2013 Vol. 23, No. 4
Display Method:
2013, 23(4): 389-402.
doi: 10.1007/s11769-013-0612-y
Abstract:
Rills are frequently observed on slope farmlands and rill erosion significantly contributes to sediment yields. This paper focuses on reviewing the various factors affecting rill erosion processes and the threshold conditions of rill initiation. Six factors, including rainfall, runoff, soil, topography, vegetation and tillage system, are discussed. Rill initiation and network are explored. Runoff erosivity and soil erodibility are recognized as two direct factors affecting rill erosion and other types of factors may have indirect influences on rill erosion through increasing or decreasing the effects of the direct factors. Certain conditions are necessary for rill initiation and the critical conditions are different with different factors. Future studies should be focused on 1) the dynamic changes of rill networks; 2) the combined effect of multiple factors; and 3) the relationships of threshold values with other related factors.
Rills are frequently observed on slope farmlands and rill erosion significantly contributes to sediment yields. This paper focuses on reviewing the various factors affecting rill erosion processes and the threshold conditions of rill initiation. Six factors, including rainfall, runoff, soil, topography, vegetation and tillage system, are discussed. Rill initiation and network are explored. Runoff erosivity and soil erodibility are recognized as two direct factors affecting rill erosion and other types of factors may have indirect influences on rill erosion through increasing or decreasing the effects of the direct factors. Certain conditions are necessary for rill initiation and the critical conditions are different with different factors. Future studies should be focused on 1) the dynamic changes of rill networks; 2) the combined effect of multiple factors; and 3) the relationships of threshold values with other related factors.
2013, 23(4): 403-420.
doi: 10.1007/s11769-013-0613-x
Abstract:
Shadow is one of the major problems in remotely sensed imagery which hampers the accuracy of information extraction and change detection. In these images, shadow is generally produced by different objects, namely, cloud, mountain and urban materials. The shadow correction process consists of two steps: detection and de-shadowing. This paper reviews a range of techniques for both steps, focusing on urban regions (urban shadows), mountainous areas (topographic shadow), cloud shadows and composite shadows. Several issues including the problems and the advantages of those algorithms are discussed. In recent years, thresholding and recovery techniques have become important for shadow detection and de-shadowing, respectively. Research on shadow correction is still an important topic, particularly for urban regions (in high spatial resolution data) and mountainous forest (in high and medium spatial resolution data). Moreover, new algorithms are needed for shadow correction, especially given the advent of new satellite images.
Shadow is one of the major problems in remotely sensed imagery which hampers the accuracy of information extraction and change detection. In these images, shadow is generally produced by different objects, namely, cloud, mountain and urban materials. The shadow correction process consists of two steps: detection and de-shadowing. This paper reviews a range of techniques for both steps, focusing on urban regions (urban shadows), mountainous areas (topographic shadow), cloud shadows and composite shadows. Several issues including the problems and the advantages of those algorithms are discussed. In recent years, thresholding and recovery techniques have become important for shadow detection and de-shadowing, respectively. Research on shadow correction is still an important topic, particularly for urban regions (in high spatial resolution data) and mountainous forest (in high and medium spatial resolution data). Moreover, new algorithms are needed for shadow correction, especially given the advent of new satellite images.
2013, 23(4): 421-434.
doi: 10.1007/s11769-013-0592-y
Abstract:
This paper compartmentalizes regional land use of rural settlements in China by employing a hierarchical clustering method. The statistic data are sourced from the National Bureau of Statistics of China (NBSC) and the data of land use change from the Ministry of Land and Resources of China (MLRC). The population of rural settlement decreases from the southeast to the northwest of China and the density of rural settlement decreases from the east to the west of China. Land-use scale of rural settlement, the proportion of one-storey houses and the average household area decrease from the north to the south of China. The ratio of area of cultivated land to rural settlement is high in the northeast and southwest of China but low in the southeast of China. The land use regionalization of rural settlement can be divided into four regions, namely: the northern region of China, Qinghai-Tibet, Yunnan-Guizhou, and the middle and eastern region of China. The northern region of China and the middle and eastern region of China can be further divided into nine sub-regions: Xinjiang, Northeast China, Ningxia and Inner Mongolia, North China, the south of the Changjiang (Yantze) River and Sichuan Basin, Jiangsu-Shanghai, South China, the Loess Plateau, and Guangxi. In consideration of the significant regional differences, it is proposed that different policies should be implemented regarding the utilization and management of rural settlements.
This paper compartmentalizes regional land use of rural settlements in China by employing a hierarchical clustering method. The statistic data are sourced from the National Bureau of Statistics of China (NBSC) and the data of land use change from the Ministry of Land and Resources of China (MLRC). The population of rural settlement decreases from the southeast to the northwest of China and the density of rural settlement decreases from the east to the west of China. Land-use scale of rural settlement, the proportion of one-storey houses and the average household area decrease from the north to the south of China. The ratio of area of cultivated land to rural settlement is high in the northeast and southwest of China but low in the southeast of China. The land use regionalization of rural settlement can be divided into four regions, namely: the northern region of China, Qinghai-Tibet, Yunnan-Guizhou, and the middle and eastern region of China. The northern region of China and the middle and eastern region of China can be further divided into nine sub-regions: Xinjiang, Northeast China, Ningxia and Inner Mongolia, North China, the south of the Changjiang (Yantze) River and Sichuan Basin, Jiangsu-Shanghai, South China, the Loess Plateau, and Guangxi. In consideration of the significant regional differences, it is proposed that different policies should be implemented regarding the utilization and management of rural settlements.
2013, 23(4): 435-444.
doi: 10.1007/s11769-012-0578-1
Abstract:
In order to investigate the transformation among the precipitation, groundwater, and surface water in the Sanjiang Plain, Northeast China, precipitation and groundwater samples which were collected at the meteorological station of the Sanjiang Mire Wetland Experimental Station, Chinese Academy of Sciences and the surface water which collected from the Wolulan River were used to identify the transformation of three types of water. The isotope composition of different kinds of water sources were analyzed via stable isotope (deuterium and oxygen-18) investigation of natural water. The results show a clear seasonal difference in the stable isotopes in precipitation. During the cold half-year, the mean stable isotope in precipitation in the Sanjiang Plain reaches its minimum with the minimum temperature. The δ18O and δD values are high in the rainy season. In the Wolulan River, the evaporation is the highest in August and September. The volume of evaporation and the replenishment to the river is mostly same. The groundwater is recharged more by the direct infiltration of precipitation than by the river flow. The results of this study indicate that the water bodies in the Sanjiang Plain have close hydrologic relationships, and that the transformation among each water system frequently occurs.
In order to investigate the transformation among the precipitation, groundwater, and surface water in the Sanjiang Plain, Northeast China, precipitation and groundwater samples which were collected at the meteorological station of the Sanjiang Mire Wetland Experimental Station, Chinese Academy of Sciences and the surface water which collected from the Wolulan River were used to identify the transformation of three types of water. The isotope composition of different kinds of water sources were analyzed via stable isotope (deuterium and oxygen-18) investigation of natural water. The results show a clear seasonal difference in the stable isotopes in precipitation. During the cold half-year, the mean stable isotope in precipitation in the Sanjiang Plain reaches its minimum with the minimum temperature. The δ18O and δD values are high in the rainy season. In the Wolulan River, the evaporation is the highest in August and September. The volume of evaporation and the replenishment to the river is mostly same. The groundwater is recharged more by the direct infiltration of precipitation than by the river flow. The results of this study indicate that the water bodies in the Sanjiang Plain have close hydrologic relationships, and that the transformation among each water system frequently occurs.
2013, 23(4): 445-459.
doi: 10.1007/s11769-013-0614-9
Abstract:
Grassland fire is one of the most important disturbance factors in the natural ecosystems. This paper focuses on the spatial distribution of long-term grassland fire patterns in the Hulun Buir Grassland located in the northeast of Inner Mongolia Autonomous Region in China. The density or ratio of ignition can reflect the relationship between grassland fire and different ignition factors. Based on the relationship between the density or ratio of ignition in different range of each ignition factor and grassland fire events, an ignition probability model was developed by using binary logistic regression function and its overall accuracy averaged up to 81.7%. Meanwhile it was found that daily relative humidity, daily temperature, elevation, vegetation type, distance to county-level road, distance to town are more important determinants of spatial distribution of fire ignitions. Using Monte Carlo method, we developed a time-dependent stochastic ignition probability model based on the distribution of inter-annual daily relative humidity and daily temperature. Through this model, it is possible to estimate the spatial patterns of ignition probability for grassland fire, which will be helpful to the quantitative evaluation of grassland fire risk and its management in the future.
Grassland fire is one of the most important disturbance factors in the natural ecosystems. This paper focuses on the spatial distribution of long-term grassland fire patterns in the Hulun Buir Grassland located in the northeast of Inner Mongolia Autonomous Region in China. The density or ratio of ignition can reflect the relationship between grassland fire and different ignition factors. Based on the relationship between the density or ratio of ignition in different range of each ignition factor and grassland fire events, an ignition probability model was developed by using binary logistic regression function and its overall accuracy averaged up to 81.7%. Meanwhile it was found that daily relative humidity, daily temperature, elevation, vegetation type, distance to county-level road, distance to town are more important determinants of spatial distribution of fire ignitions. Using Monte Carlo method, we developed a time-dependent stochastic ignition probability model based on the distribution of inter-annual daily relative humidity and daily temperature. Through this model, it is possible to estimate the spatial patterns of ignition probability for grassland fire, which will be helpful to the quantitative evaluation of grassland fire risk and its management in the future.
2013, 23(4): 460-469.
doi: 10.1007/s11769-013-0601-1
Abstract:
In this paper, a thin cloud removal method was put forward based on the linear relationships between the thin cloud reflectance in the channels from 0.4 μm to 1.0 μm and 1.38 μm. Channels of 0.66 μm, 0.86 μm and 1.38 μm were chosen to extract the water body information under the thin cloud. Two study cases were selected to validate the thin cloud removal method. One case was applied with the Earth Observation System Moderate Resolution Imaging Spectroradiometer (EOS/MODIS) data, and the other with the Medium Resolution Spectral Imager (MERSI) and Visible and Infrared Radiometer (VIRR) data from Fengyun-3A (FY-3A). The test results showed that thin cloud removal method did not change the reflectivity of the ground surface under the clear sky. To the area contaminated by the thin cloud, the reflectance decreased to be closer to the reference reflectance under the clear sky after the thin cloud removal. The spatial distribution of the water body area could not be extracted before the thin cloud removal, while water information could be easily identified by using proper near infrared channel threshold after removing the thin cloud. The thin cloud removal method could improve the image quality and water body extraction precision effectively.
In this paper, a thin cloud removal method was put forward based on the linear relationships between the thin cloud reflectance in the channels from 0.4 μm to 1.0 μm and 1.38 μm. Channels of 0.66 μm, 0.86 μm and 1.38 μm were chosen to extract the water body information under the thin cloud. Two study cases were selected to validate the thin cloud removal method. One case was applied with the Earth Observation System Moderate Resolution Imaging Spectroradiometer (EOS/MODIS) data, and the other with the Medium Resolution Spectral Imager (MERSI) and Visible and Infrared Radiometer (VIRR) data from Fengyun-3A (FY-3A). The test results showed that thin cloud removal method did not change the reflectivity of the ground surface under the clear sky. To the area contaminated by the thin cloud, the reflectance decreased to be closer to the reference reflectance under the clear sky after the thin cloud removal. The spatial distribution of the water body area could not be extracted before the thin cloud removal, while water information could be easily identified by using proper near infrared channel threshold after removing the thin cloud. The thin cloud removal method could improve the image quality and water body extraction precision effectively.
2013, 23(4): 470-481.
doi: 10.1007/s11769-013-0611-z
Abstract:
This paper summarizes the distribution and production layout of the major mineral resources in China, including coal, iron ore, copper and bauxite, from a national perspective. It also identifies the incompatibility between the mineral resources distribution and regional economic development. Significant issues with China's mineral resource industry cause challenges for the sustainable development of both the mining industry and the national socio-economy. The sustainability of regional mineral resources and the environmental pollution by mining in the western China were also analyzed. Results show that the distribution of China's mineral resources is misaligned with its regional layout of economic development. China's mineral resources have been over-exploited, and the mineral resources production in the eastern China is unsustainable. The continuously expanding production of mineral resources in the western China has heavily endangered the ecological environment. We propose strategies to boost the sustainable development of mineral resources, including measures to accelerate economic development and enhance the sustainability of domestic mineral resources. We also offer suggestions for scientifically planning the mineral resource prospecting and exploitation and regional economic layout, as well as for proactively undertaking industry transfer in the eastern China and raising the environmental benchmark requirements for the mineral industry in the central and western China.
This paper summarizes the distribution and production layout of the major mineral resources in China, including coal, iron ore, copper and bauxite, from a national perspective. It also identifies the incompatibility between the mineral resources distribution and regional economic development. Significant issues with China's mineral resource industry cause challenges for the sustainable development of both the mining industry and the national socio-economy. The sustainability of regional mineral resources and the environmental pollution by mining in the western China were also analyzed. Results show that the distribution of China's mineral resources is misaligned with its regional layout of economic development. China's mineral resources have been over-exploited, and the mineral resources production in the eastern China is unsustainable. The continuously expanding production of mineral resources in the western China has heavily endangered the ecological environment. We propose strategies to boost the sustainable development of mineral resources, including measures to accelerate economic development and enhance the sustainability of domestic mineral resources. We also offer suggestions for scientifically planning the mineral resource prospecting and exploitation and regional economic layout, as well as for proactively undertaking industry transfer in the eastern China and raising the environmental benchmark requirements for the mineral industry in the central and western China.
2013, 23(4): 482-491.
doi: 10.1007/s11769-013-0615-8
Abstract:
This paper principally focuses on the morphological differences, spatial pattern and regional types of rural settlements in Xuzhou City of Jiangsu Province in China. Using satellite images of Xuzhou City taken in 2007 and 2008 and models of exploratory spatial data analysis (ESDA) and spatial metrics, the paper conducts a quantitative analysis of the morphological pattern of rural settlements, and finds significant characteristics. First, rural settlements in Xuzhou City are significantly agglomerated in terms of their spatial distribution; meanwhile, there is significant variation in the geographical density distribution. Second, the scale of rural settlements in Xuzhou City is larger than the average in Jiangsu Province, and the histogram of the scale data is more even and more like a gamma distribution. There are a significant high-value cluster in the scale distribution, and local negative correlation between the scale and density distribution of rural settlements in Xuzhou City. Third, the morphology of rural settlements in Xuzhou City shows relative regularity with good connection and integrity, but the spatial variation of the morphology is anisotropic. Finally, according to the characteristics of density, scale, and form of rural settlements, the rural settlements of Xuzhou City are divided into three types: A high-density and point-scattered type, a low-density and cluster-like type and a mass-like and sparse type. The research findings could be used as the scientific foundation for rural planning and community rebuilding, particularly in less-developed areas.
This paper principally focuses on the morphological differences, spatial pattern and regional types of rural settlements in Xuzhou City of Jiangsu Province in China. Using satellite images of Xuzhou City taken in 2007 and 2008 and models of exploratory spatial data analysis (ESDA) and spatial metrics, the paper conducts a quantitative analysis of the morphological pattern of rural settlements, and finds significant characteristics. First, rural settlements in Xuzhou City are significantly agglomerated in terms of their spatial distribution; meanwhile, there is significant variation in the geographical density distribution. Second, the scale of rural settlements in Xuzhou City is larger than the average in Jiangsu Province, and the histogram of the scale data is more even and more like a gamma distribution. There are a significant high-value cluster in the scale distribution, and local negative correlation between the scale and density distribution of rural settlements in Xuzhou City. Third, the morphology of rural settlements in Xuzhou City shows relative regularity with good connection and integrity, but the spatial variation of the morphology is anisotropic. Finally, according to the characteristics of density, scale, and form of rural settlements, the rural settlements of Xuzhou City are divided into three types: A high-density and point-scattered type, a low-density and cluster-like type and a mass-like and sparse type. The research findings could be used as the scientific foundation for rural planning and community rebuilding, particularly in less-developed areas.
2013, 23(4): 492-505.
doi: 10.1007/s11769-013-0616-7
Abstract:
China's transition from a planned economy to a market economy has resulted in many changes in its urban structure and society and provided an opportunity for a quasi-longitudinal case study on the relationship between the built environment and activity-travel behavior. This paper draws upon data from an activity diary survey conducted in Beijing in 2007. The survey sample comprised 652 residents living in Danwei (work unit), commodity housing, and affordable housing neighborhoods. On the basis of the three-dimensional geo-visualization analysis of the space-time path and statistical multivariate regression models of daily travel and leisure time, it was found that both residential spatial factors and socio-demographics influence residents' daily behaviors. The findings show that Danwei residents have less daily travel time than those who live in commodity housing, but people living in affordable housing endure the longest travel time. Daily leisure time is associated more with individual attributes. We argue that although China's transition is currently gradual, the Danwei system may continue to play significant roles in daily life, and it might provide a valuable model for neighborhood spatial planning.
China's transition from a planned economy to a market economy has resulted in many changes in its urban structure and society and provided an opportunity for a quasi-longitudinal case study on the relationship between the built environment and activity-travel behavior. This paper draws upon data from an activity diary survey conducted in Beijing in 2007. The survey sample comprised 652 residents living in Danwei (work unit), commodity housing, and affordable housing neighborhoods. On the basis of the three-dimensional geo-visualization analysis of the space-time path and statistical multivariate regression models of daily travel and leisure time, it was found that both residential spatial factors and socio-demographics influence residents' daily behaviors. The findings show that Danwei residents have less daily travel time than those who live in commodity housing, but people living in affordable housing endure the longest travel time. Daily leisure time is associated more with individual attributes. We argue that although China's transition is currently gradual, the Danwei system may continue to play significant roles in daily life, and it might provide a valuable model for neighborhood spatial planning.
2013, 23(4): 506-518.
doi: 10.1007/s11769-013-0608-7
Abstract:
A households' production behavior directly influences the quality of the environment and determines the successful development of nature reserves. Meanwhile, the households' production behaviors are complicated by interrelated factors, such as protection attitudes, resource endowment, and family wealth. This research evaluated households near the Crested Ibis National Nature Reserve in Shaanxi Province, acquiring data from 436 households around Yang County and Ningshan County in the south slope of Qinling Mountains, China. Based on the collected data, we developed a structural equation model to evaluate the coupling relationships among households' protection attitudes, production behaviors, resource endowment, and family wealth. The results showed that: 1) households with great resource endowment had more negative attitudes, probably due to their greater protection costs; 2) the households with higher education levels had worse protection attitudes; 3) the households with more family wealth were likely to use fewer fertilizers, pesticides, and firewood; 4) the households with more resource endowment showed less production and management behaviors; 5) the enhancement of households' attitudes improved production behaviors to protection the environment, but the effects were not statistically significant. Our results provide a basis for the government's protection policy making, exploring the effective management measures that are beneficial for both nature reserve management and community development.
A households' production behavior directly influences the quality of the environment and determines the successful development of nature reserves. Meanwhile, the households' production behaviors are complicated by interrelated factors, such as protection attitudes, resource endowment, and family wealth. This research evaluated households near the Crested Ibis National Nature Reserve in Shaanxi Province, acquiring data from 436 households around Yang County and Ningshan County in the south slope of Qinling Mountains, China. Based on the collected data, we developed a structural equation model to evaluate the coupling relationships among households' protection attitudes, production behaviors, resource endowment, and family wealth. The results showed that: 1) households with great resource endowment had more negative attitudes, probably due to their greater protection costs; 2) the households with higher education levels had worse protection attitudes; 3) the households with more family wealth were likely to use fewer fertilizers, pesticides, and firewood; 4) the households with more resource endowment showed less production and management behaviors; 5) the enhancement of households' attitudes improved production behaviors to protection the environment, but the effects were not statistically significant. Our results provide a basis for the government's protection policy making, exploring the effective management measures that are beneficial for both nature reserve management and community development.
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