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Regional hard coral distribution within geomorphic and reef flat ecological zones determined by satellite imagery of the Xisha Islands,South China Sea

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Chinese Journal of Oceanology and Limnology 2017年第3期35卷 501-514页

作者：左秀玲苏奋振赵焕庭张君珏王琦吴迪 State Key laboratory of resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Collaborative Innovation Center of South China Sea Studies Nanjing 210093China University of Chinese Academy of Sciences Beijing 100049China Key laboratory of Marginal Sea Geology South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China Key laboratory of Hydrography and cartography of PLA Department of Hydrography and CartographyDalian Naval AcademyDalian 116018China

Coral reefs in the Xisha Islands （also known as the Paracel Islands in English）, South China Sea, have experienced dramatic declines in coral cover. However, the current regional scale hard coral distribution of geomorphic and ecological zones, essential for reefs management in the context of global warming and ocean acidification, is not well documented. We analyzed data from field surveys, Landsat-8 and GF-1 images to map the distribution of hard coral within geomorphic zones and reef fiat ecological zones. In situ surveys conducted in June 2014 on nine reefs provided a complete picture of reef status with regard to live coral diversity, evenness of coral cover and reef health （live versus dead cover） for the Xisha Islands. Mean coral cover was 12.5% in 2014 and damaged reefs seemed to show signs of recovery. Coral cover in sheltered habitats such as lagoon patch reefs and biotic dense zones of reef flats was higher, but there were large regional differences and low diversity. In contrast, the more exposed reef slopes had high coral diversity, along with high and more equal distributions of coral cover. Mean hard coral cover of other zones was 〈10%. The total Xisha reef system was estimated to cover 1 060 km2, and the emergent reefs covered -787 km2. Hard corals of emergent reefs were considered to cover 97 km2. The biotic dense zone of the reef flat was a very common zone on all simple atolls, especially the broader northern reef flats. The total cover of live and dead coral can reach above 70% in this zone, showing an equilibrium between live and dead coral as opposed to coral and algae. This information regarding the spatial distribution of hard coral can support and inform the management of Xisha reef ecosystems.

关键词： coral reef geomorphic zone remote sensing Xisha Islands South China Sea

Improving the Interpretability and Reliability of Regional Land Cover Classification by U-Net Using Remote Sensing Data

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Chinese Geographical Science 2022年第6期32卷 979-994页

作者： WANG Xinshuang CAO Jiancheng LIU Jiange LI Xiangwu WANG Lu ZUO Feihang BAI Mu Shaanxi Geomatics Center of Ministry of Natural resources Xi’an 710054China The First Topographic Surveying Brigade of Ministry of Natural resources Xi’an 710054China The First Geographic Information cartography Institute of Ministry of Natural resources Xi’an 710054China

The accurate and reliable interpretation of regional land cover data is very important for natural resource monitoring and environmental *** present,refined land cover data are mainly obtained by manual visual interpretation,which has the problems of heavy workload and inconsistent interpretation *** learning has greatly improved the automatic processing and analysis of remote sensing ***,the accurate interpretation of feature information from massive datasets remains a difficult problem in wide regional land cover *** improve the efficiency of deep learning-based remote sensing image interpretation,we selected multisource remote sensing data,assessed the interpretability of the U-Net model based on surface spatial scenes with different levels of complexity,and proposed a new method of stereoscopic accuracy verification(SAV)to evaluate the reliability of the classification *** results show that classification accuracy is more highly correlated with terrain and landscape than with other factors related to image data,such as platform and spatial *** the complexity of surface spatial scenes increases,the accuracy of the classification results mainly shows a fluctuating declining *** also find the distribution characteristics from the SAV evaluation results of different land cover types in each surface spatial *** on the results observed in this study,we consider the distinction of interpretability and reliability in diverse ground object types and design targeted classification strategies for different surface scenes,which can greatly improve the classification *** key achievement of this study is to provide the theoretical basis for remote sensing information analysis and an accuracy evaluation method for regional land cover classification,and the proposed method can help improve the likelihood that intelligent interpretation can replace manual acquisition.

关键词： land cover classification stereoscopic accuracy verification U-Net remote sensing interpretability reliability

Exploring the spatio-temporal impacts of farmland reforestation on ecological connectivity using circuit theory:A case study in the agro-pastoral ecotone of North China

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Journal of Geographical Sciences 2020年第9期30卷 1419-1435页

作者： LIU Xiaojing LIU Dianfeng ZHAO Hongzhuo HE Jianhua LIU Yaolin School of Resource and Environmental Science Wuhan UniversityWuhan 430079China Key laboratory of Digital cartography and Land Information Engineering Ministry of Natural ResourcesWuhan UniversityWuhan 430079China Collaborative Innovation Center for Geospatial Information Science Wuhan UniversityWuhan 430079China

Farmland reforestation can contribute substantially to ecological *** studies have extensively examined the ecological effects of farmland reforestation,but few of them have investigated the spatiotemporal responses of broad-scale landscape connectivity to *** using a typical agro-pastoral ecotone in northern China as a case study,we addressed this issue based on an innovative integration of circuit theory approach and counterfactual *** forest connectivity through multiple dispersal pathways was measured using the circuit theory approach,and its spatiotemporal changes after reforestation were evaluated by counterfactual *** results showed that from 2000–2015,the reforested farmland occupied 2095 km^2,and 12.5% was on steeply sloped *** reforestation caused a greater increase in ecological connectivity by adding new ecological corridors and stepping stones in scattered forest areas rather than in areas with dense forest *** newly added corridors and stepping stones were fragmented,short and narrow and thus deserve powerful *** reforestation to improve landscape connectivity should highlight pinch point protection and obstacle removal as well as the tradeoff between farmland loss and farmer *** findings are expected to inform the optimization of the Grain for Green policy from the perspective of broad-scale biodiversity conservation.

关键词： farmland reforestation ecological connectivity circuit theory land use change agro-pastoral ecotone China

Spatially Heterogeneous Response of Carbon Storage to Land Use Changes in Pearl River Delta Urban Agglomeration, China

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Chinese Geographical Science 2023年第2期33卷 271-286页

作者： LIU Wei LIU Dianfeng LIU Yang School of Resource and Environmental Science Wuhan UniversityWuhan 430079China Key laboratory of Digital cartography and Land Information Application Engineering Ministry of Natural ResourcesWuhan 430079China Guangzhou Urban Planning and Design Survey Research Institute Guangzhou 510060China Guangdong Enterprise Key laboratory for Urban Sensing Monitoring and Early WarningGuangzhou 510060China

Carbon storage of terrestrial ecosystems plays a vital role in advancing carbon neutrality. Better understanding of how land use changes affect carbon storage in urban agglomeration will provide valuable guidance for policymakers in developing effective regional conservation policies. Taking the Pearl River Delta Urban Agglomeration(PRDUA) in China as an example, we examined the heterogeneous response of carbon storage to land use changes in 1990–2018 from a combined view of administrative units and physical entities. The results indicate that the primary change in land use was due to the expansion of construction land(5897.16 km2). The carbon storage in PRDUA decreased from 767.34 Tg C in 1990 to 725.42 Tg C in 2018 with a spatial pattern of high wings and the low middle. The carbon storage loss was largely attributed to construction land expansion(55.74%), followed by forest degradation(54.81%). Changes in carbon storage showed significant divergences in different sized cities and hierarchical boundaries. The coefficients of geographically weighted regression(GWR) reveal that the alteration in carbon storage in Guangzhou City was more responsive to changes in construction land(-0.11) compared to other cities, while that in Shenzhen was mainly affected by the dynamics of forest land(8.32). The change in carbon storage was primarily influenced by the conversion of farmland within urban extent(5.05) and the degradation of forest land in rural areas(5.82). Carbon storage changes were less sensitive to the expansion of construction land in the urban center, urban built-up area, and ex-urban built-up area, with the corresponding GWR coefficients of 0.19, 0.04, and 0.02. This study necessitates the differentiated protection strategies of carbon storage in urban agglomerations.

关键词： land use change carbon storage Integrated Valuation of Ecosystem Services and Trade-offs(InVEST)model hierarchical urban boundaries Pearl River Delta Urban Agglomeration(PRDUA) China

Geophysical Significance of the Senegalo-Mali Discontinuity: Evidence from Secondary Structures, Kédougou-Kéniéba Inlier, Western Mali

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Open Journal of Geology 2024年第10期14卷 943-962页

作者： Mamadou Yossi Mahamadou Diallo Mamoutou Ouattara Amadou Berthé Saidou Ly Sagax Afrique S.A Geophysical Surveys and Consulting Ouagadougou Burkina Faso laboratory of cartography and mineral resources Department of Teaching and Research of Geology and Mines National School of Engineering Abderhamane Baba Tour (ENI-ABT) Bamako Mali

The present study focuses on the analysis and description of lineaments interpreted as secondary structures to describe the nature of Senegalo Malian Discontinuity. These lineaments cross-cut the large north-south oriented transcurrent lithospheric structure known as the Senegalo Malian Discontinuity (SMD). Two lineaments were selected oriented NNE (N15˚ to N25˚), one at Dialafara and one at Sadiola. Four profiles on each lineament of these 2 zones, so that there were 2 on each side of the SMD. The ground data collected were processed using proper parameter and software. Some filters were applied to enhance the signal level. These ground data were later compared to the existing airborne magnetic data for consistency and accuracy using the upward continuation filter. The results show that the quality of ground data is good. In addition, the ground magnetic data show the presence of certain local anomalies that are not visible in the regional data. The analytical signal was also used to determine domain boundaries or possible contact zones. The contact zone can be highlighted on certain profiles such as L300 and L600. The study showed that the west and east sides of the SMD are not the same. Secondary structures become wide when approaching the SMD on both sides. They are also duplicated to the east of the SMD when we move progressively away. In the Dialafara area, the ground magnetic data intersect an interpreted fold. The results of this work confirm the presence of the secondary structures and their evolution in relation to the SMD. The relationships between the secondary structures in the Dailafara and Sadiola zones and their relations with the SMD are highlighted. The technique used in this study, is an important approach to better description and interpreting of regional structures using the secondary structures and proposing a structural model.

关键词： Kédougou-Kéniéba Inlier Senegal Malian Discontinuity Secondary Structures Mapping Magnetic Data

Assessment of soil quality indicators under different agricultural land uses and topographic aspects in Central Vietnam

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International Soil and Water Conservation Research 2018年第4期6卷 280-288页

作者： Tung Gia Pham Hung Trong Nguyen Martin Kappas cartography GIS and Remote Sensing DepartmentGottingen UniversityGeorge August University of GoettingenGoldschmidstr.537077 GoettingenGermany University of Agriculture and Forestry Hue UniversityVietnam Ministry of Natural resources and Environment Vietnam

Soil quality assessment is valuable for agricultural production. In this research, 155 soil samples at two soil depths were collected from four land use types in an agricultural area of the A Luoi district in the Central Vietnam. Differences of soil organic carbon, total nitrogen in soil and soil pH under different land use types and topographic aspects were compared. Soil organic carbon contents in arable land and plantation forest are higher than those in natural forest and grassland (p < 0.05). Conversely, the total nitrogen in natural forest was significantly lesser in comparison to other land use types. Meanwhile there were no significant differences of the total nitrogen content (p < 0.05) among arable land, plantation forest, and grassland. The soil of grassland, natural and plantation forests land use types were more significantly acidic than those of the soils of the arable land use type. Soil organic carbon and total nitrogen showed a decreasing trend while soil depth increased in all land use types. The soil pH in plantation forest and arable land use types showed no significant change in relation to soil depth. Significant differences were not found in topographic aspects and soil organic carbon content;however, the different changing trends of soil organic carbon content between land use types and aspects were found. The impact of slope, elevation, farming system or soil texture accounted for the differences in these soil indicators under different land use types in the A Luoi district.

关键词： Central Vietnam Land use type Hilly area Soil quality Topographic aspects

综合气候和土地利用变化协同效应的玉米产量估算——以中国吉林省为例

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Journal of Geographical Sciences 2023年第8期33卷 1725-1746页

作者：文心远刘殿锋邱明丽王寅杰牛继强刘耀林 School of resources and Environmental Sciences Wuhan UniversityWuhan 400072China Key laboratory of Digital cartography and Land Information Application Engineering Ministry of Natural ResourcesWuhan 430072China Key laboratory for Synergistic Prevention of Water and Soil Environmental Pollution Xinyang Normal Uni-versityXinyang 464000HenanChina

Yield forecasting can give early warning of food risks and provide solid support for food security *** change and land use change have direct influence on regional yield and planting area of maize,but few studies have examined their synergistic impact on maize *** this study,we propose an analysis framework based on the integration of system dynamic(SD),future land use simulation(FLUS)and a statistical crop model to prefuture maize yield variation in response to climate change and land use change in a region of central Jilin province,*** results show that the cultivated land is likely to reduce by 862.84 km^(2) from 2030 to ***,the total maize yield is expected to increase under all four RCP scenarios due to the promotion of per hectare maize *** scenarios,RCP4.5 is the most beneficial to maize production,with a doubled total yield in ***,the yield gap between different counties will be further widened,which necessitates the differentiated policies of agricultural production and farmland protection,e.g.,strengthening cultivated land protection and crop management in low-yield areas,and taking adaptation and mitigation measures to coordinate climate change and production.

关键词： maize yield forecast land use simulation RCP scenarios models

Atlas information systems and geographical names information systems as contributants to spatial data infrastructure

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International Journal of Digital Earth 2008年第3期1卷 279-290页

作者： V.S.Tikunov F.Ormeling M.Konecny Faculty of Geography M.V.Lomonosov Moscow State UniversityMoscowRussia Faculty of Geosciences Utrecht UniversityUtrechtThe Netherlands laboratory on Geoinformatics and cartography Institute of GeographyFaculty of ScienceMasaryk UniversityKotlarska 2Czech Republic

National and international programs dealing with spatial data infrastructures(SDI)made it possible to compile a uniform digital base and a universal toolkit for the integrated description of territories on global to national *** information systems(AIS)are considered to be an integrating tool for diverse information resources(modelling,visualisation and analysis),as well as for the elaboration of various scenarios and the possible development of alternatives for such complex systems as those of *** there is an increased use of digital maps at spatial data infrastructures all aspects related to geographical names are of particular importance in this application of AIS to *** is important to realise a toponymic project,dealing with place-names and their variants depending on the language and time period when a specific place-name was *** layer of geographical names is considered to be one of the three most important data components of AIS.

关键词： atlas information system geographical names SDI

Uncertainty analysis of hydrological modeling in a tropicalarea using different algorithms

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Frontiers of Earth Science 2018年第4期12卷 661-671页

作者： Ammar RAFIEI EMAM Martin KAPPAS Steven FASSNACHT Nguyen Hoang Khanh LINH Department of cartography GIS and Remote SensingUniversity of Goettingen37077GoettingenGermany Colorado State University Fort CollinsCO 80523-1476USA Faculty of Land resources and Agricultural Environment (FLRAE) Flue University of Agriculture and Forestry (F1UAF)Hue UniversityHue City 0084Vietnam

Hydrological modeling outputs are subject to uncertainty resulting from different sources of errors (e.g., error in input data, model structure, and model parameters), making quantification of uncertainty in hydrological modeling imperative and meant to improve reliability of modeling results. The uncertainty analysis must solve difficulties in calibration of hydrological models, which further increase in areas with data scarcity. The purpose of this study is to apply four uncertainty analysis algorithms to a semi-distributed hydrological model, quantifying different source of uncertainties (especially parameter uncertainty) and evaluate their performance. In this study, the Soil and Water Assessment Tools (SWAT) eco-hydrological model was implemented for the watershed in the center of Vietnam. The sensitivity of parameters was analyzed, and the model was calibrated. The uncertainty analysis for the hydrological model was conducted based on four algorithms: Generalized Likelihood Uncertainty Estimation (GLUE), Sequential Uncertainty Fitting (SUFI), Parameter Solution method (ParaSol) and Particle Swarm Optimization (PSO). The performance of the algorithms was compared using P-factor and Rfactor, coefficient of determination (R2), the Nash Sutcliffe coefficient of efficiency (NSE) and Percent Bias (PBIAS). The results showed the high performance of SUFI and PSO with P-factor>0.83, R-factor 0.91, NSE>0.89, and 0.18<0.32. Hence, we would suggest to use SUFI-2 initially to set the parameter ranges, and further use PSO for final analysis. Indeed, the uncertainty analysis must be accounted when the outcomes of the model use for policy or management decisions.

关键词： SWAT-CUP GLUE SUFI2 ParaSol PSO Vietnam