Table of Content

05 November 2016, Volume 36 Issue 6 Previous Issue    Next Issue

Trends of Rainfall at Shantou and Their Relationships with Global Surface Temperature during 1880–2015 XIE Jianqun，OUYANG Yujie，CHEN Xiuyun，ZHAO Meixia，CHEN Tegu 2016, 36 (6):  895-900.  doi: 10.13284/j.cnki.rddl.002899 Abstract ( )   PDF (576KB) ( )   Save In recent years, some investigations have been carried out to study the inter-decadal variability of precipitation in China. The earliest record of rainfall was from 1880 and a total of 127 years of complete records were taken for Shantou. This long precipitation sequence was very important for exploring the rainfall regime for the whole eastern region of Guangdong Province. The long-term changes in precipitation during a whole year, the pre-flood period (Apr.-Jun.), or the post-flood period (Jul.-Sep.), and their relationships with global surface temperature during 1880-2015 were analyzed using precipitation data from the Central Weather Bureau (for years of 1881-1943) and Shantou Meteorology Station (for years of 1951-2015) and global surface temperature data from HadCRUT 4 dataset. The methods of filtering analysis, linear regression analysis, spectral analysis and correlation analysis were adopted in this study. The following findings were highlighted: 1) The inter-annual and inter-decadal variations in precipitation during a whole year, the pre-flood period or the post-flood period were obvious during 1880-2015, and the primary periods for the annual precipitation sequence were 6, 8, 13, and 26 years during 1880-1938 and were 7, 8, 11 and 17 years during 1951-2015. There was no significant long-term increasing or decreasing tendency basing on this long precipitation sequence. For example, the precipitation during a whole year, the pre-flood period or the post-flood period fluctuated after treatment in filtering analysis. 2) The relationship between precipitation during a whole year, the pre-flood period or the post-flood period and global warming was complicated. There was a significant positive correlation between precipitation and global surface temperature during cold periods (1880-1939), especially in the pre-flood periods (Apr.-Jun.). There was no significant correlation between precipitation and global surface temperature during warm periods (1977-2015). But the variation magnitude of precipitation in the pre-flood period and the post-flood period increased with the increase of temperature, which suggested that the risk of drought or flood would increase accordingly. 3) According to the long-term changes in precipitation during a whole year, the pre-flood period or the post-flood period and the current precipitation evaluation standard adopted by the Guangdong Meteorology Administration, the frequency of normal precipitation in the pre-flood period would increase under the background of global warming, and the probability of less precipitation in the post-flood period would increase at the same time. These results were important for exploring the variation characters of precipitation for the eastern region of Guangdong over a long term period and useful for evaluating the possible effect of global warming on precipitation at Shantou in the near future. References | Related Articles | Metrics

Projections of Maximum Sea Level Recurrence Intervalnear Shenzhen at the End of the 21 th Century NIE Yuhua，TANG Chaolian，CHENG Zemei 2016, 36 (6):  901-905.  doi: 10.13284/j.cnki.rddl.002895 Abstract ( )   PDF (1177KB) ( )   Save The Chi-wan tide gauge station is the only oceanic tidal observation site on the west coast of Shenzhen that belongs to the State Oceanic Administration. Due to its special geological location, the Chi-wan Station is of significant importance in many fields, including sea level rise, storm tide prediction, and so on, in our country. In the present study, the tidal data of Chi-wan station ever since it was established were analyzed using a P-III curve-fitting method. The maximum sea level recurrence intervals at this station during 1965-2014 were obtained. The maximum sea level was 2.31 m for a one-hundred-years return period and 2.18 m for a fifty-years return period. Using an interpolation method, the yearly maximum sea levels at Chi-wan Station (x) and North Point/Quarry Bay Station (y) in Hong Kong during 1965-2011 were analyzed. It was found that there existed a significant correlation between x and y. The maximum sea levels in the recent one hundred years at Chi-wan station can thus be hindcast to be 2.7 m in 1962 and 2.34 m in 1937. According to the RCP2.6 in IPCC-AR5, the maximum sea level recurrence interval at Chi-wan Station at the end of the 21 th century (during 2081-2100) was also projected. It is projected to be 2.55 m for a one-hundred-year return period if the global sea level rises by 0.24 m and 2.71 m if the global sea level rises by 0.4 m. Finally, the influence of land reclamation on the sea level rising rate in the Ling-Ding waters and the influence of the No.0814 typhoon Hagupit on the storm tide at Chi-wan were discussed. The near shore terrain of Xixiang, which is located at the north part of Chi-wan, is very low. When the sea level exceeds 1.40 m, sea water will flow backwards in this area. That is to say, sea level rise in the future will increase the frequency of seawater flowing-backward near Chi-wan Station. Also, by analyzing the tidal observation data when typhoon passed by, it was found that, when typhoon Hagupit passed the Pearl River Estuary, the maximum sea level at Chi-wan Station increased by 1.46 m. In the present study, the maximum sea level recurrence interval at Chi-wan station was revised. This can not only improve the accuracy of water level warning in this area, but also provide reference for the prediction and precaution of storm tide in this sea area. References | Related Articles | Metrics

Influencing Factors of SST Variation along the South China Coast during 1960-2013 CHENG Zemei，TANG Chaolian，CAI Bing，SHEN Dongfang 2016, 36 (6):  906-914.  doi: 10.13284/j.cnki.rddl.002897 Abstract ( )   PDF (6049KB) ( )   Save Sea Temperature is a conventional subject of ocean research, and sea surface temperature (SST) research is the focus in the study of ocean temperature, which is the most valuable ocean hydrological element in the research of oceanographic physics and global climate change. With the observational data of SST from seven Marine Environmental Monitoring Stations (MEMS) along South China coast, Global average surface temperature, Pacific Decadal Oscillation (PDO), El Ni?o Southern Oscillation (ENSO), SCSH index and sea surface wind-speed during the period 1960-2013, we used the methods of linear regression，Yamamoto mutation test，wavelet analysis and correlation analysis to analyze the relationship between SST and global climate change, temperature of South China coast, SST of the South China Sea and SCSH index along the South China coast over the past 54 years, we also discussed the reasons for warming hiatus phenomenon in South China coast during the period from 1998 to 2013. The conclusions were as follows: 1) The annually averaged SST of all the MEMS showed a quasi-synchronous changes and significant warming trend over the past 54 years, the climate had an tendency rate of 0.08-0.17℃/10 a, with an average of 0.12℃/10 a, the most significant warming was in winter (0.20℃/10 a), secondly in autumn (0.14℃/10a), and minimum in spring and summer (0.09℃/10 a, 0.08℃/10 a); 2) The mutation of SST occurred in 1997/1998; 3) The character of SST variation was multi-spatiotemporal, with the main cycle of 2-4 years; 4) SST changes were influenced by ENSO events, and lagged behind MEI index by about 2-4 months; 5) We also found that the main factors affecting SST were global warming, PDO, enhancement of the subtropical high and sea surface wind-speed along the South China coast. References | Related Articles | Metrics

Seasonal Responses of Symbiodinium in Stress-tolerant Porites lutea to Environmental Factors on Fringing Reefs of the Hainan Island XU Lijia，YU Kefu，LI Shu 2016, 36 (6):  915-922.  doi: 10.13284/j.cnki.rddl.002900 Abstract ( )   PDF (2841KB) ( )   Save Due to global warming and increase in human activities, coral reefs worldwide have experienced severe declines recently，and scientific studies on their important causes keep on increasing. In this study, 194 samples of stress-tolerant Porites lutea were collected seasonally between October 2013 and August 2014 at fringing reefs in Sanya and Wenchang, Hainan Island, northern South China Sea (SCS), and their algal symbiont density and effective photochemical efficiency (Φ PSII ) were measured. The results indicated that both the Symbiodinium density and Φ PSII of P. lutea were subject to significant seasonal and spatial variations (Scheffe test，p＜0.05). Seasonally, the mean Symbiodinium density in P. lutea varied from (2.23 ± 0.18) × 10 6 cells/cm 2 to (6.08 ± 0.36) × 10 6 cells/cm 2 , with the lowest density occurring in winter but a higher value in summer; the mean Φ PSII of Symbiodinium in P. lutea varied from (0.599 ± 0.01) to (0.717 ± 0.002) during seasons, with a higher Φ PSII in winter yet a lower value in spring and summer. Spatially, the mean Symbiodinium densities in P. lutea at the two reefs were (4.54 ± 0.33) × 10 6 cells/cm 2 (Wenchang, 1-2 m depth), (4.65 ± 0.33) × 10 6 cells/cm 2 (Sanya, 1-2 m depth), and (3.75 ± 0.29) × 10 6 cells/cm 2 (Sanya, 4-6 m depth). Although there were not significant differences between Wenchang and Sanya areas, the mean Symbiodinium densities of corals within 1-2 m depth were higher when compared to corals within 4-6 m depth. The mean Φ PSII of Symbiodinium in P. lutea at the two reefs were (0.625 ± 0.009) (Wenchang, 1-2 m depth), (0.680 ± 0.005) (Sanya, 1-2 m depth), and (0.672 ± 0.004) (Sanya, 4-6 m depth), indicating Φ PSII of corals in Sanya area were higher as compared to corals in Wenchang. Cumulation over the month before sampling showed high correlations with the Symbiodinium density and Φ PSII of P. lutea suggesting that there was a time-lag effect of environmental factors on coral symbiont. Further analysis suggested that SST and nutrients in the reefs were responsible for the observed seasonal variations in symbiont density and Φ PSII of P. lutea, while the spatial difference of Φ PSII probably reflected the coral’s photo acclimation; besides, the cold-water upwelling (Qiongdong upwelling, QDU) had to be taken into account for the variations as well. As the reefs have been experiencing coastal constructing, significant marine culturing and tourist diving activities, the reef waters are at the risk of anthropogenic nutrification, thus, the viability of P. lutea is facing severe threat by the effects of nutrient enrichment and temperature increase. Since local management of nutrient enrichment could reduce the effects of global warming on coral reefs, efficient nutrient management strategies are urgently required to be developed and the action should be taken immediately. References | Related Articles | Metrics

Seasonal Patterns and Major Environmental Influences of Skeletal Density Bands of Coral Porites from the South China Sea WEI Wenwen，SHI Qi 1,YU Kefu，TAO Shichen，WAN Yang 2016, 36 (6):  923-934.  doi: 10.13284/j.cnki.rddl.002893 Abstract ( )   PDF (3953KB) ( )   Save Porites corals are dominant in the South China Sea (SCS) coral reef systems. Porites have been widely used in the coral-based high-resolution paleo-climate reconstructions, based on their seasonal skeletal density bands. There were local difference and contradictions on the seasonal skeletal density bands of Porites attributing to the single sample site in the previous studies. In this paper, gray value and geochemical proxies (Sr/Ca and δ 18 O) were analyzed by using digital image processing, inductively coupled plasma atomic emission spectrometry and gas isotope ratio mass spectrometer in 4 living Porites collected from four typical coral reef sites in the northern, middle and southern SCS respectively, including Wenchang, Yongxing Island, Panshiyu Reef, and Meiji Reef. As compared with the sea surface temperatures, the skeletal density showed significant seasonal variations in all samples, but the seasonal pattern of skeletal density band varied within the different sites. The high and low skeletal density bands formed separately in summer and winter in the Porites sample from Wenchang in the northern SCS; the high and low density bands developed separately in autumn and spring in the skeletal samples from Yongxing Island and in spring and autumn in the sample from Panshiyu Reef respectively in the middle of the SCS; and the high and low density bands of the skeletal sample occurred separately in winter and summer at Meiji Reef in the southern SCS. The Generalized Additive Mixed Model was applied to reveal the relationship of skeletal density to sea surface temperature, sea surface salinity and net shortwave radiation, respectively. Regardless of the random effects from sample individuals and sites, the results showed the different relationship between skeletal gray values and environmental factors in four sites: sea surface temperature and net shortwave radiation had negative correlation to the skeletal gray values in Wenchang; while skeletal gray values in Meiji Reef had strongly positive correlation with sea surface temperature and negative with net shortwave radiation; in Yongxing Island, significant positive correlation existed between skeletal gray values and sea surface salinity; and there was positive correlation between skeletal gray values and sea surface temperature in Panshiyu Reef, showing the distinctly different responses of skeletal density to the environmental factors in the four sites. However, when the random effects of the sample individuals and sites were taken into account, non-linear relationship was found between the skeletal density and the sea surface temperature and net shortwave radiation on the whole, but there was no positive or negative relationship between salinity and skeletal gray values. It means that over the large spatial scale in the SCS, the temperature and radiation were the possible major influences on seasonal skeletal density of coral Porites samples. Coral skeletal density increased with the rising sea surface temperature, when the temperature was higher than 27℃, the slope of density/SST decreased. In addition, the optimal radiation for the Porites was found to be 150 W/m 2 , coral density decreased when the radiation was higher than the optimum, in contrast, the density increased with the increase of the radiation when the radiation was lower than the optimum. References | Related Articles | Metrics

Geological Tectonic Setting and Zoning of Danxia Landform in Guangdong Province HUANG Qiongfang 2016, 36 (6):  935-943.  doi: 10.13284/j.cnki.rddl.002901 Abstract ( )   PDF (3620KB) ( )   Save Guangdong Province has a total of 67 places of Danxia landform, which are located in 22 faulted basins and mainly controlled by five north-east deep fractures and one east-west deep fracture in the Paleogene - Neogene uplift area. The strata are mainly Danxia Formation and Nanxiong Group and the lithologies are mainly conglomerate, gravel, and sandstone. The overall distribution of Danxia landform in the region is controlled by the Paleogene–Neogene crustal up-and-down movement, which is bounded by the line of 22.5°N. The area to the north of the line is uplift zone with great development of Danxia landform while that to the south of the line is settlement area without Danxia landform. The crustal up-and-down movement since late Pleistocene has led to the difference in number and size of different regions of Danxia landform: The northern and northeastern Guangdong are uplift areas where Danxia landform is more in number and larger in size, while the central Guangdong is settlement area where Danxia is less in number and smaller in size. Deep fractures control the distribution of faulted basins, which then control the development position of Danxia landform. According to the geological tectonic setting and the development characteristics of Danxia landform, Guangdong Province can be divided into four Danxia landform development areas: northern district, central district, northeast district and western district of Guangdong. References | Related Articles | Metrics

Population Status and Conservation Strategy of the Rare and Endangered Plant Glyptostrobus Pensilis in Guangzhou CHEN Yuqing，WANG Ruijiang，ZHU Shuangshuang，JIANG Aolin，ZHOU Lianxuan 2016, 36 (6):  944-951.  doi: 10.13284/j.cnki.rddl.002898 Abstract ( )   PDF (6787KB) ( )   Save Glyptostrobus pensilis is one of the state key protected wild plants listed in Class I, mainly distributed in South and Southeast China, and also found in Vietnam and Laos. It was very common in the Pearl River Delta Region previously but decreased quickly in the past 50 years because of serious disturbance from dramatic human activities, rapid habitat loss and its own physiological defects. It has been now evaluated as “Critically Endangered” category according to IUCN criteria. Our field investigation to the remaining populations of Glyptostrobus pensilis in Guangzhou has recorded the data of habitat types, community profiles, number of individuals, diameter at breast height, tree height, crown breadth, geographic coordinates, regeneration status and threat factors. The field investigation reveals that many wild individuals of G. pensilis died in recent five years and only 14 in eight populations were found in the field in Zengcheng and Conghua Districts, these individuals usually live near the ponds or ditches at village edge or downtown, each population include only 1–4 individuals and can’t be effectively enlarged by natural regeneration. Of these extant plants, half are in bad conditions or at the edge of death. Most existing individuals can produce seeds normally, but the seeds are usually embryos dysplasia and hard to germinate, or hardly survive after sprout. And although some individuals have been protected for conservation by local forestry departments, the trees are still in worrying condition because of the improper conservation strategies. In addition, these plants have not been protected scientifically and reasonably for a very long time. And most of them will become extinct quickly in wild because of the heavy survival pressure, if no any prompt and reasonable conservation methods are provided. Therefore, we put forward the following suggestions for the protection of Glyptostrobus pensilis in Guangzhou: 1) launch in situ and ex situ conservation work, enlarge the quantity of each population, maximally maintain its normal growth to postpone their death and strive to get more time for the population propagation; 2) take the opportunities of urban wetland construction to carry out ex-situ conservation of Glyptostrobus pensilis; 3) develop the seedling propagation, disease and pest control technique; 4) construct germplasm repository of Glyptostrobus pensilis, expand population heterogeneity, enhance genetic exchange, and protect genetic diversity of the taxus; 5) strengthen the conservation genetics research, find out the branches of the pedigree of its genetic structure, so as to guide the scientific practice of conservation biology. References | Related Articles | Metrics

Field Measurement and Analysis of Wind Characteristics at Site of Sea-crossing Bridge in Guangxi HE Ru，XIE Min，ZHOU Shaoyi，SUN Ming，SU Zhi，LI Qiang 2016, 36 (6):  952-959.  doi: 10.13284/j.cnki.rddl.002891 Abstract ( )   PDF (2205KB) ( )   Save In order to learn the wind environment and the parameters of the wind environment at the sea-crossing bridge in Guangxi, the characteristics of the mean wind (mean wind velocity and directions, maximum wind velocity and instantaneous maximum wind velocity) and the fluctuation wind (the wind attack angel, turbulence versus , turbulence integral scale and turbulence power spectrum) are presented at site of the bridge, on the basis of the field measurements of the near-ground wind environment using the observation instruments of gradient wind in a wind measurement tower, which is 55m in height, at 10, 33, 38, 48, 53 m and ultrasonic anemometer at the bridge surface height (43 m) during the whole year 2012. The designing wind velocity by using the wind observation data of Fangcheng reference meteorological station is calculated for different reappearing period at site of the bridge. The results show that: 1) The change of horizontal mean wind velocity followed the power exponent law, and the vertical wind shear indexes of complete wind sample and strong wind sample were 0.148 and 0.062, respectively. The observed maximum wind speed and instantaneous maximum wind speed were 26.0 and 29.3 m/s, respectively, and both of them appeared at the height of 53 m. The mean wind velocity in the first half of the year was greater than that in the second half. The annual dominant wind direction of mean wind field was partial to N, and so was in autumn, winter and spring, while it was partial to S in summer. 2) The wind attack angel of Typhoon Kai-tak was almost ±3°, which did not exceed the test range for wind resistance performance in specification. It reflected that the terrain of the site of the bridge was relatively flat. The turbulence variation was even and stable in the observed process of Typhoon Kai-tak. The change of turbulence versus changing in 3D direction had the same trend. The 3D turbulence versus had small fluctuation in strong wind period, and the value was small too. The turbulence integral scales of 3D changed with time slightly, and it was basically in agreement with the assumption of Taylor self-correlation function method. The turbulence power spectrum followed the -5/3 power law of Kolmogrove in inertial subrange, and a decrease trend of that was with the increase of wind speed. 3) The correlation between the maximum wind speed of Fangcheng reference meteorological station and that of the site of bridge was relatively good. The correction coefficient of strong wind speed was 1.398. The designing wind velocity at the bridge surface of 50 years frequency was 39.7 m/s and that of 100 years frequency was 42.7 m/s. References | Related Articles | Metrics

Soil Permeability in Relation to Groundwater Recharge from Rainfall Infiltration in the Leizhou Peninsula LIANG Dongmei，ZHAO Xinfeng，CHEN Jianyao，LI Kun，CAO Jifu 2016, 36 (6):  960-968.  doi: 10.13284/j.cnki.rddl.002902 Abstract ( )   PDF (8163KB) ( )   Save Leizhou peninsula in South China is facing a serious water shortage problem. Because of the special regional geomorphological and geological conditions, it is lacking in surface water, but abundant in groundwater resource. As ground water is the important water source for industrial and agricultural production and domestic use, it is of great significance to study the soil permeability and groundwater recharge potential area in order to maintain the long term sustainability of water resources. In this study, inversed auge-hold and groundwater level dynamic method are used to analyze soil permeability and groundwater recharge, respectively, and we try to delimitate potential areas of groundwater recharge. Soil permeability in the peninsula varies considerably at spatial scale, and soil hydraulic conductivities range from 0.04 to 8.83 m/d. In general, soil permeability in the southern Leizhou peninsula and Northwest Suixi County is good, while that in the central is poor. There are lots of factors making impact on soil permeability, such as land use, soil particle size, and soil organic matter, etc. With the increase of soil particle of median diameter and organic matter content, hydraulic conductivity increases. The average soil hydraulic conductivity under different land use types from high to low is in the order as: uncultivated land, eucalyptus land, sugarcane field, vegetable field, pineapple field, forest land, banana field, nursery garden, rice field. The mean annual precipitation recharge coefficients range from 0.04 to 0.41, and they are high in the North and South, and much lower in the central areas. However, recharge coefficients from rainfall are high in Zhanjiang urban area, which may be associated with groundwater exploitation. It can get more lateral recharge caused by increased hydraulic gradient besides natural rainfall recharge. Except Zhanjiang urban area, infiltration coefficient distribution characteristic is consistent with that of topography and soil permeability coefficient. And recharge coefficient increases with the increase of soil hydraulic conductivity (K< 2 m/d). While soil hydraulic conductivity is greater than 2 m/d, soil permeability makes less impact on recharge, and embedded depth of groundwater and rainfall may be the main limiting factors of rainfall infiltration. Nevertheless, because of the limitation of phreatic well observation data, there is a little deviation for precipitation recharge coefficients, and it’s hard to get a more explicit relationship between recharge coefficients and soil hydraulic conductivity. Influential thematic factors, including geomorphology, soil permeability and groundwater recharge are integrated to identify groundwater recharge potential area. Results of the study reveal that higher groundwater recharge potential areas are in the Southern Leizhou peninsula, where the terrain, hydraulic conductivity, and recharge coefficient are relatively high. In order to improve the soil permeability and groundwater recharge capacity, we suggest that more trees or grasses in the uncultivated land, especially bare land, should be planted, and, in nursery garden area, if possible, fallow and crop rotation might be a better choice. References | Related Articles | Metrics

Runoff Simulation of Main Urban Area in Guangzhou City Based on the Improved Linear Spectral Mixture Analysis and SCS-CN Models XU Jianhui，ZHAO Yi，ZHONG Kaiwen，LIU Xulong 2016, 36 (6):  969-975.  doi: 10.13284/j.cnki.rddl.002894 Abstract ( )   PDF (11564KB) ( )   Save Quantitative research of the urban rainfall-runoff process is of great importance for exploiting, utilizing, planning, and managing the urban rainwater resources. In this study, an improved linear spectral mixture analysis (LSMA) method is developed by integrating the normalized difference built-up index (NDBI) and normalized difference vegetation index (NDVI). The improved LSMA method needs two steps: (1) the representative endmembers are first selected by combining a high-resolution image from Google Earth; (2) the results of LSMA are post-processed with NDBI and NDVI. During the post-process, if the NDBI value of a pixel is greater than -0.15, that pixel in the low-albedo fraction image is classified into low-albedo impervious surface; otherwise, pixels in the low-albedo fraction image are kept and classified as low-albedo pervious surface. In the low-albedo pervious surface fraction image, pixels with NDVI value less than 0.2 are classified as low-albedo soil fraction, other pixels are classified as low-albedo vegetation fraction. Finally, the impervious surface fraction is equal to the summation of high-albedo and low-albedo impervious surface fractions. The vegetation fraction can be estimated by the addition of original vegetation and low-albedo vegetation fractions. The soil fraction can be calculated by the summation of original soil and low-albedo soil fractions. Combining Landsat 8 OLI image on 18 th October, 2015 in the main urban area of Guangzhou, this improved LSMA method is then implemented to extract the fraction maps of impervious surface, vegetation, and soil. The results show that the improved LSMA with higher accurate results outperforms the conventional LSMA. This method can reduce errors in the low-albedo image. On the whole, the improved LSMA can significantly reduce the bias and root-mean-square error (RMSE). A soil conservation service curve number (SCS-CN) method is applied for simulating and analyzing the surface runoff under different return periods of precipitation. The key parameter CN in the SCS-CN is estimated with the fractions of impervious surface, vegetation, and soil and their corresponding initial CN values. The results show that high-quality impervious surface, vegetation, and soil fractions may be used to calculate the real CN. Higher CNs are located in these regions with higher impervious surface fraction except water. High CN indicates a low infiltration rate. The cumulative infiltration increases with the decreasing of CN. CN has a significant impact on the surface runoff simulation. A distinct spatial difference can be found in the surface runoff simulation. In general, if the precipitation intensity and impervious surface fraction are high, and the surface runoff is deep, the region will be easy to form waterlogging. References | Related Articles | Metrics

Remote Sensing Method Based on Multi-temporal NDVI Phenological Characters for Winter Potato Planting Area in South China HUANG Siyu，CHEN Shuisen，LI Dan，LIU Wei，WANG Chongyang，JIANG Hao 2016, 36 (6):  976-984.  doi: 10.13284/j.cnki.rddl.002892 Abstract ( )   PDF (4951KB) ( )   Save Vegetation index of each pixel in remote sensing image reflects the growth state of vegetation covered by pixels. If the vegetation index images obtained from all remote-sensing images in one year in the same area are lined up, the dynamic change of vegetation index time series can mirror the phenological rules in this area. Potato is a special kind of winter-planted crop in South China, and relevant parcels show peculiar curve characters of vegetation index time series in planting pattern–“early season rice–late season rice–winter-planted potato”. Taking Renping Peninsula in Huizhou City, Guangdong Province, as research area and the planting area of winter potato as research object, the paper makes use of those characters and employs HJ image data in 2011 as the primary data, with totaling 14 scenes’ HJ-1 A/B CCD remote sensing image data being used. After calculating the NDVI (Normalized Difference Vegetation Index) of images in each scene, NDVI time serials data set is obtained. Corresponding NDVI time serials curve of 26 training sample points is achieved for averaging, thus getting NDVI time serials character reference curve. Moreover, SAM (Spectral Angle Mapping) is used to calculate the value of spectral angle between NDVI time series curve of each pixel in the NDVI time serial data set and NDVI time series character reference curve, obtaining the image of spectral angle value. The pixel value in this image is the value of spectral angle between NDVI time serials curve of each pixel in the NDVI time serial data set and character reference curve. The 2-time standard deviation, 2.5-time standard deviation and 3-time standard deviation of the image of spectral angle value are taken as the threshold value. The spectral angle value of each pixel in the image of spectral angle value and the threshold value are compared, and if the spectral angle value is less than the threshold value, this pixel is classified as a target object, so as to separate the target pixel from pixelscovered by other types of land on the remote sensing images, for the purpose of rapidly and effectively extracting the planting area of winter potato. According to the comparative analysis, it is found that the result extracted by taking 2.5-time standard deviation as the threshold value fits best the actual planting conditions, thereby serving as the final extraction result. Research findings show that the overall extraction accuracy is 82.70% in the research area and 93.75% in key planting areas. This method, as one of the typical applications of homemade optical satellite to agriculture in South China, can extract the winter potato area effectively and will lay a firm foundation for accurately and rapidly monitoring other agricultural information (such as winter-fallowed cultivation) in South China where there is much cloud, rain and broken land. References | Related Articles | Metrics

Integrated Village Renewal Practices and Its Enlightenment on the New Urbanization in China: A Case Study of Weyarn, Germany ZHANG Junjie，OUYANG Shishu 2016, 36 (6):  985-994.  doi: 10.13284/j.cnki.rddl.002906 Abstract ( )   PDF (7925KB) ( )   Save New-type urbanization is a grand strategy for future long-term development of China, and serves as grasps of the reform in depth. Closely related village renewal would quickly become a hot spot and develop into an advanced stage. From the theory of the German integrated village renewal and the practice of the Weyarn renewal, the origin of the integrated village renewal, content definition，the Weyarn rural development policies and bidirectional influence were summarized in this paper. It is shown that Weyarn integrated village renewal development strategy includes: cohesion of common development vision and a high level of public participation, professional help and network cooperation, effective operation of land management, the rural area blocking the spread of the city to the suburbs，and the leading role of local government. For the construction of new urbanization in urban village regions, some enlightenment can be attained: “Nostalgia” is the foundation of the integrated village to extend and enrich the connotation of the construction of new urbanization. Public participation is a substantial basis for the village to update and enhance the implementation of the new urbanization cohesion. Talents are the key elements of the village updated to ensure the continued health of the new urbanization. The ideal goal is livable village renewal, guiding the new urbanization value orientation. Efficient service is a strong guarantee for village renewal, leading to the new urbanization policy breakthroughs. Integrated village renewal improves the quality of community building and strengthens the strategic basis for the construction of new urbanization. References | Related Articles | Metrics

Rural Development Types and the Spatio-temporal Changes of Rurality in Guangdong Province LIANG Zhongya，FENG Yanfen 2016, 36 (6):  995-1004.  doi: 10.13284/j.cnki.rddl.002903 Abstract ( )   PDF (3391KB) ( )   Save This paper combines the relation theories of regional economics, development economics mathematical model, the theory of regional sustainable development and human geography, and takes the Guangdong Province as the research object and its 67 cities as research units. The data is collected from Guangdong Province Statistical Yearbook. According to the industry GDP of Guangdong Province, this paper classifies the rural development types. By establishing the rurality evaluation index system and using the method of analyzing the relevant regional economy,mathematical model analysis method, and ArcGIS, this research estimates the rurality index (RI) about 67 counties area of Guangdong Province in 2001, 2005, 2009 and 2013, and then divides the counties into five types by the degree of rurality index. Currently, both rural development and urban development in China are experiencing a transition period. Assessing the rurality and making the development direction clearer is helpful to promote the balancing urban-rural development and new countryside constructions. This article masters the spatio-temporal variation characteristics of rural development in Guangdong Province in recent 10 years. Furthermore, the authors try to analyze the causation of spatial differentiation of rurality. Rural development depends on the change of its influencing factors, such as social and economic development, the changes of population structure, opening to the outside. So, the rural development types classified in this paper cannot always keep the same situation, at least the quantitative change occurs momently. The results showed: Firstly, the 67 counties in Guangdong Province are divided into four types of rural development: agricultural leading rural, industrial leading rural, service leading rural and balanced development rural. Among them, the balanced developmental rural areas in each year is the largest, agricultural leading rural areas reduce year by year, industry leading areas is in the state of fluctuation change, business travel service rural areas is relatively stable. Secondly, the average of rurality index (RI) of each county of Guangdong Province fall down from 0.60 in 2001 to 0.34 in 2013, the lowest rurality index for industry leading country, the highest for agricultural leading country, the biggest change is balanced developing country. Thirdly, this article divides the counties of Guangdong Province into five types such as the weakest rurality, weaker rurality, moderate rurality, stronger rurality and the strongest rurality. In recent 10 years, the area of the weakest rurality and weaker rurality countries are greatly increased, the area of moderate rurality countries are increased and then it shows a declining trend, stronger rurality countries reduce greatly, while the strongest rurality countries gradually disappear. Fourthly, the changes of rurality index level of rural development types differs from each other, among them, the agricultural leading and industry leading countries decrease steadily, the travel service leading countries experience a steady stage and then fall down, the balanced developing countries decrease considerably. References | Related Articles | Metrics

Spatial Evolution Characteristics of Island Rural Settlements under the Background of Rapid Urbanization: A Case Study of the Haitan Island of Fujian SU Mulan，DAI Wenyuan，HUANG Huafu，GUO Qiang，HUANG Jianbin 2016, 36 (6):  1005-1018.  doi: 10.13284/j.cnki.rddl.002890 Abstract ( )   PDF (24011KB) ( )   Save Man-Land Relationship emerging in the process of rapid urbanization exerts an important influence on the distribution of the settlements, especially for Haitan Island having been the Hercynian construction comprehensive experimental area in 2009. Our study was based on a series of digitalized vector data, including the locations of settlements, land slopes, river networks and road networks obtained from remote sensing (RS) images of the county of Pingtan in Fujian Province for 2000, 2009 and 2013.Then we combined the Geographic Information Systems (GIS) and RS spatial analysis techniques to quantitatively analyze the processes, patterns, and trends of spatial evolution in settlements. Finally, we explored landscape pattern indexes to examine in depth the factors influencing the distribution characteristics of settlements in the study area. Our results showed that: 1) In general, the rural residential areas were increased by 399.69 hm 2 from 2000 to 2013, most of which were originally farmland and woodland, and the last 4 years (2009-2013) had a higher increment and growth rate. 2） Haitan Island of rural residential expansion had two major forms: one was patch massive expansion, that was, along the original patches spreading to the surroundings outwardly; second was strip extension , namely along the highway to the two sides or one side extension of villages and towns. 3）And there was significant clustering in the spatial distribution of rural settlements in Haitan island during 2000, 2009 and 2013; This settlement pattern was even more significant in 2013. However, there was no obvious change in the concentrated locations of clusters. 4） The presence of land slopes, rivers, and roads significantly influenced the distribution of settlements in Haitan island as evidenced by the following findings. More than 80% of settlements were located in areas with slopes of less than 10 degrees; over 75% of settlements were located in the landforms of flatlands, platforms and low hills; almost 80% of settlements were located within 1 500 m from a river network and almost 95% of settlements were located within 500 m from a road network. References | Related Articles | Metrics

Spatial Effects of Shenzhen-Zhongshan Bridge on Regional Accessibility in the Pearl River Delta LAN Zhiwei，WU Qitao，ZHOU Zhiyong 2016, 36 (6):  1019-1025.  doi: 10.13284/j.cnki.rddl.002905 Abstract ( )   PDF (1836KB) ( )   Save Trans-strait bridges have significant time-space compression effect and can greatly enhance the transport and economic connection of urban agglomerations. This research used the accessibility analysis model and four indices, including weighted average travel time, daily accessibility, potential accessibility and coefficient of variance, to assess the comprehensive impacts of the Shenzhen-Zhongshan Bridge (SZB) on the Pearl River Delta regional accessibility and regional equity. The results showed that: the Shenzhen-Zhongshan Bridge greatly improved the regional accessibility, and the south region benefited more than the north part, including the Zhuhai City, Jiangmen City and Zhongshan City, while the north of the Humen Bridge was less impacted. The west region was not as significantly improved as the east region due to the high population and economic density in the east region. Zhongshan City and Zhuhai City had the largest population increase in their 1-hour isochronous rings. Shenzhen City and Hong Kong in the east part and Zhongshan City and Jiangmen City in the west part of the Pearl River Delta became the biggest winners in terms of potential accessibility. Zhongshan City, Dongguan City and Foshan City had decreased accessibility coefficients of variance, and accessibility and spatial equity were improved. Eight cities and regions, including Zhuhai City, Jiangmen City, Hong Kong, Macao, Shenzhen City, Guangzhou City, Zhaoqing City and Huizhou City had increased accessibility coefficients of variance and the accessibility and spatial equity reduced. Finally, the paper gave three decision-making suggestions to optimize the function of the Bridge. References | Related Articles | Metrics

Estimation of Value-Added in Provincial Exports and Its Impact on Industrial Structure LI Fangyi,LIU Sijia，TANG Zhipeng 2016, 36 (6):  1026-1033.  doi: 10.13284/j.cnki.rddl.002904 Abstract ( )   PDF (2089KB) ( )   Save There are significant differences existing among regions of China in terms of trade scale, trade structure and value-added in trade. With the development goals of economic development pattern transformation and innovation-driven strategy, studying the impact of provincial export on industrial structure has important theoretical meaning to optimize the regional trade structure and promote the pattern transformation. Value-added in exports of each province in China was calculated based on China's non-competitive multi-regional input-output table of 2010 in this study. Based on Exports Promotion Index, Industrial structure of value-added in exports was analyzed and compared with that at national and regional scale to assess its impact on industrial structure. The results showed that, significant differences existed in the impact of value-added in provincial exports on national industrial structure. According to the impact of value-added in exports on industrial structure, regions were divided into four types, i.e., resource-based region, technology-leading region, service-promotion region and export-starting region. The first three kinds of region promoted the percentage of resource-intensive, technology-intensive and service industry in GDP, respectively, which reflected that the resource-based region exports might hinder the transformation and upgrading of national industrial structure, and even deepen the path dependence on resource consumption, while technology-leading region and service-promotion region exports would be conducive to the transformation and upgrading of national industrial structure. However, the fourth type region showed limited impact on national industrial structure. At the provincial scale, regions were divided into six types according to the positive or negative impacts of value-added in exports on resource-intensive industry, technology-intensive industry and service industry. The first three types of regions promoted the three types of industries in regional GDP, but the last three types of regions showed the opposite effects. Value-added in exports of underdeveloped regions promoted their industrial structure upgrading. In contrast, value-added in exports of developed regions needed upgrading, because it promoted resource-intensive industry and technology-intensive industry but hindered service industry in regional GDP. Especially in Beijing, Tianjin, Shanghai and other economically developed regions, the value-added in exports of service industry was still low, which was not conductive to regional economic transformation and upgrading. The value-added structure needed to be further optimized. Suggestions to promote and improve value-added in regional exports were proposed. Firstly, building the global important advanced manufacturing base, encouraging domestic enterprises for independent innovation, extending processing trade chain that would make the processing trade develop from shallow processing to deep processing and from labor-intensive to knowledge- and technology-intensive, and finally promoting manufacturing to upgrade in eastern coastal provinces; Secondly, attaching great importance to introduce and use foreign technology, human resources and intangible assets management experience, promoting the precious experience of free trade area, attracting international high-end service business investment and operations, pushing local service industry towards high-end and internationalization to construct global or regional trade and financial center in the eastern megacities and expand services export; Moreover, further reducing the export trade costs in central and western regions and promoting the trade structure diversification. And firmly grasping the historical opportunity of “The Belt and Road” strategy implementation to strengthen international cooperation, expand international freight routes, simplify customs clearance procedures and improve extroverted degree of inland provinces. References | Related Articles | Metrics

Spatial Congregation and Social Segregation of Japanese Expatriates in Guangzhou, China HUANG Shuyu，XIAO Ling 2016, 36 (6):  1034-1044.  doi: 10.13284/j.cnki.rddl.002896 Abstract ( )   PDF (7200KB) ( )   Save With the development of economy, society, science and technology, the number and space span of global migration both have increased sharply. Moreover, the spatial congregation and social segregation of newcomers have started to be an important issue about foreigner management. In this paper, we focus on Japanese expatriates who are our research object. By the means of semi-structured interview, statistics and information collection, field reconnaissance and other methods, we analyze the condition and reasons of spatial congregation and social segregation of Japanese expatriates in Guangzhou. We find that there are three Japanese clusters have been formed in Guangzhou: 1) Huanshidong Road cluster, 2) Tianhe North-Tianhe South cluster, 3) Wuyang New Town-Zhujiang New Town cluster. The reason why these three clusters have formed is that Japanese enterprises have entered Guangzhou under the terms of global capital allocation and local development response, immediately following Japanese expatriates immigrated into Guangzhou. What’s more, the branch offices or agencies of Japanese enterprises are always located at High-grade office buildings in city center, which also attract Japanese expatriates to live in because of its convenience and comfort. We find that the mechanism of new type migration is different from that of traditional type. Influenced by transnational economy, the new type migration is passive and regular. The spatial distribution of clusters is always related to the distribution of transnational enterprises and the development of urban economy. In the other aspect of research on the social segregation of Japanese expatriates, we find that there are two types of social segregation: actively and passively. And there’s differentiation in the extent of Japanese expatriates’ social segregation, which is connected with their dwelling time in China, gender and age. The longer time in China makes Japanese expatriates less segregated. The social segregation extent of Japanese male expatriates is lower than that of the female, and that of the younger expatriates lower than the olders’. This is due to three kinds of reasons. The first reason is external objective factors, including arrangement by Japanese enterprises, Japanese media, different languages and club activities, bilateral relation and visa policy. The second reason is internal subjective factors, including national characters of Japanese and the differences in work thinking between Japanese and Chinese. The last reason is the transnational economic and social activities. Thereinto, the external objective factors play a basic role, which as preparatory condition, have a great influence on social space of Japanese. The transnational social space constructed by transnational activities of Japanese expatriates has internal unity and external exclusiveness and defensiveness. There are two research findings different from previous research results: 1) High-skilled expatriates who come from the developed countries and immigrate to the developing countries have the property of spatial congregation, and they gathered in convenient and high-end residential area generally. 2) The increase of transnational activities would lead to strengthening the social segregation of migration. Therefore, when analyze the influence of transnational activities on migration, we should consider the social and economic factors of immigration area and emigration area. The individual differences of study object need to be taken into consideration likewise. References | Related Articles | Metrics

The Culture of Place Names of South China Sea Islands from the Cultural Ecology Perspective ZHAO Jing，ZHANG Zhengsheng，CHEN Guanqi，NAN Wenlong 2016, 36 (6):  1045-1056.  doi: 10.13284/j.cnki.rddl.002907 Abstract ( )   PDF (5743KB) ( )   Save As place names have rich cultural connotation, they have attracted more and more researchers. The South China Sea is a politically sensitive area in our country, considering its constant sovereign friction. In this point, research of cultural and historical evolution of the place names can provide strong evidence for safeguarding China’s sovereignty. In this study, based on the data about place names and the changes and evolution of the South China Sea Islands, we analyzed the book “Road Change Records” and place names data of the South China Sea Islands at different times using the text analysis method. Then the place names evolution was visualized using ArcGIS, and in-depth interviews with local fishermen and old captains were conducted. It was found that, the folk place names of South China Sea Islands were named mainly based on the natural geographical environment characteristics. The replacement and disappearing of place names was closely related to social and cultural environments. Most place names published in 1935 were the transliteration of English names, and the place name change in 1947 was mainly aimed to wiping off foreign elements and replace with beautification or memorial place names. There were few changes in the place names published in 1983 compared with the standard names published in 1947. Of the 118 place names, 39 were new names which had not been published before, and almost all of them were adopted from the folk place names given by fishermen. References | Related Articles | Metrics