作者机构：
[Li, Hongyuan; Han, Chuntan; Chen, Rensheng; Yang, Yong] Chinese Acad Sci, Northwest Inst Ecoenvironm & Resources, Qilian Alpine Ecol & Hydrol Res Stn, Lanzhou 730000, Peoples R China.;[Li, Hongyuan; Han, Chuntan] Univ Chinese Acad Sci, Beijing 100049, Peoples R China.;[Liu, Guohua] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421000, Peoples R China.;[Chen, Rensheng] Northwest Univ, Coll Urban & Environm Sci, Xian 710000, Peoples R China.
通讯机构：
[Rensheng Chen] C;College of Urban and Environmental Sciences, Northwest University, Xi’an 710000, China<&wdkj&>Qilian Alpine Ecology and Hydrology Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China<&wdkj&>Author to whom correspondence should be addressed.
关键词：
frost-free period;frost days;ERA5-Land;climate change;agricultural production
摘要：
Understanding the spatio-temporal variations in the frost-free period (FFP) and the number of frost days (FD) is beneficial to reduce the harmful effects of climate change on agricultural production and enhancing agricultural adaptation. However, the spatio-temporal variations in FFP and FD and their response to climate change remain unclear across China. To investigate the impact of climate change on FFP and FD, the trends and variations in FFP and FD across China from 1950 to 2020 were quantified using ERA5-Land, a reanalysis dataset with high spatial and temporal resolution. The results showed that ERA5-Land has good applicability in quantifying the trends and variations in FFP and FD across China under climate change. The spatial distribution of multi-year average FFP and FD across China showed significant latitudinal zonality and altitude dependence, i.e., FFP decreased with increasing latitude and altitude, while FD increased with increasing latitude and altitude. As a result of climate warming across China, the FFP showed an increasing trend with an increase rate of 1.25 d/10a and the maximum increasing rate of FFP in the individual region was 6.2 d/10a, while the FD showed a decreasing trend with a decrease rate of 1.41 d/10a and the maximum decreasing rate of FD in the individual region was -6.7 d/10a. Among the five major climate zones in China, the subtropical monsoon climate zone (SUMZ) with the greatest increasing rate of 1.73 d/10a in FFP, while the temperate monsoon climate zone (TEMZ) with the greatest decreasing rate of -1.72 d/10a in FD. In addition, the coefficient of variation (C-v) of FFP showed greater variability at higher altitudes, while the C-v of FD showed greater variability at lower latitudes in southern China. Without considering the adaptation to temperature of crops, a general increase in FFP and a general decrease in FD were both beneficial to agricultural production in terms of FFP and FD promoting a longer growing period and reducing frost damage on crops. This study provides a comprehensive understanding of the trends and variations in FFP and FD under climate change, which is of great scientific significance for the adjustment of the agricultural production layout to adapt to climate change in China.
期刊：
Theoretical and Applied Climatology,2022年150(3):1545-1557 ISSN：0177-798X
通讯作者：
Lian-Tong Zhou
作者机构：
[Liu, Kui] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Hunan, Peoples R China.;[Zhou, Lian-Tong; Wang, Zhibiao; Liu, Kui; Chen, Jilong; Liu, Yong] Chinese Acad Sci, Ctr Monsoon Syst Res, Inst Atmospher Phys, POB 2718, Beijing 100190, Peoples R China.
通讯机构：
[Lian-Tong Zhou] C;Center for Monsoon System Research, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
摘要：
In this paper, Japan Meteorological Agency (JRA-55) reanalysis and observational rainfall datasets from the National Climate Center (NCC) of China, as well as satellite datasets from the Tropical Rainfall Measuring Mission (TRMM), Global Precipitation Climatology Project (GPCP), and International Satellite Cloud Climatology Project (ISCCP), are used. The correlation coefficient and fast Fourier transform (FFT) low-pass filter are also used, in order to reveal the interdecadal decrease in autumn rainfall in Southeast China (SEC) after 1990. The close and robust relationship between the interdecadal variation in autumn rainfall in SEC and sea surface temperature (SST) in the tropical Pacific is investigated. The most significant and stable region of correlation is located in 10 degrees S-10 degrees N, 160 degrees E-160 degrees W, in which there also exists interdecadal warming after 1990. Furthermore, the interdecadal warming of SST can induce Gill responses of the atmosphere: a cyclone anomaly is produced on each side of the equator in the lower troposphere, with a westerly anomaly to the west of the dateline, and an anticyclone anomaly is produced in the upper troposphere. In particular, the cyclone anomaly on the northern side of the equator is located in the Northwest Pacific (NWP), and its ambient northerly airflow weakens meridional water vapor transport, as well as the local descending motion and low-troposphere divergence, in favor of the interdecadal decrease in SEC rainfall after 1990. In addition, the sensitive experiments with ECHAM-5.4 model also confirm that the interdecadal warming in the region (10 degrees S-10 degrees N, 160 degrees E-160 degrees W) would motivate the atmospheric Gill response and thereby cause the sinking motion in SEC and support the interdecadal decrease in autumn rainfall in SEC.
作者机构：
[Fan, Xuejiao; Deng, Zhiwei; Liu, Jianxiong; Quan, Bin] Hengyang Normal Univ, Coll Geog & Tourism, Hengyang 421002, Peoples R China.;[Quan, Bin] Hunan Prov Collaborat Innovat Ctr Digital Heritag, 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&>Hunan Provincial Collaborative Innovation Center for Digital Heritage of Ancient Village and Town Cultural Heritage, Hengyang 421002, China<&wdkj&>HIST Hengyang Base, Hengyang Normal University, Hengyang 421002, China<&wdkj&>Author to whom correspondence should be addressed.
关键词：
land use change;intensity analysis;balance of cultivated land occupation and compensation;Changsha–Zhuzhou–Xiangtan
摘要：
The Changsha-Zhuzhou-Xiangtan region has experienced rapid social and economic development over the past 40 years, and cultivated land has changed dramatically. The contradiction between built and cultivated land has intensified, for which the local government has implemented a series of policies related to cultivated land protection. However, thus far, it is not clear what the substantial effects of the cultivated land protection policies are. To this end, this paper quantitatively characterizes the changes in the Changsha-Zhuzhou-Xiangtan region during the 20 years before and after the implementation of the cultivated land occupation balance policy, based on land use data from 1980, 2000, and 2020 using intensity analysis. In this paper, we examine the types of spatial land use patterns occurring in Changsha-Zhuzhou-Xiangtan since 1980 and explore the transition path of land use types in urban-rural integration. After the cultivated land protection policy, the transformation relationship between land use types and the changing trend of the cultivated land area was analyzed from the landscape scale. The influence of policy factors on the transformation of land use types was revealed. The results show that, from 1980 to 2020, the changing intensity of construction land and unused land was relatively large and was in an active state; the amount of built land in the Changsha-Zhuzhou-Xiangtan region has been growing, with a net increase of 1101 km(2), while the amount of cultivated land has been showing a net decrease, with a net reduction of 677 km(2). Moreover, the cultivated land has mainly been converted into built land, and the lost cultivated land area in Changsha-Zhuzhou-Xiangtan has not been fully compensated elsewhere in the region, indicating that the cultivated land protection policy has not been able to maintain the cultivated land area in Changsha-Zhuzhou-Xiangtan. From 2000 to 2020, cultivated land change was mainly due to exchange, which indicates that the policy has had a particular effect on the protection of cultivated land. Still, if the government wants to achieve the "balance of cultivated land occupation and compensation" goal, it must establish a complete system for the allocation of cultivated land resources. This study can provide a scientific reference for further implementing the cultivated land protection policy, which is thus of great significance for promoting the construction of the Changsha-Zhuzhou-Xiangtan region and its high-quality economic and social development.
