关键词：
morphing;simulated annealing;detection of characteristic points;matching of characteristic points;continuous generalization
摘要：
This paper presents a new method for use in performing continuous scale transformations of linear features using Simulated Annealing-Based Morphing (SABM). This study addresses two key problems in the continuous generalization of linear features by morphing, specifically the detection of characteristic points and correspondence matching. First, an algorithm that performs robust detection of characteristic points is developed that is based on the Constrained Delaunay Triangulation (CDT) model. Then, an optimal problem is defined and solved to associate the characteristic points between a coarser representation and a finer representation. The algorithm decomposes the input shapes into several pairs of corresponding segments and uses the simulated annealing algorithm to find the optimal matching. Simple straight-line trajectories are used to define the movements between corresponding points. The experimental results show that the SABM method can be used for continuous generalization and generates smooth, natural and visually pleasing linear features with gradient effects. In contrast to linear interpolation, the SABM method uses the simulated annealing technique to optimize the correspondence between characteristic points. Moreover, it avoids interior distortions within intermediate shapes and preserves the geographical characteristics of the input shapes.
通讯机构：
[Yu, GM; Tu, ZF] H;[Yu, GM; Tu, ZF] C;Hubei Prov Key Lab Geog Proc Anal & Simulat, Wuhan 430079, Hubei Province, Peoples R China.;Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.
关键词：
Water accessibility;Natural river network;SHRD model;Watershed scale;Water resources management
摘要：
Traditional assessments of water resources use water availability as an evaluating metric. Water availability is a statistical average and cannot reflect the spatial differences of water resources in a region or basin. This assessment usually engenders a paradox, that is, water resources are abundant in a region but it is difficult to obtain water for the people on some spatial points in this region. In this study we define a new term, water accessibility, to eliminate this paradox and develop a model of water accessibility (the SHRD model) to meet the need of spatial details in water resources assessment at the grid scale. In the case study the water accessibility of the Hanjiang River Basin is mapped and assessed by the SHRD model. The comprehensive index of water accessibility is 0 to 4.5 and tends to increase from northwest to southeast in the study area. The results of the SHRD model can show the spatial pattern of water accessibility in a region, and can server a more finely-tuned water resources management approach. This model and method push the macroscopic (regional) water resources assessment forward from the microcosmic (raster cell) analysis.
作者机构：
[Peng, Feifei; Liu, Pengcheng] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan 430079, Peoples R China.;[Peng, Feifei; Liu, Pengcheng] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Gong, Jianya] Wuhan Univ, Sch Remote Sensing & Informat Engn, Wuhan 430079, Peoples R China.;[Gong, Jianya; Wu, Huayi] Wuhan Univ, State Key Lab Informat Engn Surveying Mapping & R, Wuhan 430079, Peoples R China.;[Wang, Le] SUNY Buffalo, Dept Geog, Buffalo, NY 14261 USA.
通讯机构：
[Peng, Feifei] C;Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan 430079, Peoples R China.;Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.
关键词：
built-up area;stereo image;disparity;height feature;Stereo Pair Disparity Index (SPDI)
摘要：
Within-class spectral variation and between-class spectral confusion in remotely sensed imagery degrades the performance of built-up area detection when using planar texture, shape, and spectral features. Terrain slopes and building heights extracted from auxiliary data, such as Digital Surface Models (DSMs) however, can improve the results. Stereo imagery incorporates height information unlike single remotely sensed images. In this study, a new Stereo Pair Disparity Index (SPDI) for indicating built-up areas is calculated from stereo-extracted disparity information. Further, a new method of detecting built-up areas from stereo pairs is proposed based on the SPDI, using disparity information to establish the relationship between two images of a stereo pair. As shown in the experimental results for two stereo pairs covering different scenes with diverse urban settings, the SPDI effectively differentiates between built-up and non-built-up areas. Our proposed method achieves higher accuracy built-up area results from stereo images than the traditional method for single images, and two other widely-applied DSM-based methods for stereo images. Our approach is suitable for spaceborne and airborne stereo pairs and triplets. Our research introduces a new effective height feature (SPDI) for detecting built-up areas from stereo imagery with no need for DSMs.
期刊：
International Journal of Remote Sensing,2017年38(21):6007-6029 ISSN：0143-1161
通讯作者：
Li, Chang
作者机构：
[Luo, Jing; Chen, Guangping; Li, Shice; Li, Chang] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat, Wuhan, Hubei, Peoples R China.;[Luo, Jing; Chen, Guangping; Li, Shice; Li, Chang] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan, Hubei, Peoples R China.;[Ye, Jia] Georgia Inst Technol, Sch Design, Atlanta, GA 30332 USA.;[Li, Chang] Cent China Normal Univ, Key Lab Geog Proc Anal Simulat, Wuhan, Hubei, Peoples R China.
通讯机构：
[Li, Chang] C;Cent China Normal Univ, Key Lab Geog Proc Anal Simulat, Wuhan, Hubei, Peoples R China.
摘要：
In this article, the Defence Meteorological Satellite Program Operational Linescan System DMSP-OLS night-time light remotely sensed data on a small scale is proposed to evaluate port economic comprehensive scores PECS for the ports of the major cities, including Shanghai, Nanjing, Wuhan, and Chongqing, in the Yangtze River Valley, China. First, the concept and calculation method of port night-time light intensity PNLI are proposed. Second, an estimation method of PECS is proposed using factor analysis. Third, two regression models i.e. first-and second-order polynomials between PNLI and PECS are built and tested. The goodness-of-fit of the two models are compared, both with and without outliers. Finally, experimental results show that the proposed methods for evaluating PECS in the Yangtze River Valley, China are feasible. Wuhan has the strongest correlation R2 = 0.925 and passes the F-test, Ft = 55.429 >4.26 = Ft 0.05 2, 9; Shanghai has the weakest correlation R2: 0.688 but still passes as well, Ft = 9.944 >4.26 = Ft0.05 2, 9. Factors confounding the correlation for Shanghai are discussed. Overall, this study not only proposes a new set of methods to evaluate the performance of port economies but also provides a feasible way to use DMSP-OLS data to study the geographic problems of small scales.
摘要：
High-resolution satellite data have been playing an important role in agricultural remote sensing monitoring. However, the major data sources of high-resolution images are not owned by China. The cost of large scale use of high resolution imagery data becomes prohibitive. In pace of the launch of the Chinese “High Resolution Earth Observation Systems”, China is able to receive superb high-resolution remotely sensed images (GF series) that equalizes or even surpasses foreign similar satellites in respect of spatial resolution, scanning width and revisit period. This paper provides a perspective of using high resolution remote sensing data from satellite GF-1 for agriculture monitoring. It also assesses the applicability of GF-1 data for agricultural monitoring, and identifies potential applications from regional to national scales. GF-1’s high resolution (i.e., 2 m/8 m), high revisit cycle (i.e., 4 days), and its visible and near-infrared (VNIR) spectral bands enable a continuous, efficient and effective agricultural dynamics monitoring. Thus, it has gradually substituted the foreign data sources for mapping crop planting areas, monitoring crop growth, estimating crop yield, monitoring natural disasters, and supporting precision and facility agriculture in China agricultural remote sensing monitoring system (CHARMS). However, it is still at the initial stage of GF-1 data application in agricultural remote sensing monitoring. Advanced algorithms for estimating agronomic parameters and soil quality with GF-1 data need to be further investigated, especially for improving the performance of remote sensing monitoring in the fragmented landscapes. In addition, the thematic product series in terms of land cover, crop allocation, crop growth and production are required to be developed in association with other data sources at multiple spatial scales. Despite the advantages, the issues such as low spectrum resolution and image distortion associated with high spatial resolution and wide swath width, might pose challenges for GF-1 data applications and need to be addressed in future agricultural monitoring.
期刊：
International Journal of Remote Sensing,2017年38(11):3430-3444 ISSN：0143-1161
通讯作者：
Li, Chang
作者机构：
[Zheng, Yanping; Wu, Yijin; Li, Chang] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat, Hubei, Peoples R China.;[Zheng, Yanping; Wu, Yijin; Li, Chang] Cent China Normal Univ, Coll Urban & Environm Sci, Hubei, Peoples R China.
通讯机构：
[Li, Chang] C;Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat, Hubei, Peoples R China.;Cent China Normal Univ, Coll Urban & Environm Sci, Hubei, Peoples R China.
摘要：
To improve the usability of Enhanced Thematic Mapper Plus ETM+ scan line corrector SLC-off data, this article proposes using HJ-1A/1B imagery as auxiliary i.e. reference data to recover the SLC-off ETM+ data. The least-median-of-squares LMedS method is newly proposed to recover missing pixels of Landsat 7 by removing the variant or abnormal digital number values. In particular, for the visible and near-infrared bands, using HJ-1A/1B for recovery has three clear advantages: the same spatial resolution, similar spectral resolution, and approximate temporal resolution. The experiments show that all of the reference-recovery methods are better than the non-reference-recovery method. The results of using of auxiliary data in reference-recovery methods, from best to worst, are Landsat 8, HJ-1A/1B, and Landsat 7. However, for recovering missing pixels, HJ-1A/1B is superior to the ETM+ auxiliary data due to the shorter time interval in Landsat 7 a few hours. Hence, HJ-1A/1B should be considered a useful auxiliary data to recover ETM+ SLC-off imagery data. To improve the usability of Enhanced Thematic Mapper Plus ETM+ scan line corrector SLC-off data, this article proposes using HJ-1A/1B imagery as auxiliary i.e. reference data to recover the SLC-off ETM+ data. The least-median-of-squares LMedS method is newly proposed to recover missing pixels of Landsat 7 by removing the variant or abnormal digital number values. In particular, for the visible and near-infrared bands, using HJ-1A/1B for recovery has three clear advantages: the same spatial resolution, similar spectral resolution, and approximate temporal resolution. The experiments show that all of the reference-recovery methods are better than the non-reference-recovery method. The results of using of auxiliary data in reference-recovery methods, from best to worst, are Landsat 8, HJ-1A/1B, and Landsat 7. However, for recovering missing pixels, HJ-1A/1B is superior to the ETM+ auxiliary data due to the shorter time interval in Landsat 7 a few hours. Hence, HJ-1A/1B should be considered a useful auxiliary data to recover ETM+ SLC-off imagery data.
作者机构：
[Zhu, Yujia; Li, Guie; Wu, Yijin; Li, Chang] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Coll Urban & Environm Sci, Wuhan, Hubei, Peoples R China.;[Ge, Yong] Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, State Key Lab Resources & Environm Informat Syst, Beijing 100101, Peoples R China.;[Kung, Hsiang-te] Univ Memphis, Dept Earth Sci, Memphis, TN 38152 USA.
通讯机构：
[Wu, Yijin] C;Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Coll Urban & Environm Sci, Wuhan, Hubei, Peoples R China.
关键词：
DMSP/OLS nighttime light data;Likelihood-based spatial statistical transformation model (LBSSTM);Time series analysis;Prediction;ESDA;Spatial cross correlation
摘要：
In a regional economy, the central city of a metropolitan area has a radiative effect and an accumulative effect on its surrounding cities. Considering the limitations of traditional data sources (e.g., its subjectivity) and the advantages of nighttime light data, including its objectivity, availability and cyclicity, this paper proposes a likelihood spatial statistical transformation model (LBSSTM) to invert for the gross domestic product (GDP) of the surrounding cities, using time series of Sum of Lights (SOL) data covering the central city and taking advantage of the economic and spatial association between the central city and the surrounding cities within a metropolitan area and the correlation between SOL and GDP. The Wuhan Metropolitan Area is chosen to verify the model using time series analysis and exploratory spatial data analysis (ESDA). The experimental results show the feasibility of the proposed LBSSTM. The prediction accuracy of our model is verified by cross-validation using data from 1998, 2004 and 2011, based on the 3 sigma rule. This model can quantitatively express the agglomeration and diffusion effect of the central city and reveal the spatial pattern of this effect. The results of this work are potentially useful in making spatiotemporal economic projections and filling in missing data from some regions, as well as gaining a deeper quantitative and spatio-temporal understanding of the laws underlying regional economic development. (C) 2017 Elsevier B.V. All rights reserved.
摘要：
Seed re-dispersal following initial harvesting by ants may have important implications for the distribution and fate of myrmecochorous seeds. However, the probability of seed re-dispersed by ants and the effect it may have on subsequent survival appear variable, the functional role of diaspore, disperser and seed predator to the fate of discarded seeds remain unclear. To clarify the ecology, we compared the consequences of seed re-dispersal by a keystone seed-dispersing ant (Myrmica ruginodis Nylander) for four sympatric myrmecochorous plants common to the temperate deciduous forests in Qinling Mountains, central China. Plants varied in the probability of re-dispersal and in elaiosome condition. Ants preferred seeds with residual elaiosomes, while rodents only consumed the two larger-seeded species, regardless of the elaiosome presence. The scattered distribution of discarded seeds increased the probability of ant re-harvesting and, to some extent, reduced rodent predation. Thus, difference in the probability of seed re-dispersal and its subsequent effect on seed fate in relation to ants and rodents was attributed primarily to the elaiosome condition, seed size and seed spatial pattern. The results imply that seed re-dispersal could affect the fitness of plants and ultimately influence the plant abundance and distribution pattern. This highlights the necessity to incorporate re-dispersal into myrmecochory to advance our understanding of the benefits of myrmecochory to plants.
摘要：
Urban parks composed mostly of vegetation and water bodies can effectively mitigate the urban heat island effect. Many studies have investigated the cooling effects of urban parks; however, little attention has been given to park landscape structure. Based on landscape metrics, this study has explored the influences of the park landscape structure on its inner thermal environment, taking heavily urbanized Beijing Municipality in China as the study area. Three indices, including the percentage of landscape (PLAND), landscape shape index (LSI) and aggregation index (AI), were used to measure the composition and configuration characteristics of the landscape components inside the parks. The indices were calculated for five landscape types being interpreted from Quickbird images. Urban thermal conditions were measured using the land surface temperature (LST) derived from Landsat TM images. The results showed that the park LST had a negative relationship with the park size, but no significant relationship was found with park shape. For the park's interior landscape, however, the configuration and composition characteristics of the landscape components inside the park explained 70% of the park LST variance. The area percentage of water bodies and the aggregation index of woodland were identified as the key influencing characteristics. In addition, when the composition and configuration characteristics of the park landscape components were separately considered, the configuration characteristics (LSI and AI) explained approximately 54% of the variance in park LST, which was comparable with that explained by the composition characteristics (PLAND). Thus, this study suggested that an effective and practical way for urban cooling park design is the optimization of spatial configuration of landscape components inside the park.
通讯机构：
[Li, Chang] K;[Li, Chang] C;Key Lab Geog Proc Anal & Simulat, Wuhan, Hubei, Peoples R China.;Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Hubei, Peoples R China.
摘要：
There are two major problems in Rational Function Model (RFM) solution: (a) Data source error, including gross error, random error, and systematic error; and (b) Model error, including over-parameterization and over-correction issues caused by unnecessary RFM parameters and exaggeration of random error in constant term of error-in-variables (EIV) model, respectively. In order to solve two major problems simultaneously, we propose a new approach named stepwise-thenorthogonal regression (STOR) with quality control. First, RFM parameters are selected by stepwise regression with gross error detection. Second, the revised orthogonal distance regression is utilized to adjust random error and address the overcorrection problem. Third, systematic error is compensated by Fourier series. The performance of conventional strategies and the proposed STOR are evaluated by control and check grids generated from SPOT5 high-resolution imagery. Compared with the least squares regression, partial least squares regression, ridge regression, and stepwise regression, the proposed STOR shows a significant improvement in accuracy.
作者机构：
[Li, Jianyong; Dodson, John; Li, JY; Dodson, J; Yan, Hong; Lu, Fengyan] Chinese Acad Sci, State Key Lab Loess & Quaternary Geol, Inst Earth Environm, Xian 710075, Peoples R China.;[Dodson, John] Univ New South Wales, Sch Biol Earth & Environm Sci, Sydney, NSW 2033, Australia.;[Zhang, David D.; Lee, Harry F.] Univ Hong Kong, Dept Geog, Pokfulam Rd, Hong Kong, Hong Kong, Peoples R China.;[Zhang, David D.; Lee, Harry F.] Univ Hong Kong, Int Ctr China Dev Study, Pokfulam Rd, Hong Kong, Hong Kong, Peoples R China.;[Zhang, Xiaojian] Nanjing Univ, Sch Geog & Oceanog Sci, Nanjing 210093, Jiangsu, Peoples R China.
摘要：
Our understanding on the spatial-temporal patterns of climatic variability over the last few millennia in the East Asian monsoon-dominated northern China (NC), and its role at a macro-scale in affecting the prosperity and depression of Chinese dynasties is limited. Quantitative high-resolution, regionally-synthesized palaeoclimatic reconstructions as well as simulations, and numerical analyses of their relationships with various fine-scale, numerical agro-ecological, social-economic, and geo-political historical records during the period of China's history, are presented here for NC. We utilize pollen data together with climate modeling to reconstruct and simulate decadal- to centennial-scale variations in precipitation or temperature for NC during the last 2200 years (-200-2000 AD). We find an overall cyclic-pattern (wet/warm or dry/cold) in the precipitation and temperature anomalies on centennial- to millennial-scale that can be likely considered as a representative for the entire NC by comparison with other related climatic records. We suggest that solar activity may play a key role in driving the climatic fluctuations in NC during the last 22 centuries, with its quasi similar to 100, 50, 23, or 22-year periodicity clearly identified in our climatic reconstructions. We employ variation partitioning and redundancy analysis to quantify the independent effects of climatic factors on accounting for the total variation of 17 fine-grained numerical Chinese historical records. We quantitatively illustrate that precipitation (67.4%) may have been more important than temperature (32.5%) in causing the overall agro-ecological and macro-geopolitical shifts in imperial China with NC as the central ruling region and an agricultural heartland over the last 2200 years. (C) 2017 Elsevier Ltd. All rights reserved.
