摘要：
A high-quality remote sensing interpretation dataset has become crucial for driving an intelligent model, i.e., deep learning (DL), to produce land-use/land-cover (LULC) products. The existing remote sensing datasets face the following issues: the current studies (1) lack object-oriented fine-grained information; (2) they cannot meet national standards; (3) they lack field surveys for labeling samples; and (4) they cannot serve for geographic engineering application directly. To address these gaps, the national-standards- and DL-oriented raster and vector benchmark dataset (RVBD) is the first to be established to map LULC for conducting soil water erosion assessment (SWEA). RVBD has the following significant innovation and contributions: (1) it is the first second-level object- and DL-oriented dataset with raster and vector data for LULC mapping; (2) its classification system conforms to the national industry standards of the Ministry of Water Resources of the People's Republic of China; (3) it has high-quality LULC interpretation accuracy assisted by field surveys rather than indoor visual interpretation; and (4) it could be applied to serve for SWEA. Our dataset is constructed as follows: (1) spatio-temporal-spectrum information is utilized to perform automatic vectorization and label LULC attributes conforming to the national standards; and (2) several remarkable DL networks (DenseNet161, HorNet, EfficientNetB7, Vision Transformer, and Swin Transformer) are chosen as the baselines to train our dataset, and five evaluation metrics are chosen to perform quantitative evaluation. Experimental results verify the reliability and effectiveness of RVBD. Each chosen network achieves a minimum overall accuracy of 0.81 and a minimum Kappa of 0.80, and Vision Transformer achieves the best classification performance with overall accuracy of 0.87 and Kappa of 0.86. It indicates that RVBD is a significant benchmark, which could lay a foundation for intelligent interpretation of relevant geographic research about SWEA in the Yangtze River Basin and promote artificial intelligence technology to enrich geographical theories and methods.
摘要：
Cadmium (Cd) contamination poses a considerable threat to human health through grain enrichment and limits biological nitrogen fixation (BNF) in paddy fields. Biochar has shown great potential for agricultural soil remediation because it inactivates Cd, but uncertainties remain as to how biochar amendments affect BNF and grain N use efficiency in paddies. To elucidate these issues, we investigated the effects of biochar amendment on the structure and function of diazotrophic bacterial communities in different rice growth stages in Cd-contaminated paddy fields, and evaluated the contribution of BNF to grain N use efficiency under biochar amendment. The results showed that biochar amendment significantly increased the abundance of diazotrophic bacteria in the tillering and jointing stages. Furthermore, the community structure of soil diazotrophic bacteria markedly changed with biochar amendment, with a significant reduction in the abundances of Euryarchaeota, Desulfobacterales (Proteobacteria), and Sphingomonadales (Bacteroidetes) in the tillering stage. Changes in the soil carbon/nitrogen (C/N) ratio was the main factor driving diazotrophic microbial community characteristics caused by the release of available C from biochar at the tillering stage, rather than the Cd. Moreover, biochar amendment increased the efficiency of BNF (especially for autotrophic N2 fixation) in the vegetative phase of rice growth. Notably, biochar amendment significantly decreased BNF efficiency during the filling stage and reduced grain N use efficiency. The limited available nutrients in biochar and the toxicity of polycyclic aromatics and phenols in biochar-derived dissolved organic matter were responsible for the varied impacts of biochar on BNF in different rice growth stages. For the first time, we report that biochar amendment in paddy soils reduces Cd toxicity but also inhibits BNF and thereby decreases N use efficiency. Therefore, before applying biochar to inactivate Cd in paddy fields, there should be a trade-off between agricultural production and ecological safety to achieve sustainable agriculture.
期刊：
Global Change Biology,2023年29(8):2203-2226 ISSN：1354-1013
通讯作者：
Linchuan Fang
作者机构：
[Liu, Ji; Fang, Linchuan; Liu, Lanfa; Zhou, Baitao] Cent China Normal Univ, Hubei Prov Key Lab Geog Proc Anal & Simulat, Wuhan, Peoples R China.;[Liu, Ji] Leibniz Inst Freshwater Ecol & Inland Fisheries, Dept Ecohydrol, Berlin, Germany.;[Fang, Linchuan; Qiu, Tianyi; He, Haoran; Cui, Qingliang] Northwest A&F Univ, Chinese Acad Sci, State Key Lab Soil Eros & Dryland Farming Loess Pl, Yangling, Shaanxi, Peoples R China.;[Sardans, Jordi; Penuelas, Josep] UAB, CSIC, Global Ecol Unit CREAF, Bellaterra, Catalonia, Spain.;[Sardans, Jordi; Penuelas, Josep] CREAF, Cerdanyola Del Valles, Catalonia, Spain.
通讯机构：
[Linchuan Fang] H;Hubei Province Key Laboratory for Geographical Process Analysis and Simulation, Central China Normal University, Wuhan, China<&wdkj&>State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Chinese Academy of Sciences, Northwest A&F University, Yangling, Shaanxi, China<&wdkj&>School of Resource and Environmental Engineering, Wuhan University of Technology, Wuhan, China
摘要：
Crop residues coupled with inorganic fertilizers balance soil ecological stoichiometry and thus improve soil carbon, nitrogen, and phosphorus sequestration. Subsequently, environmental effects are mitigated and grain yields are increased. Abstract Although soil ecological stoichiometry is constrained in natural ecosystems, its responses to anthropogenic perturbations are largely unknown. Inputs of inorganic fertilizer and crop residue are key cropland anthropogenic managements, with potential to alter their soil ecological stoichiometry. We conducted a global synthesis of 682 data pairs to quantify the responses of soil carbon (C), nitrogen (N), and phosphorus (P) and grain yields to combined inputs of crop residue plus inorganic fertilizer compared with only inorganic fertilizer application. Crop residue inputs enhance soil C (10.5%–12%), N (7.63%–9.2%), and P (2.62%–5.13%) contents, with an increase in C:N (2.51%–3.42%) and C:P (7.27%–8.00%) ratios, and grain yields (6.12%–8.64%), indicating that crop residue alleviated soil C limitation caused by inorganic fertilizer inputs alone and was able to sustain balanced stoichiometry. Moreover, the increase in soil C and C:N(P) ratio reached saturation in ~13–16 years after crop residue return, while grain yield increase trend discontinued. Furthermore, we identified that the increased C, N, and P contents and C:N(P) ratios were regulated by the initial pH and C content, and the increase in grain yield was not only related to soil properties, but also negatively related to the amount of inorganic N fertilizer input to a greater extent. Given that crop residual improvement varies with soil properties and N input levels, we propose a predictive model to preliminary evaluate the potential for crop residual improvement. Particularly, we suggest that part of the global budget should be used to subsidize crop residue input management strategies, achieving to a win‐win situation for agricultural production, ecological protection, and climate change mitigation.
期刊：
ISPRS Journal of Photogrammetry and Remote Sensing,2023年204:397-420 ISSN：0924-2716
通讯作者：
Meng, R;Zhao, F
作者机构：
[Meng, Ran; Lv, Zhengang; Zhou, Longfei; Meng, R; Huang, Zehua; Xu, Binyuan; Sun, Rui] Huazhong Agr Univ, Coll Resources & Environm, Wuhan 430070, Peoples R China.;[Zhong, Liheng] Ant Grp, Hangzhou 311121, Peoples R China.;[Zhao, Feng] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Wu, Jin] Univ Hong Kong, Sch Biol Sci, Hong Kong, Peoples R China.;[Wu, Jin] Chinese Univ Hong Kong, State Key Lab Agrobiotechnol, Shatin, Hong Kong, Peoples R China.
通讯机构：
[Zhao, F ] C;[Meng, R ] H;Huazhong Agr Univ, Coll Resources & Environm, Wuhan 430070, Peoples R China.;Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;HIT Artificial Intelligence Res Inst Co Ltd, Harbin, Heilongjiang, Peoples R China.
关键词：
Tree species mapping;Key phenological stage;Transformer;Attention mechanism;Deep learning;Plantation forests
摘要：
Plantation forests provide critical ecosystem services and have experienced worldwide expansion during the past few decades. Accurate mapping of tree species through remote sensing is critical for managing plantation forests. The typical temporal behaviors and traits of tree species in satellite image time series (SITS) generate temporal and spectral features in multiple phenological stages that are critical to improve tree species mapping. However, the diverse input features, sequential relations and complex structures in SITS drastically increase the dimension and difficulty of spectral-temporal feature extraction, which challenges the capacity of many general classifiers not explicitly adapted for spectral-temporal learning. As a result, there is still a lack of a method that could automatically extract spectral-temporal features with high separability and regional adaptability from highdimensional SITS for tree species mapping of plantation forests. Moreover, the effects of varying temporal resolution and feature combination on the plantation tree species mapping are under-explored. Here, we developed a multi-head attention-based method for automatically extracting spectral-temporal features with high separability based on a modified Transformer network (Transformer4SITS) for improved plantation tree species mapping. The end-to-end network model consists of a feature extraction module to learn deep spectral-temporal features from SITS and a fusion module to combine multiple features for improving mapping accuracy. We applied this method to two representative plantation forests in southern and northern China for tree species mapping. The results show that: (1) Transformer4SITS method could self-adaptively extract typical spectraltemporal features of key phenological stages (e.g., greenness rising and falling) from SITS, and achieved significantly improved accuracies by at most 15% in comparison with all four baseline methods (i.e., long shortterm memory, harmonic analysis, time-weighted dynamic time warping, linear discriminant analysis); (2) time series with higher temporal resolution tended to produce more accurate species maps consistently across two sites, with their overall accuracies (OA) respectively increasing from 91.05% and 84.33% (60-day) to 94.88% and 88.72% (5-day), but the effect of high temporal resolution respectively leveled off around 90-day and 50-day resolution across two sites; (3) the mapping results using all available bands and two-band spectral indices outperformed the results using a subset of them, but with only modest increase in the accuracy (i.e., OA increased from 93.63% and 86.01% to 94.88% and 88.72%. This study thus provides a state-of-the-art deep learning-based method for improved tree species mapping, which is critical for sustainable management and biodiversity monitoring of plantation forests across large scales.
作者机构：
[Han, Yong; Ni, Ruixing; Deng, Yating] Xinyang Normal Univ, Sch Geog Sci, Xinyang 464000, Peoples R China.;[Zhu, Yuanyuan; Zhu, YY] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan 430079, Peoples R China.
通讯机构：
[Zhu, YY ] C;Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan 430079, Peoples R China.
摘要：
The imbalanced regional development of higher vocational education, particularly the disparity between the supply and demand of educational resources, has emerged as the primary factor impeding the provision of high-quality higher education in China during the establishment of a universal education system. Based on the 1,482 higher vocational education institutions recognized by the Ministry of Education of China in 2021 as the research objects, the development of higher vocational education in China was explored from the perspective of supply and demand using the entropy weight TOPSIS method and coupling coordination degree model. It was found that China's higher vocational institutions were mainly located in provincial capitals, representing a point distribution pattern. From a comprehensive evaluation of the supply level, areas such as the Beijing-Tianjin-Hebei region, Yangtze River Delta, and central Henan Province have become the catchment areas for the development of higher vocational education, laying the foundation for regional network cooperation. From the perspective of educational equality, the higher vocational education in China was found to be sufficient to match the supply and demand, and a balance between supply and demand was apparent in provincial capitals. The coupling degree between supply and demand exhibited an "olive-type" spatial structure pattern, indicating that the development of higher vocational education in most cities in China is still in the transformation stage. The results provide a scientific basis for optimizing resources in the provision of higher vocational education.
作者机构：
[Fu, Yongshuo H.; Xiao, Yi] Beijing Normal Univ, Coll Water Sci, Beijing 100875, Peoples R China.;[Hao, Fanghua; Guo, Yahui; Chen, Jiahao; Nie, Xingyu; Li, Xiran; Xu, Yue; Guo, Shihui] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.
通讯机构：
[Fu, YH ] B;Beijing Normal Univ, Coll Water Sci, Beijing 100875, Peoples R China.
关键词：
High spatial resolution;Optical Satellite;Inland waters;Chlorophyll-a;Suspended sediment;Unmanned aerial vehicle (UAV)
摘要：
In recent decades, phytoplankton proliferation and sediment input to rivers (especially urban rivers) have become more dramatic under the compound pressure of climate change and human activities. Given the generally narrow width of rivers and current high spatial resolution satellites, which are limited by band settings, bandwidth, and the signal-to-noise ratio, UAVs with their exceptional spatiotemporal resolution can be used as a useful tool for river environmental monitoring and inversion uncertainty assessment. In this study, UAV-based hyperspectral (X20P) and multispectral (P4M) images, along with Sentinel-2 MultiSpectral Instrument (MSI), Landsat-8 Operational Land Imager (OLI) and Landsat-9 OLI2 data, were used to assess the uncertainty in retrieving chlorophyll-a (Chla) and suspended sediment (SS) concentrations in rivers. Chla and SS models based on UAV and satellite data were constructed using stepwise multiple regression and typical Chla and SS retrieval algorithms, respectively, and the performance of the models was the focus of our research. The results demonstrated that in the Chla concentration inversion, each sensor performed as follows: X20P > P4M > Landsat9 OLI2 > Sentinel-2 MSI > Landsat8 OLI, and the performance in the SS concentration inversion was as follows: X20P > Sentinel-2 MSI > P4M > Landsat9 OLI2 > Landsat8 OLI. In addition, the uncertainty of high spatial resolution satellite retrievals was analyzed with the assistance of the UAV-based model. Results showed that narrow bandwidths and finely tuned band settings are more essential for the Chla inversion. The typical Chla retrieval algorithm, NDCI, is only effective in certain bands (band 1 from 684 to 724 nm and band 2 from 660 to 680 nm). It is also noted that Landsat8 and Landsat9 lack some key band settings (e.g., the red-edge band of 700-710 nm), severely limiting practical application in relation to Chla. However, specific variances in different sensor bands have a relatively small impact on SS inversion, for example, the correlation between SS and the R/B (a typical SS retrieval algorithm) constructed by each sensor ranged from 0.68 to 0.77. Chla monitoring, on the other hand, necessitates a higher spatial resolution than SS monitoring. The accuracy decreased markedly when UAV images were resampled to 10 m and 30 m spatial resolution. However, it is not as crucial for the SS inversion, images with the original spatial resolution (RMSE<30cm = 6.28 mg/L) were resampled to 10 m resolution (RMSE10m = 5.85 mg/L) and 30 m resolution (RMSE30m = 4.08 mg/L) while using P4M for SS inversion, and the accuracy increased. Our results demonstrated and highlighted various options for future monitoring of Chla and SS, while exploiting the synergy between UAVs and satellites to achieve more precise observations at greater spatial and temporal scales, which will benefit aquatic environment management and protection.
作者机构：
[Li, Xiaojing] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Chen, Jing] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan 430079, Peoples R China.
通讯机构：
[Chen, J ] C;Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan 430079, Peoples R China.
关键词：
spatial spillovers;related variety;unrelated variety;regional economic resilience;the middle reaches of the Yangtze River urban agglomeration
摘要：
A growing body of literature has studied the empirical relationship between industrial diversity and economic resilience since the 2008 Great Recession. However, many existing studies are based on a nonspatial perspective, and little is known about the local or global spatial spillover effect of industrial diversity on economic resilience. This paper employs Bayesian spatial econometric methods to investigate the roles of related variety and unrelated variety on economic resilience in the middle reaches of the Yangtze River urban agglomeration, China and explores the possible local or global spatial spillover effect in the diversity-resilience relationship. The empirical results from the spatial Durbin error model estimation show that: (1) regions with high levels of related variety are economically resilient to the external shock in the postcrisis era, whereas unrelated variety has no significant direct effect on recovery resilience; (2) both related and unrelated variety have local spatial spillovers with respect to the one-year resilience of 2008-2009, but these spillovers are negligible in longer study periods. These results confirm the role of industrial relatedness and immediate neighbors in promoting regions' short-run capabilities of recovery from external economic shocks.
作者机构：
[Tian, Lingling; Han, Tingting; Tian, LL; Wang, Hafo; Luo, Jing; Gan, Yilin] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan 430079, Peoples R China.;[Tian, Lingling; Han, Tingting; Tian, LL; Wang, Hafo; Luo, Jing; Gan, Yilin] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Liu, Jianwei] Hubei Tiandiyun Geomat Technol Grp, Wuhan 430010, Peoples R China.
通讯机构：
[Tian, LL ] 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：
value realization of ecological products;capital circulation theory;path research;Zhengjiabang village
摘要：
Transforming ecological products into sources of economic value can help mitigate the tension between environmental conservation and economic growth. Using the capital cycle theory and the unique qualities of eco-friendly items, this study utilizes a case study approach, focusing on Zhengjiabang Village located in Changyang, Hubei Province. Meanwhile, we build a value realization chain of ecological products by combining the practical process of the village. On this basis, we reveal the roles of each subject and object in the evolutionary process, from ecological resources to ecological products. We also identify the key issues of eco-industrial expansion and spatial evolution. Taking the industrialization of ecological capital as the key, we add a step of value feedback to create a cycle of ecological product value realization and strengthen the sustainability of capital and industry. Ultimately, we aim to promote the transformation of ecological environmental advantages into economic advantages, and provide a new concept able to promote the construction of endogenous mechanisms for realizing the value of ecological products in rural areas.
期刊：
IEEE Transactions on Geoscience and Remote Sensing,2023年61:1-14 ISSN：0196-2892
作者机构：
[Xu, Baodong; Zhang, Zhewei; Wei, Haodong; Yang, Jingya; Cai, Zhiwen] Huazhong Agr Univ, Coll Resources & Environm, Macro Agr Res Inst, Wuhan 430070, Peoples R China.;[Wang, Cong] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Zhao, Jing; Li, Jing] Chinese Acad Sci, Jointly Sponsored Aerosp Informat Res Inst, State Key Lab Remote Sensing Sci, Beijing 100101, Peoples R China.;[Zhao, Jing; Li, Jing] Beijing Normal Univ, Beijing 100101, Peoples R China.;[Qu, Yonghua] Beijing Normal Univ, Fac Geog Sci, Inst Remote Sensing Sci & Engn, State Key Lab Remote Sensing Sci,Beijing Key Lab, Beijing 100875, Peoples R China.
关键词：
Gaofen satellites;high spatiotemporal resolution;LAINet;leaf area index (LAI);time-series reconstruction
摘要：
High spatiotemporal resolution time series of leaf area index (LAI) are essential for monitoring crop dynamics and validating coarse-resolution LAI products. The optical satellite sensors at decametric resolution have historically suffered from a long revisit cycle and cloud contamination issues that hampered the acquisition of frequent and high-quality observations. The 16-m/four-day resolution of the new-generation Gaofen-1 (GF-1) and Gaofen-6 (GF-6) satellites provide an unprecedented opportunity to address these limitations. Here, we developed an effective strategy to generate daily 16-m LAI maps combining GF-1/6 data and ground LAINet measurements. All high-quality GF-1/6 observations were utilized first to derive smoothed time series of vegetation indices (VIs). Second, a random forest regression (RF-r) model was trained to link the VIs with corresponding field LAI measurements. The trained RF-r was finally employed to generate the LAI maps. Results demonstrated the reliability of the reconstructed daily VIs (relative error (RE) < 1%) and the derived LAI time series, which greatly benefited from GF-1/6 high-frequency observations. The direct comparison with field LAI measurements by LAI-2200/LI-3000 showed the good performance of retrieved LAI maps, with bias, root mean square error (RMSE), and $R^{\mathbf {2}}$ of 0.05, 0.59, and 0.75, respectively. The LAI time series well captured the spatiotemporal variation of crop growth. Furthermore, the continuous GF-1/6 LAI maps outperformed Sentinel-2 LAI estimates both in terms of temporal frequency and accuracy. Our study indicates the potential of GF-1/6 to generate continuous decametric-resolution LAI maps for fine-scale agricultural monitoring.
作者机构：
[Zhao, Yutao; Meng, Ran; Lv, Zhengang; Zhou, Longfei; Zeng, Linglin; Huang, Zehua; Xu, Binyuan] Huazhong Agr Univ, Coll Resources & Environm, Wuhan 430070, Peoples R China.;[Yan, Jianbing; Chen, Gengshen] Huazhong Agr Univ, Natl Key Lab Crop Genet Improvement, Wuhan 430070, Peoples R China.;[Zhao, Feng] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Yan, Jianbing] Hubei Hongshan Lab, Wuhan 430070, Peoples R China.;[Meng, Ran] HIT Artificial Intelligence Res Inst Co Ltd, Harbin 150000, Peoples R China.
通讯机构：
[Ran Meng] C;College of Resources and Environment, Huazhong Agricultural University, Wuhan, China<&wdkj&>HIT Artificial Intelligence Research Institute Co., Ltd, Harbin, China
摘要：
Southern corn leaf blight (SCLB) seriously threatens corn production. The timely and accurate monitoring of SCLB conditions (e.g., detection during the asymptomatic stage and severity classification during the symptomatic stage) is valuable for precision agriculture, because the application of pesticides depends on disease conditions. Compared with time-consuming and laborious field surveys, spectroscopy is a promising tool for plant disease monitoring. The unique advantages of combining multiple spectral enhancement features for monitoring rice and wheat diseases have been recognized. However, physiological and biochemical differences between maize leaves and rice and wheat leaves, along with the specific spectral response of SCLB, are likely to affect the performance of combining multiple spectral enhancement features. In addition, similar previous studies have not combined spectral slope features, i.e., first-order spectral derivatives (FSDs), with spectral bands (SBs) and spectral indices (SIs) and wavelet features (WFs) to improve plant disease detection. Thus, the performance of a method that combines FSDs, WFs, SBs, and SIs for SCLB asymptomatic detection, symptomatic detection, and symptomatic severity classification should be evaluated further. Here, the utility of combining SBs, SIs, WFs, and FSDs was quantified and evaluated in the asymptomatic detection, symptomatic detection, and symptomatic severity classification of SCLB. Various forms of spectral enhancement features that were sensitive to SCLB infection from the asymptomatic stage to the severe stage were first identified and combined using the RELIEF-F and sequential floating forward selection algorithms on the basis of two independent inoculation experiments. Finally, SCLB asymptomatic detection, symptomatic detection, and symptomatic severity classification models were developed and evaluated using the support vector machine algorithm. Results showed that combining FSDs with SBs, SIs, and WFs achieved the best performance in SCLB spectroscopic monitoring. (1) SCLB asymptomatic detection and symptomatic detection were moderately improved, i.e., overall accuracy (OA) and macro F1 (MF1) improved by similar to 1% to 2%. The OA of SCLB asymptomatic detection was 87.1% with an MF1 of 0.87, and that of symptomatic detection was 93.1% with an MF1 of 0.93. (2) SCLB symptomatic severity classification was significantly improved, i.e., OA and MF1 improved by similar to 7%. The OA of severity classification was 81.8% with am MF1 of 0.82. This study demonstrated that the complementary relationships among SBs, SIs, WFs, and FSDs could effectively improve SCLB spectroscopic monitoring. The proposed method provides a novel tool for large-scale SCLB spectroscopic monitoring. It has broad implications for assisting management decisions (i.e., when and where to apply pesticides and how much to apply) in precision agriculture.
关键词：
Ice albedo;data harmonization;spatial window size;validation;arctic and alpine;Google Earth Engine
摘要：
Albedo plays a key role in regulating the absorption of solar radiation within ice surfaces and hence strongly regulates the production of meltwater. A combination of Landsat and Sentinel 2 data provides the longest continuous medium resolution (10-30 m) earth surface observatory records. An albedo product (harmonized satellite albedo, hereafter HSA) has already been developed and validated for the Greenland Ice Sheet (GrIS), using harmonized Landsat 4-8 and Sentinel 2 datasets. In this paper, the HSA was validated for various Arctic and alpine glaciers and ice caps using in situ measurements. We determine the optimal spatial window size in point-to-pixel analysis, the best practices in evaluating remote sensing algorithms with groundtruth data, and cross sensor comparison of the Landsat 9 (L9) and Landsat 8 (L8) data. The impact of the spatial window size on measured ice surface homogeneity and albedo validation was analysed at both local and regional scales. Homogeneity statistics calculated from the grey-level co-occurrence matrix (GLCM) suggest that the ice surface becomes more homogeneous as the image resolution becomes coarser. The optimal spatial window size was found to be 90 m, based on maximizing the statistical and graphical measures while minimizing the root mean square error and bias. HSAs generally agree closely with in situ albedo measurements (e.g. Pearson's R ranges from 0.68 to 0.92) across various Arctic and alpine glaciers and ice caps. Cross sensor differences between L9 and L8 are minor, and we suggest that no harmonization is necessary to add L9 to our HSA product.
作者机构：
[Zheng, Wensheng; Xiong, Yajun; Wang, Xuzheng; Wang, Xiaofang; Zhou, Ying] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Zheng, Wensheng; Wang, Xiaofang] China Tourism Acad, Wuhan Branch, Wuhan 430079, Peoples R China.;[Zheng, Wensheng] Cent China Normal Univ, Hubei High qual Dev Inst, Wuhan 430079, Peoples R China.
通讯机构：
[Wensheng Zheng] C;College of Urban and Environment Science, Central China Normal University, Wuhan, China<&wdkj&>Wuhan Branch of China Tourism Academy, Wuhan, China<&wdkj&>Hubei High-quality Development Institute, Central China Normal University, Wuhan, China
期刊：
Journal of Soil Science and Plant Nutrition,2023年23(4):6813-6826 ISSN：0718-9508
通讯作者：
Yi, Jun;Zhang, HL
作者机构：
[Zhang, HL; Li, Shenglong; Nan, Xin; Liu, Muxing; Yi, Jun; Yi, J; Fei, Yuanhang; Xu, Tianxiang; Nie, Hanjiang; Hu, Kang; Ren, Qian; Zhang, Hailin] Cent China Normal Univ, Hubei Prov Key Lab Geog Proc Anal & Simulat, Wuhan 430079, Peoples R China.;[Liu, Xiaoli] Chinese Acad Sci, Inst Soil Sci, Nanjing 210008, Peoples R China.
通讯机构：
[Yi, J; Zhang, HL ] C;Cent China Normal Univ, Hubei Prov Key Lab Geog Proc Anal & Simulat, Wuhan 430079, Peoples R China.
关键词：
Soil Moisture;Rainfall;Land use Types;Soil Properties;Soil Water Storage
摘要：
Purpose Studying the response of soil moisture (theta) to rainfall is highly significant for comprehending water transport and balance. Nevertheless, the response of theta to rainfall in pristine forest land and farmland after forest reclamation in the Chinese red soil region is rarely compared.Methods In this study, the theta dynamics and the response characteristics of theta to rainfall in upland field (UF), paddy field (PF), and forest land (FL) were revealed, with continuous and high-frequency theta monitoring data at 5, 10, 20, 40, and 70 cm depths, respectively.Results The results showed that the average theta in PF (0.418 cm(3) cm(-3)) was much higher than that in UF (0.317 cm(3) cm(-3)) and FL (0.291 cm(3) cm(-3)). Meanwhile, the longest lag time (16.8 h) and largest required rainfall amount (16.4 mm) for triggering theta response (RRSR) were observed in FL as compared with UF (11.3 h, 10.2 mm) and PF (12.6 h, 8.7 mm). The maximum increment of theta was significantly positively correlated with the rainfall amount (P < 0.01). The RRSR exhibited significant negative correlations with root density, saturated hydraulic conductivities, and the soil pores content with a diameter > 0.1 mm (P < 0.01). Furthermore, the cumulative increment of soil water storage in FL (190.1 mm) was larger than that in UF (160.6 mm) and PF (143.8 mm).Conclusions The land use conversion from FL to UF and PF reduced the rainfall infiltration capacity and may increase runoff potential.
摘要：
Promoting ratoon rice is a critical measure for ensuring food security in China. Understanding the mechanism underlying farmers' decision-making involving ratoon rice production may contribute to the design and implementation of extension policies. This study examined the impact of off-farm employment and outsourced machinery services on farmers' ratoon rice production behavior. We used a representative household survey of 1752 rice farmers in Hubei province in central China and a multinomial endogenous treatment effect model to address potential self-selection biases from both observable and unobservable factors. Our estimates suggest that the probability of ratoon rice production decreases by 17.2% for farmers with off-farm employment, while the probability of ratoon rice production increases by 78.9% and 57% for farmers with outsourced machinery services and those with simultaneous off-farm employment and outsourced machinery services, respectively. Moreover, we found that outsourced machinery services can mitigate the negative impact of agricultural labor aging and feminization on ratoon rice production to some extent. Outsourced machinery services have regional heterogeneity effects as farmers in non-plain areas are more likely to engage in ratoon rice production.
期刊：
Journal of Environmental Management,2023年327:116880 ISSN：0301-4797
通讯作者：
Guangming Yu
作者机构：
[Gu, Yinxue; Xu, Lili; Zhang, Chenlei; Chen, Xiaoxu; Yu, Guangming; Tu, Zhenfa] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Yu, Guangming] Kashi Univ, Coll Life & Geog Sci, Kashi 844000, Peoples R China.;[Xu, Lili; Tu, Zhenfa] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan 430079, Peoples R China.;[Yang, Jian] Hubei Univ Arts & Sci, Fac Resource Environm & Tourism, Xiangyang 441053, Peoples R China.
通讯机构：
[Guangming Yu] C;College of Urban and Environmental Sciences, Central China Normal University, Wuhan, 430079, China<&wdkj&>College of Life and Geographic Sciences, Kashi University, Kashi, 844000, China
关键词：
Citizen water use;Han river basin;SHRD model;Water accessibility;Water price
摘要：
Water resource, with properties of scarcity, is one of the vital resource endowments. Like land resources, the prices of these resource endowments should be correlated to their locations to follow fair and reasonable principles. The current water price systems are mainly policy-oriented fixed regimes. And the water use was charged according to the regional-average situation with scarce consideration of the fine-scale geographical water accessibility. With a combination of the water accessibility and the current water pricing regime, this paper first proposed a novel water pricing model, the Water Price at Grid-scale (WPG) model, to dynamically allocate water prices to fine grids for urban residents. The WPG model was examined in the case study of the Han River Basin in the Hubei province of China. The specific results were: (1) the P(grid) of Tier I is between 0.66 and 3.94 yuan/m³, the P(grid) of Tier II is between 0.57 and 5.44 yuan/m³, and the P(grid) of Tier III is between 0.47 and 6.94 yuan/m³ in the study area. (2) the grids with more water acquisition generally have lower water prices than others and vice versa. (3) the average water prices in tiers obtained by the WPG model are generally higher than that derived from the current water pricing system. The results proved that the proposed WPG model spatially allocates the three-tier water prices into grids of urban areas. The WPG framework can be adopted in any society by involving its water price regimes and adjusting the scale of grids and the pricing year. This study provided a new viewpoint of domestic water pricing involving fine-scale water accessibility. The WPG model has great potential to ease water shortage pressure in water-limited societies and can be utilized and loaded into the current smart-city network for efficient and fine-scale water resource management.
摘要：
Extracting crop phenophases from satellite remote sensing data is crucial for managing agricultural activities and estimating crop yield over large scales. The traditional Vegetation Indices (VIs), such as the Enhanced Vegetation Index (EVI) and Normalized Difference Vegetation Index (NDVI), primarily indicate changes in vegetation greenness, which characterize crop phenophases well in vegetative growth period but may be difficult to associate with phenophases in reproductive growth period that are more related with physiology status. In this study, we investigated the potential of the satellite Solar-Induced chlorophyll Fluorescence (SIF) on extracting the crop phenophases in reproductive growth period, i.e., milk-ripe phase and maturity phase, using single-season cropland in mid-temperate zone in China as a test bed. We found that SIF outperformed EVI and NDVI in extracting milk-ripe phase and maturity phase of maize, rice and wheat using double logistic method. In particular, SIF-derived maturity phase were closer to field-observed phenophases (Mean Bias = 0.73 days) with higher R2 (0.87) than that from EVI and NDVI. At a regional scale, the milk-ripe phase and maturity phase were observed from August to mid-September, and from mid-September to mid-October, respectively, which varied with crop types and in spatial distribution. Out of all crops in mid-temperate zone in China, 65% experienced a delay in the milk-ripe phase, whereas 77% exhibited a delay in the maturity phase from 2001 to 2019. In addition to the adjustment of human managements under climate warming, we further found that crop phenophases in reproductive growth period exhibited the strongest correlation with preseason water-related environmental variables, particularly vapor pressure deficit and total precipitation. This work highlighted the potential of satellite SIF in identifying the crop-specific milk-ripe and maturity phases, and improving our understanding for spatio-temporal variations of crop phenophases in reproductive growth period as well as their responses to preseason environmental variables, which will in turn promote SIF applications in agriculture.
作者机构：
[Fang, Jian; Tao, Kai] Cent China Normal Univ, Key Lab Geog Proc Anal & Simulat Hubei Prov, Wuhan 430079, Peoples R China.;[Fang, Jian; Tao, Kai] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Yang, Wentao] Beijing Forestry Univ, Sch Soil & Water Conservat, Beijing 100083, Peoples R China.;[Fang, Jiayi] Hangzhou Normal Univ, Inst Remote Sensing & Earth Sci, Sch Informat Sci & Technol, Hangzhou 311121, Peoples R China.;[Fang, Jiayi] Hangzhou Normal Univ, Zhejiang Prov Key Lab Urban Wetlands & Reg Change, Hangzhou 311121, Peoples R China.
关键词：
Flood;Compound event;Extreme precipitation;Middle Yangtze River
摘要：
The potential damages of flood would be magnified by the compounding effect of local heavy rainfall and extreme river flow from upstream/downstream, which has brought significant challenges to traditional flood risk management. To better understand the risk of these compound extreme events, we used the latest datasets to characterize compound inland floods in the middle Yangtze River region. The frequency, intensity, duration, timing, and dependence of the compound events from heavy rainfall in Wuhan and upstream–downstream floods in the Dongting Lake and Poyang Lake Basin were investigated from 1980 to 2020. In addition, we explored the effects of different compounding scenarios and discussed the synoptic and topographic conditions for these events. The results show that the frequency, intensity, and duration of all compound events had increased significantly after 2004; the occurrence time of most compound events had become more concentrated and advanced slightly in 2004–2020. Significantly positive correlation between extreme precipitation and corresponding upstream river flow and downstream water level were found, and the correlation became stronger in 2004–2020. The favorable synoptic and topographic conditions in this area make it prone to compound floods, and the influence from the concurrence with downstream flood was more profound than the concurrence with upstream flood. Higher risk of compound floods could be expected, given the increase in the drivers and their dependence in future, highlighting the necessity of more comprehensive study toward the mechanism, dynamics and risk of compound floods and more systematic strategies for flood risk management.
摘要：
Exploring the utilization effect of water-land resources under the evolution of dietary patterns is of great significance in achieving sustainable global food consumption and the effective allocation of national resources. Our selected study area was China, a country with rapidly changing dietary consumption patterns, and the research period was between 1987 and 2020. Based on the material called Chinese Dietary Guidelines 2021, this study introduced the "virtual water" and the "virtual land" to quantify the utilization effect of water-land resources under the evolution of Chinese dietary patterns. Results showed that the dietary patterns gradually changed from "cereal-vegetable-based consumption" to "diversified consumption". Food consumption's total water footprint (WF) increased from 471.1 Gm(3) in 1987 to 848.8 Gm(3) in 2020, with a growth rate of 80.2%. Moreover, the total land requirement for food (LRF) increased from 88.8 Mha in 1987 to 129.9 Mha in 2020, with a growth rate of 46.3%. Furthermore, the meat consumption was the major contributor to the increase in total WF (104.0%) and LRF (102.1%). In contrast to the balanced diet pattern, there was no waste of water-land resources consumption for the food consumption of urban-rural residents in China between 1987 and 2020. However, the consumption of water resources would gradually approach the resource cost under the balanced diet patterns. It would eventually break through the critical value and reach the state of resource waste. In addition, the findings showed that urban residents' waste rate of water-land resources for meat consumption increased by 142.3% compared with that in 1987. The research results can provide scientific guidance for resolving the food crisis under the supply of water-land resources in China and have an essential reference for national food security and sustainable development of resources and environment.
