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Characterizing extreme drought and wetness in Guangdong,China using global navigation satellite system and precipitation data

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Satellite Navigation 2024年第1期5卷 258-274页

作者： Hai Zhu Kejie Chen Haishan Chai Yuanbin Ye Wenjian Liu Department of Earth and Space Sciences Southern University of Science and TechnologyShenzhen518055China lands and Resource Department of Guangdong Province Surveying and Mapping InstituteGuangzhou510500China

As global temperature rises,the frequency of extreme climate events,e.g.,severe droughts and floods,has increased significantly and caused severe damage over the past *** this regard,precipitation efficiency,a crucial meteorological parameter,could provide valuable insights for a better understanding of the patterns and characteristics of these extreme *** this study,taking Guangdong province as an exemplary region,we first obtained long-term and high-resolution historical records of precipitation efficiency by integrating the observations from a dense network of Global Navigation Satellite System(GNSS)stations with precipitation data,and then characterized the extreme drought and wetness through climate *** found a distinct seasonal trend in precipitation efficiency in Guangdong,with annual fluctuations ranging from 10 to 25%.Notably,precipitation efficiency is higher in proximity to the Pearl River Delta Plain and gradually decreases towards the east and *** occurrence of anomalous peaks and valleys in precipitation efficiency generally corresponds to dry and wet conditions,respectively.A total of 9 extreme wet events and 6 dry events occurred from January 2007 to May 2022,with durations from 3 to 6 *** results also demonstrated that both wet and dry frequencies exhibit an increasing trend with the expansion of the time scale,and the frequency of extreme events near the Pearl River Delta Plain surpasses that of other ***,the propagation time from meteorological anomalies to agricultural and hydrological anomalies is about 3 *** periodic characteristics of meteorological anomalies are identified as the primary driver for other anomalous periodic *** work unveils the long-term dynamic behavior of precipitation efficiency,as well as the characteristics of extreme drought and wetness events in the regions characterized by intricate land–atmosphere interactions.

关键词： GNSS Precipitation efficiency Extreme drought and wetness

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Neomicrocoleus ***.(Microcoleaceae,Oscillatoriales),a novel cyanobacterial genus from benthic mats in a water channel

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Journal of Oceanology and Limnology 2024年第1期42卷 263-276页

作者： Ruozhen GENG Zhongshi HE Kaihui GAO Peng XIAO He ZHANG Si CHEN Hua LI Gongliang YU Renhui LI College of Life and Environmental Sciences Wenzhou UniversityWenzhou 325035China Key Laboratory of Algal Biology Institute of HydrobiologyChinese Academy of SciencesWuhan 430072China University of Chinese Academy of Sciences Beijing 100049China Hubei Institution of land surveying and mapping Wuhan 430072China

A new filamentous cyanobacterial strain(CHAB 4127)was successfully isolated from the algal mat during the field investigation of the open channel from Luanhe River to Tianjin,*** polyphasic approach combining morphological,ultrastructural,ecological,and molecular features was used to characterize this studied *** strain is morphologically similar to the Microcoleus-like cyanobacterial taxa under light microscopy,and the radial arrangement of thylakoids is also consistent with that of Microcoleus-like *** phylogenetic position of CHAB 4127 based on 16S rRNA gene sequences,is shown to be clearly clustered into an independent clade with the newly established genus *** maximum similarity of 16S r RNA gene of the studied strain with other existing related cyanobacterial taxa is 93.97%,and the ITS secondary structures is also obviously different from other members of *** on all the above evidence,we proposed the establishment of this novel cyanobacterial genus as Neomicrocoleus,with its type species,Neomicrocoleus tianjinensis.

关键词： Neomicrocoleus tianjinensis morphology 16S rRNA taxonomy polyphasic approach

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Influence of Human Activity Intensity on Habitat Quality in Hainan Tropical Rainforest National Park,China

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Chinese Geographical Science 2024年第3期34卷 519-532页

作者： HAN Nianlong YU Miao JIA Peihong ZHANG Yucheng HU Ke School of Geography and Tourism Huizhou UniversityHuizhou 516007China School of Public Administration Hainan Uni-versityHaikou 570228China Department of land surveying and Geo-Informatics The Hong Kong Polytechnic UniversityHong KongChina School of Geographic Sciences and Remote Sensing Guangzhou UniversityGuangzhou 510006China School of Public Administration Nanjing Agricultural UniversityNanjing 210095China

Due to long-term human activity interference,the Hainan Tropical Rainforest National Park(HTRNP)of China has experienced ecological problems such as habitat fragmentation and biodiversity loss,and with the expanding scope and intensity of human activity impact,the regional ecological security is facing serious challenges.A scientific assessment of the interrelationship between human activity intensity and habitat quality in the HTRNP is a prerequisite for achieving effective management of ecological disturbances caused by human activities and can also provide scientific strategies for the sustainable development of the *** on the land use change data in 2000,2010,and 2020,the spatial and temporal variations and the relationship between habitat quality(HQ)and human activity intensity(HAI)in the HTRNP were explored using the integrated valuation of ecosystem services and trade-offs(InVEST)*** dynamics and land use simulation models were also combined to conduct multi-scenario simulations of their *** results showed that during 2000–2020,the habitat quality of the HTRNP improved,the intensity of human activities decreased each year,and there was a negative correlation between the ***,the system dynamic model could be well coupled with the land use simulation model by combining socio-economic and natural *** simulation scenarios of the coupling model showed that the harmonious development(HD)scenario is effective in curbing the increasing trend of human activity intensity and decreasing trend of habitat quality,with a weaker trade-off between the two compared with the baseline development(BD)and investment priority oriented(IPO)*** maintain the authenticity and integrity of the HTRNP,effective measures such as ecological corridor construction,ecological restoration,and the implementation of ecological compensation policies need to be strengthened.

关键词： human activity intensity(HAI) habitat quality(HQ) bivariate spatial autocorrelation system dynamics model integrated valuation of ecosystem services and trade-offs(InVEST)model Hainan Tropical Rainforest National Park(HTRNP)of China

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Impact of climate and human activity on NDVI of various vegetation types in the Three-River Source Region, China

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Journal of Arid land 2024年第8期16卷 1080-1097页

作者： LU Qing KANG Haili ZHANG Fuqing XIA Yuanping YAN Bing Research Center of Resource and Environment Economics East China University of TechnologyNanchang 330013China Jiangxi Key Laboratory of Watershed Ecological Process and Information East China University of TechnologyNanchang 330013China School of surveying and Geoinformation Engineering East China University of TechnologyNanchang 330013China Nanchang Key Laboratory of landscape Process and Territorial Spatial Ecological Restoration East China University of TechnologyNanchang 330013China institute of Energy Research Jiangxi Academy of SciencesNanchang 330096China

The Three-River Source Region(TRSR)in China holds a vital position and exhibits an irreplaceable strategic importance in ecological preservation at the national *** the basis of an in-depth study of the vegetation evolution in the TRSR from 2000 to 2022,we conducted a detailed analysis of the feedback mechanism of vegetation growth to climate change and human activity for different vegetation *** the growing season,the spatiotemporal variations of normalized difference vegetation index(NDVI)for different vegetation types in the TRSR were analyzed using the Moderate Resolution Imaging Spectroradiometer(MODIS)-NDVI data and meteorological data from 2000 to *** addition,the response characteristics of vegetation to temperature,precipitation,and human activity were assessed using trend analysis,partial correlation analysis,and residual *** indicated that,after in-depth research,from 2000 to 2022,the TRSR's average NDVI during the growing season was *** preliminary ranking of the average NDVI for different vegetation types was as follows:shrubland(0.5762)>forest(0.5443)>meadow(0.4219)>highland vegetation(0.2223)>steppe(0.2159).The NDVI during the growing season exhibited a fluctuating growth trend,with an average growth rate of 0.0018/10a(Pland *** contrast,steppes,meadows,and highland vegetation demonstrated relatively high vulnerability to temperature fluctuations.A further detailed analysis revealed that climate change had a significant positive impact on the TRSR from 2000 to 2022,particularly in its

关键词： growing season normalized difference vegetation index(NDVI) highland vegetation trend analysis partial correlation analysis residual analysis contribution rate

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A labor-free index-guided semantic segmentation approach for urban vegetation mapping from high-resolution true color imagery

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International Journal of Digital Earth 2023年第1期16卷 1640-1660页

作者： Peng Zhang Cong Lin Shanchuan Guo Wei Zhang Hong Fang Peijun Du Jiangsu provincial Key Laboratory of Geographic Information Science and Technology Key Laboratory for Land Satellite Remote Sensing Applications of Ministry of Natural ResourcesSchool of Geography and Ocean ScienceNanjing UniversityNanjingPeople’s Republic of China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application NanjingPeople’s Republic of China c Nanjing Research institute of surveying Mapping&Geotechnical InvestigationCo.LtdNanjingPeople’s Republic of China

Accurate and timely information on urban vegetation(UV)can be used as an important indicator to estimate the health of *** to the low cost of RGB cameras,true color imagery(TCI)has been widely used for high spatial resolution UV ***,the current index-based and classifier-based UV mapping approaches face problems of the poor ability to accurately distinguish UV and the high reliance on massive annotated samples,*** address this issue,an index-guided semantic segmentation(IGSS)framework is proposed in this ***,a novel cross-scale vegetation index(CSVI)is calculated by the combination of TCI and Sentinel-2 images,and the index value can be used to provide an initial UV ***,reliable UV and non-UV samples are automatically generated for training the semantic segmentation model,and then the refined UV map can be *** experimental results show that the proposed CSVI outperformed the existingfive RGB vegetation indices in highlighting UV cover and suppressing complex backgrounds,and the proposed IGSS workflow achieved satisfactory results with an OA of 87.72%∼88.16%and an F1 score of 87.73%∼88.37%,which is comparable with the fully-supervised method.

关键词： Urban vegetation mapping Sustainable Development Goals(SDGs) cross-scale vegetation index(CSVI) semantic segmentation high-resolution true color imagery(TCI)

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Combined multi-kernel support vector machine and wavelet analysis for hyperspectral remote sensing image classification

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Chinese Optics Letters 2011年第1期9卷 45-48页

作者：谭琨杜培军 Key Laboratory for land Environment and Disaster Monitoring of State Bureau of surveying and mapping of China China University of Mining and Technology

Many remote sensing image classifiers are limited in their ability to combine spectral features with spatial features. Multi-kernel classifiers, however, are capable of integrating spectral features with spatial or structural features using multiple kernels and summing them for final outputs. Using a support vector machine （SVM） as classifier, different multi-kernel classifiers are constructed and tested using 64-band Operational Modular Imaging Spectrometer II hyperspectral image of Changping Area, Beijing City. Results show that by integrating spectral and wavelet texture information, multi-kernel SVM classifiers can obtain more accurate classification results than sole-kernel SVM classifiers and cross-information SVM kernel classifiers. Moreover, when the multi-kernel SVM classifier is used, the combination of the first four principal components from principal component analysis and wavelet texture provides the highest accuracy （97.06%）. Multi-kernel SVM is therefore an effective approach to improve the accuracy of hyperspectral image classification and to expand possibilities for remote sensing image interpretation and application.

关键词： Image analysis Image classification Image reconstruction Remote sensing Support vector machines Textures Wavelet analysis

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Urban Expansion in Major Grain Producing Area from 1978 to 2017:A Case Study of Zhengzhou Metropolitan Area,China

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Chinese Geographical Science 2023年第1期33卷 1-20页

作者： YANG Yongju ZHANG Hebing QIAO Xuning LIU Liang ZHENG Jinchan School of surveying and land Information Engineering Henan Polytechnic UniversityJiaozuo 454003China Research Centre of Arable land Protection and Urban-rural High-quality Development of Yellow River Basin Henan Polytechnic UniversityJiaozuo 454003China

The spatial form of urbanization in China has developed from single-core city expansion to a multi-center metropolitan ***,little attention has been paid to the growth process of the emerging metropolitan area situated in major grain producing locations in the central *** the Zhengzhou metropolitan area(ZZMA)as a case study,we developed an inverse S-shape model to characterize the spatial distribution of urban land density,and constructed an urban expansion core index,urban expansion intensity index,and urban compactness index to quantify the spatial structure change that has taken place from 1978 to 2017 during the process of urban ***,cropland contribution rate(CR)was constructed to evaluate the impacts of urban expansion on *** uncovered four key ***,over the past 40 yr,the ZZMA has experienced dramatic expansion,and the central city of Zhengzhou expanded faster than other *** gravity centers of urban expansion of surrounding cities were moving toward to Zhengzhou ***,the urban land density decreased with the distance from the city center to the *** the only large city,Zhengzhou has experienced the fastest and most compact centralized urban expansion,especially after 2000,while other medium-and small-sized cities have experienced low-intensity decentralized ***,the urban core has been gradually expanding *** 1978 to 2017,the hot-zone of urban growth has moved progressively with the acceleration of *** cities except Jiaozuo had a single peak in different ***,the cities in national core grain-producing areas has higher cropland contribution rates and lower urban expansion areas,which was closely related to cropland *** analysis showed that large city was relatively better positioned than smaller cities in the efficiency of their urban infrastructure and the effectiveness of wealth creation efficiency in the urbanized area could be

关键词： urban expansion major grain producing area inverse S-shape cropland contribution rate(CR) policy factor Zhengzhou metropolitan area(ZZMA)

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Properties of L-band differential InSAR for monitoring mining-induced subsidence in coalfield of Jining, Northern China

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Journal of Central South University 2014年第4期21卷 1508-1517页

作者：陶秋香刘国林 Geomatics College Shandong University of Science and Technology Key Laboratory of surveying and mapping Technology on Island and Reef of National Administration of surveying mapping and Geoinformation

The properties and feasibility of L-band differential InSAR for detecting and monitoring mining-induced subsidence were systematically analyzed and demonstrated. The largest monitored subsidence gradient of 7.9×10-3 and magnitude of 91 cm were firstly derived by theoretical derivation. Then, the stronger phase maintaining capacity and weaker sensitivity to minor land subsidence compared with C-band DInSAR were illustrated by phase simulation of the actual mine subsidence. Finally, the data processing procedure of two-pass DInSAR was further refined to accurately observe subsidence of a coalfield of Jining in Northern China using 7 ALOS PALSAR images. The largest monitored subsidence magnitude of 39.22 cm and other properties were better investigated by testing results interpretation and subsidence analysis, and the absolute difference varying from 0.5 mm to 17.9 mm was obtained by comparison with leveling-measured subsidence. All of results show that L-band DInSAR technique can investigate the location, amount, area and other detailed subsidence information with relatively higher accuracy.

关键词： L-band differential InSAR ALOS PALSAR mine subsidence monitoring

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GIS-based landslide susceptibility mapping using hybrid integration approaches of fractal dimension with index of entropy and support vector machine

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Journal of Mountain Science 2019年第6期16卷 1275-1293页

作者： ZHANG Ting-yu HAN Ling ZHANG Heng ZHAO Yong-hua LI Xi-an ZHAO Lei School of Earth Science and Resources Chang’an UniversityKey Laboratory of Degraded and Unutilized Land Remediation EngineeringMinistry of Land and ResourcesShaanxi Provincial Key Laboratory of Land RehabilitationXi’an 710064China School of Geological and surveying&mapping Engineering Chang’an UniversityXi’an 710064China Shaanxi provincial land Engineering Construction Group Xi’an 710075China College of Geology&Environment Xi’an University of Science and TechnologyXi’an 710054China

The loess area in the northern part of Baoji City, Shaanxi Province, China is a region with frequently landslide occurrences. The main aim of this study is to quantitatively predict the extent of landslides using the index of entropy model(IOE), the support vector machine model(SVM) and two hybrid models namely the F-IOE model and the F-SVM model constructed by fractal dimension. First, a total of 179 landslides were identified and landslide inventory map was produced, with 70%(125) of the landslides which was optimized by 10-fold crossvalidation being used for training purpose and the remaining 30%(54) of landslides being used for validation purpose. Subsequently, slope angle, slope aspect, altitude, rainfall, plan curvature, distance to rivers, land use, distance to roads, distance to faults, normalized difference vegetation index(NDVI), lithology, and profile curvature were considered as landslide conditioning factors and all factor layers were resampled to a uniform resolution. Then the information gain ratio of each conditioning factors was evaluated. Next, the fractal dimension for each conditioning factors was calculated and the training dataset was used to build four landslide susceptibility models. In the end, the receiver operating characteristic(ROC) curves and three statistical indexes involving positive predictive rate(PPR), negative predictive rate(NPR) and accuracy(ACC) were applied to validate and compare the performance of these four models. The results showed that the F-SVM model had the highest PPR, NPR, ACC and AUC values for training and validation datasets, respectively, followed by the F-IOE ***, it is concluded that the F-SVM model performed best in all models, the hybrid model built by fractal dimension has advantages than original model, and can provide reference for local landslide prevention and decision making.

关键词： GIS landslide susceptibility Hybrid model Fractal dimension

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Chinese Cropland Quality and Its Temporal and Spatial Changes due to Urbanization in 2000–2015

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Journal of Resources and Ecology 2019年第2期10卷 174-183页

作者： WANG Chunyu SUN Xiaofang WANG Meng WANG Junbang DING Qingfu College of Geography and Tourism Qufu Nonnal University Rizhao Shandong 276826 China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China shangdong provincial institute of land surveying and mapping Jinan 250013 China

The acceleration of urbanization has led to the occupation of more cropland, especially higher quality cropland, which could pose a huge threat to food security and have other implications for the inadequate cropland resource supply in China. Though the spatial status of Chinese cropland quality has been assessed, its temporal changes since 2000 to 2015 are still not clear. An accumulated probability distribution method was used to determine the criteria of cropland quality using the net primary production data product(MOD17) from Moderate Resolution Imaging Spectroradiometer(MODIS). Then the cropland quality of higher, median and lower production was spatially mapped and its changes due to occupation by urbanization were analyzed through the land use changes(LUCC) data primarily from landsat TM images in the three periods of 2000–2005, 2005–2010, and 2010–*** results showed that of the total cropland reduction area the proportion taken by urbanization increased from47.29% in the early stage to 77.46% in the recent period. The quality of Chinese cropland was dominated by lowand medium-yield fields, accounting for 40.81% and 48.74%, respectively, with high-yield fields accounting for only 10.44% of the total cropland in the country in 2000. The high-yield areas have been seriously threatened by the expansion of construction land fields, with the ratio of high-yield area to total area occupied by urbanization increasing from 9.71% in 2000–2005 to 15.63% in 2010–2015. Spatially, this phenomenon has been moving from eastern and southern China to central and western China, especially in Northwest China where the ratio has arrived at the highest proportion, with 52.97% of high-yield cropland in the total land taken by the expansion by 2015. This study not only provides a method to assess cropland quality but also reveals the threatening trend from the expansion of urbanization on high-quality cropland. More attention should be paid to the latter in land use planning

关键词： cropland quality cropland quantity urbanization spatial-temporal changes remote sensing

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