• 2015 Volume 35 Issue 3
    Published: 05 June 2015

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  • LIU Xilin,ZHANG Dalin
    2015, 35(3): 291-297.
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    In South China, a disintegrated hill caused by serious soil erosion is called Benggang. On 8 positioned points, a total of 6 times field monitoring for soil moisture in Liantanggang, a Benggang in Wuhua County, Guangdong, was implemented by PR2/6 soil moisture sensor during the 3 consecutive years during 2011-2013. The distributional patterns, variations and influencing factors of Benggang soil moisture were analyzed in this paper. The 3-years monitoring data of the 8 monitoring points showed that the vertical changes of the Benggang soil moisture could be divided into three modes: gradual augmentation, equilibrium and fluctuation. The coefficient of variation of soil moisture in each layer decreased from the top to the bottom of the Benggang, that indicated that the moisture in the upper layers of soil changed obviously and in the lower layers were stable. Horizontally, the coefficient in each layer became smaller from the gully mouth to the headwall, that reflected that the soil moisture changed greatly in the lower part and changed slightly in the upper part. Overall, the top soil moisture was low. The soil layers of 100 and 200 mm in depth were the driest with the moisture below 20%. As the depth of the soil increased, the moisture increased. In the depths of 300 mm, 400 mm and 600 mm, the soil moisture was greater than 20%. The soil moisture in each layer increased gradually from Benggang gully outlet to the inside. Spatial distribution of the soil moisture was influenced by vegetation covers, soil properties, and local landforms, showing the spatial distribution pattern with stochastic changes. 7-days antecedent cumulative rainfall had a significant influence on soil moisture, which was the major factor that should be considered in the studies of the relationship among soil moisture and Benggang instability as well as slope runoff on talus surface.

  • ZHU Aiping,CHEN Jianyao,JIANG Tao,LI Kun,GAO Qingwang,CHEN Yidong,ZHONG Jinlong
    2015, 35(3): 298-305.
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    In order to investigate the spatial and seasonal variation of nutrients and associated flux within a tidal cycle in the Maozhou Estuary, thirty-six water samples were collected from 3 sites (A1, A2 and A3) every two hours in January 2014 and analyzed for NH4+-N, -N, DTN,PO43--P, DTP, and  

    In order to investigate the spatial and seasonal variation of nutrients and associated flux within a tidal cycle in the Maozhou Estuary, thirty-six water samples were collected from 3 sites (A1, A2 and A3) every two hours in January 2014 and analyzed for NH4+-N, -N, DTN, PO43--P, DTP, and SiO32--Si. The results showed that the concentrations of NH4+-N, DTN, PO43--P, SiO32--Si were 15.8~19.8, 18.0~29.0, 0.25~2.15 and 6.16~9.03 mg/L at A1, 11.5~23.4, 25.9~53.6, 1.70~2.70 and 5.04~6.28 mg/L at A2, and 0.74~7.39, 3.06~24.9, 0.01~0.98 and 2.77~4.17 mg/L at A3, respectively. The changes of -N, DTN were consistent with that of tide at A2 except  PO43--P, DTP and SiO32--Si. NH4+-N and  PO43--P were found to be the major components of nitrogen and phosphorus. All nutrients except nitrate were correlated at a significant level of 0.01 with each other, indicating a common source of nutrients. Sewage discharge to the Maozhou River contributed principally to the high concentration of NH4+-N in the estuary. According to the results of nutrient ratios, it was considered that phosphate was a limiting factor for phytoplankton growth in the Maozhou Estuary. The fluxes of nutrients were calculated, yielding a high flux of -N of 48.0 and 71.8 g/s at A1 and A2 respectively.

    Si. The results showed that the concentrations of NH4+-N, DTN, PO43--P, SiO32--Si were 15.8~19.8, 18.0~29.0, 0.25~2.15 and 6.16~9.03 mg/L at A1, 11.5~23.4, 25.9~53.6, 1.70~2.70 and 5.04~6.28 mg/L at A2, and 0.74~7.39, 3.06~24.9, 0.01~0.98 and 2.77~4.17 mg/L at A3, respectively. The changes of -N, DTN were consistent with that of tide at A2 except PO43--P, DTP and SiO32--Si.  NH4+-N and PO43--P were found to be the major components of nitrogen and phosphorus. All nutrients except nitrate were correlated at a significant level of 0.01 with each other, indicating a common source of nutrients. Sewage discharge to the Maozhou River contributed principally to the high concentration of NH4+-N in the estuary. According to the results of nutrient ratios, it was considered that phosphate was a limiting factor for phytoplankton growth in the Maozhou Estuary. The fluxes of nutrients were calculated, yielding a high flux of -N of 48.0 and 71.8 g/s at A1 and A2 respectively.

  • SHENG Yingying,LAI Geying,LI Shiwei
    2015, 35(3): 306-314.
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    SWAT (Soil and Water Assessment Tools) model was used to calculate the non-point source pollution in the Meijiang River Watershed, which is a red soil region under the background of subtropical monsoon climate in Jiangxi Province. According to the measured data, SWAT model was adjusted to analyze the temporal-spatial distribution patterns of the non-point pollution load in the region. The hydrological processes and Nitrogen and Phosphorus nutrient loads were also calculated. Results showed that there was significant temporal-spatial characteristic in the watershed. In the time series, Nitrogen and Phosphorus pollution loads had obvious correlation with rainfall, the correlation coefficient was 0.909 and 0.921 respectively. The average annual emissions were mainly composed of infiltration, the contribution rate was 63%, that was associated with high vegetation coverage in the basin. On the spatial distribution, pollutants in the basin were mainly distributed in the Huangpi and Huitong valleys in the middle-lower reaches of the Meijiang, the spatial distribution of organic Nitrogen and that of organic phosphorus were basically identical. The loss amount of soil nutrient such as Nitrogen and Phosphorus under different land-use showed a great spatial variability in the region, the farmland had a high contribution to the non-point source pollution load. The results reveal the temporal-spatial distribution characteristics of non-point source pollution, and can be for reference of the conservation of soil and water and control of non-point source pollution in the watershed.

  • WU Xiaoning,FANG Weihua,LIN Wei,YE Yanting
    2015, 35(3): 315-323.
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    Hainan Island, located in the tropical and sub-tropical areas of South China, has been the largest base for rubber tree (Hevea brasiliensis) plantation and rubber production in China. Rubber trees are fragile to high wind, and therefore they have been suffering from the frequent tropical cyclones (TC) impacting Hainan. The quantitative evaluation of rubber tree fragility to TC wind is of vital importance to risk management, especially for catastrophe risk modeling. In this paper, firstly, the footprints of 16 TCs (1971-2010) are simulated at 1km grids with parametric TC windfield models considering both topographic and land use roughness effects. Then, the damage ratios of 2 rubber tree age groups (mature and young) from 5 damage types (overthrown, trunk snapped below 2 m, trunk snapped above 2 m, half-overthrown, and sheared) at farm scale are calculated based on rubber tree historical exposure and damage data. Thirdly, 3s peak gust wind (V3s) is selected to reflect wind hazard intensity, and the fragility curves for the 2 age groups and their 5 damage types are estimated through Beaufort Scale 6~14. In addition, the uncertainty of damage ratios is also quantitatively expressed. It is found that mature (young) rubber tree damage begins at Beaufort Scale 6 (7) and then increases with the wind speed, leading to almost 70% (55%) total damage ratio at Beaufort Scale 14; mature trees demonstrate a higher fragility than young trees; the uncertainty of the 10 vulnerability curves varies with wind speed interval, tree age group, and damage type. Fragility curves developed in this study have been applied in a catastrophe risk model for designing a parametric wind insurance scheme on rubber tree TC disasters in Hainan Province.

  • WANG Xuan,YIN Zhan’e,CHI Xiaoxiao,SUN Yuke,YIN Jie
    2015, 35(3): 324-333.
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    In order to understand the characteristics of precipitation under climate change, develop and manage the water resources rationally in Shanghai, the daily rainfall data during 1961-2010 of 10 meteorological stations and high-precision underlying surface data were used. The inter-annual and seasonal variations of different precipitation indexes in recent 50 years in Shanghai were analyzed by the methods of cumulative departure, smoothing averages, linear trend analysis, Statistical down-Scaling Model, Mann-Kendall mutation analysis and so on. Besides, percentile and DFA methods were used to define extreme precipitation threshold and the extreme precipitation frequency were added. Combined with DEM and land-use data, spatial distribution of high risk areas of flood disasters in Shanghai was studied by using the spatial analysis based on ArcGIS platform. The research indicates that: Firstly, there was an increasing trend about precipitation intensity, mainly displayed in that the frequency under rainstorm decreased while the amount increased, and the frequency increased in rainstorm as well as heavy rain, but there were significant time and intensity differences in urban, suburban and outer suburban districts; Secondly, there was an obvious increasing trend in precipitation amount in summer and winter and annual increasing rate of precipitation amount sliding 5 years reached 56.23 and 16.71 mm/10 a while spring and autumn experienced an unobvious decreasing trend; Thirdly, it is predicted that the precipitation would still experience a stable increase before 2050, but after that, the total amount of precipitation would reduce significantly and there would be an obvious mutation in 2075; Finally, it is expected that the upper reaches of the Huangpu River area would experience a much higher frequency of extreme precipitation and the high risk areas of flood disasters mainly would be distributed in the upper reaches and estuary of the Huangpu River.

  • ZHONG Wenting,BAI Aijuan,CAI Qinbo
    2015, 35(3): 334-342.
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    Based on the TRMM satellite data and NCAR/NCEP reanalysis data, this paper analyses the variations of precipitation characteristics of Typhoon ‘Nanmadol’ in 2011, especially its thermal and dynamic structures in its weakening phase after landing on the south part of Taiwan Island. The results show that: 1) The rainfall distribution of ‘Nanmadol’ is significantly asymmetric, and severe precipitation occurs at the eye-wall region, which mainly resulted from the convective cloud, but stratiform cloud contributes much to the total rainfall of typhoon than convective clouds. Within the four kinds of particles in the clouds, the content of cloud-water particles is the lowest, followed by ice-water, and the content of rain-water particles is the most than any others. Around the typhoon, precipitation mainly occurs in its southwest direction during the stage of infancy and weakening, but in the southeast direction in maturity stage with a more clear and complete structure. 2) The precipitation cloud of ‘Nanmadol’ is columnar in the vertical direction and can be extended up to about 10 km, while the heavy rainfall echo concentrates below the height of 5 km, especially at the level of 2-4 km. 3) After its landing, severe precipitation mainly occurs in its southwest direction, but in other orientations there is scattered and weak rainfall. The warm-moist core of typhoon inclines towards southwest with the height. At the same time the strong latent heat releases at the middle troposphere, which is about the height of 5 km. In one word, the air flows in the typhoon from the lower troposphere with strong convergence, and flows out it at the level of the tropopause with divergence in the unstable atmospheric stratification, which is benefit to the formation of heavy rainfall in the southwest part of typhoon center.

  • ZHOU Chunshan,DAI Dandan
    2015, 35(3): 343-353.
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    This paper discusses the driving characteristics of urbanization in the PRD by analyzing data on population, industry, resource, economic, et al in the last 30 years, based on the Grey Correlation Analysis Method. Then we use the panel data model to further explore the difference and evolution of the driving force influencing the transformation of urbanization in the PRD. The results find that industry, labors and land resources are still as its major impetus. However, in recent years, the push from factors, like land resources and labors, is significantly weaken. ‘export-oriented’ pattern of the urbanization, depending on foreign trade industry, gradually fades out. The ‘knowledge-oriented’ urbanization, based on production, usage and consumption of knowledge, technology and management, is gradually emerging. In a word, the urbanization in the PRD becomes gradually diversified, as well as faces transformation. But some new problems are also revealed, including the unsustainability of traditional factor-driven urbanization, the slow development and low quality of new pushing effects of knowledge in urbanization, the lagged system construction, the under developed domestic demand, etc. All the problems demonstrate that the transition of urbanization in the PRD is urgently needed. In order to further speed up the transition of urbanization, some suggestions are raised, such as to boost ‘innovative driving forces’ of urbanization, so as to realize the ‘transition of dynamics’ of urbanization, to promote ‘quality transition’ and ‘system transition’ of urbanization by building livable environments in urban and rural areas, and speeding up the urbanization of rural migrant workers and so on.

  • WANG Kun,LIU Zhen,HE Shenjing
    2015, 35(3): 354-363.
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    With the deepening of housing reform and socio-economic restructuring, gated communities have become the predominant residential form in Chinese cities. Much scholarly attention has been paid to understanding of the emergence, typology, and socio-spatial consequences of gated communities. Nevertheless, the subjects of gated communities, i.e. residents and their community living, have not been fully explored. There is a lack of empirical study, especially quantitative analysis on the topic. Drawing on a large-scale household survey conducted in Guangzhou in 2013, this paper aims to measure residents’ subjective perception and the intensity of community attachment based on three perspectives of community sentiment, i.e. ‘community loss’, ‘community saved’ and ‘community liberated’. Building upon multivariate regression models, this study systematically analyzes the determinants of community attachment in gated communities from three aspects, namely individual characteristics, social interactions, and built environment. The empirical evidence shows that intense community attachment still maintains in Guangzhou’s gated communities, although ‘community saved’ remains in a very limited way among residents. As this study unfolds, community attachment is largely affected by individual characteristics such as gender, age, marital status, and residential period, as well as social interactions within the community, such as neighborly relationship, neighborhood communication, community participation. Notably, apart from the degree of gatedness and the subjective assessment of built environment, the characteristics of built environment does not show much statistical significance to the attachment to gated communities.

  • GUO Huan,LI Shijie,ZHOU Chunshan
    2015, 35(3): 364-371.
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    The renewal of Guangzhou Civil Financial Street differs from other ones, most of which are driven by cultural tourism or creative industry. Based on deep interviews with government, firms, owners and other subjects, which were assisted by data analysis, the paper investigated the industry selection, model and effects of the renewal. It shows that civil financial industry brings along the renewal, which consists of environmental renewal, building emptying and industry injection, and it results in better environment, advanced function and protected cultural. Moreover, through analyzing problems of renewal driven by cultural tourism or creative industry, it suggests that other industries can also promote the renewal of historic districts.

  • TIAN Meiling,FANG Shiming
    2015, 35(3): 372-378.
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    The national central cities are the products of economic globalization. They play an irreplaceable role in the global economy and social development. However, there is no clear definition about the connotation and discriminant standard of national central city. On the basis of related literature research, the paper introduced the concept and functional characteristics of national central city systematically, and made it clear that national central cities are those who have core control effect in nationwide urban system, and have important node functions in the global urban network system. And then, the paper established a six-elements discriminant index system of national central city—economic agglomeration index, space radiation index, opening to the outside index, cultural innovation index, management service index and ecological protection index, by which confirmed 12 national central cities in China: Beijing, Shanghai, Guangzhou, Chongqing, Tianjin, Shenzhen, Wuhan, Nanjing, Chengdu, Hangzhou, Shenyang, and Dalian. Finally, according to the result, the paper comprehensively analyzed the discriminant index scores and the advantage and disadvantage of the 12 national central cities, and pointed out their construction emphasis in the future. Namely, to strengthen the management service function construction of national central cities, enhance the space radiation level overall, ensure sustained stable growth of the cultural innovation level, further speed up the construction of the economic agglomeration function, the opening to the outside world function and the ecological protection function.

  • CHAI Ziwei,WANG Shuailei,QIAO Jigang
    2015, 35(3): 379-385.
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    Though the high resolution data of GDP distribution is difficult to collect, it is very important for small scale regional development research. Night-time satellite images can be used to estimate GDP of administrative unit. In this paper, DMAP-OLS and NPP-VIIRS are used to estimate township GDP of the Pearl River Delta district: DMAP-OLS data are employed to modify NPP-VIIRS data, and then regression model about GDP and NPP-VIIRS Pixel brightness are built to estimate township GDP. Regional difference coefficients are employed to adjust the township GDP based on city level GDP data. Experiments show that the estimating accuracy of township GDP value in 2013 a reaches to 85%, and NPP-VIIRS data is valid data resource for township GDP estimation.

  • LI Song,LUO Xuqiang
    2015, 35(3): 386-392.
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    A segmentation approach based on small watershed patches to karst rocky desertification information extraction was presented to improve the objectivity of karst rocky desertification mapping. Taking the western region of Guizhou Province as a study case, this paper tested the segmentation approach based on small watershed patches to rocky desertification information extraction by using DEM (30 m) and an image of Landsat 8 captured on June 16, 2013. Consequentially, desertification stability index (DSI) was developed to analyze the effects of different patches on karst rocky desertification information, which were extracted from land use patches based on the image captured in 2013. The results showed that the percentage of moderate desertification or better extracted from two kinds of patches was over 80% of the karst area in study case. There was a variable difference in rocky desertification based on the two categories of patches, and the values of non-obvious, slight, moderate, severe and intense desertification were 66.5%, 26.8%, 72.4%, 75.4% and 55.9% respectively. The value of DSI was just 0.15. The segmentation method based on small watershed patches had a significant effect on karst rocky desertification information extraction. Finally, the image segmentation method based on small watershed patches indicated a geographical significance and stability, which was an effective method of karst rocky desertification information extraction.

  • PENG Shenghua,YIN Kuihao,WANG Yuexing,YANG Sheng
    2015, 35(3): 393-402.
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    The environment security situations of water sources in China’s highly urbanized areas are worrying; meanwhile, there exists an obvious application deficiency of advanced methods and tools to support the environment security management. To solve this problem, the functional requirements and the development schemes are discussed first and a GIS-based information system with several practical functions is developed then, taking a reservoir in Shenzhen for example. An actual application of the system to the example reservoir achieves following results: the environmental risk evaluation module indicates that Shawan Sewage Interception Sluice, municipal roads near the reservoir, and bridges across the reservoir surface are the major risk sources of accidental water pollution; the sensitive zoning module reveals the most sensitive zones of the water source are mainly located near around the head and the west side of the reservoir, however, there are still some such as Shatangbu community located relatively far away, which displays that this module can offset the defect of the technical guideline currently in effect for delineating source water protection areas concerning environmental risk prevention; the environmental prediction module shows that pollutants will cost at least 20 hours to disperse and be transferred to the intake near the dam, supposing an accidental pollution event takes place respectively at each site of the major risk sources; also using the environmental prediction module, both the flood flow at Shawan Sluice and the discharge from the sluice into the reservoir because of flood releasing can be forecasted in advance by using hourly measured rainfall, besides, the pollutants’ situation of transferring and diffusion in the reservoir can be simulated after the flood releasing; a real-time video surveillance and on-line monitoring of the reservoir water environment can be realized with the environmental monitoring module by installing associated equipments at suitable sites of both the sensitive zones and in the waters. The achievements demonstrate that the developed information system is both powerful and practical, and can be used to effectively support the environment security management of reservoir-type water sources in China’s highly urbanized areas.

  • TIAN Yichao,LIANG Mingzhong,HU Baoqing
    2015, 35(3): 403-415.
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    Based on land use data of the Qinjiang River Basin of the Beibu Gulf Rim in 2000 and 2012,This paper analyzed the temporal-spatial dynamic changes of land system and its spatial agglomeration effect with methods of land use transfer flow network and GIS density mapping, and evaluated the temporal-spatial heterogeneity of land use ecosystem service value with geostatistics methods. The results show that: 1) The built-up area, water body and garden land were increased, while the farmland, woodland and grassland were decreased in the Qinjiang River Basin; 2) There are 30 kinds of land transfer network flow relations in the whole land system on the basin, the upstream exists 27 kinds, the midstream 26 and downstream 17 kinds. The network transfer relationship between the farmland, built-up area, grassland and woodland dominates the main direction of land use change in the study area. 3) With different variogram function models for the spatial structure of the ecological service value, the best model for ecological service value matched in 2000 is the exponential model, while in 2010 it is the spherical model; 4) The overall amount of ecosystem services value in the Qinjiang River Basin reduced from 8.02 billion yuan in 2000 to 7.88 billion yuan in 2012, with a reduction of 142.83 million yuan. The ecological service value is highest in the midstream, followed by the upstream, and the downstream is minimum.

  • DENG Yan,JIANG Zhongcheng,LI Yanqing,HU Yang
    2015, 35(3): 416-421.
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    Using the stable isotope technique and water potentials, we research the water sources of typical plants in Guangxi and their respond to rocky desertification in three different rocky desertification grades. Results show that: Plant water potential and carbon isotope reduce with the increase of rocky desertification. No significant difference is found between the two dominant species both in water potential and carbon isotope in different rocky desertification areas. In slight and moderate rocky desertification area, an average of >70% of water for the two species comes from soil water, where soil is scattered only in rock fractures and is underlain by rigid carbonate rock. In intense rocky desertification area, V. negundo mainly uses rainwater which stored in fissures, and A. trewioides relies on a mixture of soil water and rainwater, which account for 57.6% and 42.4% of the total, respectively. These two deciduous shrub species use more previous rainwater (>40%) and little recent rainwater in intense rocky desertification area. Soil water is the important water sources for plant growth in rocky desertification area. Water quantity that plant uptake from shollow fractured rock zone is increased gradually in intense rocky desertification area. Plants have the same water use strategy against rocky desertification, such as low water potential and photosynthetic rate, high water use efficiency, and change of water sources.

  • LIANG Chunling,YU Quanzhou,LIU Yujie,ZHANG Zulu
    2015, 35(3): 422-426.
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    The normalized difference vegetation index (NDVI) of the Nansi Lake wetland vegetation in Shandong province were calculated on the basis of MSS, TM and ETM+ remote sensing data collected by the Landsat satellites. The main meteorological factors which influence wetland vegetation activities were deduced by NDVI. And combined with meteorological data in the study area, the asymmetric effects of daytime and nighttime air temperature on wetland vegetation were revealed. The results are as follows: 1) In the past 40 years, Tmax, Tmin and Tave have been increased in Nansi Lake wetland. The change feature between Tmaxand Tmin (R2=0.13 and 0.26 respectively) was different and increased 0.174℃ and 0.235℃ respectively. The change tendency of Tmin  was more significant. 2) If the human influences were removed, the asymmetric effects of circadian air temperature on wetland vegetation would be quite obvious. The wetland NDVI increased significantly with the increase of Tmax, and had no correlation with Tmin . This may be related to wetland adequate moisture and ecological effect of wetland vegetation caused by circadian air temperature. This study may have important reference for understanding vegetation response characteristic to air temperature in different ecosystems.

  • YAO Long,LIU Yuting
    2015, 35(3): 427-436.
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    This paper takes Conghua in Guangzhou City as the research area to analyze the types of rural development. The multi-factor indexes, including topography, location, size, economy and urbanization,tourism, etc., are selected. Using two-step cluster analysis of SPSS, five types of rural development in Conghua, including plain planting type, hills planting / forestry type, mountainous forest type, tourist type, and urbanization affected type, are categorized. And then, according to the classification, this paper explores rural development strategy, including large-scale, specialization, mountainous characteristic, cluster development and urban agriculture.

  • ZHAN Chijia
    2015, 35(3): 437-442.
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    The terrain is one of the important geographic features which affects place names in the natural environment. According to the statistics of 88 town names in Maoming City and 1 513 village names in the 88 towns, combined with the source of the place names in gazetteer and other literature information, the author concludes that there is close relationship between the place names in Maoming and its terrain, and the place names in mountain regions are related the most to the terrain, followed by those in hilly areas, and then by those in plain areas. Terrain not only has an impact on the place names, but also reflects people’s choice of their residential places, showing the toponymy culture in Maoming City. It is shown that the residents in mountain regions generally build their villages in lower areas of the valleys, and the residents in hilly regions often choose the hillsides or the valleys as their settlement sites. The place names in plains and terraces are normally related to the single hills there.