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Big spatial data for urban and environmental sustainability

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Geo-Spatial Information science 2020年第2期23卷 125-140页

作者： Bo Huang Jionghua Wang department of geography and resource management The Chinese University of Hong KongHong KongChina

Eighty percent of big data are associated with spatial information,and thus are Big Spatial Data(BSD).BSD provides new and great opportunities to rework problems in urban and environmental sustainability with advanced BSD *** fully leverage the advantages of BSD,it is integrated with conventional data(*** sensing images)and improved methods are *** paper introduces four case studies:(1)Detection of polycentric urban structures;(2)Evaluation of urban vibrancy;(3)Estimation of population exposure to PM2.5;and(4)Urban land-use classification via deep *** results provide evidence that integrated methods can harness the advantages of both traditional data and ***,they can also improve the effectiveness of big data ***,this study makes three key recommendations for the development of BSD with regards to data fusion,data and predicting analytics,and theoretical modeling.

关键词： Big spatial data analytics review spatial modeling data fusion

Wetland Preservation in Australia:The Administrative and Policital Threats

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湿地科学 2008年第2期6卷 142-147页

作者： Mark Yaolin Wang department of resource management and geography The University of Melbourne

The wetlands in Australia are of great physical,chemical and biological variety due to the continent's age,geological history and *** traditional physical and biological threats remain as the main challenges for wetland preservation in ***,it has been increasingly recognized that the immediate survival of wetlands are being affected by more subtle threats,such as administrative and political *** paper identifies these non-physical threats and discusses how and why they have become the major barriers for sustainable wetland preservation in ***,this paper calls for more practical policies and solutions to be implemented for sustainable wetland preservation in Australia.

关键词：澳大利亚湿地保护环保政策环境管理

MAGE ANALYSIS OF GEOSTATIONARY METEOROLOGICAL SATELLITE FOR MONITORING MOVEMENT OF MESOSCALE CONVECTIVE SYSTEMS OVER TIBETAN PLATEAU

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Chinese Geographical science 2005年第3期15卷 231-237页

作者： DAI Xiao-yan WU Jian-ping LIN Hui Ministry of Education Key laboratory of Geographic lnJbrmation science East China Normal UniversityShanghai 200062 P. R. China department of geography and resource management ＆ joint laboratory for geolnformation science the Chinese University of Hong Kong Hong Kong P. R. China

Disaster weather forecasting is becoming increasingly important. In this paper, the trajectories of Mesoscale Convective Systems （MCSs） were automatically tracked over the Chinese Tibetan Plateau using Geostationary Meteorological Satellite （GMS） brightness temperature （Tbb） from June to August 1998, and the MCSs are classified according to their movement direction. Based on these, spatial data mining methods are used to study the relationships between MCSs trajectories and their environmental physical field values. Results indicate that at 400hPa level, the trajectories of MCSs moving across the 105°E boundary are less influenced by water vapor flux divergence, vertical wind velocity, reIative humidity and K index. In addition, if the gravity central longitude locations of MCSs are between 104°E and 105°E, then geopotential height and wind divergence are two main factors in movement causation. On the other hand, at 500hPa level, the trajectories of MCSs in a north-east direction are mainly influenced by K index and water vapor flux divergence when their central locations are less than 104°E. However, the MCSs moving in an east and south-east direction are influenced by a few correlation factors at this level.

关键词： Tibetan Plateau Mesoscale Convective Systems automatically tracking spatial data mining

Modelling for registration of remotely sensed imagery when reference control points contain error

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science China Earth sciences 2006年第7期49卷 739-746页

作者： Leung Yee The department of geography and resource management The Chinese University of Hong Kong Shatin Hong Kong China

Reference control points (RCPs) used in establishing the regression model in the regis-tration or geometric correction of remote sensing images are generally assumed to be “perfect”. That is, the RCPs, as explanatory variables in the regression equation, are accurate and the coordinates of their locations have no errors. Thus ordinary least squares (OLS) estimator has been applied exten-sively to the registration or geometric correction of remotely sensed data. However, this assumption is often invalid in practice because RCPs always contain errors. Moreover, the errors are actually one of the main sources which lower the accuracy of geometric correction of an uncorrected image. Under this situation, the OLS estimator is biased. It cannot handle explanatory variables with errors and cannot propagate appropriately errors from the RCPs to the corrected image. Therefore, it is essential to develop new feasible methods to overcome such a problem. This paper introduces a consistent adjusted least squares (CALS) estimator and proposes relaxed consistent adjusted least squares (RCALS) estimator, with the latter being more general and flexible, for geometric correction or regis-tration. These estimators have good capability in correcting errors contained in the RCPs, and in propagating appropriately errors of the RCPs to the corrected image with and without prior information. The objective of the CALS and proposed RCALS estimators is to improve the accuracy of measure-ment value by weakening the measurement errors. The conceptual arguments are substantiated by a real remotely sensed data. Compared to the OLS estimator, the CALS and RCALS estimators give a superior overall performance in estimating the regression coefficients and variance of measurement errors.

关键词： error modelling, registration, ordinary least squares, relaxed consistent adjusted least squares, remote sensing images.

An evaluation of digital elevation modeling in GIS and Cartography

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Geo-Spatial Information science 2014年第2期17卷 139-144页

作者： Bola AYENI Kayode Julius SAMUEL department of geography University of IbadanIbadanNigeria department of geography&resource management Osun State UniversityOkukuNigeria

This study considers seven commonly used surface fitting methods within Golden Software and ArcGIS^(TM) *** grid sizes of 68 rows by 100 columns(6800 grids)and 680 rows by 1000 columns(680,000 grids)and 294,208 elevation points covering the entire landmass of Nigeria,the study evaluates the performance of these methods in terms of execution time and faithfulness in the representation of the spatial *** show marked differences in time taken to execute the fitting and that Inverse Distance,the Natural Neighbor,the Nearest Neighbor,and Triangulation with Linear Interpolation seem to give the highest level of correspondence or faithfulness.

关键词： image surface fitting digital elevation modelling GIS cartography

Effect of drainage on CO_2, CH_4, and N_2O fluxes from aquaculture ponds during winter in a subtropical estuary of China

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Journal of Environmental sciences 2018年第3期30卷 72-82页

作者： Ping Yang Derrick Y.F Lai Jia F.Huang Chuan Tong School of Geographical sciences Fujian Normal University Key laboratory of Humid Sub-tropical Eco-geographical Process of Ministry of Education of China Fujian Normal University department of geography and resource management and Centre for Environmental Policy and Resource ManagementThe Chinese University of Hong Kong

Aquaculture ponds are dominant features of the landscape in the coastal zone of ***,aquaculture ponds are drained during the non-culture period in ***,the effects of such drainage on the production and flux of greenhouse gases（GHGs）from aquaculture ponds are largely *** the present study,field-based research was performed to compare the GHG fluxes between one drained pond（DP,with a water depth of 0.05 m）and one undrained pond（UDP,with a water depth of 1.16 m）during one winter in the Min River estuary of southeast *** the entire study period,the mean CO2flux in the DP was（0.75±0.12）mmol/（m^2·hr）,which was significantly higher than that in the UDP of（-0.49±0.09）mmol/（m^2·hr）（p0.01）.This indicates that drainage drastically transforms aquaculture ponds from a net sink to a net source of CO2in *** CH4and N2O emissions were significantly higher in the DP compared to those in the UDP（CH4=（0.66±0.31）vs.（0.07±0.06）mmol/（m^2·hr）and N2O=（19.54±2.08）vs.（0.01±0.04）μmol/（m^2·hr））（p〈0.01）,suggesting that drainage would also significantly enhance CH4and N2O *** in environmental variables（including sediment temperature,p H,salinity,redox status,and water depth）contributed significantly to the enhanced GHG emissions following pond ***,analysis of the sustained-flux global warming and cooling potentials indicated that the combined global warming potentials of the GHG fluxes were significantly higher in the DP than in the UDP（p〈0.01）,with values of739.18 and 26.46 mg CO2-eq/（m^2·hr）,*** findings suggested that drainage of aquaculture ponds can increase the emissions of potent GHGs from the coastal zone of China to the atmosphere during winter,further aggravating the problem of global warming.

关键词： Aquaculture pond Drainage management Greenhouse gas flux Global warming Min River estuary

Relationships of exponents in multifractal detrended fluctuation analysis and conventional multifractal analysis

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Chinese Physics B 2011年第9期20卷 106-114页

作者：周煜梁怡喻祖国 department of geography and resource management The Chinese University of Hong Kong Center for Environmental Policy and resource management The Chinese University of Hong Kong Institute of Space and Earth Information science The Chinese University of Hong Kong Discipline of Mathematical sciences Faculty of Science and TechnologyQueensland University of Technology School of Mathematics and Computational science Xiangtan University

Multifractal detrended fluctuation analysis (MF-DFA) is a relatively new method of multifractal *** is extended from detrended fluctuation analysis (DFA),which was developed for detecting the long-range correlation and the fractal properties in stationary and non-stationary time *** MF-DFA has become a widely used method,some relationships among the exponents established in the original paper seem to be incorrect under the general *** this paper,we theoretically and experimentally demonstrate the invalidity of the expression τ (q)=qh(q)-1 stipulating the relationship between the multifractal exponent τ (q) and the generalized Hurst exponent h(q).As a replacement,a general relationship is established on the basis of the universal multifractal formalism for the stationary series as τ(q)=qh(q)-qH’-1,where H’ is the nonconservation parameter in the universal multifractal *** singular spectra,α and f(α),are also derived according to this new relationship.

关键词： fractals Hurst exponent multifractal detrended fluctuation analysis time series analysis

Effects of hedgerows on sediment erosion in Three Gorges Dam Area, China

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International Journal of Sediment Research 2008年第2期23卷 119-129页

作者： Sai-Leung NG Kwai-Cheong CHAU department of geography and resource management the Chinese University of Hong KongHong KongChinaProf

The Three Gorges Dam Area refers to the river section from Chongqing to Yichang on the Yangtze River,which has a drainage area of 75,098 km2,and involves 19 cities and *** hedgerows have been used in this area to control soil erosion and to improve hillslope stability in the catchment of this river *** experimental hedgerow plots were established in 1994 in order to study the effects of hedgerows on erosion *** the period of 1994-1997,runoff and soil loss data were collected on these test plots,including the chemical and physical properties of soil and related topographical *** results indicate that:(1) after 4 years of cultivation and crop planting,soil fertility increased dramatically in the hedgerow *** organic matter,total nitrogen,and total phosphorus contents in the hedgerow plots were 5-9 times higher than that in the control *** each of the hedgerow plots,soil structure became more stable,the quantity of granules larger than 0.02 mm increased and those finer than 0.02 mm decreased;(2) All hedgerow plots showed a major effect on reducing soil loss and surface runoff;(3) Overland flow velocity along the upper portion of the hedgerow plots was greatly reduced due to hedgerow resistance,which explains the significant decrease in soil losses in hedgerow plots,despite the fact that the hedgerow plots and the control plots had the same total runoff.

关键词： Hedgerow Erosion Runoff Soil properties Three Gorges Dam Project

A NOVEL METHOD FOR PLANNING A STAGED EVACUATION

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Journal of Systems science & Complexity 2012年第6期25卷 1093-1107页

作者： Xiang LI Bo HUANG Zhengjun LIU Xihui ZHANG Jing SUN Key laboratory of Geographical Information science Ministry of EducationEast China Normal University department of geography and resource management The Chinese University of Hong Kong Institute for Photogrammetry and Remote Sensing Chinese Academy of Surveying and Mapping department of Computer science and Information Systems College of BusinessUniversity of North Alabama

This paper presents an innovative method to facilitate making such a plan. Using an algorithm to schedule the starting time of each evacuation group, the method guarantees that the time of completing a large-scale evacuation is very close to its theoretically shortest evacuation time. Meanwhile, unlike a simultaneous evacuation, during a staged evacuation planned with the proposed method, all evacuees can take the shortest path to a safe exit. Once evacuees start off, they will not suffer any traffic congestion. The above advantages of this innovative method are achieved by using an algorithm with three nested loops. Experiments have been conducted, and their results have validated the proposed method.

关键词： Algorithm disaster staged evacuation starting time.