关键词：
Comprehensive assessment of cultivated land quality;Land use and production conditions (LUPCs);Spatial variability;Sustainable land management;Unconsolidated cultivated land (UCL)
摘要：
Socioeconomic factors are extrinsic factors that drive spatial variability. They play an important role in land resource systems and sometimes are more important than that of the natural setting. The study aims to build a comprehensive framework for assessing unconsolidated cultivated land (UCL) in the south-central and southwestern portions of Hubei Province, China, which have not experienced project management and land consolidation, to identify the roles of natural and especially socioeconomic factors. Moreover, the study attempts to identify the attributes and indicators that describe the characteristics of the extrinsic factors affecting land spatial variability. Assessment supplement 12 proposed land use indicators on the basis of natural factors using the method of gradation of agricultural land quality (GALQ). The overall level of cultivated land quality (CLQ) in the two study areas is moderate, and this quantity is significantly correlated with topography. Excellent and high-quality UCL are mainly distributed in the south-central plain division of Hubei Province (SCPDHP), whereas lower grades are mainly distributed in the area of the southwestern mountainous division of Hubei Province (SWMDHP). These results suggest that the pattern of small-scale agricultural development depends strongly on the labor force and is the key land use-related factor that limits the improvement of regional CLQ. Such assessments and their findings are essential for the protection of cultivated land and the adjustment of agricultural structure to promote the sustainable use of UCL.
摘要：
Understanding how hydrological extremes would respond to global warming and its associated uncertainties is important for better designing mitigation and adaption strategies to cope with global change. Very few works have investigated the changes in future hydrological extremes and, especially, the more devastating joint hydrological extremes over China. In this article, two combinations of joint extremes [i.e. high runoff/high soil moisture (HRHS) and low runoff/low soil moisture (LRLS)] are designed for analysis. To derive the scenarios of hydrological conditions, the bias-corrected daily climate projections from five global circulation models (GCMs) under the historical and Representative Concentration Pathways 8.5 (RCP8.5) emission scenarios are used to drive the calibrated Variable Infiltration Capacity (VIC) model from 1951 to 2099 over China. Results show notable increase of occurrence of HRHS in Northeast China, LRLS in Northwest and South of China under 2 °C global warming. The spatial pattern of changes in joint extremes tends to remain stable with global temperature increase up to 3 °C. Compared with the individual extreme risk, joint extreme are much more concentrated in Northwest and South China and the magnitude of changes is several times larger. Larger areas experiencing changes are found when using lower standards of extreme definition. Because hydrological regime may change gradually in response to climate change, the threshold derived from present regime may lead to misrepresentation of extreme risk analysis. This was demonstrated by the ten times smaller magnitude of changes when adopting the updated transient threshold representing the changing hydrological regime, thus providing a low-boundary of potential changes in extremes. Our results highlight the importance of considering the changing hydrological regime in addition to choosing various levels of threshold for extreme definition in order to cover the full range of possible extreme changes in a warming climate.
期刊：
Theoretical and Applied Climatology,2016年125(1-2):353-363 ISSN：0177-798X
通讯作者：
Tan, Wenxia
作者机构：
[Tan, Wenxia] Cent China Normal Univ, Coll Urban & Environm Sci, Key Lab Geog Proc Anal & Simulat, Wuhan 430079, Hubei, Peoples R China.;[LeDrew, Ellsworth] Univ Waterloo, 200 Univ Ave West, Waterloo, ON N2L 3G1, Canada.
通讯机构：
[Tan, Wenxia] C;Cent China Normal Univ, Coll Urban & Environm Sci, Key Lab Geog Proc Anal & Simulat, Wuhan 430079, Hubei, Peoples R China.
关键词：
Decision Tree Classifier;Canadian Arctic Archipelago;Phenological Metrics;North Water Polynya
摘要：
Arctic sea ice has undergone a significant decline in recent years. Previous studies have demonstrated that the annual sea ice cycle has experienced earlier melt and later freeze up, leading to a significant reduction in minimum sea ice extents and the lengthening of the melting season. The Arctic is being transformed into a regime of widespread seasonal ice with a large loss of old and thick multiyear ice in recent years. However, the sea ice change exhibits considerable interannual and regional variability at different spatial and temporal scales. In this study, we present a new method for hypertemporal sea ice data change detection based on the annual sea ice concentration (SIC) profile for the melt months of each year. A decision tree-based classification is adopted to group pixels with similar annual SIC profiles, and a phenology map of each year is generated for visualization. The phenoregion map visualizes the spatial and temporal configurations of ice melt process for a year. The change detection objective is achieved by comparing the phenoregion number of the same pixel in different years. The algorithm further leads to interpretation of anomalies to obtain change maps at the pixel level. Compared to previous sea ice studies that mainly focused on a particular spatial region and commonly use time period averages, the proposed pixel-based approach has the potential to map sea ice data change both temporally and spatially.
通讯机构：
[Yu, Guangming] C;Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.
关键词：
China;Crop water requirements;Food production;Regional water balance;Water resource management;Water-satisfied degree
摘要：
Water resources are one of the important factors that influence regional crop production and the food security of humans. Most traditional models of crop water demand analysis are built on the basis of a certain crop or macroscopic analysis, which neglect regional crop allocation and the difference of water demand in different crop growing periods. In this paper, a new assessing model, the satisfied degree of crop water requirement, is developed to assess the impacts of water resources on production of six main food crops in China. The six main food crops are spring wheat, winter wheat, corn, early season rice, middle-season rice and late rice. The results show that: (1) there are serious risks of water shortage in China, even in south China with its abundant precipitation; (2) the satisfied degree of crop water demand represents great temporal-spatial changes. On spatial distribution the risks are high in major bases of food production due to influences of cropping system and crop-combinations. Northwest China is a special interesting case. In seasonal fluctuation water shortage is severe in March and September. These risks seriously restrict food production in China. The results also show that the strategic measures of water resources management must be chosen carefully to deal with food security and regional sustainable development in China. (C) 2015 Elsevier B.V. All rights reserved.
期刊：
CURRENT SCIENCE,2016年110(6):1079-1085 ISSN：0011-3891
通讯作者：
Zeng, Qun
作者机构：
[Tian, Liqiao; Li, Jian] Wuhan Univ, State Key Lab Informat Engn Surveying Mapping & R, Wuhan 430079, Peoples R China.;[Zeng, Qun; Tian, Xiaojuan] Huazhong Normal Univ, Sch Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Wang, Zheng] Nanjing Univ, Nanjing 210023, Jiangsu, Peoples R China.;[Wang, Zheng] State Ocean Adm, State Key Lab Satellite Ocean Environm Dynam, Inst Oceanog 2, Hangzhou 310012, Zhejiang, Peoples R China.;[Li, Wenbo] Chinese Acad Sci, Inst Intelligent Machines, Hefei 230031, Peoples R China.
通讯机构：
[Zeng, Qun] H;Huazhong Normal Univ, Sch Urban & Environm Sci, Wuhan 430079, Peoples R China.
关键词：
Artificial neural network;Atmospheric correction;Ocean color imager;Remote sensing;Turbid coastal waters
摘要：
The Geostationary Ocean Color Imager (GOCI) can produce good ocean colour products in the open sea. However, an atmospheric correction problem continues to occur for turbid coastal water environment monitoring. In this communication, a regional atmospheric correction method based on an artificial neural network (ANN) model has been proposed. The ANN model was built according to differences in the spatial and radiometric characteristics between the Medium Resolution Imaging Spectrometer (MERIS) and GOCI, with 3000 pixels of the top-of-atmosphere (TOA) reflectance of seven GOCI images from 2011 to 2012 above turbid water used as the inputs and coinciding validated remote-sensing reflectance (Rrs) of MERIS used as the outputs. Subsequently, the water-leaving reflectance of GOCI in turbid coastal water areas of the Bohai Sea was derived. Compared with the products produced by the standard GOCI Data Processing System (GDPS Version 1.3), the Rrs retrieved according to the proposed method showed a significant improvement in spatial pattern. Although the ANN model displayed a degree of difficulty in representing high water-leaving reflectance values, a comparison with three in situ measurements collected on 11 November 2011 in the study area showed encouraging results. The results suggest that the ANN method can be used for atmospheric correction process in turbid waters without requiring numerous in situ measurements.
作者：
Tian, Liqiao;Wai, Onyx W. H.;Chen, Xiaoling*;Li, Wenbo;Li, Jian;...
期刊：
International Journal of Remote Sensing,2016年37(14):3400-3413 ISSN：0143-1161
通讯作者：
Chen, Xiaoling
作者机构：
[Tian, Liqiao; Chen, Xiaoling] Wuhan Univ, State Key Lab Informat Engn Surveying Mapping & R, Wuhan 430079, Peoples R China.;[Wai, Onyx W. H.] Hong Kong Polytech Univ, Dept Civil & Environm Engn, Hong Kong, Hong Kong, Peoples R China.;[Li, Wenbo] Chinese Acad Sci, Hefei Inst Phys Sci, Hefei, Peoples R China.;[Li, Jian] Wuhan Univ, Sch Remote Sensing & Informat Engn, Wuhan, Peoples R China.;[Li, Wenkai; Zhang, Haidong] Huazhong Normal Univ, Sch Urban & Environm Sci, Wuhan, Peoples R China.
通讯机构：
[Chen, Xiaoling] W;Wuhan Univ, State Key Lab Informat Engn Surveying Mapping & R, Wuhan 430079, Peoples R China.
摘要：
This study proposed a method for developing high spatial resolution Gaofen-1 satellite GF-1 Wide Field Imager WFI-based total suspended matter concentration CTSM retrieval model with the assistance of Moderate Resolution Imaging Spectroradiometer MODIS data, using the Deep Bay in China as a case. Based on long-term calibrated CTSM measurements of optical backscatter OBS 3A turbidity and temperature monitoring system of two stationary stations from January 2007 through November 2008, 33 match-ups were selected to build an exponential retrieval model for MODIS atmospherically corrected remote-sensing reflectance Rrs ratio Rrs,645/Rrs,555. Validation of the MODIS model showed well agreement with the seven in situCTSM measurements with a root mean squared error RMSE of 5.06 mg l−1 and a coefficient of determination R2 of 0.80. Aided with six MODIS retrieved CTSM products, different band combinations single band Rrc,660, band subtraction Rrc,660–Rrc,560, band ratio Rrc,660/Rrc,560, and total suspended matter index at 660 nm band TSMI660 were evaluated for simultaneous GF-1 WFI Rayleigh-corrected reflectance Rrc. The results showed that the exponential model based on the Rayleigh-corrected reflectance ratio Rrc,660/Rrc,560 could achieve acceptable accuracy, with RMSE of 14.80 mg l−1 and R2 of 0.62. The proposed method would be helpful for dynamic monitoring in the Deep Bay, and more important could also provide an alternative approach for studies when in situ measurements are unreachable. This study proposed a method for developing high spatial resolution Gaofen-1 satellite GF-1 Wide Field Imager WFI-based total suspended matter concentration CTSM retrieval model with the assistance of Moderate Resolution Imaging Spectroradiometer MODIS data, using the Deep Bay in China as a case. Based on long-term calibrated CTSM measurements of optical backscatter OBS 3A turbidity and temperature monitoring system of two stationary stations from January 2007 through November 2008, 33 match-ups were selected to build an exponential retrieval model for MODIS atmospherically corrected remote-sensing reflectance Rrs ratio Rrs,645/Rrs,555. Validation of the MODIS model showed well agreement with the seven in situCTSM measurements with a root mean squared error RMSE of 5.06 mg l−1 and a coefficient of determination R2 of 0.80. Aided with six MODIS retrieved CTSM products, different band combinations single band Rrc,660, band subtraction Rrc,660–Rrc,560, band ratio Rrc,660/Rrc,560, and total suspended matter index at 660 nm band TSMI660 were evaluated for simultaneous GF-1 WFI Rayleigh-corrected reflectance Rrc. The results showed that the exponential model based on the Rayleigh-corrected reflectance ratio Rrc,660/Rrc,560 could achieve acceptable accuracy, with RMSE of 14.80 mg l−1 and R2 of 0.62. The proposed method would be helpful for dynamic monitoring in the Deep Bay, and more important could also provide an alternative approach for studies when in situ measurements are unreachable.
通讯机构：
[Wu Wenbin] C;Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat, Hubei Prov Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.
关键词：
land use change;CLUE-S;Northeast China;two-way simulation
摘要：
Spatially explicit modeling techniques recently emerged as an alternative to monitor land use changes. This study adopted the well-known CLUE-S (Conversion of Land Use and its Effects at Small regional extent) model to analyze the spatio-temporal land use changes in a hot-spot in Northeast China (NEC). In total, 13 driving factors were selected to statistically analyze the spatial relationships between biophysical and socioeconomic factors and individual land use types. These relationships were then used to simulate land use dynamic changes during 1980-2010 at a 1 km spatial resolution, and to capture the overall land use change patterns. The obtained results indicate that increases in cropland area in NEC were mainly distributed in the Sanjiang Plain and the Songnen Plain during 1980-2000, with a small reduction between 2000 and 2010. An opposite pattern was identified for changes in forest areas. Forest decreases were mainly distributed in the Khingan Mountains and the Changbai Mountains between 1980 and 2000, with a slight increase during 2000-2010. The urban areas have expanded to occupy surrounding croplands and grasslands, particularly after the year 2000. More attention is needed on the newly gained croplands, which have largely replaced wetlands in the Sanjiang Plain over the last decade. Land use change patterns identified here should be considered in future policy making so as to strengthen local eco-environmental security.
作者机构：
[Zhuo Rongrong; Zheng Wensheng; Jiang Yupei; Wang Xiaofang] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat, Wuhan 430079, Hubei Province, Peoples R China.;[Zhuo Rongrong; Zheng Wensheng; Jiang Yupei; Wang Xiaofang] Hubei Dev & Reform Commiss & Cent China Normal Un, Acad Wuhan Metropolitan Area, Wuhan 430079, Peoples R China.;[Run Jiying] Chongqing Geomat Ctr, Chongqing 401121, Peoples R China.
通讯机构：
[Wang Xiaofang] C;[Wang Xiaofang] H;Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat, Wuhan 430079, Hubei Province, Peoples R China.;Hubei Dev & Reform Commiss & Cent China Normal Un, Acad Wuhan Metropolitan Area, Wuhan 430079, Peoples R China.
关键词：
Defence Meteorological Satellite Program's Operational Linescan System (DMSP/OLS);urban spatial pattern;point-axis-area;Hubei Province, China
摘要：
This paper intends to investigate the urban spatial patterns of Hubei Province and its evolution from three different perspectives: urban nodes, urban connections and urban clusters. The research adopts nighttime light imagery of cities in Hubei Province, the viewpoint of 'point-axis-area' in the 'point-axis system' theory, and employs light index model, gravity model and social network analysis. The findings are as follows: 1) In terms of urban nodes, the urbanization process of Hubei has been carried out mainly on the basis of external expansion rather than internal increasing. The polarization trend of urban connection network is strengthening. 2) As for urban connections, the estimation of urban connections using light index model is capable of containing various actual flow, and the connections are getting increasingly closer. 3) In regard to urban groups, seven urban groups of varying sizes have formed. On that basis, three stable and relatively independent urban groups as the centers, namely Wuchang, Yichang and Xiangyang emerge as well. But the structures of 'Wuhan Metropolitan Area', 'Yichang-Jingzhou-Jingmen City Group' and 'Xiangyang-Shiyen-Suizhou City Group', which are defined by local development strategy in Hubei Province, are different from the above three urban groups.
期刊：
International Journal of Remote Sensing,2016年37(1):1-13 ISSN：0143-1161
通讯作者：
Tao, Jianbin
作者机构：
[Tao, Jianbin] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan, Peoples R China.;[Tao, Jianbin; Wang, Yu; Zhang, Yanbing] Cent China Normal Univ, Sch Urban & Environm Sci, Wuhan, Peoples R China.;[Shu, Ning; Hu, Qingwu] Wuhan Univ, Sch Remote Sensing & Informat Engn, Wuhan 430072, Peoples R China.
通讯机构：
[Tao, Jianbin] C;Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan, Peoples R China.
摘要：
This article proposes a Gaussian-mixture-model (GMM)-based method with optimal Gaussian components to address the high intra-class spectral variability in urban land-cover mapping using remote sensing images with very high resolution (VHR). GMMs can simulate and approximate any data distribution provided the optimal Gaussian components can be found. Through improving the model parameters in view of the characteristic of VHR remote sensing images, the parameter space of GMM is optimized significantly, and the model can find the optimal Gaussian components that are suitable for remote sensing images with different resolutions. Experimental results of Wuhan urban area using two images with different resolutions have demonstrated the efficiency and effectiveness of the model. The optimized GMM-based method performs at least comparably or superior to the state-of-the-art classifiers such as support vector machines (SVMs), characterizes man-made land-cover types better than conventional methods, fuses spectral and textural features of VHR image properly, and meanwhile has lower computational complexity.
作者机构：
[Hu Jing; Li Ya-juan] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Hu Jing; Li Ya-juan] China Tourism Acad, Wuhan Branch, Wuhan 430079, Peoples R China.;[Yu Hu; Chen Tian] Univ Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Beijing 100101, Peoples R China.;[Cui Hai-yang] Guizhou Univ, ASEAN Assoc Southeast Asian Nations Res Ctr, Guiyang 550025, Peoples R China.
通讯机构：
[Cui Hai-yang] G;Guizhou Univ, ASEAN Assoc Southeast Asian Nations Res Ctr, Guiyang 550025, Peoples R China.
关键词：
Community evolution;Tourism livelihood;Livelihood assets;Ethnic tourism;Guizhou
摘要：
As an effective livelihood approach to alleviate poverty without rural population migration, ethnic tourism has become the primary choice of economic development in ethnic areas worldwide in addition to traditional livelihood approaches. This article applies the theories of livelihood to study the community evolution driven by tourism livelihood and examine three mountainous tourism communities in different stages of tourist area life cycle. Drawing on the methods of GIS spatial analysis, semi-structured interviews and questionnaires, this article proposes a sustainable livelihood framework for ethnic tourism to explore the evolution of ethnic tourism communities by identifying changes in livelihood assets (natural, financial, social, cultural and human capitals) in the process of tourism development. The results show that the development of ethnic tourism has led to changes in the increase of building land, and the diversification of land use functions with a trend of shifting from meeting local villagers' living needs to satisfying tourists, income composition and uneven distribution of tourism income spatially. Ethnic tourism also led to the deterioration of traditional social management structure, collapse of neighboring relationship, the over- commercialization and staged authenticity of ethnic culture, as well as the gradual vanish of agricultural knowledge with a trend of increasing modern business knowledge and higher education. In addition, these changes, involving livelihood assets from natural, economic, human, social and cultural aspects are interrelated and interactive, which form new evolution characters of ethnic community. This study reveals the conflicts over livelihood approaches which have formed new vulnerabilities to impact on sustainable evolution of ethnic communities. This research provides implications for achieving the sustainable development of ethnic communities with the driving force of tourism livelihood.
