期刊：
Journal of Hydrology: Regional Studies,2024年52:101690 ISSN：2214-5818
通讯作者：
Zhang, XP
作者机构：
[Xiao, Xiong; Rao, Zhiguo; Li, Jiajie; Zhang, Xinping; Dai, Junjie; He, Xinguang; Zhang, Cicheng] Hunan Normal Univ, Coll Geog Sci, Changsha, Peoples R China.;[Xiao, Xiong; He, Xinguang; Zhang, Xinping] Hunan Normal Univ, Key Lab Geospatial Big Data Min & Applicat Hunan P, Changsha, Peoples R China.;[Liu, Na] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang, Hunan, Peoples R China.
通讯机构：
[Zhang, XP ] H;Hunan Normal Univ, Coll Geog Sci, Changsha, Peoples R China.
关键词：
Stable isotopes;Seasonal origin index;Xylem water;Leaf water;Soil water
摘要：
Study region: From 2017 to 2019, xylem and leaf samples of Cinnamomum camphora were sampled and soil water samples at 0-100 cm depth were sampled 65 times simultaneously in a typical East Asian monsoon region. Study focus: The seasonal origin of plant and soil water from precipitation was inferred based on the stable isotope techniques, including the evaporation line slope (SEL) estimations and the seasonal origin index (SOI) calculation. New hydrological insights for the region: The regression SEL of leaf water was close to the theoretical SELs estimated based on the Craig-Gordon model, but xylem water and soil water showed higher regression SELs than the theoretical SELs, this may be due to the seasonality of the precipitation isotopes and evaporative fractionation. The fractionation-compensated isotopic values calculated based on the theoretical SELs of different water types were close, with the differences within 2.4%o for 618O and 20.0%o for 62H of each other, and the uncertainty of the fractionationcompensated isotopic values was low enough in the calculation of SOI. The SOI results showed that summer precipitation was more prevalent in plant and soil water, and more winter precipitation may recharge runoff when evapotranspiration demand is weak. Overall, the leaf sampling and the theoretical method have the potential to infer the seasonal water origin over a relatively long period.
通讯机构：
[Feng, C ] H;Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.
关键词：
Event-based extreme precipitation;Time distribution pattern;Contribution rate of urbanization;Xiangjiang River Basin
摘要：
An in-depth understanding of event-based extreme precipitation (EEP), emphasizing precipitation process, can help to prevent the risk posed by regional high-intensity and persistent precipitation. The concept of time distribution pattern (TDP) is used to distinguish EEPs, which classifies EEPs according to the occurrence time of extreme precipitation. Furthermore, TDP1,2,3 is that the distribution of daily precipitation above the threshold is in the first half, in the second half, and both the first half and second half of EEP, respectively. We analyze temporal characteristics, spatial distribution, future trends of EEP, and the contribution rate of urbanization to EEP in this study. EEP thresholds exhibit a latitudinal gradient from central to northern and southern regions except for Nanyue Station (NY). TDP1 and TDP2 account for more than 60% among the total of EEPs. However, TDP3 is the dominant precipitation type observed at each station from the perspective of precipitation, intensity, duration, especially, in summer. EEP is less and TDP is unstable in autumn and winter. In general, there is an increasing trend in EEP and it is predicted that the trend of EEP will continue to rise. Moreover, the contribution rate of urbanization to EEP varies significantly, with a more pronounced inhibitory effect observed. The inhibitory effect of urbanization on the frequency and duration of TDP3 reached 60.83% and 72.77%, respectively. However, it is more significant on the extreme nature of TDP1 under urbanization, with a positive contribution rate of 9.63% and 21.83% to precipitation and intensity of TDP1, respectively. The results conclude that the higher the level of urbanization, the more pronounced the extreme trend of TDP1 becomes.
摘要：
The accurate estimation of forest aboveground biomass is of great significance for forest management and carbon balance monitoring. Remote sensing instruments have been widely applied in forest parameters inversion with wide coverage and high spatiotemporal resolution. In this paper, the capability of different remote-sensed imagery was investigated, including multispectral images (GaoFen-6, Sentinel-2 and Landsat-8) and various SAR (Synthetic Aperture Radar) data (GaoFen-3, Sentinel-1, ALOS-2), in aboveground forest biomass estimation. In particular, based on the forest inventory data of Hangzhou in China, the Random Forest (RF), Convolutional Neural Network (CNN) and Convolutional Neural Networks Long Short-Term Memory Networks (CNN-LSTM) algorithms were deployed to construct the forest biomass estimation models, respectively. The estimate accuracies were evaluated under the different configurations of images and methods. The results show that for the SAR data, ALOS-2 has a higher biomass estimation accuracy than the GaoFen-3 and Sentinel-1. Moreover, the GaoFen-6 data is slightly worse than Sentinel-2 and Landsat-8 optical data in biomass estimation. In contrast with the single source, integrating multisource data can effectively enhance accuracy, with improvements ranging from 5% to 10%. The CNN-LSTM generally performs better than CNN and RF, regardless of the data used. The combination of CNN-LSTM and multisource data provided the best results in this case and can achieve the maximum R2 value of up to 0.74. It was found that the majority of the biomass values in the study area in 2018 ranged from 60 to 90 Mg/ha, with an average value of 64.20 Mg/ha.
作者机构：
[Hu, Yong; Fu, Jing; Liu, Jianxiong; Yang, Liguo; Deng, Yunyuan; Su, Baoling] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang, Hunan, Peoples R China.;[Fu, Jing; Yang, Liguo; Deng, Yunyuan] Hengyang Normal Univ, Hunan Natl Local Joint Engn Lab Digital Preservat, Hengyang, Hunan, Peoples R China.;[Fu, Jing; Qin, Jianxin] Hunan Normal Univ, Hunan Key Lab Geospatial Big Data Min & Applicat, Changsha, Hunan, Peoples R China.;[Fu, Jing; Yang, Liguo; Deng, Yunyuan] UNESCO, Int Ctr Space Technol Nat & Cultural Heritage HIST, Hengyang Base, Hengyang, Hunan, Peoples R China.;[Zhang, Zhongbo] Hunan Weather Modificat Off, Changsha, Hunan, Peoples R China.
通讯机构：
[Fu, J ] H;Hengyang Normal Univ, Coll Geog & Tourism, Hengyang, Hunan, Peoples R China.;Hengyang Normal Univ, Hunan Natl Local Joint Engn Lab Digital Preservat, Hengyang, Hunan, Peoples R China.;Hunan Normal Univ, Hunan Key Lab Geospatial Big Data Min & Applicat, Changsha, Hunan, Peoples R China.;UNESCO, Int Ctr Space Technol Nat & Cultural Heritage HIST, Hengyang Base, Hengyang, Hunan, Peoples R China.
摘要：
Abstract Vegetation plays a crucial role in nature, with intricate interactions between it and the geographical environment. The Yangtze River Basin (YRB) refers to the third largest river basin globally and an essential ecological security barrier in China. Monitoring vegetation dynamics in the basin is of profound significance for addressing climate change, soil erosion, and biodiversity loss in the basin's ecosystems. Here, we investigate the spatiotemporal variations of vegetation at both the basin and land cover scales in the YRB from 2000 to 2020. We elucidate the determinants driving the changes and explore future normalized difference vegetation index (NDVI) trends. The results indicate that NDVI in the YRB increased at a rate of 0.0032 year−1 (p < 0.01) over the past 21 years, and it is anticipated to maintain an upward trend in the future. Regions in the upper and middle reaches of the YRB demonstrated higher NDVI, whereas regions in the headwater area and the lower reaches showed lower NDVI. Significant vegetation improvement was primarily concentrated in the central part of the basin, while noticeable vegetation degradation was observed in the eastern region. Temperature and wind speed were identified as the primary controlling factors affecting vegetation greenness. Global‐scale climate oscillations played a significant role in driving periodic variations in NDVI, with La Niña events tending to increase NDVI, while El Niño events hindered its rise. Land cover types were influenced by long‐term interactions between natural factors and human activities, although short‐term vegetation variations might be more affected by the latter. Our findings provide valuable insights into the mechanisms behind vegetation variability driven by multiple variables, and the strong vegetation carbon sink capacity advances the conservation and development of ecosystems.
作者机构：
[Li, Suxun] Changan Univ, Sch Earth Sci & Resources, Xian 710054, Peoples R China.;[Feng, Chang; Yang, Liu; Li, Suxun] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.;[Feng, C] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.
通讯机构：
[Feng, C ] ;Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.
关键词：
driving factors;evapotranspiration;MODIS;spatiotemporal patterns;standard deviation ellipse;Xiangjiang River Basin
摘要：
Evapotranspiration (ET) is a crucial parameter in the process of the hydrological cycle. It is of great significance for water resource management and the improvement of ecological systems in the Xiangjiang River Basin (XRB) to explore the spatial and temporal dynamic characteristics of ET. Based on MOD16, this study revealed the characteristics of spatial and temporal patterns of ET in the XRB from 2000 to 2020. We first applied land use data and change rate for overall trend analysis on ET. Then, we obtained spatiotemporal migration routes of ET through standard deviation ellipse (SDE). Furthermore, we demonstrated the effects of monsoon and urban expansion on ET change. Accordingly, we observed the following novel spatiotemporal patterns of ET: (1) while the ET of artificial surfaces decreased from 2000 to 2020, the change rate in most regions of the XRB was 8.83%, indicating that the overall trend of ET in the XRB was increasing. (2) At 10-year intervals, the SDE center of ET all migrated in a clockwise direction. (3) The correlation between precipitation and ET is more obvious than that between temperature and ET. (4) With the direct effects of monsoon on precipitation in East Asia, we found that the changes in precipitation are consistent with the ET change.
作者机构：
[Deng, Zhiwei; Quan, Bin] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.;[Quan, Bin] Hengyang Base Int Ctr Space Technol Nat & Cultural, Hengyang 421002, Peoples R China.
通讯机构：
[Quan, B ] H;Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.;Hengyang Base Int Ctr Space Technol Nat & Cultural, Hengyang 421002, Peoples R China.
关键词：
land use and land cover change;Intensity Analysis;change detection;Chang-Zhu-Tan Metropolitan Region
摘要：
In this study, two hybrid residual deep learning models coupled with physical knowledge are proposed for improving daily transpiration (Ec) estimation. A Hybrid-Physics-Data-Residual Learning (HPDRL) model is constructed by mixing a Hybrid-Physics-Data (HPD) model with a Physics-based Residual Learning (PRL) model. To this purpose, the HPD model is first formed by adding a complementary physical variable (EcPHY), which is generated by a recently presented physics-based Ec model (hereafter "BTA-& psi;"), to a deep learning (DL) model along with driving variables to regress Ec. Then, the PRL model is developed by using the residual learning method to integrate the BTA-& psi; and DL models. Three hybrid models, HPD, PRL, and HPDRL, are used to estimate daily Ec for the three species of trees and compared with two baseline models, the BTA-& psi; and pure DL models. The results show that the PRL and HPDRL models benefit from the integration of the BTA-& psi; and DL models via the residual learning method, and thus effectively improve daily Ec estimation. In contrast, the HPD model, limited by the flawed physics-based BTA-& psi; model, exhibits the weakest estimation skill among all three hybrid models. Moreover, the HPDRL model further exhibits better generalization capability than the PRL and pure DL models. Although both hybrid residual learning models can capture the range between the minimum and maximum observed Ec more completely than the pure DL model, the HPDRL model extrapolates better than the PRL model in unseen scenarios with limited training samples.
关键词：
western North Pacific summer monsoon;tropical central-western Pacific;SST;interdecadal change
摘要：
This study reveals the strengthened interdecadal relationship between the western North Pacific summer monsoon (WNPSM) and tropical central-western Pacific sea surface temperature anomaly (SSTA) in summer after the early 1990s. In the first period (1979-91, P1), the WNPSM-related precipitation anomaly and horizontal wind anomaly present themselves as an analogous Pacific-Japan (PJ)-like pattern, generally considered to be related to the Nino-3 index in the preceding winter. During the subsequent period (1994-2019, P2), the WNPSM-related precipitation anomaly presents a zonal dipole pattern, correlated significantly with the concurrent SSTA in the Nino-4 and tropical western Pacific regions. The negative (positive) SSTA in the tropical western Pacific and positive (negative) SSTA in the Nino-4 region, could work together to influence the WNPSM, noting that the two types of anomalous SSTA configurations enhance (weaken) the WNPSM by the positive (negative) phase PJ-like wave and Gill response, respectively, with an anomalous cyclone (anticyclone) located in the WNPSM, which shows obvious symmetry about the anomalous circulation. Specifically, the SSTA in Nino-4 impacts the WNPSM by an atmospheric Gill response, with a stronger (weaker) WNPSM along with a positive (negative) SSTA in the Nino-4 region. Furthermore, the SSTA in the tropical western Pacific exerts an influence on the WNPSM by a PJ-like wave, with a stronger (weaker) WNPSM along with a negative (positive) SSTA in the tropical western Pacific. In general, SSTAs in the tropical western Pacific and Nino-4 areas could work together to exert influence on the WNPSM, with the effect most likely to occur in the El Nino (La Nina) developing year in P2. However, the SSTAs in the tropical western Pacific worked alone to exert an influence on the WNPSM mainly in 2013, 2014, 2016, and 2017, and the SSTAs in the Nino-4 region worked alone to exert an influence on the WNPSM mainly in Central Pacific (CP) La Nina developing years. The sensitivity experiments also can reproduce the PJ-like wave/Gill response associated with SSTA in the tropical western Pacific/Nino-4 regions. Therefore, the respective and synergistic impacts from the Nino-4 region and the tropical western Pacific on the WNPSM have been revealed, which helps us to acquire a better understanding of the interdecadal variations of the WNPSM and its associated climate influences.
作者机构：
[Zhou, Jialu; Wang, Cheng] Yunnan Normal Univ, Fac Geog, Kunming, Peoples R China.;[Zhou, Jialu; Nie, Sheng; Wang, Cheng] Int Res Ctr Big Data Sustainable Dev Goals, Beijing, Peoples R China.;[Zhou, Jialu; Nie, Sheng; Wang, Cheng] Chinese Acad Sci, Aerosp Informat Res Inst, Key Lab Digital Earth Sci, Beijing, Peoples R China.;[Zheng, Wenwu; Deng, Yunyuan; Fu, Jing] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang, Peoples R China.;[Sun, Yue] Natl Forestry & Grassland Adm, East China Survey & Planning Inst, Hangzhou, Peoples R China.
通讯机构：
[Nie, S ] I;Int Res Ctr Big Data Sustainable Dev Goals, Beijing 100094, Peoples R China.;Chinese Acad Sci, Aerosp Informat Res Inst, Key Lab Digital Earth Sci, Beijing 100094, Peoples R China.
关键词：
Forest height;terrain height;ICESat-2;space-borne LiDAR;photon-counting;leaf-on and leaf-off
摘要：
Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) provides effective photon-counting light detection and ranging (LiDAR) data for estimating forest height across extensive geographical areas. Although prior studies have illustrated canopy conditions during leaf-on and leaf-off phases may influence ICESat-2 derived forest heights, a comprehensive understanding of this effect remains incomplete. This study seeks to comprehensively assess how varying canopy conditions (leaf-on/leaf-off) affect ICESat-2 forest height retrieval and modelling. First, the accuracies of ICESat-2 terrain and canopy heights under leaf-on and leaf-off conditions were validated. Second, random forest algorithm was utilized to model forest height by integrating ICESat-2, Sentinel-2, and other ancillary datasets. Finally, we evaluated the influence of leaf-on and leaf-off conditions on forest height retrieval and modelling. Results reveal higher consistency between ICESat-2 and airborne LiDAR-derived terrain heights compared to the agreement between two canopy height datasets. Accuracies of ICESat-2 terrain and canopy heights are higher under leaf-off conditions in contrast to leaf-on conditions. Notably, the accuracies of ICESat-2 terrain and canopy heights under various conditions are closely linked to canopy cover. Furthermore, the accuracy of forest height modelling can be enhanced by combining ICESat-2 data collected during both leaf-on and leaf-off seasons with further eliminating low-quality samples.
作者机构：
[Guo, Binbin; Dai, Zhong; Yang, Qin; Deng, Yunyuan; Zou, Jun] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.;[Xu, Tingbao] Australian Natl Univ, Fenner Sch Environm & Soc, Canberra, ACT 2601, Australia.;[Yang, Qin] China Univ Geosci, Sch Informat Engn, Beijing 100083, Peoples R China.;[Zhang, Jing] Capital Normal Univ, Beijing Lab Water Resources Secur, Beijing 100048, Peoples R China.;[Dai, Zhong] Int Ctr Space Technol Nat & Cultural Heritage HIST, Hengyang Base, Hengyang 421002, Peoples R China.
通讯机构：
[Binbin Guo] C;College of Geography and Tourism, Hengyang Normal University, Hengyang 421002, China<&wdkj&>Author to whom correspondence should be addressed.
关键词：
precipitation;satellite observation;evaluation;hydrologic modelling;Xiangjiang River basin
摘要：
Satellite precipitation products (SPPs) have emerged as an important information source of precipitation with high spatio-temporal resolutions, with great potential to improve catchment water resource management and hydrologic modelling, especially in data-sparse regions. As an indirect precipitation measurement, satellite-derived precipitation accuracy is of major concern. There have been numerous evaluation/validation studies worldwide. However, a convincing systematic evaluation/validation of satellite precipitation remains unrealized. In particular, there are still only a limited number of hydrologic evaluations/validations with a long temporal period. Here we present a systematic evaluation of eight popular SPPs (CHIRPS, CMORPH, GPCP, GPM, GSMaP, MSWEP, PERSIANN, and SM2RAIN). The evaluation area used, using daily data from 2007 to 2020, is the Xiangjiang River basin, a mountainous catchment with a humid sub-tropical monsoon climate situated in south China. The evaluation was conducted at various spatial scales (both grid-gauge scale and watershed scale) and temporal scales (annual and seasonal scales). The evaluation paid particular attention to precipitation intensity and especially its impact on hydrologic modelling. In the evaluation of the results, the overall statistical metrics show that GSMaP and MSWEP rank as the two best-performing SPPs, with KGE(Grid) >= 0.48 and KGE(Watershed) >= 0.67, while CHIRPS and SM2RAIN were the two worst-performing SPPs with KGE(Grid) <= 0.25 and KGE(Watershed) <= 0.42. GSMaP gave the closest agreement with the observations. The GSMaP-driven model also was superior in depicting the rainfall-runoff relationship compared to the hydrologic models driven by other SPPs. This study further demonstrated that satellite remote sensing still has difficulty accurately estimating precipitation over a mountainous region. This study provides helpful information to optimize the generation of algorithms for satellite precipitation products, and valuable guidance for local communities to select suitable alternative precipitation datasets.
摘要：
Forest aboveground biomass (AGB) retrieval using synthetic aperture radar (SAR) backscatter has received extensive attention. The water cloud model (WCM), because of its simplicity and physical significance, has been one of the most commonly used models for estimating forest AGB using SAR backscatter. Nevertheless, forest AGB estimation using the WCM is usually based on simplified assumptions and empirical fitting, leading to results that tend to overestimate or underestimate. Moreover, the physical connection between the model and the polarimetric synthetic aperture radar (PolSAR) is not established, which leads to the limitation of the inversion scale. In this paper, based on the fully polarimetric SAR data from the Advanced Land Observing Satellite-2 (ALOS-2) Phased Array-type L-band Synthetic Aperture Radar (PALSAR-2), the relative contributions of the three major scattering mechanisms were first analyzed in a hilly area of southern China. On this basis, the traditional WCM was extended by considering the secondary scattering mechanism. Then, to establish the direct relationship between the vegetation scattering mechanism and forest AGB, a new relationship equation between the PolSAR decomposition model and the improved water cloud model (I-WCM) was constructed without the help of external data. Finally, a nonlinear iterative method was used to estimate the forest AGB. The results show that volume scattering is the dominant mechanism, accounting for more than 60%. Double-bounce scattering accounts for the smallest fraction, but still about 10%, which means that the contribution of the double-bounce scattering component is not negligible in forested areas because of the strong penetration capability of the long-wave SAR. The modified method provides a correlation coefficient R2 of 0.665 and a root mean square error (RMSE) of 21.902, which is an improvement of 36.42% compared to the traditional fitting method. Moreover, it enables the extraction of forest parameters at the pix scale using PolSAR data without the need for low-resolution external data and is thus helpful for high-resolution mapping of forest AGB.
期刊：
Journal of Glaciology,2023年69(274):266-280 ISSN：0022-1430
通讯作者：
Guangjian Wu
作者机构：
[Wu, Guangjian; Yu, Zhengliang; Li, Fei; Chen, Wenfeng] Chinese Acad Sci, Inst Tibetan Plateau Res, State Key Lab Tibetan Plateau Earth Syst Resource, Beijing 100101, Peoples R China.;[Li, Fei; Chen, Wenfeng] Univ Chinese Acad Sci, Beijing 100049, Peoples R China.;[Maussion, Fabien] Univ Innsbruck, Dept Atmospher & Cryospher Sci, Innsbruck, Austria.;[Li, Yaojun] Chinese Acad Sci, Northwest Inst Ecoenvironm & Resources, State Key Lab Cryospher Sci, Lanzhou 730000, Peoples R China.;[Liu, Guohua] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421200, Peoples R China.
通讯机构：
[Guangjian Wu] S;State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
摘要：
The Tian Shan mountain range, known as the water towers of Central Asia, plays a key role in local water supply, yet large uncertainties remain about the amount of water that is stored in its glaciers. In this study, we assess the impact of the boundary conditions on ice thickness estimates using two inversion models: a mass conservation (MC) model and a basal shear stress (BS) model. We compare the widely used Randolph Glacier Inventory version 6 with the updated Glacier Area Mapping for Discharge from the Asian Mountains glacier inventory, as well as two digital elevation models (SRTM DEM and Copernicus DEM). The results show that the ice volume (in similar to 2000 CE) in the Tian Shan range is 661.0 +/- 163.5 km(3) for the MC model and 552.8 +/- 85.3 km(3 )for the BS model. There are strong regional differences due to inventory, especially for glaciers in China (17-25%). However, the effect of different DEM sources on ice volume estimation is limited. By the end of the 21st century, the projected mass loss differences between inventories are higher than between adjacent emission scenarios, illustrating the vital importance of high-quality inventories. These differences should be carefully considered during water resource planning.
作者机构：
[Wu, Jing; Yang, Xia; Peng, Bo; Peng, B; Wu, Sicheng; Chen, Haisheng; Guo, Xintong; Xie, Shurong; Fang, Xiaohong; Dai, Yanan] Hunan Normal Univ, Sch Geog Sci, Changsha 410081, Peoples R China.;[Wu, Jing; Yang, Xia; Peng, Bo; Peng, B; Wu, Sicheng; Chen, Haisheng; Guo, Xintong; Dai, Yanan] Hunan Normal Univ, Key Lab Environm Heavy Met Contaminat & Ecol Remed, Changsha 410081, Peoples R China.;[Fang, Xiaohong] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.;[Xie, Shurong] East China Univ Technol, Sch Earth Sci, Nanchang 330013, Peoples R China.
通讯机构：
[Peng, B ] H;Hunan Normal Univ, Sch Geog Sci, Changsha 410081, Peoples R China.;Hunan Normal Univ, Key Lab Environm Heavy Met Contaminat & Ecol Remed, Changsha 410081, Peoples R China.
期刊：
Global Ecology and Conservation,2023年46:e02617 ISSN：2351-9894
通讯作者：
Liu, N
作者机构：
[Deng, Yunyuan; Jiang, Wulin; Zou, Jun] Hengyang Normal Univ, Hunan Natl Local Joint Engn Lab Digital Preservat, Hengyang 421002, Peoples R China.;[Jiang, Wulin] Hengyang Normal Univ, Cooperat Innovat Ctr Digitalizat Cultural Heritage, Hengyang 421002, Peoples R China.;[Wang, Chunmei; Liu, Na; Liu, N; Deng, Yunyuan; Jiang, Wulin; Zou, Jun] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.;[Jiang, Wulin] Int Ctr Space Technol Nat & Cultural Heritage HIST, Hengyang Base, Hengyang 421002, Peoples R China.;[Wang, Chunmei] Chongqing Normal Univ, Sch Geog & Tourism, Chongqing 401331, Peoples R China.
通讯机构：
[Liu, N ] H;Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.
关键词：
Ecological quality;RSEI-2;Net primary productivity;Xiangxi UNESCO Global Geopark
摘要：
Geoparks are home to unique and precious geological sites and have a rich historical and cultural heritage. Most studies have focused on their tourism value and/or educational significance. However, far too little attention has been paid to the impact of geopark construction on the local ecological environment. The Xiangxi UNESCO Global Geopark (XXGG) was used as a case study to explore the impact of global geopark construction on local ecological quality. Three ecological indices, including an ecological quality index based on productive, residential, and ecological land use, an improved remote-sensing ecological index (RSEI-2), and net primary productivity (NPP), were adopted to evaluate the ecological quality of XXGG during two periods: before construction (from 2015 to 2017) and during construction of XXGG (from 2018 to 2020). The results show that: (1) in general, all ecological quality indicators showed a downtrend (from 2015 to 2017) followed by an uptrend (from 2018 to 2020), indicating that construction and development of XXGG has had a significant positive effect on local ecological quality. This occurred because a series of environmental protection measures were taken after application to the United Nations Educational, Scientific, and Cultural Organization (UNESCO) Global Geoparks (UGGPs) for membership at the end of 2017. (2) The areas of XXGG with excellent and improved ecological quality are mainly distributed in the northern and southeastern portions, which are located in the protected area with high coverage rates of forest and other vegetation. Poor ecological quality in the east and south is closely related with human activities, such as ethnic tourism development. The results explore the relationship between regional construction of the geopark and ecological effects and provide a scientific reference for sustainable development of global geoparks.
作者机构：
[Gao, Chanchan] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421000, Peoples R China.;[Gao, Chanchan; Liu, Min] East China Normal Univ, Sch Ecol & Environm Sci, Shanghai Key Lab Urban Ecol Proc & Ecorestorat, Shanghai 200241, Peoples R China.;[Fang, Dekun; Zhang, Fengying] China Natl Environm Monitoring Ctr, Beijing 100012, Peoples R China.;[Wang, Qingtao] Hebei Univ Engn, Sch Landscape & Ecol Engn, Handan 056038, Hebei, Peoples R China.;[Liu, Min] China Acad Forens Sci, Key Lab Forens Sci, Minist Justice, Shanghai 200063, Peoples R China.
通讯机构：
[Min Liu] K;Key Lab of Forensic Science, Ministry of Justice, China (Academy of Forensic Science), Shanghai 200063, China<&wdkj&>Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
关键词：
Air pollution controls;Air quality;COVID-19;China;Harmonic model
摘要：
Air pollution is a threat to public health in China, and several actions and plans have been implemented by Chinese authorities in recent years to mitigate it. This study examined the spatial distribution of changes in urban air pollutants (UAP) in 336 Chinese cities from 2016 to 2020 and their responses to air pollution controls and the COVID-19 pandemic. Based on the harmonic model, decreases in fine particles (PM(2.5)), inhalable particles (PM(10)), nitrogen dioxide (NO(2)), sulfur dioxide (SO(2)), and carbon monoxide (CO) levels were found in 90.7%, 91.9%, 75.2%, 94.3%, and 88.7% of cities, respectively, while an increase in ozone (O(3)) was found in 87.2% of cities. Notable spatial heterogeneity was observed in the air pollution trends. The greatest improvement in air quality occurred mainly in areas with poor air quality, such as Hebei Province and its surrounding cities. However, some areas (i.e., Yunnan and Hainan provinces) with good air quality showed a worsening trend. During the 13th Five-Year Plan period (2016-2020), the remarkable effects of PM(2.5) and SO(2) pollution control plans were confirmed. Additionally, economic growth in 74.2% of the Chinese provinces decoupled from air quality after implementing pollution control measures. In 2020, several Chinese cities were locked down to reduce the spread of COVID-19. Except for SO(2), the national air pollution in 2020 improved to a greater extent than that in 2016-2019; In particularly, the contribution of simulated COVID-19 to NO(2) reduction was 66.7%. Overall, air pollution control actions improved urban PM(2.5), PM(10), SO(2), and CO, whereas NO(2) was reduced primarily because of the COVID-19 pandemic.
通讯机构：
[Feng, C ] H;Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.
关键词：
river network system evolution;adaptation;urbanization;GTWR model;Xiangjiang River Basin
摘要：
The research focuses on the difficult problem of quantifying the adaptation state of river network system development under rapid urbanization. Based on the river network system data and remote sensing image data of the past 30 years, this study discusses the evolution of the river network system and its adaptability. The geographically and temporally weighted regression (GTWR) model was used to reveal the response of the river network system in the Xiangjiang River Basin to urbanization. The results suggest that the Xiangjiang River Basin has experienced a significant increase in urban land due to the strong disturbance by human activities in the last 25 years. The number indicators of river network system such as overall water surface rate and river network density have decreased by 10.04% and 13.99%, respectively. Drainage structure indicators such as tributary development coefficient and structural stability decreased by 6.89% and 4.40%, respectively. The influence of three-dimensional urbanization on the intensity of river network density change is spatiotemporal heterogeneity during 1995-2020. It shows that population factors have a significant negative impact on the upstream area. The regression coefficient between river network density and per capita GDP in the basin is positive. The regression coefficient of urban land is negative, indicating that urban expansion has a significant negative effect on river network density in Xiangjiang River basin. The analysis of the relationship between urbanization and river network system evolution by using the coordination degree model shows that: in the early stage, the level of urbanization is low, the adjustment capacity and carrying capacity of river network are strong, and the coordination degree of urbanization and river network system is small. The level of urbanization has reached a new height, especially in the upstream central cities such as Chang-Zhu-Tan from 2015 to 2020. At this time, the increase of coordination degree is characterized by the mutual promotion of urbanization and river network development, and the improvement of their adaptive development requirements. This study quantitatively reveals the changing characteristics and influencing factors of the adaptability of river network systems and urban spatial development, which can provide scientific support for regional human-water harmony, flood prevention and mitigation, and green urbanization development.
通讯机构：
[Bo Zhang] S;Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China<&wdkj&>Guangdong Provincial Center for Urban and Migration Studies, Guangzhou 510006, China<&wdkj&>School of Geography and Remote Sensing, Guangzhou University, Guangzhou 510006, China<&wdkj&>Author to whom correspondence should be addressed.
关键词：
population aging;green total factor productivity;spatiotemporal analysis;spatial clustering;spatial spillover effect;spatial Durbin model
摘要：
China is a rapidly aging nation. Therefore, it is a matter of urgency to address the challenges of aging in China and to coordinate the relationships between population aging, environmental issues, and socio-economic development. However, few empirical studies have thus far analyzed the impact of aging on green total factor productivity (GTFP) in China. Hence, this study employs a global Malmquist–Luenberger index method (GMLI) to calculate the GTFP scores of 30 Chinese provinces from 2002 to 2018. We apply spatiotemporal analysis methods to identify the variations of population aging and GTFP scores and then build a spatial econometric model to examine the impact of population aging on GTFP. Our study findings are as follows. (1) Whereas at the beginning of the 21st century, provinces with deep aging were mostly situated in the east, the population aging issue in China is now spreading across the entire country. (2) From a dynamic perspective, the overall GTFP growth rate in China during the sample period depicts a U-shaped structure with time. (3) Results of the spatial Durbin model show that the impact of population aging in a given region on GTFP is negative, but the spatial spillover effect of aging in neighboring regions on GTFP in a given region is positive, resulting in the loss of younger local labor forces in some provinces due to low birth rates and migration to neighboring regions. Finally, to cope with a growing aging population and to possibly eliminate the negative impacts of population aging on high-quality sustainable development, the government should promote the establishment of the old-age security system; increased investment in R & D and wide use of advanced technology should also be urgently encouraged.
关键词：
water yield;InVEST;model revision;cold alpine regions
摘要：
Watershed management requires reliable information about hydrologic ecosystem services (HESs) to support decision-making. In cold alpine regions, the hydrology regime is largely affected by frozen ground and snow cover. However, existing special models of ecosystem services usually ignore cryosphere elements (such as frozen ground and snow cover) when mapping water yield, which limits their application and promotion in cold alpine regions. By considering the effects of frozen ground and snow cover on water yield, a new version of the Seasonal Water Yield model (SWY) in the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) was presented and applied in the Three-River Headwaters Region (TRHR) in southeastern Qinghai-Tibetan Plateau (QTP). Our study found that incorporating the effects of frozen ground and snow cover improved model performance. Frozen ground acts as a low permeable layer, reducing water infiltration, while snow cover affects water yield through processes of melting and sublimation. Both of these factors can significantly impact the distribution of spatial and temporal quickflow and baseflow. The annual average baseflow and water yield of the TRHR would be overestimated by 13 mm (47.58 x 10(8) m(3)/yr) and 14 mm (51.24 x 10(8) m(3)/yr), respectively, if the effect of snow cover on them is not considered. Furthermore, if the effect of frozen ground on water yield were not accounted for, there would be an average of 6 mm of quickflow misestimated as baseflow each year. Our study emphasizes that the effects of frozen ground and snow cover on water yield cannot be ignored, particularly over extended temporal horizons and in the context of climate change. It is crucial to consider their impacts on water resources in cold alpine regions when making water-related decisions. Our study widens the application of the SWY and contributes to water-related decision-making in cold alpine regions.
作者：
Deng, Zhiwei;Quan, Bin;Zhang, Haibo;Xie, Hongqun;Zhou, Ze
期刊：
Forests,2023年14(11):2131- ISSN：1999-4907
通讯作者：
Quan, B
作者机构：
[Deng, Zhiwei; Zhou, Ze; Quan, Bin; Xie, Hongqun; Zhang, Haibo] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.;[Quan, Bin] Hengyang Base Int Ctr Space Technol Nat & Cultural, Hengyang 421002, Peoples R China.
通讯机构：
[Quan, B ] H;Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.;Hengyang Base Int Ctr Space Technol Nat & Cultural, Hengyang 421002, Peoples R China.
关键词：
land use and cover change;ecological security pattern;multiple scenarios simulation;PLUS model;Chang-Zhu-Tan metropolitan area
摘要：
Scenario-based simulation in land use and cover change (LUCC) is a practical approach to maintaining ecological security. Many studies generally set constraints of LUCC utilizing ecological patches but without consideration of corridors connecting these patches. Here, we constructed a framework to balance urban growth and ecological security by integrating ecological security patterns (ESPs) into the PLUS model. This study selected Chang-Zhu-Tan Metropolitan Area (CZTMA) in central China as a typical case. Specifically, coupling quantitative demand with spatial constraints of multiple levels of ESPs, this study designed four scenarios, including historical tendency (HT), urban growth (UG), ecological conservation (EC), and coordinating city development and ecological protection (CCE). Then, the transformations and landscape patterns of LUCC were analyzed to evaluate the future land change from 2020 to 2050. The results show sixty-one key ecological sources in the CZTMA, mainly in higher-elevation forested areas. Forty-six ecological corridors were estimated using circuit theory. The building expansion was driven by accessibility to transportation and government locations and will contribute to the loss of forest and cropland in the future. The feature of different scenarios in alleviating the increasing fragmentation of patches and reducing the loss amount of ecological land showed EC > CCE > HT > UG. This study developed the ESP-PLUS framework and its modeling idea, which has the potential to be applied in other regions. This extension would assist decision-makers and urban planners in formulating sustainable land strategies that effectively reconcile eco-environmental conservation with robust economic growth, achieving a mutually beneficial outcome.
作者机构：
[Zhou, Ze; Deng, Zhiwei; Quan, Bin] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.;[Quan, Bin] Hengyang Normal Univ, HIST Hengyang Base, Hengyang 421002, Peoples R China.
通讯机构：
[Bin Quan] C;College of Geography and Tourism, Hengyang Normal University, Hengyang 421002, China<&wdkj&>HIST Hengyang Base, Hengyang Normal University, Hengyang 421002, China<&wdkj&>Author to whom correspondence should be addressed.
关键词：
LULC;ecosystem service value;Intensity Analysis;Xiangjiang River Basin
摘要：
The study of land use and land cover (LULC) change and the evolution of ecosystem service values (ESV) is important for optimizing the allocation of regional land resources and achieving sustainable development, but traditional land use analysis methods cannot dig deeper into the information on the internal transitions between different land types. Therefore, in this paper, we use the component analysis and Intensity Analysis methods to systematically analyze the land use landscape changes at multiple levels. In addition, the spatial and temporal dynamic characteristics of ESV in the Xiangjiang River Basin are carved with the help of equivalence factors and GIS spatial analysis methods, which reveal the response of ESV changes to land use changes in the Xiangjiang River Basin in the past four decades. Our results showed that, (1) in the past 40 years, the intensity of land use change in the Xiangjiang River Basin has been increasing, mainly in quantity and shift. The increase of built-up and bare land and the decrease of cultivated land are stable and active, and the loss of forest land is large, but it is dormant. The loss of cultivated and forested land flows mainly to built-up land. (2) In the Xiangjiang River Basin, ESV increases first and then decreases, mainly in the middle and high grades and changes faster in the east. (3) The cross-sensitivity coefficient reflected that the net conversion of cultivated land to forest land and water area had a promoting effect on ESV. Our results provide important knowledge to inform land use decisions and facilitate sustainable development in the Xiangjiang River Basin.
