Topographic and seasonal modulation of satellite precipitation errors in the Yangtze River Delta: a cross-scale analysis for climate adaptation

The estuary delta is an area where human economic activities are active and natural ecological environment is fragile. With global change and the intensification of human activities, coastal and seabed erosion around the world is becoming more and more serious. In this paper, we used the Delft 3D numerical simulation to compare the hydrodynamic effects of sediment transport paths in the Yellow River delta (river-controlled type), Yangtze River delta (tidal type) and Mekong River delta (tidal wave type) in the East Asian monsoon area, and analyzed the causes of accumulation erosion landform distribution in three different types of subaqueous deltas. This study finds the Yellow River Delta has experienced varying degrees of erosion at the estuary, but its subaqueous delta is still dominated by deposition; the Yangtze River Delta has ensured the stability of its shoreline under the influence of artificial shoreline reinforcement, but the subaqueous delta (water depth: 0–15 m) is in a state of erosion all year round; and in the Mekong River Delta the erosion occurs in both its shoreline and subaqueous delta. Additionally, only by analyzing the erosion and deposition within the transport range of resuspended sediment, the changes in the properties of the entire subaqueous delta could be recognized. The research results can not only be helpful to analyze whether the change of river sediment will lead to the change of delta type under human influence, but also provide more powerful scientific support for the protection of delta ecological environment, geological environment safety and geological disaster prevention.

Different fates of the Yangtze and Mississippi deltaic wetlands under similar riverine sediment decline and sea-level rise

At present, the Yangtze River Delta region is one of the regions with the highest level of economic development in China. The development status of regional tourism integration in the Yangtze River Delta is mainly manifested in that the Yangtze River Delta is an important tourist source and destination in China, the scale of tourism industry in the Yangtze River Delta tends to be balanced, Shanghai is the tourist distribution and service center of the Yangtze River Delta and the Yangtze River Angle tourism integration has laid a good foundation, Shanghai cruise port and tourism city integration has made remarkable progress, but there are still some problems such as the Yangtze River Delta has not yet formed a perfect cruise port system, the Yangtze River Delta cruise port and tourism hinterland integration still need to be developed. In the aspect of integrated development path, it is proposed to form a perfect cruise port system, form multiple single port cruise tourism destinations, and form a single multi-port cruise tourism destination. Based on detailed data analysis and government investigation, this paper will study the development path to promote the integration of cruise tourism destinations in the Yangtze River Delta.

The Yangtze River Delta, located in East China, is an important passage on the eastern pathway of the northward migration of fall armyworm Spodoptera frugiperda (Smith) in China, connecting China's year-round breeding area and the Huang-Huai-Hai summer maize area. Clarifying the migration dynamics of S. frugiperda in the Yangtze River Delta is of great significance for the scientific control and prevention of S. frugiperda in the Yangtze River Delta, even in the Huang-Huai-Hai region and Northeast China. This study is based on the pest investigation data of S. frugiperda in the Yangtze River Delta from 2019 to 2021, combining it with the migration trajectory simulation approach and the synoptic weather analysis. The result showed that S. frugiperda migrated to the Yangtze River Delta in March or April at the earliest, and mainly migrated to the south of the Yangtze River in May, which can be migrated from Guangdong, Guangxi, Fujian, Jiangxi, Hunan and other places. In May and June, S. frugiperda migrated further into the Jiang-Huai region, and its source areas were mainly distributed in Jiangxi, Hunan, Zhejiang, Jiangsu, Anhui and Hubei provinces. In July, it mainly migrated to the north of Huai River, and the source areas of the insects were mainly distributed in Jiangsu, Anhui, Hunan, Hubei and Henan. From the south of the Yangtze River to the north of the Huai River, the source areas of S. frugiperda were constantly moving north. After breeding locally, S. frugiperda can not only migrate to other regions of the Yangtze River Delta, but also to its surrounding provinces of Jiangxi, Hunan, Hubei, Henan, Shandong and Hebei, and even cross the Shandong Peninsula into Northeast China such as Liaoning and Jilin provinces. Trajectory simulation showed that the emigrants of S. frugiperda from the Yangtze River Delta moved northward, westward and eastward as wind direction was quite diverse in June-August. This paper analyzes the migration dynamics of S. frugiperda in the Yangtze River Delta, which has important guiding significance for the monitoring, early warning and the development of scientific prevention and control strategies for whole country.

IntroductionThe Yangtze River Delta is where “the Belt and Road” and China’s Yangtze River Economic Belt converge, which plays a crucial strategic location. However, with the demands of economic growth, environmental issues are frequently present in the Yangtze River Delta as a result of human and exploitation of ecological resources, and there is an urgent need to coordinate the relationship between human development and ecology.MethodsThe Yangtze River Delta region is used as the research subject, quantitatively analyzing various ecosystems within the region from three dimensions: ecosystem services value, ecological carrying capacity, and ecological footprint, and analyzing various factors that affect economic and environmental balance. Then calculate eco-compensation and its payment order based on this information, in order to build a foundation for coordinating ecological interests and safeguarding the environment in the Yangtze River Delta region.Results and discussion(1) Jiangsu Province was the main provider of ecosystem services in the Yangtze River Delta; the Yangtze River Delta’s three main ecosystems-waters, forests, and wetlands-accounted for 90% of the ecosystem services valued in the area and must be preserved. (2) The Yangtze River Delta as a whole belonged to an ecological deficit area, showing varying degrees of unsustainable development; In terms of ecological deficits, cultivated land and fossil energy had the worst, and both need to be treated severely. (3) The Yangtze River Delta was a region that paid ecological compensation. The payment order and total amount was 6825.596 billion yuan in Shanghai, 6412.264 billion yuan in Jiangsu, 12088.852 billion yuan in Zhejiang, and 3675.637 billion yuan in Anhui. At the same time, considering the current state of Anhui, the amount of eco-compensation can be appropriately reduced. Finally, recommendations are made based on the findings above, in order to improve the overall ecological benefits of the Yangtze River Delta region and foster ecological integration, all provincial and municipal governments should take reasonable action to reverse the ecological deficit of fossil energy and cultivated land, and also aim to achieve an ecological surplus in both land uses.

In recent years, environmental problems have attracted attention at home and abroad, so exploring the causes of environmental pollution has become a research content for scholars. The opening of high-speed railway has improved the economic development of China's Yangtze River Delta, and with the economic growth, the construction of high-speed railway has also led to environmental pollution in China's Yangtze River Delta. Therefore, using the data from 41 prefecture-level cities in China's Yangtze River Delta from 2003 to 2020, the SDID model was constructed, and the comprehensive index of environmental pollution was calculated by factor analysis to calculate the impact of high-speed railway construction on environmental pollution in China's Yangtze River Delta. The conclusions are as follows: The opening of high-speed railway significantly reduces the overall pollution level in China's Yangtze River Delta. The opening of high-speed rail has played a role in restraining the environmental pollution of the first and second tier cities and the third and fourth tier cities, but the pollution level of the third and fourth tier cities has decreased significantly.

Based on the research of digital economy and digital transformation of manufacturing industry, the article constructs the evaluation index system of digital economy development level and digital transformation of manufacturing industry in Yangtze River Delta respectively. The entropy weight TOPSIS method is used to measure and analyze the level of digital economy development and the level of digital transformation of manufacturing industry in the Yangtze River Delta respectively. The coupling coordination degree of digital economy and manufacturing digital transformation in the Yangtze River Delta in general and in each province and city is calculated and analyzed. On the basis of the relevant conclusions, recommendations for the digital transformation of the manufacturing industry and the elimination of the “digital divide” in the Yangtze River Delta are proposed. The overall trend of digital economy in the Yangtze River Delta (YRD) is on the rise, but there is a significant “digital divide”. The increase in the level of digital economy development in the Yangtze River Delta over the past 10 years is 10.76%. The average value of digital economy development water in Shanghai, Jiangsu, Zhejiang and Anhui is 0.358, 0.549, 0.491, 0.185 respectively, and the development of digital economy in Anhui is insufficient. Shanghai’s manufacturing digitalization water average is 0.750, the highest level in the Yangtze River Delta. Zhejiang and Anhui are slightly behind in manufacturing digital transformation. The coupling coordination degree of digital economy and manufacturing digital transformation in the Yangtze River Delta grew from 0.592 to 0.879, and the type of coupling coordination development shifted from barely coordinated to well coordinated. Shanghai and Jiangsu have reached the good coordination level. Zhejiang is at the intermediate coordination level. And Anhui is at the barely coordinated stage, which is the lowest level in the Yangtze River Delta.

Objective In order to know the sustainable and suitable strategy about nursing tasks in Yangtze River Delta under the backgroud of integration. Methods According to the results of inves-tigation, using SWOT method to analyze the development strategy about nursing tasks in Yangtze River Delta. Results The nursing tasks in Yangtze River Delta had their own strengths and weaknesses, the opprotunities coexisted with threaten. Conclusions Based on the analysis, it put forward its strategic countermeasures including government guide and aid strategy, promote by education, science and technol-ogy strategy, specialization nursing and name brand strategy, stabilize and enlarge nursing person with a-bility strategy, nursing management innovation strategy, develop community nursing ,strategy energetically. Key words: Yangtze River Delta; Nursing; SWOT; Strategy

The Yangtze River Delta (also called Yangzi Jiang Delta, Tai Lake Region) is at the intersection of Chinese coastal regions and the lower reaches of the Yangtze River, including the triangular-shaped territory of Shanghai city, Jiangsu province and Zhejiang province. The urban build-up in the area has given rise what may be the largest concentration of adjacent metropolitan areas in the world (Gottmann, 1961). It covers an area of 99,600 km2 and is home to over 105 million people as of 2010, of which an estimated 80 million are urban. Lo and Marcotullio (2001) referred the delta as a major player in the newly emerged “world manufacturing belt” of Asia, due to its huge manufacturing capacity. Scholars have focused on the Yangtze River Delta since the 1990s, when the region’s economic performance and urban changes caught the world’s attention (Zhang, 2006). Hall (2002) contended that the Yangtze River Delta provides a paradigm (the Yangtze paradigm) of the 21st century megacity in terms of economic growth and spatial expansion. Friedmann (2005) studied the Yangtze River Delta in an examination of China’s urban transition and its bottom-up urbanization. More recently, the Institute for Yangtze River Delta Socioeconomic Development at Nanjing University has published a series of research reports on the Yangtze River Delta, including Liu and Zheng (2011, 2012).

Abstract. Regional air pollution is significantly associated with dominant weather systems. In this study, the relationship between the particle pollution over the Yangtze River Delta (YRD) region and weather patterns is investigated. First, the pollution characteristics of particles in the YRD are studied using in situ monitoring data (PM2.5 and PM10) in 16 cities and Terra/MODIS AOD (aerosol optical depth) products collected from December 2013 to November 2014. The results show that the regional mean value of AOD is high in the YRD, with an annual mean value of 0.71±0.57. The annual mean particle concentrations in the cities of Jiangsu Province all exceed the national air quality standard. The pollution level is higher in inland areas, and the highest concentrations of PM2.5 and PM10 are 79 and 130 µg m−3, respectively, in Nanjing. The PM2.5 : PM10 ratios are typically high, thus indicating that PM2.5 is the overwhelmingly dominant particle pollutant in the YRD. The wintertime peak of particle concentrations is tightly linked to the increased emissions during the heating season as well as adverse meteorological conditions. Second, based on NCEP (National Center for Environmental Prediction) reanalysis data, synoptic weather classification is conducted and five typical synoptic patterns are objectively identified. Finally, the synthetic analysis of meteorological fields and backward trajectories are applied to further clarify how these patterns impact particle concentrations. It is demonstrated that air pollution is more or less influenced by high-pressure systems. The relative position of the YRD to the anti-cyclonic circulation exerts significant effects on the air quality of the YRD. The YRD is largely influenced by polluted air masses from the northern and the southern inland areas when it is located at the rear of the East Asian major trough. The significant downward motion of air masses results in stable weather conditions, thereby hindering the diffusion of air pollutants. Thus, this pattern is quite favorable for the accumulation of pollutants in the YRD, resulting in higher regional mean PM10 (116.5 ± 66.9 µg m−3), PM2.5 (75.9 ± 49.9 µg m−3), and AOD (0.74) values. Moreover, this pattern is also responsible for the occurrence of most large-scale regional PM2.5 (70.4 %) and PM10 (78.3 %) pollution episodes. High wind speed and clean marine air masses may also play important roles in the mitigation of pollution in the YRD. Especially when the clean marine air masses account for a large proportion of all trajectories (i.e., when the YRD is affected by the cyclonic system or oceanic circulation), the air in the YRD has a lesser chance of being polluted. The observed correlation between weather patterns and particle pollution can provide valuable insight into making decisions about pollution control and mitigation strategies.

Based on remote sensing data of the Yangtze River Delta (YRD) in the years of 1991, 2001 and 2008, the paper built an index system of land use potential restraint factors in YRD, according to geological condition, terrain condition, water area, natural reserve area and basic farmland, and evaluated construction land potential based on the platform of GIS spatial analysis model. The results showed that: (1) the construction land increased rapidly since 1991 and reached 24,951.21 km2 in 2008, or 21.27% of the total area. Among all the cities in the YRD, Shanghai took the greatest percentage, followed by Jiangsu and Zhejiang. Spatially, areas where government departments are located became the growth center of construction land. Prefecture-level cities were the fastest growth region and the changing trend showed circle layered characteristics and significant increase with Shanghai and Suzhou as the core. (2) The higher the quality of construction land potentials (CLP), the smaller the number of CLP units. High sensitive area accounted for the largest percentage (40.14%) among all types of constraint regions and this was followed by medium sensitive region (31.53%) of the whole region. (3) The comprehensive CLP in the YRD was 24,989.65 km2, or 21.76% of the total YRD. The land use potential showed spatial distribution imbalance. CLP of Zhejiang was obviously larger than that of Jiangsu. CLP was insufficient in regional central city. Moreover, CLP in the YRD formed a circle layered spatial pattern that increasingly expanded centered in prefecture-level cities. Low potential area expanded from north to south. High potential area was mainly located in south YRD. Areas with zero potential in the YRD formed a northwest-southeast “Y-shaped” spatial pattern in north Hangzhou Bay. (4) CLP per capita in YRD was 0.045 ha/person and also unevenly distributed. Some 25.57% of the study units at county level nearly had no construction land and 8.24% of the units had CLP per capita below the national average level. CLP per capita in less than 25% of the county-level units was larger than the YRD average level, which were mainly located in Zhejiang. Therefore, research on the construction potential area in YRD was favorable for analysis of the development status and potential space of this region under the background of rapid urbanization and industrialization.

The “Regional Development Plan of the Yangtze River Delta (YRD)”, or the “YRD Development Policy”, is a national policy of China aimed at promoting industrial structure upgrading and the high-quality development of the regional economy in the YRD. To test the implementation effect of this policy, this work applied the synthetic control method (SCM) to explore the impact of the YRD Development Policy on industrial structure upgrading in the YRD based on 15-year panel data of 30 provinces in mainland China. The results showed that, as a whole, the implementation of the YRD Development Policy has contributed to industrial structure upgrading in the YRD. The trend of industrial structure upgrading is more rapid in the original YRD than in the new YRD. From a local perspective, the YRD Development Policy has hindered the upgrading of the industrial structure in Anhui Province but promoted upgrading in the rest of the YRD. From a long-term perspective, the effectiveness of the YRD Development Policy is limited, presenting a clear N-shaped development trend. In terms of industrial structure changes, the impact of the YRD Development Policy on the three types of industries in the YRD shows obvious regional differences. Furthermore, economic development, urbanization, and technology innovation have a significant and positive impact on the industrial structure upgrading of the YRD. These findings have policy-making implications, enrich the research on the impact of the YRD Development Policy on industrial structure upgrading, and provide empirical reference for subsequent policy improvements.

Given the conflicts over the proposed formation mechanisms of Xiashu loess, the question of the provenance of sediments comprising the Xiashu loess in the Yangtze River Delta has not been satisfactorily resolved. In this study, the provenance of aeolian sediments of the Yangtze River Delta, China was examined by applying the detrial zircon U–Pb dating technique, Sr–Nd isotopic and trace element compositional analysis. U-Pb dating analysis was conducted on the Xiashu loess at three locations over the Yangtze River Delta, including Huangnishan (HNS) hill, Shengshan (SS) island and the Xuancheng (XC) area. The Xiashu loess and the sediments of the Yangtze River Valley share considerable similarity in their zircon U-Pb age spectra with the same main age peak and comparable age distribution. By contrast, significant differences in the age spectra, exist between the Xiashu loess and loess deposits of Chinese Loess Plateau (CLP). Coarse grains of the Yangtze River Delta loess may have a proximal material source identical to the sediments from the Yangtze River valley. Sr–Nd isotopic values of the Xiashu loess match those from the northern margin of the Tibetan Plateau. Rare earth element ratios independent of grain size illustrate that the values from loess of the Yangtze River Delta mostly overlap with those of CLP loess. This feature implies that loess from the Yangtze River Delta has a dominant source of distant material similar as the CLP loess. As such, we conclude that multi-proxy analysis of sediments can shed new light on tracing the provenance of aeolian loess in the Yangtze River Delta.

Economic agglomeration and emissions reduction: Does high agglomeration in China's urban clusters lead to higher carbon intensity?

Environmental change in the Yangtze River delta since 12,000 years B.P.