Pearl River Delta Area Research Articles

Observations of air quality on the outskirts of an urban agglomeration during the implementation of pollution reduction measures

Based on observations at Heshan, a boundary area in the city agglomeration of the Pearl River Delta region in China, atmospheric pollutants such as PM2.5, O3, CO, SO2, NOZ, NO2 and NO were monitored between the 12th and 29th November, 2010. Meteorological parameters, including temperature, humidity, dew point, air pressure, ultraviolet light, wind direction, and wind speed were also measured. By combining the meteorological parameters with the atmospheric pollutant data, we performed Positive Matrix Factorization (PMF) and ozone production efficiency (OPE) analysis to objectively understand the interrelations among the pollutants, as well as between the pollutants and the meteorological factors. During the observation period, there were various meteorological changes such as rainfall, cold air transit, and sunshine that created conditions for the formation or dispersal of pollutants. The study period coincided with the 16th Asian Games, during which time the government adopted strict measures to reduce the discharge of pollutants around the Pearl River Delta area. However, we still observed serious pollution of PM2.5 and O3, of which the highest value of PM2.5 was 210 μg m−3 and the highest value of O3 reached 117 ppb. At the same time, the high concentrations of CO, NO, NO2, NOZ, and SO2 could not be cleared away with rainfall in such a short period of time. On the basis of PMF analysis, we found that three factors influence the air quality of this region: local biomass burning, secondary pollutants of regional transport, and high industrial pollutant emissions. According to OPE analysis, the O3 pollution was mostly found to be VOC–sensitive but occasionally NOX–sensitive for OPE values greater than 10.

A Simplified Concrete Creep and Shrinkage CEB-FIP90 Model in Long-Span Bridge Design

The concrete shrinkage strain and creep coefficient calculation method in CEB - FIP MC90 model is briefly introduced. For application convenience in bridge design, a simplified formula for calculation of the concrete shrinkage strain and creep coefficient is derived. Considering the varying range of every influence factor, a correlation analysis for the factor is carried out. And the weights of those factors related to concrete shrinkage and creep coefficient are discussed. Considering the climate characteristics and the bridge structure features in the Pearl River Delta area, the variation ranges of concrete nominal shrinkage strain and nominal creep coefficient are calculated respectively.

Climate-related flood risks and urban responses in the Pearl River Delta, China

Growing concern on climate-related flood hazards has led to increasing interest in understanding the interactions between climate, flood, and human responses. This paper jointly investigates climate change trends, impacts on flood events, flood vulnerability and risk, and response strategies in the Pearl River Delta (PRD), a rapidly urbanizing coastal area in southeast China. Our analysis based on a reanalysis dataset and model projections are integrated with literature results, which indicates a climate scenario of increasing mean temperature, precipitation, sea level, typhoon intensity, and the frequency of extreme weather events in the PRD. These trends, together with the continuing urbanization in flood-prone areas, are expected to increase flood frequency and aggravate both the scale and degree of flooding in the PRD area. We further estimate the flood vulnerability of the 11 PRD cities using the indicator system method. The results suggest that the exposure and sensitivity of central cities (Hong Kong, Macao, Shenzhen, and Guangzhou) are very high because of highly exposed populations and assets located in lowland areas. However, the potential vulnerability and risk can be low due to high adaptive capacities (both by hard and soft flood-control measures). A novel framework on flood responses is proposed to identify vulnerable links and response strategies in different phases of a flood event. It further suggests that the flood risks can be mitigated by developing an integrated climate response strategy, releasing accurate early warning and action guidance, sharing flood-related information, and applying the advantages of online social network analysis.

Detection and analysis of 12 heavy metals in blood and hair sample from a general population of Pearl River Delta area.

To detect the content of 12 heavy metals in blood and hair sample from a general population of Pearl River Delta area, and to analyze the influence of duration of residence, gender, age, smoking and drinking on the heavy metal content. Use inductively coupled plasma mass spectrometry to detect the content of 12 heavy metals lead (Pb), mercury (Hg), cadmium (Cd), aluminum (Al), arsenic (As), copper (Cu), chrome (Cr), manganese (Mn), nickel (Ni), zinc (Zn), tin (Sn) and antimony (Sb) in blood and hair samples of a total of 50 subjects from a general population, collected by multistage stratified cluster random sampling method. The geometric mean of heavy metal content in blood samples of general population (μg/L): blood aluminum 214.00; blood chrome 92.82; blood manganese 21.43; blood nickel 20.59; blood copper 0.67; blood zinc 11.50; blood arsenic 0.55; blood cadmium 2.45; blood tin 0.00; blood antimony 1.92; blood lead 158.84; and blood mercury 1.19. The geometric mean of heavy metal content in hair samples of general population (μg/g): hair aluminum is 84.65; hair chrome 0.00; hair manganese 2.44; hair nickel 0.61; hair copper 28.49; hair zinc 136.65; hair arsenic 0.75; hair cadmium 0.46; hair tin 1.04; hair antimony 0.05; hair lead 8.97; and hair mercury 0.69. Some heavy metals were correlated with duration of residence, gender, age, smoking and drinking. This was the first time that simultaneously detecting heavy metal content in blood and hair was used to analyze the internal heavy metal burden in resident population of Pearl River Delta area. These data can serve as reference for further research.

An Analysis of Temporal and Spatial Distribution Characteristics of Water Resources in Guangdong Province, China

In view of the difficulty in giving a quantitative description of the degree of uneven distribution of water resources, this paper, based on a cloud model, explores the temporal and spatial distribution characteristics of water resources in some research areas in Guangdong Province by using quantitative methods. The results show that, firstly, cloud images of a cloud model make it possible to describe intuitively the characteristics of the temporal and spatial distribution of water resources and present the differences of these characteristics in different areas through numerical characteristic values. Secondly, there are the least amounts of water resources in western Guangdong and the most in the Pearl River Delta Area. Temporal allocation of water resources is difficult in the northern and eastern parts of this province while spatial allocation difficult in the eastern and western parts. Thirdly, there are more water resources, less non-uniformity in the temporal distribution, greater stability in terms of temporal and spatial distribution but greater non-uniformity in the spatial distribution of water resources in the downstream than upstream of the Pearl River in Guangdong Province. Fourthly, there is less non-uniformity in the spatial distribution than in the temporal distribution in northern Guangdong while stability of spatial distribution is worse than that of the temporal distribution in western Guangdong. In addition, there is less uniformity but greater stability in the spatial distribution than in the temporal distribution of water resources in each research area.

An improved dark object method to retrieve 500 m-resolution AOT (Aerosol Optical Thickness) image from MODIS data: A case study in the Pearl River Delta area, China

This paper presents an improved Dark Dense Vegetation (DDV) method for retrieving 500m-resolution aerosol optical depth (AOT) based on MOD04-C005 arithmetic with the Moderate Resolution Imaging Spectroradiometer (MODIS) from the National Aeronautics and Space Administration (NASA). The improvements include change of the movement pattern of retrieval window, selection of a more suitable aerosol type, and storage of the look-up table. The method is then applied to obtain the AOT over the Pearl River Delta region (PRD). By comparing the results with the co-temporal ground sunphotometer observations in 2010, the correlation coefficient is found to be 0.794 with RMSE 0.139 and their variations remain consistent. Contrasts between model values in 2008 and MODIS AOT products in the same date also reveal a high accuracy of the improved DDV method. We also performed sensitivity tests to analyze the impacts of several parameters on apparent reflectance at different bands, and the results show that apparent reflectance is much more sensitive to surface reflectance and AOT than to elevation.

Screening for five prevalent mutations of SLC25A13 gene in Guangdong, China: a molecular epidemiologic survey of citrin deficiency.

Citrin is the liver-type aspartate/glutamate carrier isoform 2 (AGC2) encoded by SLC25A13 gene, playing important roles in the urea cycle and the malate-aspartate shuttle. Citrin deficiency (CD) has proven a disease entity with high prevalence in south China, including Guangdong with the largest population, but CD epidemiology in this province has not been well characterized. This study aims to screen for five prevalent SLC25A13 mutations, c.851_854del (p.R284fs286X), c.1638_1660dup (p.A554fs570X), c.615+5G>A (p.A206fs212X), IVS16ins3kb (p.A584fs585X) and c.1399C>T (p.R467X), to calculate the mutation carrier rate in Guangdong. A total of 2,428 used blood samples for health examination were collected as the research subjects, including 1,558 from 5 cities in the Pearl River Delta area and the remaining 870 from 4 peripheral cities, and the 5 mutations screened using High Resolution Melting Assay and HybProbe assay. A total of 52 carriers were detected, including 2 carriers of a novel c.1420G>A (p.V474M) mutation that impairs citrin function, as judged by the functional analysis in the yeast system. The carrier rate was higher in Pearl River Delta area than that in the peripheral cities (26/1,558 vs. 26/870, with χ(2) = 4.639 and P < 0.05). The carrier rate was around 1/47 (52/2,428), theoretically with the CD morbidity of 1/8,800 and the number of CD patients over 11,800 in Guangdong population. This study has provided primary epidemiologic data for the evaluation of CD effect in Guangdong province. Moreover, the newly identified c.1420G>A mutation that impairs AGC2 function has enriched the mutation spectrum of human SLC25A13 gene.

Seasonal Variation of Mass Absorption Efficiency of Elemental Carbon in the Four Major Emission Areas in China

As an important site-specific optical parameter widely used in climate models, the mass absorption efficiency (MAE) of elemental carbon (EC), varies dramatically with the source types and governs the direct radiative forcing (DRF) estimation. In this study, the MAE of EC for ambient samples collected from four major emission areas in China, i.e., Beijing-Tianjin-Hebei area (BTH), Yangtze River Delta area (YRD), Sichuan Basin area (SB), and Pearl River Delta area (PRD), as well as emissions from burning of residential honeycomb briquette, firewood and rice straw were investigated by using a filter-based method. The annual mean MAEEC over the four major emission areas is 7.51 m2/g.MAEEC in BTH and YRD during summer appears significantly higher than MAEEC in other seasons, while seasonal variations of MAEEC in SB and PRD suggest MAEEC in summer and autumn is higher than that in winter and spring. MAEEC for samples from fossil fuels burning and biomass open-burning is 2.10 times higher than that from residential biofuel burning, which could be one of the reasons for the higher MAEEC values during the seasons heavily affected by fossil fuels burning and biomass open-burning (i.e., summer and autumn) than winter for the four locations. Difference between the measured and AeroCom median value of MAEEC may cause underestimation of DRFEC over the studied area by a factor of 0.13. Spatial and temporal variations of MAEEC would also result in underestimations of DRFEC to different degrees varying with seasons and areas.

Evolution assessment of china’s three mega-city regions based on entire-array-polygon method

Mega-city region is the mainstream of global urban development and also the dominant model of the neo urbanization process in China. The Beijing-Tianjin-Hebei area, Yangtze River Delta area and Pearl River Delta area are China’s three largest and most mature mega-city regions, the status of which represents the general level of the urban and regional development in China. Based on entire-array-polygon method, this paper makes a comprehensive evolution assessment of the three mega-city regions in terms of urban population index, urban economy index, urban life index, urban culture index and urban primacy index. In terms of general developing level, the three mega-city regions have progressed to optimize the structure. With their respective advantages and disadvantages, the three mega-city regions initially realize a “diversified” regional layout. The difference and gap among the three mega-city regions are obviously decreasing, which contributes to the regional balance of China metropolitan development. The rankings of the three mega-city regions will be in a continuous adjustment. The Beijing-Tianjin-Hebei area is possible to catch up and take the lead.

Atmospheric depositional fluxes and sources apportionment of organochlorine pesticides in the Pearl River Delta region, South China

Organochlorine pesticides (OCPs) have variously been phased out in agricultural activities, but they are still widely detected in air, water, and soil systems due to their recalcitrant nature in the environment. The purposes of this study were to assess potential OCP pollution via dry and wet deposition over the fast developing Pearl River Delta area with 41,700 km(2), where the main effort has been focused on emerging pollutants such as petroleum hydrocarbons and PM2.5. We quantified both the dry and wet deposition fluxes of 19 OCPs including dichlorodiphenyltrichloroethanes (DDTs), endosulfans (Endos), and hexachlorocyclohexanes (HCHs). The results showed that each year about 67.4, 42.0, 15.0, and 8.07kg of total OCPs, DDTs, Endos, and HCHs were returned to the ground, among which 11.7, 10.4, 0.84, and 0.16kg were in the dry deposition forms. The large spatial variations in OCP deposition fluxes indicated that OCP pollution in the air is mainly influenced on local scales because evaporation from local soil is likely the major source of the phased out OCPs. Source analysis indicated that DDTs may be still in use as antifouling agent and/or dicofol, but Endos and HCHs were mainly derived from the residual of historical usage. The study suggests that the historical OCP pollutants are persistent at high levels in this area and should not be overlooked, while we tackle emerging pollutants.

Using the variation of anammox bacteria community structures as a bio-indicator for anthropogenic/terrestrial nitrogen inputs in the Pearl River Delta (PRD)

The variation of anammox bacteria community composition was evaluated in sediments collected from the Pearl River Delta area with an anthropogenic/terrestrial input gradient. Results indicated that the community composition of anammox bacteria shifted from estuarine environment to the South China Sea deep ocean along with the anthropogenic/terrestrial input gradient, where Scalindua genus of anammox bacteria predominated in the area with less anthropogenic/terrestrial influences, such as in the open oceanic area, while genera of Kuenenia/Brocadia anammox bacteria have higher proportions in the area with higher anthropogenic/terrestrial impacts. The canonical correspondence analysis demonstrated that salinity, organic matter contents, and ratio of NH4 (+) to (NO2 (-)+NO3 (-)) strongly affected the shifting of anammox bacterial community compositions within the same gradients. The results obtained in this study, together with the similar variation of anammox bacteria community structures in other several estuaries in the world, indicated that anammox bacteria might have a habitat-specific distribution pattern according to their living habits, and their community composition could be served as a bio-indicator to monitor the anthropogenic/terrestrial N inputs in coastal environments.

Statistical features of tropical cyclones affecting China and its key economic zones

Recent trends and variability in tropical cyclone (TC) frequency and intensity are examined for TCs that affected China, with particular focus on those TCs that affected China’s key economic zones (e.g., the Yangtze River Delta, the Pearl River Delta, and the Beijing-Tianjin area). The results show that the frequency of TCs affecting China weakly declined during the 1980s and 2000s, followed by a slight increase. The time series of TC frequency shows insignificant variations at periods of 2–6 yr during the past 60 years; these variations are significantly correlated with ENSO activity. The frequency of TCs affecting the Pearl River Delta area is strongly correlated with the ENSO cycle while the frequency of TCs affecting the Yangtze River Delta is not. The TC frequency varies differently for TCs of different intensities. Tropical storms (TSs) affecting China were small in total number, but have clearly increased in frequency. The frequencies of severe tropical storm (STS), typhoon (TY), severe typhoon (STY), and super typhoon (super TY) affecting China declined significantly during the 1970s and 1980s, but the numbers of STY and super TY have increased over the 2000s. The typical intensity of TCs affecting China declined over the 60-yr timeframe, but increased over the most recent 10 years (2000–2010). This increase in the intensity of TCs has particularly impacted the Yangtze River Delta area, which has experienced increased numbers of STYs and super TYs. These tendencies are observed in changes of the maximum intensity of TCs affecting both China in general and the Yangtze River Delta in particular during both the full 60-yr analysis period and the latest 10-yr period; however, these tendencies are not observed in changes of the average intensity of TCs. By contrast, both the extreme intensity and the average intensity of TCs affecting the Pearl River Delta have decreased throughout the analysis period, including the most recent decade.

Modern pollen assemblages from cultivated rice fields and rice pollen morphology: Application to a study of ancient land use and agriculture in the Pearl River Delta, China

Pollen from a series of surface soil samples collected along a transect spanning southeast China was investigated to better understand palynological signals of ancient agriculture and other human activity. The transect surface samples consist of pairs taken inside and outside rice paddy fields. Pollen assemblages from these samples are valuable as modern analogs of human-altered environments and rice agriculture. Our measurements of Poaceae pollen grains from inside the modern rice fields discovered that 34–40 µm is the statistically significant size range for identifying domesticated rice in fossil pollen samples. This conclusion is also based on a size comparison of raw and chemically treated modern pollen grains from the plants. Pollen measurements for local wild grasses show that most native weeds have pollen grains less than 30 µm in size. The modern analogs and our study of the influence of chemical treatment on pollen grain size made it possible to examine a sediment core from the Pearl River delta for evidence of anthropogenic influence, including rice farming. Pollen assemblages from around 2200 cal. yr BP are highly similar to those of our modern analogs representing disturbed landscapes outside modern rice fields. The pollen spectra reveal abrupt increases in Poaceae, Dicranopteris, Artemisia and Pinus indicative of rice farming and forest clearance, at around 2200 cal. yr BP. Major factors associated with this abrupt transition were the rapid formation of the deltaic flood plain and massive increases in the Pearl River delta area population during the Qin Dynasty.

Returns to scale of Chinese cities, 2002–2009

In this article 242 cities are analyzed and their returns to scale are measured. Many cities in Guangdong province have a long history of introducing foreign capital and are full of small companies owned by foreign and domestic investors. Decreasing returns to scale are shown in these congested urban areas. The cities under high decreasing returns to scale are located in the Pearl River Delta area in Guangdong province. Physical capital investment seems to have little positive effect on improving the situation of the cities under decreasing returns to scale. As an urban economy shows capital deepening, it moves nearer to or deeper into decreasing returns to scale zone. Even though it is not possible to know when an urban economy falls under a decreasing returns to scale condition, it is clear that an urban economy comes close to decreasing returns to scale zone when physical capital deepens.

Spatiotemporal analysis of indigenous and imported dengue fever cases in Guangdong province, China.

BackgroundDengue fever has been a major public health concern in China since it re-emerged in Guangdong province in 1978. This study aimed to explore spatiotemporal characteristics of dengue fever cases for both indigenous and imported cases during recent years in Guangdong province, so as to identify high-risk areas of the province and thereby help plan resource allocation for dengue interventions.MethodsNotifiable cases of dengue fever were collected from all 123 counties of Guangdong province from 2005 to 2010. Descriptive temporal and spatial analysis were conducted, including plotting of seasonal distribution of cases, and creating choropleth maps of cumulative incidence by county. The space-time scan statistic was used to determine space-time clusters of dengue fever cases at the county level, and a geographical information system was used to visualize the location of the clusters. Analysis were stratified by imported and indigenous origin.Results1658 dengue fever cases were recorded in Guangdong province during the study period, including 94 imported cases and 1564 indigenous cases. Both imported and indigenous cases occurred more frequently in autumn. The areas affected by the indigenous and imported cases presented a geographically expanding trend over the study period. The results showed that the most likely cluster of imported cases (relative risk = 7.52, p < 0.001) and indigenous cases (relative risk = 153.56, p < 0.001) occurred in the Pearl River Delta Area; while a secondary cluster of indigenous cases occurred in one district of the Chao Shan Area (relative risk = 471.25, p < 0.001).ConclusionsThis study demonstrated that the geographic range of imported and indigenous dengue fever cases has expanded over recent years, and cases were significantly clustered in two heavily urbanised areas of Guangdong province. This provides the foundation for further investigation of risk factors and interventions in these high-risk areas.

Prevalence and major risk factors of peripartum thromboembolic disease in different regions of Guangdong province

To investigate the prevalence and major risk factors of peripartum thromboembolic disease in different regions of Guangdong province. Data from 169 218 pregnant women in different regions of Guangdong province from January 2005 to June 2010 were analyzed retrospectively. The prevalence and epidemiological characteristics of thromboembolic disease during pregnancy or puerperium were investigated. Of the studied population, (1) 201 cases (1.3‰) suffered from thromboembolic disease during pregnancy or puerperium including 128 cases of deep vein thrombosis (DVT), 68 cases of cerebral venous thrombosis (CVT) and 5 pulmonary embolism, the prevalence rates were 0.8‰, 0.4‰, and 0.02‰ respectively. (2) Risk factors in different regions showed that, in the Pearl River Delta area, the major risk factors for DVT would include previous or family history of thrombosis, pregnancy complications, with medically involved diseases, prolonged bed rest and pregnancy weight gain>15 kg etc. While in eastern, western, northern parts of Guangdong, the major risk factors for DVT would include pregnancy weight gain>15 kg, prolonged bed rest, preeclampsia, cesarean section and complications during pregnancy. In Pearl River Delta region, the major risk factors for CVT would include eclampsia, preeclampsia, pregnancy complications, prolonged bed rest>3 days, past history or family history of thrombosis. While eclampsia, preeclampsia, advanced age or younger age, pregnancy weight gain>15 kg, complications during pregnancy were the major risk factors for CVT in the eastern, western or northern parts of Guangdong. Prevalence and major risk factors of peripartum thromboembolic disease in different regions of Guangdong were different. It was crucial to take effective measures in pregnant women with different epidemiological characteristics and risk factors to prevent and reduce the incidence of peripartum thromboembolic disease.

Regional Economic Growth and Spillover Effects: An Analysis of China's Pan Pearl River Delta Area

AbstractThe Pan Pearl River Delta (PPRD) Regional Co‐operation Framework Agreement was signed in 2004. It aims to bring prosperity through partnership among nine Chinese Mainland provinces and China's two special administrative regions. In this paper, we use a dynamic panel data model to examine the economic growth of the PPRD economies from 1985 to 2009. Our analysis confirms the existence of regional growth spillover effects in the PPRD area. Our results also show that economic growth spillover effects of non‐PPRD regions on the PPRD regions are greater than those among the PPRD members themselves. These findings imply that economic integration between Chinese provinces has generated considerable spillover effects on regional growth. However, the anticipated benefits of the implementation of the PPRD agreement have not been realized thus far. Therefore, greater effort should be made to promote further economic integration among these members so that their local economies can benefit from the positive spillover effects.

Atmospheric aerosol compositions in China: spatial/temporal variability, chemical signature, regional haze distribution and comparisons with global aerosols

Abstract. From 2006 to 2007, the daily concentrations of major inorganic water-soluble constituents, mineral aerosol, organic carbon (OC) and elemental carbon (EC) in ambient PM10 samples were investigated from 16 urban, rural and remote sites in various regions of China, and were compared with global aerosol measurements. A large difference between urban and rural chemical species was found, normally with 1.5 to 2.5 factors higher in urban than in rural sites. Optically-scattering aerosols, such as sulfate (~16%), OC (~15%), nitrate (~7%), ammonium (~5%) and mineral aerosol (~35%) in most circumstance, are majorities of the total aerosols, indicating a dominant scattering feature of aerosols in China. Of the total OC, ~55%–60% can be attributed to the formation of the secondary organic carbon (SOC). The absorbing aerosol EC only accounts for ~3.5% of the total PM10. Seasonally, maximum concentrations of most aerosol species were found in winter while mineral aerosol peaks in spring. In addition to the regular seasonal maximum, secondary peaks were found for sulfate and ammonium in summer and for OC and EC in May and June. This can be considered as a typical seasonal pattern in various aerosol components in China. Aerosol acidity was normally neutral in most of urban areas, but becomes some acidic in rural areas. Based on the surface visibility observations from 681 meteorological stations in China between 1957 and 2005, four major haze areas are identified with similar visibility changes, namely, (1) Hua Bei Plain in N. China, and the Guanzhong Plain; (2) E. China with the main body in the Yangtze River Delta area; (3) S. China with most areas of Guangdong and the Pearl River Delta area; (4) The Si Chuan Basin in S.W. China. The degradation of visibility in these areas is linked with the emission changes and high PM concentrations. Such quantitative chemical characterization of aerosols is essential in assessing their role in atmospheric chemistry and weather-climate effects, and in validating atmospheric models.

Gourmets in the Land of Famine: The Culture and Politics of Rice in Modern Canton (review)

Reviewed by: Gourmets in the Land of Famine: The Culture and Politics of Rice in Modern Canton Tae-Ho Kim (bio) Gourmets in the Land of Famine: The Culture and Politics of Rice in Modern Canton. By Seung-Joon Lee. Palo Alto, Calif.: Stanford University Press, 2011. Pp. xviii+300. $55. Seung-Joon Lee’s book delves into the issue of taste and quality of food, with the case of Canton (now officially known as Guangzhou) in the early twentieth century. It shows how Canton, southern China’s biggest city, had developed a sophisticated system of rice trade that could provision its people, and how that system was interrupted and eventually broken by the new Republican (Guomindang) government. This new government was driven by a vision of reforming Chinese society through Western science and technology. The Cantonese had developed a unique system of commercial agriculture, often described as “sericulture combined with pisciculture.” Although it increasingly reduced the area of cultivable lands, the Cantonese secured their rice supply from Southeast Asia in exchange for their commercial products. They preferred Southeast Asian rice because it was easier to access and, more important, tasted better than rice transported from other Chinese provinces. Guangdong’s geographical isolation and lack of effective interprovincial transportation made it difficult to maintain the quality of Chinese rice in the Cantonese market. Massive importation of Southeast Asian rice continued until the late 1920s, because the Cantonese could rely on a wide maritime trade network, one stretching throughout Southeast Asia and dominated by overseas Chinese merchants. The commercial network of Chinese émigrés was so elaborate that Canton could provision its people through the Hong Kong rice market, even in the turbulent years from the late Qing to the early Republic. However, political upheavals politicized the issue of provisioning. The Hong Kong–Canton tie was problematized with the rise of an anti-imperialist movement in China. Canton’s reliance on foreign rice was also perceived as a problem when Nationalists consolidated their hegemony in Guangdong. The Guomindang elites embraced science and technology—especially statistics—using them to define and diagnose problems in China. Determined to solve China’s chronic food problems, which had [End Page 225] given it the disgraceful nickname of the “land of famine,” government statisticians identified Canton as the biggest importer of foreign rice. They argued that it was, therefore, responsible for the “biggest ‘leak’ of national wealth” (p. 128) and for aggravating the economic distress of the agrarian provinces in the country. To reduce the “leak” from Canton, and eventually to integrate Canton into the national economy, Guomindang technocrats launched ambitious programs to “reform” both the culture and geography of Canton. First, they launched a “national rice movement,” which encouraged the consumption of Chinese rice over foreign imports, while pursuing “‘scientific’ reform of daily eating habits” (p. 121) to reduce wasted food. These “northerners” saw the sophistication of Cantonese food culture as urban extravagance. In addition, they also built the magnificent Canton-Hankow Railroad, which connected Canton and the Pearl River Delta area to the northern province of Hunan, the rice bowl of China. Meanwhile, the network of Southeast Asian rice trade was disrupted by a new tax imposed by the Republican government. Ironically, right after the completion of the railroad, Canton experienced an unprecedented shortage of rice in 1936–37. Mistrust between the central government and the local elites made the provincial government incapable of importing enough foreign rice. The chaos in the rice market could not be easily solved, because the Guomindang technocrats already had dismembered the provisioning network of Cantonese merchants. In the end, with the increasing military threat from Japan, the central government monopolized the foreign rice trade. The author concludes that the Guomindang elites’ grandiose planning failed not because of their incompetence, but because of “their progressive stance and their audacious embrace of Western science and technology” (p. 220). Recently, one can notice an increasing amount of literature on food and nutrition from the perspective of the history of technology. Most studies are still done by Western scholars on “Western” foods. On the other hand, historical research on rice, the staple food of East and Southeast Asian people, has mainly relied...

Holocene delta evolution and sequence stratigraphy of the Pearl River Delta in South China

We analyzed the sedimentary characteristics and chronostratigraphy of the Pearl River Delta in South China, and discussed the Holocene stratigraphic characteristics and the filling process since the Holocene, based on 90 boreholes. Our results showed that the maximum transgressive surface of the Pearl River Delta was located in the soft marine silt horizons, whereas it was shown as an erosion surface in areas with tidal scour. From bottom to top, Holocene sedimentary sequences were fluvial facies, floodplain-estuary facies, and estuary-delta facies in the paleo-valley, while the paleo-interfluve sequences were described as littoral facies, estuary facies, and delta facies. Vertical accumulation sequences of Holocene sediments were shown primarily as positive tapering-shaped sequences with no typical foreset, topset, or other sedimentary sequences of the Gilbert Delta. The paleo-Pearl River estuary had different evolution models in the highstand systems tract (HST) compared with other large deltas worldwide, in that it is dominated by a unique and complex geomorphologic boundary, and that it is a multi-sourced delta compounded by the independent and parallel development of fluvial sedimentary bodies with different scales. A huge estuary was formed in the present Pearl River Delta area when the post-glacial transgression reached maximum at about 6 ka BP. The estuary was divided into two parts by obstruction of a series of islands, an upper part composed of the semi-enclosed inner paleo-bay connected to rivers and a lower part consisting of the outer paleo-bay connected to the ocean. Both of these areas were interlinked by only a few narrows, in which the fluvial sediments are accumulated primarily in the inner paleo-bay. During 6-2 ka BP, the sedimentation in various regions of the inner paleo-bay occurred simultaneously with independent development under the remodeling and transformation effect of complex boundaries on river and ocean dynamics. After 2 ka BP, the evolution of the delta is no longer a simple natural process, but rather a common remodeling process accomplished by nature and humans.