlin Key Laboratory of Oasis Ecology Xinjiang University Earth and Environmental Studies Montclair State University

Soil salinization is a major concern for agricultural development in arid areas. In this paper, a modified Dobson dielectric model was applied to simulate the dielectric constant of saline soil in the Ugan-Kuqa river delta oasis of Xinjiang Uygur autonomous region, northwestern China. The model performance was examined through analyzing the influences of its parameters on the soil dielectric constant and the relationship between radar back- scattering coefficient and the dielectric constant of saline soil. The results of the study indicate that：（1） The real part of the soil dielectric constant is affected by soil water content at low radar frequencies; the imaginary part is closely related with both the soil water content and soil salt content. （2） The soil water and salt contents are related with the coefficient of dialectical loss, which is consistent with the natural conditions of saline soil in arid areas and provides valuable references for the study of soil dielectric properties. （3） The changes of soil water content and soil salt content have instant influences on the dielectric constant of saline soil. Subsequently, the radar backscattering coefficient is affected to respond to the dielectric constant of saline soil. The radar backscattering coefficient is most responsible to the radar＇s cross polarization pattern with a correlation coefficient of R2=0.75. This study provides a potential method to monitor soil salinization and soil water content by using a soil dielectric model and radar tech- niques.

关键词： saline soil dielectric constant dielectric constant model backscattering coefficient Radarsat-2 images

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Characterizing urban expansion of Korla City and its spatial-temporal patterns using remote sensing and GIS methods

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Journal of Arid Land 2017年第3期9卷 458-470页

作者： Bumairiyemu MAIMAITI ding jianli Zibibula SIMAYI Alimujiang KASIMU College of Resource and Environment Sciences Xinjiang University Urumqi 830046 China Key Laboratory of Oasis Ecology Xinjiang University Urumqi 830046 China Key Laboratory of Wisdom City and Environment Modeling of Colleges and Universities Xinjiang University Urumqi 830046 China School of Management Xinjiang Agricultural University Urumqi 830052 China School of Geographic Science and Tourism Xinjiang Normal University Urumqi 830054 China

Cities provide spatial contexts for populations and economic activities. Determining the spatial-temporal patterns of urban expansion is of particular significance for regional sustainable development. To achieve a better understanding of the spatial-temporal patterns of urban expansion of Korla City, we explore the urban expansion characteristics of Korla City over the period 1995-2015 by employing Landsat TM/ETM＋ images of 1995, 2000, 2005, 2010, and 2015. Urban land use types were classified using the supervised classification method in ENVI 4.5. Urban expansion indices, such as expansion area, expansion proportion, expansion speed, expansion intensity, compactness, and fractal dimension, were calculated. The spatial-temporal patterns and evolution process of the urban expansion （e.g., urban gravity center and its direction of movement） were then quantitatively analyzed. The results indicated that, over the past 25 years, the area and proportion of urban land increased substantially with an average annual growth rate of 15.18%. Farmland and unused land were lost greatly due to the urban expansion. This result might be attributable to the rapid population growth and the dramatic economic development in this area. The city extended to the southeast, and the urban gravity center shifted to the southeast as well by about 2118 m. The degree of urban compactness tended to decrease and the fractal dimension index tended to increase, indicating that the spatial pattern of Korla City was becoming loose, complex, and unstable. This study could provide a scientific reference for the studies on urban expansion of oasis cities in arid land.

关键词： urban expansion spatial-temporal changes urban land remote sensing and GIS Korla City

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