Yansui Liu

Spatio-temporal analysis of land-use conversion in the eastern coastal China during 1996-2005

Based on the acquaintance of the regional background of urban-rural transformational development and investigations on the spot, this paper discusses the holistic situation, dominant factors and mechanism of arable land loss and land for construction occupation in the coastal area of China over the last decade, with the aid of GIS technology. Conclusions of the research are summarized as follows: (1) the arable land had been continuously decreasing from 1996 to 2005, with a loss of 1,708,700 hm2 and an average decrement of 170,900 hm2 per year; (2) land for construction increased 1,373,700 hm2, with an average increment of 153,200 hm2 per year; (3) total area of encroachment on arable land for construction between 1996 and 2005 was 1,053,100 hm2, accounting for 34.03% of the arable land loss in the same period, the percentages of which used for industrial land (INL), transportation land (TRL), rural construction land (RUL) and town construction land (TOL) are 45.03%, 15.8%, 15.47% and 11.5%, respectively; and (4) the fluctuation of the increase of construction land and encroachment on arable land in the area were deeply influenced by the nation’s macroscopic land-use policies and development level of regional economy. The growth of population and advancement of technology promoted the rapid industrialization, construction of transportation infrastructures, rural urbanization and expansion of rural settlements in the eastern coastal area, and therefore were the primary driving forces of land-use conversion.

Analysis of arable land loss and its impact on rural sustainability in southern Jiangsu Province of China.

Rapid urbanization and industrialization in southern Jiangsu Province have consumed a huge amount of arable land. Through comparative analysis of land cover maps derived from TM images in 1990, 2000 and 2006, we identified the trend of arable land loss. It is found that most arable land is lost to urbanization and rural settlements development. Urban settlements, rural settlements, and industrial park-mine-transport land increased, respectively, by 87 997 ha (174.65%), 81 041 ha (104.52%), and 12 692 ha (397.99%) from 1990 to 2006. Most of the source (e.g., change from) land covers are rice paddy fields and dryland. These two covers contributed to newly urbanized areas by 37.12% and 73.52% during 1990-2000, and 46.39% and 38.86% during 2000-2006. However, the loss of arable land is weakly correlated with ecological service value, per capita net income of farmers, but positively with grain yield for some counties. Most areas in the study site have a low arable land depletion rate and a high potential for sustainable development. More attention should be directed at those counties that have a high depletion rate but a low potential for sustainable development. Rural settlements should be controlled and rationalized through legislative measures to achieve harmonious development between urban and rural areas, and sustainable development for rural areas with a minimal impact on the ecoenvironment.

Assessment of grassland degradation near Lake Qinghai, West China, using Landsat TM and in situ reflectance spectra data

The severity of grassland degradation near Lake Qinghai, West China was assessed from a Landsat Thematic Mapper (TM) image in conjunction with in situ samples of per cent grass cover and proportion (by weight) of unpalatable grasses (PUG) collected over 1 m2 sampling plots. Spectral reflectance at each sampling plot was measured with a spectrometer and its location determined with a Global Positioning System (GPS) receiver. After radiometric calibration, the TM image was geometrically rectified. Ten vegetation indices were derived from TM bands 3 and 4, and from the spectral reflectance data at wavelengths corresponding most closely to those of TM3 and TM4. Regression analyses showed that NDVI and SAVI are the most reliable indicators of grass cover and PUG, respectively. Significant relationships between TM bands-derived indices and in situ sampled grass parameters were established only after the former had been calibrated with in situ reflectance spectra data. Through the established regression models the TM image was converted into maps of grass cover parameters. These maps were merged to form a degradation map at an accuracy of 91.7%. It was concluded that TM imagery, in conjunction with in situ grass samples and reflectance spectra data, enabled the efficient and accurate assessment of grassland degradation inside the study area.

A HOLISTIC APPROACH TOWARDS ASSESSMENT OF SEVERITY OF LAND DEGRADATION ALONG THE GREAT WALL IN NORTHERN SHAANXI PROVINCE, CHINA

The farming and grazing interlocked transitional zone along theGreat Wall in northern Shaanxi Province is particularly vulnerable to desertification due to its fragile ecosystem and intensive human activity. Studies reveal that desertification isboth a natural and anthropogenic process. Four desertificationindicators (vegetative cover, proportion of drifting sand area, desertification rate, and population pressure) were used to assess the severity of desertification in a GIS. The first threefactors were derived from multitemporal remote sensing and landinventory data. The last factor was calculated from census data.It was found that the overall severity of land degradation in thestudy area has worsened during the last two decades with severely, highly and moderately degraded land accounting for 84.2% of the total area in 1998. While the area affected by desertification has increased, the rate of desertification has also accelerated from 0.74 to 0.87%. Risk of land degradation in the study area has increased, on an average, by 155% since 1985. Incorporation of both natural and anthropogenic factors inthe analysis provides realistic assessment of risk of desertification.

GIS-based assessment of land suitability for optimal allocation in the Qinling Mountains, China

A GIS-based method was used to assess land suitability in the Qinling Mountains, Shaanxi Province of China through simultaneous consideration of physical features and current land use. Through interpretation of Landsat TM images and extensive field visits the area was modeled into 40 land types in five altitudinal zones (valleys and gullies, hillsides and terraces, foothills, mid-mountain, and sub-alpine mountain). Then, a suitability score was assigned to five physical factors (climate, hydrology, topography, soil, and vegetation). Next, their integrated overall suitability value scores were compared with the observed land cover to determine whether it should be reallocated a new use. Results showed that the five suitability classes of agriculture, forest, grassland, farmland-woodland, and scrub-pasture had altitudinal stratification and a total of 1151 km2 (8.89%) of lands on the northern slopes of the Qinling Mountains had to be reallocated. To achieve this reallocation, 657 km2 of arable land should be reduced, and forest, grassland and scrub-pasture increased by 615 km2, 131 km2 and 405 km2, respectively. Implementation of these recommended land reallocations should help achieve suitable use of land resources and prevent land degradation.

Spatio-temporal characteristics of rural settlements and land use in the Bohai Rim of China

Based on multiple remote-sensing image interpretation and classification, and economic and social data, this study focused on rural settlement and land use change amidst rapid urbanization. Rural settlements, spatial and temporal patterns of land use and influencing factors in the Bohai Rim were explored within 5×5 km grid cells, as per GIS spatial analysis and geostatistical analysis. Results show that the spatial distribution of rural settlements in the Bohai Rim is remarkably varied. The number of rural settlement sites in a 5×5 km grid cell exceeding 5.0 are distributed in a six-area pattern in the Bohai Rim; rural settlement dispersion is particularly high in agricultural regions in south Hebei and southwest Shandong, suggesting rural settlement density keeps increasing from northeast to southwest, characterized by high density and dispersed spatial distribution in traditional agricultural regions. Furthermore, rural settlements show dramatic spatial differences in terms of distribution and dynamic change degrees in the Bohai Rim. In terms of spatial distribution, rural residential land is always extensive in plains, with a high density of rural settlements, on the North China Plain in particular, and rural residential land in the south of Shandong province is also extensive, with most rural settlement land use areas in the 5×5 km grid cells exceeding 3 km2. However, traditional agricultural regions have underdeveloped economies, industrialization and tertiary industries, characterized by low urbanization rates, with farmers not feeling assimilated in rural or urban areas. In terms of the temporal sequence, urban expansion rapidly promotes the transformation of rural residential lands in rural-urban transitional belts of provincial capital or prefecture-level city into urban lands, and in traditional rural areas, residential lands are growing. The natural environment, transportation conditions, economic development and farmers’ incomes all have effects on type of land use change and pattern of rural settlements. It is a core objective for future rural development to reconstruct a rational spatial pattern of villages or towns and well-organized village-town systems, build central villages, key towns or central towns, optimize or reconstruct production, living and eco-space of rural areas. It is of significance for rural geographical research to further interpret and explore spatial reconstruction theory.

Urbanization, economic growth, and carbon dioxide emissions in China: A panel cointegration and causality analysis

Elucidating the complex mechanism between urbanization, economic growth, carbon dioxide emissions is fundamental necessary to inform effective strategies on energy saving and emission reduction in China. Based on a balanced panel data of 31 provinces in China over the period 1997–2010, this study empirically examines the relationships among urbanization, economic growth and carbon dioxide (CO2) emissions at the national and regional levels using panel cointegration and vector error correction model and Granger causality tests. Results showed that urbanization, economic growth and CO2 emissions are integrated of order one. Urbanization contributes to economic growth, both of which increase CO2 emissions in China and its eastern, central and western regions. The impact of urbanization on CO2 emissions in the western region was larger than that in the eastern and central regions. But economic growth had a larger impact on CO2 emissions in the eastern region than that in the central and western regions. Panel causality analysis revealed a bidirectional long-run causal relationship among urbanization, economic growth and CO2 emissions, indicating that in the long run, urbanization does have a causal effect on economic growth in China, both of which have causal effect on CO2 emissions. At the regional level, we also found a bidirectional long-run causality between land urbanization and economic growth in eastern and central China. These results demonstrated that it might be difficult for China to pursue carbon emissions reduction policy and to control urban expansion without impeding economic growth in the long run. In the short-run, we observed a unidirectional causation running from land urbanization to CO2 emissions and from economic growth to CO2 emissions in the eastern and central regions. Further investigations revealed an inverted N-shaped relationship between CO2 emissions and economic growth in China, not supporting the environmental Kuznets curve (EKC) hypothesis. Our empirical findings have an important reference value for policy-makers in formulating effective energy saving and emission reduction strategies for China.

Tourism-Led Land-Use Changes and their Environmental Effects in the Southern Coastal Region of Hainan Island, China

ABSTRACT Wang, J. and Liu, Y., 2013. Tourism-led land-use changes and their environmental effects in the southern coastal region of Hainan Island, China. Tourism has been often considered as an effective way to promote economic growth for coastal areas in developing countries. As the most important tourist destination and the largest Special Economic Zone in China, Hainan chose tourism-led development and achieved rapid economic growth. This paper analyzes land-use changes driven by tourism-led development and their environmental effects during a period of time from 1991 to 2007 in Sanya City, southern coastal region of Hainan Island. High-resolution remote sensing and detailed socioeconomic data were used in the study. Based on a combination of remote sensing and geographic information systems methods, a matrix of land-use change was constructed to identify land-use changes between 1991 and 2007. The outcomes indicate that the changes from farmland to construction land and from forestland to orchard are the main transformation types. From 1991 to 2007, farmland and forestland decreased by 15% and 29% respectively; on the contrary, construction land and orchard increased by 242% and 258%. The transformation from farmland to construction land mainly occurred in plains along the coastline, while the changes from forestland to orchard mainly occurred in middle platform areas. Booming tourism not only led to the increased demand for tourism infrastructure and rapid urban expansion, but also boosted the demand for tropical fruit products quickly. However, rapid increases of tourism infrastructures occupied large fertile farmland, urban expansion caused construction land increase and farmland loss, and forest was converted to orchard, driven by the high speed of market demand of fruit products. Tourism-led development restructured the land-use pattern dramatically, which brought about landscape fragmentation, vegetation degeneration, and coastal erosion. Irrational tourism and land development have destroyed Sanyas tourism resources and dissipated its initial advantage to some extent, which will hinder the sustainable development of tourism. Finally, some suggestions are given to coordinate the tourism-led land development in coastal regions.

Integrated risk assessment of multi-hazards in China

Maps of population exposure, vulnerability and risk to natural hazards are useful tools for designing and implementing disaster risk mitigation programs in China. The ranking of provinces by relative risk to natural hazards would provide a metric for prioritizing risk management strategies. Using provinces as our study unit, from the perspectives of hazard exposure, susceptibility, coping capacity and adaptive capacity, this study first constructed China’s disaster risk index for five types of major natural hazards: earthquakes, floods, droughts, low temperatures/snow and gale/hail. Then, the relative risk level at the provincial scale in China was assessed. Finally, the hotspots with the highest hazard exposure, vulnerability and risk were identified. The results showed that high exposure was a significant risk driver in China, whereas high vulnerability, especially social vulnerability, amplified the risk levels. Similar to the population exposure to disasters, the relative risk levels in the southwestern, central and northeastern regions of China were significantly higher than those in the eastern, northern and western regions. The high-risk regions or hotspots of multi-hazards were concentrated in southern China (less-developed regions), while the low-risk regions were mainly distributed in the eastern coastal areas (well-developed regions). Furthermore, a nonlinear relationship existed between the disaster risk level and poverty incidence as well as per capita GDP, demonstrating that disaster losses in middle-income areas are likely to increase if economic policies are not modified to account for the rising disaster risk. These findings further indicated that research on disaster risk should focus not only on hazards and exposure but also on the vulnerability to natural disasters. Thus, reducing vulnerability and population exposure to natural hazards would be an effective measure in mitigating the disaster risk at hotspots in China.

Regional diversity of peasant household response to new countryside construction based on field survey in eastern coastal China

To tackle the issues concerning agriculture, farmers, and rural areas, the central government of China initiated a new strategy called ‘new countryside construction’ in 2005. For better understanding its actual effect, this paper analyzes the regional diversity of peasant household response to this new countryside construction strategy based on Kruskal-Wallis H test and sampling survey data from 586 households in the Bohai Rim Region (BRR), Yangtze River Delta Region (YDR), and Pan Pearl River Delta Region (PPR). The result indicates that regional diversity in eastern coastal China (ECC) does exist in the form of recognized priority sequence, policy requirements, expected policy effects, and behavior response. As a result of the deviation between local policy practice and households’ inherent demand, peasants fulfill their de facto demand via individual effort instead of government aid, and therefore the new countryside construction fails to carry out the expected target. It thus needs to shift the current policy priority, ensure the peasants’ mainstay role, and formulate scientific ‘Rules for new countryside construction’.