作者： Du, Shiqiang;Shen, Ju;Fang, Jian*;Fang, Jiayi*;Liu, Wei;...

期刊： Environmental Science & Policy,2021年116:128-135 ISSN：1462-9011

通讯作者： Fang, Jiayi;Fang, Jian

作者机构： [Du, Shiqiang; Huang, Xiaoxuan; Shen, Ju; Wen, Jiahong] Shanghai Normal Univ, Sch Environm & Geog Sci, Shanghai 200234, Peoples R China.;[Du, Shiqiang] Vrije Univ Amsterdam, Inst Environm Studies, NL-1081 HV Amsterdam, Netherlands.;[Fang, Jiayi] East China Normal Univ, Sch Geog Sci, Key Lab Geog Informat Sci, Minist Educ, Shanghai 200241, Peoples R China.;[Fang, Jian] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Liu, Wei] Int Inst Appl Syst Anal, A-2361 Laxenburg, Austria.

通讯机构： [Fang, Jiayi] E;[Fang, Jian] C;East China Normal Univ, Sch Geog Sci, Key Lab Geog Informat Sci, Minist Educ, Shanghai 200241, Peoples R China.;Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.

关键词： Flood;Flood detention zone;Land use;Nature-based solutions;Plain restoration;Risk migration

摘要： Land resources can accommodate extra floodwaters, thus playing an important role in integrated flood risk management (FRM). However, potential conflicts emerge as the lands that are used as temporal room for floodwaters are also home to human beings, which is common in the flood detention zones (FDZs) in China. To date, little is known about how Chinese policies address the conflicts and how local stakeholders perceive the policies. This paper aims to address this research gap using a case study of the FDZs in the middle Huaihe River, China. A mixed method is applied including an official document survey, a multi-layer interview (15 respondents), and questionnaires (123 respondents). We find that three major strategies are employed to enhance the flood detention function and reduce flood risk inside the FDZs: 1) returning parts of the FDZs to rivers; 2) flood-adaptive farming; and 3) reducing population density via a massive relocation. However, the local residents have a low engagement willingness, which are associated with a poor perception of the policies and a lack of short-term economic attractiveness. Policy delivery gaps thus exist. Information sharing should be enhanced to encourage public participation. A public-private partnership involving more social and financial resources, particularly including the downstream beneficiaries, could help to increase the policy's economic feasibility. The findings can enrich a policy shift toward a more land-based FRM, particularly in developing countries. © 2020 Elsevier Ltd

语种： 英文

作者： Hong, Yongsheng;Guo, Long;Chen, Songchao;Linderman, Marc;Mouazen, Abdul M.;...

期刊： Geoderma,2020年365:114228 ISSN：0016-7061

通讯作者： Chen, Yiyun;Liu, Yaolin

作者机构： [Hong, Yongsheng; Cheng, Hang; Chen, Yiyun; Liu, Yaolin; Liu, YL; Liu, Yi; Liu, Yanfang] Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430079, Peoples R China.;[Hong, Yongsheng; Mouazen, Abdul M.] Univ Ghent, Dept Environm, Coupure Links 653, B-9000 Ghent, Belgium.;[Guo, Long] Huazhong Agr Univ, Coll Resources & Environm, Wuhan 430070, Peoples R China.;[Chen, Songchao] INRA, Unite InfoSol, F-45075 Orleans, France.;[Chen, Songchao] INRA, UMR SAS, Agrocampus, F-35042 Rennes, France.

通讯机构： [Chen, YY; Liu, YL] W;Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430079, Peoples R China.

关键词： Airborne hyperspectral image;Fractional-order derivative;Optimal band combination algorithm;Random forest;Soil organic carbon

摘要： Estimating soil organic carbon (SOC) in topsoil can help improve soil quality and food production. This study aimed to explore the potential of airborne hyperspectral image to estimate the SOC of bare topsoil at an agricultural site located in the southeast part of Iowa State, United States. To magnify the subtle spectral signals concerning SOC, and accelerate calibration and improve predictive ability, we developed a framework to combine two advanced spectral algorithms, namely, fractional-order derivative (FOD) and optimal band combination algorithm for SOC predicting. Our case was based on 49 soil samples and a scattered airborne hyperspectral image. Random forest (RF) was utilized to establish SOC estimation models by incorporating the optimal spectral indices processed by different FOD transformations on the basis of the optimal band combination algorithm. Results indicated that when the fractional order increased, overlapping peaks and baseline drifts were gradually removed. However, the magnitude of spectral strength decreased concurrently. More detailed and abundant spectral variability was captured by FOD as compared with those by original reflectance and first and second derivatives. The estimation accuracies developed from the optimal band combination algorithm (cross-validation R2, 0.36–0.66) were generally better than those from full-spectrum data (cross-validation R2, 0.32–0.54). The RF model based on the combination of 0.75-order reflectance and optimal band combination algorithm obtained the highest estimation accuracy for SOC with cross-validation R2 of 0.66. This research provides guidance for future studies in selecting the most appropriate FOD transformation to preprocess spectral data and in using the optimal band combination algorithm to determine the spectral index. Airborne hyperspectral image-based modeling can be further used to map agricultural topsoil SOC to support local-scale agricultural planning. © 2020 Elsevier B.V.

语种： 英文

作者： Luo Jing（罗静）;Chen Siyun;Sun Xuan*;Zhu Yuanyuan;Zeng Juxin;...

期刊： 地理学报：英文版,2020年30(4):515-534 ISSN：1009-637X

通讯作者： Sun Xuan

作者机构： [Luo Jing; Chen Siyun; Zhu Yuanyuan; Zeng Juxin] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan 430079, Peoples R China.;[Luo Jing; Chen Siyun; Zhu Yuanyuan; Zeng Juxin] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Luo Jing; Chen Siyun; Zhu Yuanyuan; Zeng Juxin] Cent China Normal Univ, Acad Wuhan Metropolitan Area, Hubei Prov Dev & Reform Commiss, Wuhan 430079, Peoples R China.;[Sun Xuan] Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Beijing 100101, Peoples R China.;[Chen Guangping] Zhejiang Univ, Sch Earth Sci, Hangzhou 310027, Peoples R China.

通讯机构： [Sun Xuan] C;Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Beijing 100101, Peoples R China.

关键词： city centrality;entropy weight TOPSIS;population mobility;Yangtze River Economic Belt;obstacle degree model

摘要： Based on statistical data and population flow data for 2016, and using entropy weight TOPSIS and the obstacle degree model, the centrality of cities in the Yangtze River Economic Belt (YREB) together with the factors influencing centrality were measured. In addition, data for the population flow were used to analyze the relationships between cities and to verify centrality. The results showed that: (1) The pattern of centrality conforms closely to the pole-axis theory and the central geography theory. Two axes, corresponding to the Yangtze River and the Shanghai-Kunming railway line, interconnect cities of different classes. On the whole, the downstream cities have higher centrality, well-defined gradients and better development of city infrastructure compared with cities in the middle and upper reaches. (2) The economic scale and size of the population play a fundamental role in the centrality of cities, and other factors reflect differences due to different city classes. For most of the coastal cities or the capital cities in the central and western regions, factors that require long-term development such as industrial facilities, consumption, research and education provide the main competitive advantages. For cities that are lagging behind in development, transportation facilities, construction of infrastructure and fixed asset investment have become the main methods to achieve development and enhance competitiveness. (3) The mobility of city populations has a significant correlation with the centrality score, the correlation coefficients for the relationships between population mobility and centrality are all greater than 0.86 (P<0.01). The population flow is mainly between high-class cities, or high-class and low-class cities, reflecting the high centrality and huge radiating effects of high-class cities. Furthermore, the cities in the YREB are closely linked to Guangdong and Beijing, reflecting the dominant economic status of Guangdong with its geographical proximity to the YREB and Beijing’s enormous influence as the national political and cultural center, respectively. © 2020, Science Press Springer-Verlag.

语种： 英文

作者： Chen, Songchao;Xu, Dongyun;Li, Shuo;Ji, Wenjun;Yang, Meihua;...

期刊： Land Degradation & Development,2020年31(8):1026-1038 ISSN：1085-3278

通讯作者： Shi, Zhou

作者机构： [Xu, Hanyi; Shi, Zhou; Chen, Songchao; Zhou, Yin; Xu, Dongyun; Yang, Meihua] Zhejiang Univ, Coll Environm & Resource Sci, Inst Appl Remote Sensing & Informat Technol, Hangzhou 310058, Peoples R China.;[Hu, Bifeng; Chen, Songchao] INRA, Unite InfoSol, Orleans, France.;[Chen, Songchao] INRA, SAS, Rennes, France.;[Li, Shuo] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat, Wuhan, Peoples R China.;[Ji, Wenjun] China Agr Univ, Coll Land Sci & Technol, Beijing, Peoples R China.

通讯机构： [Shi, Zhou] Z;Zhejiang Univ, Coll Environm & Resource Sci, Inst Appl Remote Sensing & Informat Technol, Hangzhou 310058, Peoples R China.

关键词： deep learning;hyperparameter optimization;proximal soil sensing;Qinghai-Tibet Plateau;soil monitoring

摘要： Soil quality in alpine ecosystems requires regular monitoring to assess its dynamics under changes in climate and land use. Visible near-infrared (vis-NIR) spectroscopy could offer an option, as sampling and transporting large numbers of soil samples in the Qinghai-Tibet Plateau is extremely difficult. However, the potential for in situ vis-NIR spectra and the optimal algorithms need to be defined in this region. We have therefore evaluated the performance of a deep learning method, multilayer perceptron (MLP), for in situ spectral measurement of soil organic carbon (SOC) with in situ vis-NIR spectroscopy in southeastern Tibet, China. A total of 39 soil cores (maximum depth 1 m), including 547 soil samples taken from each 5-cm depth interval, were collected. The spectra were also measured at each 5-cm depth interval accordingly. After spectral preprocessing, 4,096 MLP models were generated by taking all the combinations from six parameters defined in the MLP. The 10-fold-core cross-validation showed that MLP had a good performance for in situ SOC prediction, and the best MLP model had an R2 of.92, which were much better than those of the partial least squares regression model (R2 =.80). The results also suggested that the number of epochs, number of neurons, and dropout rate were the most important parameters in the MLP model. We concluded that in situ vis-NIR spectroscopy coupled with an MLP model has high potential for large-scale SOC monitoring in the Qinghai-Tibet Plateau. Our results also provide a reference for rapid hyperparameter optimization using MLP for future soil spectroscopic modeling. © 2019 John Wiley & Sons, Ltd.

语种： 英文

作者： Hong, Yongsheng;Chen, Songchao;Chen, Yiyun;Linderman, Marc;Mouazen, Abdul M.;...

期刊： SOIL & TILLAGE RESEARCH,2020年199:104589 ISSN：0167-1987

通讯作者： Liu, Yaolin;Guo, Long

作者机构： [Hong, Yongsheng; Cheng, Hang; Chen, Yiyun; Liu, Yaolin; Liu, Yanfang] Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430079, Peoples R China.;[Hong, Yongsheng; Mouazen, Abdul M.] Univ Ghent, Dept Environm, Coupure Links 653, B-9000 Ghent, Belgium.;[Chen, Songchao] INRA, Unite InfoSol, F-45075 Orleans, France.;[Chen, Songchao] INRA, UMR SAS, Agrocampus Ouest, F-35042 Rennes, France.;[Chen, Yiyun] Chinese Acad Sci, State Key Lab Soil & Sustainable Agr, Nanjing 210008, Peoples R China.

通讯机构： [Liu, YL; Guo, L] H;Huazhong Agr Univ, Wuhan Univ, Sch Resource & Environm Sci, Coll Resources & Environm, Wuhan 430070, Peoples R China.

关键词： Airborne hyperspectral imagery;Topsoil organic carbon;Feature selection;Digital soil mapping;Prediction uncertainty

摘要： Rapid monitoring of soil organic carbon (SOC) with fine sampling resolution is vital for further understanding of the global carbon cycle and sustainable management of soil resources. Proximal visible and near-infrared (Vis–NIR) spectroscopy is an effective approach to analyze SOC. However, this technique can only be used for point-to-point monitoring and not for grid pixels evenly spread throughout the area. Airborne hyperspectral imagery with high-spectral- and spatial-resolution provides a promising tool for mapping topsoil SOC at a fine scale, but suffers from the interference of some external factors. Using 45 topsoil samples collected from an agricultural field in the United States, this study aimed to compare the potential of airborne hyperspectral image in estimating and mapping of bare topsoil SOC with that derived from proximal laboratory Vis–NIR spectral data. Random forest (RF) along with two advanced feature selection algorithms, namely, continuous wavelet transform (CWT) and competitive adaptive reweighted sampling (CARS), was applied to optimize the performance of the prediction models. Results showed that laboratory and airborne spectra presented similar spectral shapes and strengths, but laboratory spectral curves were smoother than airborne spectral curves, which were noisier. Laboratory spectra (R2 = 0.79–0.87) performed better than airborne hyperspectral imagery (R2 = 0.49–0.76) in cross-validation, regardless of feature selection algorithms. The CWT-RF models resulted in the highest cross-validation results for laboratory (R2 = 0.87) and airborne (R2 = 0.76) spectra, suggesting their robustness in SOC prediction. The SOC maps retrieved from full-spectrum-RF, CWT-RF, and CARS-RF models all exhibited similar spatial distribution patterns. With airborne hyperspectral imagery serving as a valuable data source at pixel level for digital soil mapping, the methodological framework proposed in this paper could improve the accuracy and reduce the prediction uncertainty of SOC maps by selecting and adopting the optimal subset of spectral variables. © 2020 Elsevier B.V.

语种： 英文

作者： Xu, Dongyun;Chen, Songchao;Rossel, R. A. Viscarra;Biswas, Asim;Li, Shuo;...

期刊： Geoderma,2019年352:61-69 ISSN：0016-7061

通讯作者： Shi, Zhou

作者机构： [Shi, Zhou; Zhou, Yin; Xu, Dongyun] Zhejiang Univ, Coll Environm & Resource Sci, Inst Agr Remote Sensing & Informat Technol Applic, Hangzhou 310058, Zhejiang, Peoples R China.;[Chen, Songchao] INRA, Unite InfoSol, F-45075 Orleans, France.;[Rossel, R. A. Viscarra] Curtin Univ, Sch Mol & Life Sci, Bentley, WA 6102, Australia.;[Biswas, Asim] Univ Guelph, Sch Environm Sci, 50 Stone Rd, Guelph, ON N1G 2W1, Canada.;[Li, Shuo] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Hubei, Peoples R China.

通讯机构： [Shi, Zhou] Z;Zhejiang Univ, Coll Environm & Resource Sci, Inst Agr Remote Sensing & Informat Technol Applic, Hangzhou 310058, Zhejiang, Peoples R China.

关键词： Granger–Ramanathan averaging;Outer-product analysis;Proximal soil sensor;Soil spectroscopy

摘要： Anthropogenic activities, such as sewage irrigation and application of pesticides and fertilizers, are the main cause of chromium (Cr) contamination in agricultural soils. Cr contamination reduces soil quality and threatens environmental and human health. Conventional Cr measurement methods, although accurate, involve complex sample processing steps and sophisticated laboratory analysis, which are time-consuming, costly, and often environmentally unfriendly. X-ray fluorescence (XRF) and visible near-infrared (vis–NIR) spectroscopy have been recognized as alternatives to measure soil heavy metal contamination in a cheap, fast, non-destructive, and environmentally conscious manner. In this study, 301 paddy soil samples from Fuyang, Zhejiang Province, China were used to explore the feasibility and effectiveness of XRF and vis–NIR spectra separately and in combination for estimating the soil Cr content. Two strategies, including outer-product analysis (OPA) and Granger–Ramanathan averaging (GRA), were used to combine the spectra and spectral models, respectively, from the two instruments (sensor fusion). Partial least-squares regression (PLSR) was used to train the models using a single sensor (XRF or vis-NIR spectra) and OPA fused spectra. Fifty boot straps were used to assess the uncertainty of the predictions for the aforementioned models. The results indicated that XRF spectra performed better than vis–NIR spectra for predictions of Cr content, with a Lin's concordance correlation coefficient (ρc) of 0.83, a root mean square error (RMSE) of 8.80, and a ratio of prediction derivation (RPD) of 1.75. Sensor fusion by OPA gave the highest prediction accuracy with a ρc of 0.90, RMSE of 6.80, and RPD of 2.30. The sensor fusion by GRA gave similar results with a ρc of 0.88, RMSE of 7.40, and RPD of 2.13. The predictions using both methods (OPA and GRA) were acceptable when considering the standard deviation of differences (SDD = 4.23). This suggests that OPA and the GRA sensor fusion methods are efficient and accurate for rapid measurement of Cr and provide a way forward for using these technologies for fast, sensor-based soil characterization. © 2019 Elsevier B.V.

语种： 英文

作者： Hong, Yongsheng;Shen, Ruili;Cheng, Hang;Chen, Songchao;Chen, Yiyun*;...

期刊： Geoderma,2019年354:113875 ISSN：0016-7061

通讯作者： Chen, Yiyun;Liu, Yaolin

作者机构： [Hong, Yongsheng; Cheng, Hang; Chen, Yiyun; Liu, Yi; Liu, Yaolin; He, Jianhua] Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430079, Hubei, Peoples R China.;[Shen, Ruili] Hubei Acad Environm Sci, Wuhan 430072, Hubei, Peoples R China.;[Chen, Songchao] INRA, Unite InfoSol, F-45075 Orleans, France.;[Chen, Songchao] Agrocampus Ouest, INRA, UMR SAS, F-35042 Rennes, France.;[Chen, Yiyun] Chinese Acad Sci, State Key Lab Soil & Sustainable Agr, Nanjing 210008, Jiangsu, Peoples R China.

通讯机构： [Chen, YY; Liu, YL] W;Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430079, Hubei, Peoples R China.

关键词： Optimal band combination algorithm;Random forest;Soil auxiliary information;Soil Cd;Visible and near-infrared spectroscopy

摘要： The regular monitoring of soil cadmium (Cd) in peri-urban agricultural soils is critical in maintaining soil security and balancing the local environment and ecosystem. Visible and near-infrared (Vis–NIR) spectroscopy provides an alternative to soil Cd estimation. Previous studies found a mild to moderate correlation of soil Cd against soil auxiliary information, including soil organic matter (SOM), Fe, and pH. This study aimed to determine whether the combination of spectral data and soil covariates would improve the model accuracy for soil Cd estimation. We collected 93 samples from a peri-urban agricultural area of Wuhan City, Central China. The reflectance spectra, Cd concentration, and soil properties, including SOM, Fe, and pH, were measured. In addition to the original spectra, the first (FDR) and second derivative reflectance were compared to process the spectra. Estimation models were developed using random forest. In particular, we tested two spectral reduction methods, namely, principle component analysis (PCA) and optimal band combination algorithm, to derive the spectral parameters. We compared three modeling strategies for soil Cd estimation as follows: strategy I with spectral data as input variables, strategy II with soil covariates as predictors, and strategy III with the combination of strategies I and II as predictors. Results indicated that the optimal band combination algorithm outperformed PCA regardless of the spectral transformations used. The inclusion of soil covariates into the spectral data improved the model prediction for soil Cd (validation r2, 0.70–0.83) compared with the individual application of either spectral data (validation r2, 0.55–0.68) or soil covariates (validation r2 = 0.62) for modeling. The most successful prediction for soil Cd was achieved (validation r2 = 0.83) using the combination of the optimal band combination algorithm on the basis of the FDR and additional soil information, for which the sum index, difference index, product index, and SOM were identified as important predictor variables. In summary, the proposed strategy of combining Vis–NIR spectroscopy with soil auxiliary information will increase the model performance for soil Cd and can be extended to other study sites. © 2019 Elsevier B.V.

语种： 英文

作者： Chen, Shaojun;Wang, Dong*

期刊： MARINE AND FRESHWATER RESEARCH,2019年70(4):554-562 ISSN：1323-1650

通讯作者： Wang, Dong

作者机构： [Chen, Shaojun; Wang, Dong] Cent China Normal Univ, Sch Life Sci, Key Lab Geog Proc Anal & Simulat, 152 Luoyu Rd, Wuhan 430079, Hubei, Peoples R China.

通讯机构： [Wang, Dong] C;Cent China Normal Univ, Sch Life Sci, Key Lab Geog Proc Anal & Simulat, 152 Luoyu Rd, Wuhan 430079, Hubei, Peoples R China.

关键词： abundance;burial (geology);decomposition;eutrophic environment;invertebrate;lake ecosystem;macrophyte;seagrass;shallow water;species richness;vertical distribution;China;Hubei;Nanhu Lake;Wuhan;Invertebrata;Vallisneria natans

摘要： Aquatic invertebrates play an important role in plant decomposition. However, little information is available regarding the relative importance of micro-, meio- and macroinvertebrates in this process, particularly their role in the decomposition of buried organic matter. To investigate the role of these invertebrates in the decomposition of the aquatic macrophyte Vallisneria natans, leaves of V. natans were placed in litterbags with four different mesh sizes (0.025, 0.042, 0.5 and 5 mm) and the bags were either incubated at the sediment-water (SW) interface or buried at a depth of 10 cm (B10) for 60 days in Lake Nanhu, China, in July 2015. Increased mesh size significantly increased the loss of plant mass. The decomposition rate ranged from 0.0173 to 0.0467 day -1 in the SW treatment, and from 0.0083 to 0.0280 day -1 in the B10 treatment. Excluding microinvertebrates, burial significantly affected microbial respiration and invertebrate abundance. Increased mesh size increased invertebrate abundance and richness, but did not significantly affect microbial respiration in either treatment. The average contribution of micro-, meio- and macroinvertebrates and microbes to plant mass loss in the SW treatment was 23.1, 13.5, 7.0 and 56.5% respectively, compared with 19.7, 24.5, 12.3 and 43.5% respectively in the B10 treatment. The results of this study reveal the important but underestimated role of micro- and meioinvertebrates in macrophyte decomposition. © 2019 CSIRO.

语种： 英文

作者： Hong, Yongsheng;Chen, Songchao;Liu, Yaolin;Zhang, Yong;Yu, Lei;...

期刊： CATENA,2019年174:104-116 ISSN：0341-8162

通讯作者： Chen, Yiyun;Liu, Yanfang

作者机构： [Hong, Yongsheng; Chen, Yiyun; Liu, Yanfang; Cheng, Hang; Liu, Yaolin; Liu, Yi] Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430079, Hubei, Peoples R China.;[Hong, Yongsheng; Cheng, Hang; Chen, Yiyun; Liu, Yi] Chinese Acad Sci, State Key Lab Soil & Sustainable Agr, Nanjing 210008, Jiangsu, Peoples R China.;[Chen, Songchao] INRA, Unite InfoSol, F-45075 Orleans, France.;[Chen, Songchao] INRA, Agrocampus Ouest, UMR SAS, F-35042 Rennes, France.;[Zhang, Yong] Anhui Univ Finance & Econ, Sch Publ Finance & Adm, Bengbu 233030, Peoples R China.

通讯机构： [Chen, YY; Liu, YF] W;Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430079, Hubei, Peoples R China.

关键词： Visible and near infrared spectroscopy;Soil organic matter;Fractional order derivative;Local modeling;Memory-based learning

摘要： Visible and near-infrared (Vis NIR) spectroscopy is used to estimate soil organic matter (SOM). Spectral preprocessing techniques and multivariate modeling methods play important roles in the quantitative analysis of SOM. First and second derivatives (i.e., the conventional integer order derivatives) are commonly used spectral derivatives, which, however, may ignore some detailed spectral information regarding SOM. Here, we presented a fractional order derivative (FOD) method to preprocess the reflectance spectra. Robust modeling methods are still required for accurate estimation of SOM. Local modeling technique (memory-based learning, MBL) was introduced to compare with two global modeling approaches, namely, partial least square (PIS) and random forest (RF). A total of 535 topsoil samples were gathered from Hubei Province, Central China, with their reflectance spectra and SOM contents measured in the laboratory. FOD was allowed to vary from 0 to 2 with an increment of 0.25 at each step. Coefficient of determination (R-2) and ratio of the performance to deviation (RPD) were employed as performance statistics during validation. Results showed that with the increase of derivative order, the baseline drifts and overlapping peaks were gradually removed but the spectral strength decreased concurrently. Higher derivative order reflectance (i.e., 1.5-order, 1.75-order, and 2-order reflectance) were more susceptible to spectral noise interferences. The correlation coefficient of SOM with FOD processed spectra at some specific wavelengths was larger than that with the original reflectance. MBL performed better than PLS and RF, regardless of FOD transformation. Calibration with 0.25-order reflectance and MBL provided the most accurate estimation of SOM, with an RPD of 2.23. Our results confirm the effectiveness of FOD and local modeling (MBL) in the development of Vis NIR models for SOM estimation.

语种： 英文

作者： Chen, Shaojun;Wang, Dong*

期刊： Chemistry and Ecology,2019年35(7):660-677 ISSN：0275-7540

通讯作者： Wang, Dong

作者机构： [Wang, Dong] Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China;[Wang, Dong] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat, Wuhan 430079, Hubei, Peoples R China

通讯机构： [Wang, Dong] C;Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China. Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat, Wuhan 430079, Hubei, Peoples R China.

关键词： Decomposition rate;macroinvertebrates;microbes;microalgae;Vertical depth;Vallisneria natans (Lour.) Hara

摘要： Knowledge on aquatic macrophyte decomposition has well developed, yet the decomposition and associated biotic factors along a vertical gradient in waters remain less examined. Here, we used Vallianeria natans leaves to investigate the decomposition rate and associated decomposers and microalgae at different vertical depths, by placing V. natans leaves into litterbags (0.5 and 5 mm meshes) and incubating them at the air-water interface (AW), sediment-water (SW) interface, and 10 cm (B10) or 20 cm (B20) burial in sediment over 60 days in a littoral zone of lake. Decomposition rates decreased with increased depths in each mesh size, with significant differences among and between AW (0.028 d(-1)), SW (0.022 d(-1)), B10 (0.014 d(-1)) and B20 (0.011 d(-1)) treatments in 0.5 mm litterbags and no significant difference between B10 (0.027 d(-1)) and B20 (0.025 d(-1)) in 5 mm litterbags. The average contribution of macroinvertebrates to biomass loss was highest in B20 (44.66%), lowest in AW (22.66%) and midst in both SW (25.35%) and B10 (38.78%), and was much less than that of both microbes and microalgae at each location. We show the importance of macroinvertebrates, microbes and microalgae in mediating macrophyte decomposition rate in response to different vertical locations in freshwaters.

语种： 英文

作者： Chen, Shaojun;Wang, Dong*

期刊： Chemistry and Ecology,2019年35(5):431-444 ISSN：0275-7540

通讯作者： Wang, Dong

作者机构： [Chen, Shaojun; Wang, Dong] Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.;[Wang, Dong] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat, Wuhan 430079, Hubei, Peoples R China.

通讯机构： [Wang, Dong] C;Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat, Wuhan 430079, Hubei, Peoples R China.

关键词： eutrophic lake;littoral zone;Macrophyte decomposition;mass remaining;nutrient release

摘要： A leaf-bag field experiment was conducted to investigate the decomposition and release of nutrients from leaves of two aquatic macrophytes (floating-leaved Trapa bispinosa and submerged Vallisneria natans) deposited in the four vertical locations (i.e. air-water interface, AW; sediment-water interface, SW; buried at a depth of 10 cm, B10; buried at a depth of 20 cm, B20) of littoral zone in Nanhu Lake, China, for 60 days from July to August 2015. Leaf initial quality significantly influenced mass loss and nutrient release except TN (total nitrogen) remaining. Compared to V.natans, T.bispinosa leaves decomposed faster under the same treatments. The decomposition was greatly affected by both leaf chemical quality and the location of deposition. With the increasing depth of vertical locations, leaf biomass loss and nutrient release of both T.bispinosa and V.natans decreased. In addition, initial N:P ratio and cellulose were the major determinants for decomposition in AW and SW treatments while total phenol in B10 and B20. Our results suggest that the combined effect of leaf chemical quality and burial could mediate macrophyte mass loss and release of nutrients and carbon, which in turn can influence organic matter accumulation and nutrient cycling in shallow freshwater lakes. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group.

语种： 英文

作者： Hong, Yongsheng;Chen, Songchao;Zhang, Yong;Chen, Yiyun*;Yu, Lei;...

期刊： Science of The Total Environment,2018年644:1232-1243 ISSN：0048-9697

通讯作者： Chen, Yiyun;Liu, Yanfang

作者机构： [Hong, Yongsheng; Chen, Yiyun; Liu, Yanfang; Cheng, Hang; Liu, Yaolin; Liu, Yi] Wuhan Univ, Sch Resource & Environm Scrences, Wuhan 430079, Hubei, Peoples R China.;[Hong, Yongsheng; Cheng, Hang; Chen, Yiyun; Liu, Yi] Chinese Acad Sci, State Key Lab Soil & Sustainable Agr, Nanjing 210008, Jiangsu, Peoples R China.;[Chen, Songchao] INRA, Unite InfoSol, F-45075 Orleans, France.;[Chen, Songchao] INRA, UMR SAS, Agrocampus Ouest, F-35042 Rennes, France.;[Zhang, Yong] Anhui Univ Finance & Econ, Sch Publ Finance & Adm, Bengbu 233030, Peoples R China.

通讯机构： [Chen, YY; Liu, YF] W;Wuhan Univ, Sch Resource & Environm Scrences, Wuhan 430079, Hubei, Peoples R China.

关键词： Correlation coefficient;Machine learning model;Remote sensing;Soil organic matter fertility level

摘要： Accurate estimation of soil organic matter (SOM) is essential in understanding the spatial distribution of SOM to identify areas that need fertilization and the required grade of those fertilizers. Visible and near-infrared spectroscopy is a promising alternative to time consuming and costly conventional soil assessment methods. However, this approach is highly dependent on selecting suitable preprocessing strategies and data mining techniques for regression analysis. In this study, 2D correlation coefficients, including ratio, difference, and normalized difference indices, were introduced to select sensitive spectral parameters. The performance of extreme learning machine (ELM) was evaluated via comparison with that of support vector machine (SVM) for SOM estimation. A total of 257 soil samples were collected from Hubei Province, Central China, with SOM contents and reflectance spectra measured in the laboratory. Five spectral pretreatments, except for the raw spectra, were applied. SVM and ELM models were calibrated on spectral parameters selected by one-dimensional and 2D correlation coefficients and subsequently applied to predict SOM. Results showed that 2D correlation coefficient can effectively highlight the detailed SOM information compared with that of one-dimensional correlation coefficient. The ELM models yielded superior predictability relative to SVM models in all eight established models. The most excellent estimation accuracy was obtained by 2D ratio index and ELM (TRI-ELM) method, with an independent validation R-2 and a ratio of performance to interquartile range of 0.83 and 3.49, respectively. The SOM fertility levels of predicted SOM showed that TRI-ELM method presented the largest similarity to laboratory-measured SOM levels, and misclassified samples were all concentrated within one error level. In summary, our study indicates that the TRI-ELM model is a rapid, inexpensive, and relatively accurate method for identifying SOM fertility level. (c) 2018 Elsevier B.V. All rights reserved.

语种： 英文

作者： Luo, Jing（罗静）;Chen, Guangping;Li, Chang*;Xia, Bingyan;Sun, Xuan;...

期刊： International Journal of Environmental Research and Public Health,2018年15(7):1503 ISSN：1661-7827

通讯作者： Li, Chang

作者机构： [Luo, Jing; Sun, Xuan; Chen, Guangping; Xia, Bingyan; Chen, Siyun; Li, Chang] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat, 152 Luoyu Rd, Wuhan 430079, Hubei, Peoples R China.;[Luo, Jing; Sun, Xuan; Chen, Guangping; Xia, Bingyan; Chen, Siyun; Li, Chang] Cent China Normal Univ, Coll Urban & Environm Sci, 152 Luoyu Rd, Wuhan 430079, Hubei, Peoples R China.

通讯机构： [Li, Chang] C;Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat, 152 Luoyu Rd, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Coll Urban & Environm Sci, 152 Luoyu Rd, Wuhan 430079, Hubei, Peoples R China.

关键词： accessibility;aging population;elderly care;elderly population;health services;spatial analysis;threshold;travel time;urban area;accessibility of medical services for the elderly;Article;China;enhanced two step floating catchment area;geographic information system;geriatric care;health care access;health care delivery;highway;human;medical service;railway;residential care;rural area;scoring system;sensitivity analysis;spatial analysis;urban area;vulnerable population;aged;health care delivery;travel;China;Hubei;Wuhan;Aged;Catchment Area (Health);China;Health Services Accessibility;Humans;Travel

摘要： Current studies on measuring the accessibility of medical services for the elderly (AMSE) have ignored the potential competition among supply and demand and the distance decay laws. Hence, an enhanced two-step floating catchment area (E2SFCA) method (i.e., the road network-based Gaussian 2SFCA method) is proposed to calculate AMSE scores after considering different types of roads, including urban rail transit, freeways, major roads, minor roads and rural roads. Based on the first National Geographic Conditions Monitoring (NGCM) data, this study took Wuhan, China, as a case study and assessed the variation of AMSE using two different threshold times (i.e., Platinum Ten and Golden Hour). Next, global (i.e., sensitivity and hot spot analysis) and local analyses (i.e., three regional area internal comparisons) of AMSE scores were conducted to accurately identify details in the variation of spatial accessibility. It was observed that the E2SFCA method could be easily applied to measure AMSE. The results showed that 48.63% of the elderly population in Wuhan had a higher or the highest level of medical accessibility in “Platinum Ten”, while 72.97% had a higher or the highest level in the “Golden Hour”, and hot spots of AMSE scores were located in central urban areas and presented an enclosure structure using both threshold travel times, which could provide guidance to governments or planners on issues of spatial planning and identifying elderly medical services shortage areas. © 2018 by the authors. Licensee MDPI, Basel, Switzerland.

语种： 英文

作者： Hou, Jiannan;Chen, Feng*;Chen, Shujiang;Hou, Bozhan

期刊： BALTIC FORESTRY,2016年22(2):307-314 ISSN：1392-1355

通讯作者： Chen, Feng

作者机构： [Hou, Jiannan] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat, Wuhan 430079, Peoples R China.;[Hou, Jiannan; Chen, Shujiang; Hou, Bozhan] Xinjiang Normal Univ, Sch Geog & Tourism, Urumqi 830054, Peoples R China.;[Chen, Feng] China Meteorol Adm, Key Lab Tree Ring Phys & Chem Res, Xinjiang Lab Tree Ring Ecol, Inst Desert Meteorol, Urumqi 830002, Peoples R China.

通讯机构： [Chen, Feng] C;China Meteorol Adm, Key Lab Tree Ring Phys & Chem Res, Xinjiang Lab Tree Ring Ecol, Inst Desert Meteorol, Urumqi 830002, Peoples R China.

关键词： Climate response;Pinus tabuliformis;Secondary forests;The Qinling Mountains;Tree rings

摘要： In dendroclimatic studies, it is generally assumed that the relationships between the climate factor and tree-ring variations are stable over time. However, a strong age-related growth trend was found in the earlier part of the chronology and may result in time-dependent variance and climate signal changes. In this paper, the tree-ring width chronologies were developed to assess the sensitivity of young pine trees (Pinus tabuliformis) growing at moisture stressed sites in the natural secondary forests of the Qinling Mountains, China. The analysis shows that total February-June precipitation is the main factor limiting the radial growth of young pine trees within our study area. Based on the relationships derived from climate response analyses, the potential of tree-ring chro­nologies of young pine trees to provide precipitation reconstructions in the Qinling Mountains has been established. Similar with old pine trees, young trees in the natural secondary forest of the Qinling Mountains also can capture the precipitation signals accurately. These results also suggest that tree-ring data from moisture stressed sites in relatively humid environments may be regarded as proxies of drought variability. © 2016, Lietuvos Misku Institutas. All rights reserved.

语种： 英文

作者： Zhao, Hua;Yu, Lei;Huai, Zexun;Wang, Xiaohua;Ding, Guangda;...

期刊： ACTA PHYSIOLOGIAE PLANTARUM,2014年36(4):859-870 ISSN：0137-5881

通讯作者： Xu, Fangsen

作者机构： [Huai, Zexun; Wang, Xiaohua; Chen, Shuisen; Ding, Guangda; Xu, Fangsen; Zhao, Hua] Huazhong Agr Univ, Natl Key Lab Crop Genet Improvement, Wuhan 430070, Peoples R China.;[Wang, Xiaohua; Zhao, Hua] Huazhong Agr Univ, Coll Plant Sci & Technol, Wuhan 430070, Peoples R China.;[Yu, Lei] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Li, Peng] Northeast Forestry Univ, Coll Landscape Architecture, Harbin 150000, Heilongjiang, Peoples R China.

通讯机构： [Xu, Fangsen] H;Huazhong Agr Univ, Natl Key Lab Crop Genet Improvement, Wuhan 430070, Peoples R China.

关键词： Brassica napus mutant;BnChd1-1;Genetic mapping;Chlorophyll;Chloroplast

摘要： The chlorophyll-deficient mutant (Bnchd1) is a spontaneous mutant of Brassica napus. Compared with the wild type, 'Qingyou 10', Bnchd1 exhibits distinct phenotypes, including interveinal yellowing leaves at the seedling stage and light-green leaves at the bolting stage, dwarfism throughout the lifespan, extremely low seed yields and abnormally shaped and early degradation of chloroplasts. Defective chloroplasts significantly reduce the levels of pigment in Bnchd1 at the seedling and bolting stages. Genetic analysis showed that two recessive genes, designated BnChd1-1 and BnChd1-2, are responsible for the light-green phenotype. BnChd1-1 was determined to be a single Mendelian factor in a BC2F1 population based on a phenotypic segregation ratio of 1:1. BnChd1-1 was mapped to a region of A01 using a BC3F1 population of 394 individuals with 198 green and 196 light-green plants. Within the collinear region in Brassica rapa, six genes that might be involved in chloroplast thylakoid development and NDH dehydrogenase activity were annotated. Among the six candidate genes, reverse transcription-polymerase chain reaction revealed that the mRNA levels of Bra021529 and Bra040517 were undetectable in the mutant and high in Qingyou10 and Westar plants at the seedling stage. Additionally, DNA sequence differences were identified across the gene and promoter region. Protein sequence differences were also observed in Bra040517, while no sequence differences in Bra021529 were observed between Bnchd1 and Qingyou10. Therefore, the homologue of Bra040517 is the most likely candidate gene for BnChd1-1. © 2013 Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków.

语种： 英文

作者： 陈实

作者机构： 华中师范大学城市与环境科学学院武汉43007

会议名称： 中国教育学会地理教育学研究会2007年学术年会

会议时间： 2007-11-01

会议地点： 上海

会议论文集名称： 中国教育学会地理教育学研究会2007年学术年会论文集

关键词： Flash动画;地理教师;现代媒体;运用技能

摘要： 文章从新课程改革的一个侧面——提高地理教师的运用现代媒体的技能出发，主要介绍了Flash 动画的基本形式运动动画、形变动画、遮照动画及引导动画在地理教学中的运用，并举例说明了各种动画在地理教学中的制作步骤、使用效果和使用技巧。

语种： 中文

作者： 陈实

作者机构： [陈实] 华中师范大学城市与环境科学学院

会议名称： 中国地理学会2003年学术年会

会议时间： 2003-01-01

会议地点： 中国武汉

会议论文集名称： 认识地理过程 关注人类家园--中国地理学会2003年学术年会文集

摘要： <正> 教育要回归学生的生活世界。“教师不再是带着教材走向学生,而是带着学生走向现实中的地理问题”。建构主义学习理论认为,学习不仅是一种知识获得的过程,而且是一个不断丰富和建构自身的过程。它强调以学生为中心,认为“情境”、“协作’、“会话”、“意义建构”是学习活动的四大要素。本文以建构主义学习理论在中学地理教学设计中的应用研究为出发点,着重研究建构主义学习理论的教学设计模式之一——抛锚式教学设计的

语种： 中文