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.
作者机构：
[聂艳; 周勇; 朱强; 李冀云; 洪永胜; 于雷] Key Laboratory for Geographical Process Analysis &, Simulation, Hubei Province, Central China Normal University, Wuhan, 430079, China;[徐良] Hubei Institute of Economic and Social Development, Central China Normal University, Wuhan, 430079, China;[聂艳; 周勇; 朱强; 李冀云; 洪永胜; 于雷] College of Urban &, Environmental Science, Central China Normal University, Wuhan, 430079, China
期刊：
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives,2016年41(B3):65-69 ISSN：1682-1750
通讯作者：
Li, C.
作者机构：
[Li, C.] Key Lab Geog Proc Anal & Simulat, Wuhan, Hubei Province, Peoples R China.;[Li, C.; Liu, X. J.] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan, Peoples R China.;[Deng, T.] Cent China Normal Univ, Sch Fine Arts, Wuhan, Peoples R China.
通讯机构：
[Li, C.] K;[Li, C.] C;Key Lab Geog Proc Anal & Simulat, Wuhan, Hubei Province, Peoples R China.;Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan, Peoples R China.
会议名称：
23rd Congress of the International-Society-for-Photogrammetry-and-Remote-Sensing (ISPRS)
会议时间：
JUL 12-19, 2016
会议地点：
Prague, CZECH REPUBLIC
会议主办单位：
[Li, C.] Key Lab Geog Proc Anal & Simulat, Wuhan, Hubei Province, Peoples R China.^[Li, C.;Liu, X. J.] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan, Peoples R China.^[Deng, T.] Cent China Normal Univ, Sch Fine Arts, Wuhan, Peoples R China.
会议论文集名称：
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
关键词：
RFM;High-resolution satellite imagery;over-parameterization;overcorrection;stepwise regression;orthogonal distance regression;Fourier series fitting
摘要：
Over-parameterization and over-correction are two of the major problems in the rational function model (RFM). A new approach of optimized RFM (ORFM) is proposed in this paper. By synthesizing stepwise selection, orthogonal distance regression, and residual systematic error correction model, the proposed ORFM can solve the ill-posed problem and over-correction problem caused by constant term. The least square, orthogonal distance, and the ORFM are evaluated with control and check grids generated from satellite observation Terre (SPOT-5) high-resolution satellite data. Experimental results show that the accuracy of the proposed ORFM, with 37 essential RFM parameters, is more accurate than the other two methods, which contain 78 parameters, in cross-track and along-track plane. Moreover, the over-parameterization and over-correction problems have been efficiently alleviated by the proposed ORFM, so the stability of the estimated RFM parameters and its accuracy have been significantly improved.
作者机构：
[Zeng, Qun] Editorial Department of Journal, Central China Normal University, Wuhan, 430079, China;[王国良; 田礼乔; 陈晓玲] State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan, 430079, China;[张海东; Zeng, Qun; 李文凯] School of Urban and Environment Science, Central China Normal University, Wuhan, 430079, China
通讯机构：
State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan, China
作者：
Li, C.;Zhu, Y. J.;Li, G. E.;Zhu, Y. Q.;Li, R. H.;...
期刊：
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives,2016年41(B8):947-951 ISSN：1682-1750
通讯作者：
Wu, Y. J.
作者机构：
[Li, C.; Wu, Y. J.] Key Lab Geog Proc Anal & Simulat, Wuhan, Hubei Province, Peoples R China.;[Li, C.; Zhu, Y. J.; Li, G. E.; Wu, Y. J.] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan, Peoples R China.;[Li, R. H.; Wang, L.] Changjiang Soil & Water Conservat Monitoring Ctr, Wuhan, Peoples R China.
通讯机构：
[Wu, Y. J.] K;[Wu, Y. J.] C;Key Lab Geog Proc Anal & Simulat, Wuhan, Hubei Province, Peoples R China.;Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan, Peoples R China.
会议名称：
23rd Congress of the International-Society-for-Photogrammetry-and-Remote-Sensing (ISPRS)
会议时间：
JUL 12-19, 2016
会议地点：
Prague, CZECH REPUBLIC
会议主办单位：
[Li, C.;Wu, Y. J.] Key Lab Geog Proc Anal & Simulat, Wuhan, Hubei Province, Peoples R China.^[Li, C.;Zhu, Y. J.;Li, G. E.;Wu, Y. J.] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan, Peoples R China.^[Li, R. H.;Wang, L.] Changjiang Soil & Water Conservat Monitoring Ctr, Wuhan, Peoples R China.
会议论文集名称：
International Archives of the Photogrammetry Remote Sensing and Spatial Information Sciences
关键词：
Soil and Water Loss;Intensity Estimation;Dynamic Interpretation;Spatial Analysis;Uncertainty;Quality Control
摘要：
Water and soil loss problems are serious in China, especially in the upper and middle reaches of big rivers. This paper dynamically observed water and soil loss in key control regions in Jialing River Basin. Based on remotely sensed images, the method used in this paper is a combination of field investigation and indoor artificial interpretation under the technologies of RS and GIS. The method was proven to be effective of improving the accuracy of interpreting. The result shows the land use types of the researched regions and how they changed among the previous years. Evaluation of water and soil conservation was made. This result can provide references for further policy-making and water and soil loss controlling.
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.
作者机构：
[罗静; 郑文升; 卓蓉蓉; 余斌; 王晓芳] Key Laboratory for Geographical Process Analysis & Simulation, Hubei Province, Central China Normal University, Wuhan;430079, China;Academy of Wuhan Metropolitan Area, Hubei Development and Reform Commission & Central China Normal University, Wuhan;[罗静; 郑文升; 卓蓉蓉; 余斌; 王晓芳] 430079, China<&wdkj&>Academy of Wuhan Metropolitan Area, Hubei Development and Reform Commission & Central China Normal University, Wuhan;[罗静; 郑文升; 卓蓉蓉; 余斌; 王晓芳] 430079, China
通讯机构：
[Wang, X.] K;Key Laboratory for Geographical Process Analysis & Simulation, Hubei Province, Central China Normal University, Wuhan, China
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：
[刘目兴; 周勇; 朱亚星; 洪永胜; 夏天; 于雷] Key Laboratory for Geographical Process Analysis &, Simulation, Central China Normal University, Wuhan, Hubei Province, 430079, China;[刘目兴; 周勇; 朱亚星; 洪永胜; 夏天; 于雷] College of Urban &, Environmental Science, Central China Normal University, Wuhan, 430079, China
