Mei-hui PAN, An-na YANG, Yong-qiu WU, Jian-jun MA, and Wen-xuan XUE
Mountain rivers are generally featured by deep-cut river valley and steep side slopes, which is prone to landslide-dammed lake and outburst floods. Taking 2018.10.10 Baige landslide-dammed lake in Jinsha river as an example, wind reworked the outburst flood sediments and developed a plenty of sand dunes at the bank of Jinsha river. This studies about aeolian dunes in the Yarlung Zangbo River, to some extent, could provide some implication for the sedimentary distinction of aeolian sand and original flood deposit, and has some significance for engineering control of aeolian dune in this region. In this paper, a slope climbing dune in the floodplain of the middle and lower reaches of Yarlung Zangbo River, we analyzed the grain size characteristics and and spatial differentiation of surface sediments on four overlapping crescent-shaped dunes of a climbing dune, named Fozhang dune in the lower Yarlung Zangbo. The results of particle size analysis show that frequency distribution curves of the surface sediment of Fozhang dune, dominated by poorly sorted medium sand, is extremely positive biased and narrowly peaked. In the case of four individual superimposed crescent-shaped dune, the coarsest and best sorted particle fraction emerges at the top of the slope. On the whole, the surface sediment of Fozhang dune has become finer and better sorted towards the crest, which results from the combined sorting of wind and gravity. The grain size characteristics of Fozhang dune is comparable to other aeolian dunes of similar genesis. However, Sahu criterion indicates that the Fozhang dune is fluvial-originated. Maybe Sahu criterion cannot identify aeolian sand of very proximal material source from river floodplain. The comparison of grain size characteristics of sand samples with those of floodplain suggests that Fozhang dune is mainly provided with sand source by materials carried by rivers.Mountain rivers are generally featured by deep-cut river valley and steep side slopes, which is prone to landslide-dammed lake and outburst floods. Taking 2018.10.10 Baige landslide-dammed lake in Jinsha river as an example, wind reworked the outburst flood sediments and developed a plenty of sand dunes at the bank of Jinsha river. This studies about aeolian dunes in the Yarlung Zangbo River, to some extent, could provide some implication for the sedimentary distinction of aeolian sand and original flood deposit, and has some significance for engineering control of aeolian dune in this region. In this paper, a slope climbing dune in the floodplain of the middle and lower reaches of Yarlung Zangbo River, we analyzed the grain size characteristics and and spatial differentiation of surface sediments on four overlapping crescent-shaped dunes of a climbing dune, named Fozhang dune in the lower Yarlung Zangbo. The results of particle size analysis show that frequency distribution curves of the surface sediment of Fozhang dune, dominated by poorly sorted medium sand, is extremely positive biased and narrowly peaked. In the case of four individual superimposed crescent-shaped dune, the coarsest and best sorted particle fraction emerges at the top of the slope. On the whole, the surface sediment of Fozhang dune has become finer and better sorted towards the crest, which results from the combined sorting of wind and gravity. The grain size characteristics of Fozhang dune is comparable to other aeolian dunes of similar genesis. However, Sahu criterion indicates that the Fozhang dune is fluvial-originated. Maybe Sahu criterion cannot identify aeolian sand of very proximal material source from river floodplain. The comparison of grain size characteristics of sand samples with those of floodplain suggests that Fozhang dune is mainly provided with sand source by materials carried by rivers.
- May. 08, 2021
- Journal of Natural Resources
- Vol. 35, Issue 12, 3076 (2020)
- DOI：10.31497/zrzyxb.20201221
Meng WANG, Shi-tao CHEN, Wan-chun HUANG, Wen-qin CAI... and Yong-jin WANG|Show fewer author(s)
The study of various proxies of stalagmites is conducive to understand the characteristics and mechanisms of monsoon climate events comprehensively. Here, we present a high-resolution and multi-proxy stalagmite record from Yongxing Cave, Central China, spanning the interval between 65 and 35 ka B.P. based on high precision U/Th dating method and multi-proxy analyses. A total of 371 subsamples were drilled for oxygen and carbon isotopic measurements along the growth axis at a spacing of 0.5-mm-diameter carbide dental burrs. The analyses were conducted using a Finnigan MAT 253 mass spectrometer linked to a Kiel Carbonate Device at the School of Geography, Nanjing Normal University. The precision is 0.06‰ for δ18O and 0.05‰ for δ13C at the 1σ level. For the gray-level measurements, the polished surface of the studied section was scanned at a resolution of 1200 dpi using an EPSON Perfection 4990 Photo Scanner. The gray level was then obtained from the image using the Environment for Visualizing Images (ENVI 4.8) software while traversing down the growth axis. The values range between 0 and 442, with a spatial resolution of 20 μm. The experimental results show that during the period of 65-40 ka B.P., the stalagmite records of gray-level, δ13C and δ18O all presented millennial to sub-millennial changes, but the amplitude of δ13C is much smaller than that of δ18O. This indicates that the local climate indicators of δ13C, gray-level and lithology also respond to the Heinrich (H) events and Dansgaard-Oeschger (DO) events, but their sensitivities to events are different. During the H4 episode (about 40-38 ka B.P.), δ13C and the gray-level of the stalagmite showed anomalous changes. The significantly positive shift of δ13C reached an amplitude of 4.5‰ during H4, which was 2-3 times than other H events, while the gray-level presented the same characteristics to that of the DO cycles. We imply that the state of soil erosion may play an important role in such correspondence during H4. When the monsoon weakened to a certain threshold, the soil cover above the permeable cave was greatly deteriorated, thus weakening and/or preventing the infiltration ability of the soil-karst system and increasing the impurity contents in the stalagmite.The study of various proxies of stalagmites is conducive to understand the characteristics and mechanisms of monsoon climate events comprehensively. Here, we present a high-resolution and multi-proxy stalagmite record from Yongxing Cave, Central China, spanning the interval between 65 and 35 ka B.P. based on high precision U/Th dating method and multi-proxy analyses. A total of 371 subsamples were drilled for oxygen and carbon isotopic measurements along the growth axis at a spacing of 0.5-mm-diameter carbide dental burrs. The analyses were conducted using a Finnigan MAT 253 mass spectrometer linked to a Kiel Carbonate Device at the School of Geography, Nanjing Normal University. The precision is 0.06‰ for δ18O and 0.05‰ for δ13C at the 1σ level. For the gray-level measurements, the polished surface of the studied section was scanned at a resolution of 1200 dpi using an EPSON Perfection 4990 Photo Scanner. The gray level was then obtained from the image using the Environment for Visualizing Images (ENVI 4.8) software while traversing down the growth axis. The values range between 0 and 442, with a spatial resolution of 20 μm. The experimental results show that during the period of 65-40 ka B.P., the stalagmite records of gray-level, δ13C and δ18O all presented millennial to sub-millennial changes, but the amplitude of δ13C is much smaller than that of δ18O. This indicates that the local climate indicators of δ13C, gray-level and lithology also respond to the Heinrich (H) events and Dansgaard-Oeschger (DO) events, but their sensitivities to events are different. During the H4 episode (about 40-38 ka B.P.), δ13C and the gray-level of the stalagmite showed anomalous changes. The significantly positive shift of δ13C reached an amplitude of 4.5‰ during H4, which was 2-3 times than other H events, while the gray-level presented the same characteristics to that of the DO cycles. We imply that the state of soil erosion may play an important role in such correspondence during H4. When the monsoon weakened to a certain threshold, the soil cover above the permeable cave was greatly deteriorated, thus weakening and/or preventing the infiltration ability of the soil-karst system and increasing the impurity contents in the stalagmite.
- May. 08, 2021
- Journal of Natural Resources
- Vol. 35, Issue 12, 3064 (2020)
- DOI：10.31497/zrzyxb.20201220
Long FEI, Guo-rong DENG, Hong-yan ZHANG, Xiao-yi GUO, and Xiao-dong WANG
Drought and flood are the main agrometeorological disasters in the Democratic People's Republic of Korea (DPRK), which have great influences on the growth of the crops and directly affect grain yield. The level of agricultural production is low because of insufficient investment and poor irrigation installation. Drought and flood are prone to a reduction in grain yield in DPRK. The food security issue in DPRK is not only related to this country's domestic stability but also related to the geo-security in Northeast Asia. Therefore, understanding the spatial and temporal patterns of drought and flood is very important for preventing disasters in this country. In this study, the Tropical Rainfall Measuring Mission (TRMM) 3B43 time series dataset was used to reveal the spatial and temporal patterns of drought and flood in DPRK from 1998 to 2018. The drought and flood levels were developed by a Z-index. In addition, the trend of Z-index is tested by the Mann-Kendall (M-K) method. The result shows that the precipitation in the study area has an obvious seasonal pattern, with more than 57.29% of the rainfall concentrated in summer, and only 6.90% in winter. The precipitation in spring is slightly higher than that in autumn. Both interannual and seasonal precipitation show increasing trends during the study period. The spatial pattern of precipitation increases from the northeast to the southeast along the coastline. Generally, the regional comprehensive drought and flood levels in DPRK are normal at the national scale. Moderate drought and flood levels occur most frequently, followed by severe drought and flood, and the frequency of extreme drought and flood eventd is the lowest. The floods frequently occur in autumn, and droughts frequently occur in summer and winter. The frequency of drought and flood events appear in the north of DPRK, particularly in Hamgyeong Mountains and the Gaema Plateau. Flood intensity shows an increasing trend in spring, summer, and autumn, while drought and flood level tended to be normal in winter. The central and northern regions passed the significance of 95%. It is expected that the trend of drought and flood in DPRK will be consistent in future. The results of the study provide a unique insight for understanding the agricultural production in DPRK.Drought and flood are the main agrometeorological disasters in the Democratic People's Republic of Korea (DPRK), which have great influences on the growth of the crops and directly affect grain yield. The level of agricultural production is low because of insufficient investment and poor irrigation installation. Drought and flood are prone to a reduction in grain yield in DPRK. The food security issue in DPRK is not only related to this country's domestic stability but also related to the geo-security in Northeast Asia. Therefore, understanding the spatial and temporal patterns of drought and flood is very important for preventing disasters in this country. In this study, the Tropical Rainfall Measuring Mission (TRMM) 3B43 time series dataset was used to reveal the spatial and temporal patterns of drought and flood in DPRK from 1998 to 2018. The drought and flood levels were developed by a Z-index. In addition, the trend of Z-index is tested by the Mann-Kendall (M-K) method. The result shows that the precipitation in the study area has an obvious seasonal pattern, with more than 57.29% of the rainfall concentrated in summer, and only 6.90% in winter. The precipitation in spring is slightly higher than that in autumn. Both interannual and seasonal precipitation show increasing trends during the study period. The spatial pattern of precipitation increases from the northeast to the southeast along the coastline. Generally, the regional comprehensive drought and flood levels in DPRK are normal at the national scale. Moderate drought and flood levels occur most frequently, followed by severe drought and flood, and the frequency of extreme drought and flood eventd is the lowest. The floods frequently occur in autumn, and droughts frequently occur in summer and winter. The frequency of drought and flood events appear in the north of DPRK, particularly in Hamgyeong Mountains and the Gaema Plateau. Flood intensity shows an increasing trend in spring, summer, and autumn, while drought and flood level tended to be normal in winter. The central and northern regions passed the significance of 95%. It is expected that the trend of drought and flood in DPRK will be consistent in future. The results of the study provide a unique insight for understanding the agricultural production in DPRK.
- May. 08, 2021
- Journal of Natural Resources
- Vol. 35, Issue 12, 3051 (2020)
- DOI：10.31497/zrzyxb.20201219
Wei-dong MA, Feng-gui LIU, Qiang ZHOU, Qiong CHEN... and Yong-ping CHEN|Show fewer author(s)
Using the daily precipitation data of the long-term series of meteorological stations on the Qinghai-Tibet Plateau, the percentile threshold method is used to determine the extreme precipitation threshold, calculate the extreme precipitation index and analyze its spatial and temporal distribution characteristics, in order to provide reference for regional climate change prediction and disaster prevention and mitigation countermeasures. The results show that: (1) From 1961 to 2017, the annual precipitation of Qinghai-Tibet Plateau showed an upward trend, with a rate of 8.06 mm/10 a, and the average annual precipitation reached 472.36 mm. The minimum precipitation tendency rate of 78 stations is -25.46 mm/10 a, and the maximum value is 43.02 mm/10 a. The precipitation of 15.38% of the stations is decreasing, which is mainly distributed in the east and south of the plateau, and the precipitation of the remaining 84.62% of the stations is increasing. (2) The average threshold value of extreme precipitation in the Qinghai-Tibet Plateau is 23.11 mm, with error values ranging from 7.84 mm to 51.90 mm. The high value centers are located in Gongshan and Muli of Hengduan Mountains, while the low value centers are located in the northern flank of Qaidam Basin and Kunlun Mountains. (3) The extreme precipitation, the number of days of extreme precipitation and the contribution rate of extreme precipitation at all the stations in the Qinghai-Tibet Plateau show an obvious upward trend. Although the intensity of extreme precipitation is also rising, the trend is not obvious, which shows that the increase of extreme precipitation in the plateau is not caused by the intensity of extreme precipitation, but by the increase of the frequency of extreme precipitation. Although the extreme precipitation and days of extreme precipitation in the Qaidam Basin do not show a high value level, the contribution rate of extreme precipitation is larger, which suggests that although there is less precipitation, extreme precipitation events frequently occur in this area.Using the daily precipitation data of the long-term series of meteorological stations on the Qinghai-Tibet Plateau, the percentile threshold method is used to determine the extreme precipitation threshold, calculate the extreme precipitation index and analyze its spatial and temporal distribution characteristics, in order to provide reference for regional climate change prediction and disaster prevention and mitigation countermeasures. The results show that: (1) From 1961 to 2017, the annual precipitation of Qinghai-Tibet Plateau showed an upward trend, with a rate of 8.06 mm/10 a, and the average annual precipitation reached 472.36 mm. The minimum precipitation tendency rate of 78 stations is -25.46 mm/10 a, and the maximum value is 43.02 mm/10 a. The precipitation of 15.38% of the stations is decreasing, which is mainly distributed in the east and south of the plateau, and the precipitation of the remaining 84.62% of the stations is increasing. (2) The average threshold value of extreme precipitation in the Qinghai-Tibet Plateau is 23.11 mm, with error values ranging from 7.84 mm to 51.90 mm. The high value centers are located in Gongshan and Muli of Hengduan Mountains, while the low value centers are located in the northern flank of Qaidam Basin and Kunlun Mountains. (3) The extreme precipitation, the number of days of extreme precipitation and the contribution rate of extreme precipitation at all the stations in the Qinghai-Tibet Plateau show an obvious upward trend. Although the intensity of extreme precipitation is also rising, the trend is not obvious, which shows that the increase of extreme precipitation in the plateau is not caused by the intensity of extreme precipitation, but by the increase of the frequency of extreme precipitation. Although the extreme precipitation and days of extreme precipitation in the Qaidam Basin do not show a high value level, the contribution rate of extreme precipitation is larger, which suggests that although there is less precipitation, extreme precipitation events frequently occur in this area.
- May. 08, 2021
- Journal of Natural Resources
- Vol. 35, Issue 12, 3039 (2020)
- DOI：10.31497/zrzyxb.20201218
Ke-yi WANG, Yuan LIU, Bu-chun LIU, Mei-juan QIU... and Jing-yi PANG|Show fewer author(s)
The daily cooling rate of station was calculated based on daily minimum temperature data of 54 meteorological stations in the middle and lower reaches of the Yangtze River from 1958 to 2015. A quantitative analysis of the evolutionary characteristics and spatial changes of cold wave occurrence and development was conducted in the region. The results showed that in the past 58 years, the frequency of cold wave presented an insignificant decrease trend with an average of 1.2 times/station (P>0.05). During cold wave processing, the spatial distribution of average difference of the minimum temperature was higher in the south and lower in the north; and the extreme of average difference of the minimum temperature gradually decreased from the regional center to the surroundings. The first cold wave occurred on August 1 (Jiujiang), and the last on May 4 (Shouxian and Lu'an). The spatial distribution of the time difference was significant. The frequent cold waves occurred in winter, followed by spring and autumn.The daily cooling rate of station was calculated based on daily minimum temperature data of 54 meteorological stations in the middle and lower reaches of the Yangtze River from 1958 to 2015. A quantitative analysis of the evolutionary characteristics and spatial changes of cold wave occurrence and development was conducted in the region. The results showed that in the past 58 years, the frequency of cold wave presented an insignificant decrease trend with an average of 1.2 times/station (P>0.05). During cold wave processing, the spatial distribution of average difference of the minimum temperature was higher in the south and lower in the north; and the extreme of average difference of the minimum temperature gradually decreased from the regional center to the surroundings. The first cold wave occurred on August 1 (Jiujiang), and the last on May 4 (Shouxian and Lu'an). The spatial distribution of the time difference was significant. The frequent cold waves occurred in winter, followed by spring and autumn.
- May. 08, 2021
- Journal of Natural Resources
- Vol. 35, Issue 12, 3029 (2020)
- DOI：10.31497/zrzyxb.20201217
Huan LUO, Xiu-hong CHEN, Qiong WU, Na LUO, and Xu HUANG
With the effective control of point source pollution, non-point source and sewer overflow pollution becomes the main type of water pollution. Based on materials of land use, urban drainage network and so on, the basin-bay integrated water environmental model was established, and the spatio-temporal characteristics of non-point source and sewer overflow pollution in Shenzhen Bay Basin as well as its impacts on water environment were analyzed. Results showed that (1) The non-point source and sewer overflow pollution loading per unit area of COD, NH3-N and TP in rainy season was 17.21 t/km2and 10.21 t/km2, 0.17 t/km2and 0.69 t/km2, 0.04 t/km2 and 0.07 t/km2, respectively; (2) The non-point source and sewer overflow pollution was concentrated in May and August with more heavy rainfall observed in Shenzhen River Basin, Dasha River Basin and Xinzhou River Basin with larger area, steeper surface slope and more sewerage cutting projects; (3) The COD, NH3-N and TP concentrations of non-point source and sewer overflow pollution could approach 3.7, 18.2 and 8.5 times the values of water quality standards, respectively; (4) The areas where the COD, NH3-N and TP concentrations in rainy season were higher than those in dry season exceeded 40%, 60% and 65% of the total area of Shenzhen Bay, respectively.With the effective control of point source pollution, non-point source and sewer overflow pollution becomes the main type of water pollution. Based on materials of land use, urban drainage network and so on, the basin-bay integrated water environmental model was established, and the spatio-temporal characteristics of non-point source and sewer overflow pollution in Shenzhen Bay Basin as well as its impacts on water environment were analyzed. Results showed that (1) The non-point source and sewer overflow pollution loading per unit area of COD, NH3-N and TP in rainy season was 17.21 t/km2and 10.21 t/km2, 0.17 t/km2and 0.69 t/km2, 0.04 t/km2 and 0.07 t/km2, respectively; (2) The non-point source and sewer overflow pollution was concentrated in May and August with more heavy rainfall observed in Shenzhen River Basin, Dasha River Basin and Xinzhou River Basin with larger area, steeper surface slope and more sewerage cutting projects; (3) The COD, NH3-N and TP concentrations of non-point source and sewer overflow pollution could approach 3.7, 18.2 and 8.5 times the values of water quality standards, respectively; (4) The areas where the COD, NH3-N and TP concentrations in rainy season were higher than those in dry season exceeded 40%, 60% and 65% of the total area of Shenzhen Bay, respectively.
- May. 08, 2021
- Journal of Natural Resources
- Vol. 35, Issue 12, 3018 (2020)
- DOI：10.31497/zrzyxb.20201216
Meng-wen WANG, Wei QI, Peng-tao WANG, and Zhuo-ran WANG
Based on field monitoring and 3S technology, Qixia city in the low hilly area of Eastern Shandong province was taken as the research area. Pearson correlation, unconstrained PCA and corresponding canonical analysis (CCA) were used to study the coupling between landscape pattern and non-point source pollution at different watershed scales. The results show that: (1) The spatial variation of landscape pattern is obvious; the patches of agricultural land and construction land are relatively fragmented at the characteristic scale; and the patches of other types of land are highly aggregated. (2) The river surface source pollutants in the study area are mainly TN-based, and the main river outlet is the more polluted area. (3) The influence of landscape pattern on water quality during the wet period is greater than that of the normal water period, and TN and EC are most sensitive to the change of land use type area ratio and landscape pattern index. At different scales, water quality affected by landscape pattern and land use type is different. (4) In normal period at riverside scale, landscape that has the greatest impact on TN is the patch density, and EC is most affected by landscape edge density. At small basin scale TN is greatly affected by landscape spread, and COD is closely related to landscape diversity. The diversity of landscape on the scale of the riverbank during the wet period has the greatest influence on TN, the EC is greatly affected by the polymerization of the plaques, and the biggest factors affecting TN on the small basin scale are consistent with the flat water period, and EC is closely related to landscape spread. (5) At small basin landscape, TN is mainly affected by the density of forest land patch, TP and cultivated land dispersion are closely related to the parallel index, the abundance of water TN is significantly influenced by the forest land dispersion and juxtaposition index, TP is sensitive to the change of the average dimensionality of forest land, and EC is most influenced by grassland aggregation. Basically, the study clarified the spatial distribution characteristics of landscape pattern and non-point source pollution in the study area, and discussed the correlation between them at different scales, which provided a scientific basis for sustainable utilization of water and land resources in Qixia city.Based on field monitoring and 3S technology, Qixia city in the low hilly area of Eastern Shandong province was taken as the research area. Pearson correlation, unconstrained PCA and corresponding canonical analysis (CCA) were used to study the coupling between landscape pattern and non-point source pollution at different watershed scales. The results show that: (1) The spatial variation of landscape pattern is obvious; the patches of agricultural land and construction land are relatively fragmented at the characteristic scale; and the patches of other types of land are highly aggregated. (2) The river surface source pollutants in the study area are mainly TN-based, and the main river outlet is the more polluted area. (3) The influence of landscape pattern on water quality during the wet period is greater than that of the normal water period, and TN and EC are most sensitive to the change of land use type area ratio and landscape pattern index. At different scales, water quality affected by landscape pattern and land use type is different. (4) In normal period at riverside scale, landscape that has the greatest impact on TN is the patch density, and EC is most affected by landscape edge density. At small basin scale TN is greatly affected by landscape spread, and COD is closely related to landscape diversity. The diversity of landscape on the scale of the riverbank during the wet period has the greatest influence on TN, the EC is greatly affected by the polymerization of the plaques, and the biggest factors affecting TN on the small basin scale are consistent with the flat water period, and EC is closely related to landscape spread. (5) At small basin landscape, TN is mainly affected by the density of forest land patch, TP and cultivated land dispersion are closely related to the parallel index, the abundance of water TN is significantly influenced by the forest land dispersion and juxtaposition index, TP is sensitive to the change of the average dimensionality of forest land, and EC is most influenced by grassland aggregation. Basically, the study clarified the spatial distribution characteristics of landscape pattern and non-point source pollution in the study area, and discussed the correlation between them at different scales, which provided a scientific basis for sustainable utilization of water and land resources in Qixia city.
- May. 08, 2021
- Journal of Natural Resources
- Vol. 35, Issue 12, 3007 (2020)
- DOI：10.31497/zrzyxb.20201215
Er-fu DAI, Xiao-fan WANG, Jian-jia ZHU, and Xiao-li WANG
Plantations in China are facing a series of issues, such as structure degradation and function reduction. Thus, it is urgently requested to implement effective measures on plantations through reasonable forest management strategies. The Moshao forest farm of Huitong ecological station, which is a typical forest ecosystem in Red Soil Hilly Region of South China, is the study area to examine the dynamics of forest area and aboveground biomass (AGB) in the next century. The landscape disturbance model named LANDIS-II was employed in this study to simulate the effects of harvesting intensities and artificial regeneration on artificial coniferous forest, artificial broad-leaved forest, and natural broad-leaved forest by six scenarios. The scenarios included low, middle, high harvest intensity and each scenario had an artificial regeneration option after harvesting. The results showed that as the harvesting intensity went heavier, the area of artificial coniferous forest decreased. Conversely, natural forest area increased. And the forest AGB decreased sharply when the harvesting intensity was high. Plantations could take advantages of artificial regeneration to remain the area and facilitate the AGB accumulation. The scheme of harvesting with 20% of plantations every 10 years and followed by artificial regeneration would basically retained the area and AGB at the initial level in the next century. Therefore, this scheme was more applicable to the long term development of the forest in the study area and helpful to achieve the forest sustainable management of Chinese fir and masson pine plantations.Plantations in China are facing a series of issues, such as structure degradation and function reduction. Thus, it is urgently requested to implement effective measures on plantations through reasonable forest management strategies. The Moshao forest farm of Huitong ecological station, which is a typical forest ecosystem in Red Soil Hilly Region of South China, is the study area to examine the dynamics of forest area and aboveground biomass (AGB) in the next century. The landscape disturbance model named LANDIS-II was employed in this study to simulate the effects of harvesting intensities and artificial regeneration on artificial coniferous forest, artificial broad-leaved forest, and natural broad-leaved forest by six scenarios. The scenarios included low, middle, high harvest intensity and each scenario had an artificial regeneration option after harvesting. The results showed that as the harvesting intensity went heavier, the area of artificial coniferous forest decreased. Conversely, natural forest area increased. And the forest AGB decreased sharply when the harvesting intensity was high. Plantations could take advantages of artificial regeneration to remain the area and facilitate the AGB accumulation. The scheme of harvesting with 20% of plantations every 10 years and followed by artificial regeneration would basically retained the area and AGB at the initial level in the next century. Therefore, this scheme was more applicable to the long term development of the forest in the study area and helpful to achieve the forest sustainable management of Chinese fir and masson pine plantations.
- May. 08, 2021
- Journal of Natural Resources
- Vol. 35, Issue 12, 2995 (2020)
- DOI：10.31497/zrzyxb.20201214
Tao ZHENG, Shuang CHEN, Tong ZHANG, Li-ting XU, and Li-ya MA
From the micro perspective, the driving factors of ecological land loss in urban riverside area are analyzed, especially based on the quantitative analysis of the factors with crucial influences such as policy and planning, which has important reference significance for the formulation of ecological land protection policies. In this paper, the Bayesian network model is used to integrate the neighborhood factors, natural factors, policy and planning factors that lead to ecological land loss. And the relationship between ecological land change and its driving factors is clearly illustrated by a good graphical description method. The research results show that from 2005 to 2018, about 11.0% of the ecological land in Nanjing riverside area is lost, and the stable proportion of ecological land is 89.0%. The sensitivity of ecological land protection intensity to ecological land loss is as high as 9.37%, the sensitivity of construction potential factor is 2.53%, and the sensitivity of development difficulty is only 0.21%. The effect of shoreline planning is better than that of land use planning, which indicates that the protection policy based on the function goal of ecological land should be made to ensure the long-term existence of ecological space.From the micro perspective, the driving factors of ecological land loss in urban riverside area are analyzed, especially based on the quantitative analysis of the factors with crucial influences such as policy and planning, which has important reference significance for the formulation of ecological land protection policies. In this paper, the Bayesian network model is used to integrate the neighborhood factors, natural factors, policy and planning factors that lead to ecological land loss. And the relationship between ecological land change and its driving factors is clearly illustrated by a good graphical description method. The research results show that from 2005 to 2018, about 11.0% of the ecological land in Nanjing riverside area is lost, and the stable proportion of ecological land is 89.0%. The sensitivity of ecological land protection intensity to ecological land loss is as high as 9.37%, the sensitivity of construction potential factor is 2.53%, and the sensitivity of development difficulty is only 0.21%. The effect of shoreline planning is better than that of land use planning, which indicates that the protection policy based on the function goal of ecological land should be made to ensure the long-term existence of ecological space.
- May. 08, 2021
- Journal of Natural Resources
- Vol. 35, Issue 12, 2980 (2020)
- DOI：10.31497/zrzyxb.20201213
Li HE, Lei SHEN, Wei-min ZHANG, Jian-ge TAO, and Zhen-lin FAN
Natural resources play a vital role in the economic development of a country. Natural resources accounting has become an important natural resources management tool in recent years, and it is an important part of the natural resource governance system. Natural resources accounting is an effective way to improve the governance capacity of natural resources. SEEA 2012 and SNA 2008 play a crucial role in the theoretical research and accounting practice of natural resources. They are the important theoretical framework of natural resources accounting at home and abroad. In the new era of rapid development of informatization technology, China's balance sheet and resources accounting idea of natural resource asset management promote the construction of China's natural resource governance system and improve China's natural resource governance capacity. At present, in the theory of natural resources accounting, there is still a lack of unified understanding of the accounting framework and method, and in practice, there is also a lack of an effective accounting system. Therefore, it is necessary to systematically analyze the theoretical results of current natural resources accounting and establish the natural resources accounting system in China to guide the practice of natural resources accounting. Based on WSR methodology, this paper studies the theory and literature of natural resources accounting, and considers the establishment of China's natural resources accounting system. The main conclusions of this study are as follows: The natural resources accounting system should systematically analyze the "WSR" of natural resources accounting; based on the "WSR" analysis, the natural resources accounting consists of the national economic accounting of natural resources, the government asset management accounting of natural resources and the enterprise operation asset accounting of natural resources. The national economic accounting of natural resources is helpful for making macro-economic plan and economic decision-making, government asset management accounting of natural resources is helpful for government asset management, and enterprise asset accounting of natural resources is helpful for enterprise natural resource asset management and market element allocation. Based on WSR method, the natural resources accounting system can make wiser choices for accounting purpose, accounting framework, way of realization and accounting method. After a systematic analysis, the construction of accounting theoretical structure of natural resources accounting is helpful to improve the theory and practice, and to solve the divergence in the field of natural resources accounting research.Natural resources play a vital role in the economic development of a country. Natural resources accounting has become an important natural resources management tool in recent years, and it is an important part of the natural resource governance system. Natural resources accounting is an effective way to improve the governance capacity of natural resources. SEEA 2012 and SNA 2008 play a crucial role in the theoretical research and accounting practice of natural resources. They are the important theoretical framework of natural resources accounting at home and abroad. In the new era of rapid development of informatization technology, China's balance sheet and resources accounting idea of natural resource asset management promote the construction of China's natural resource governance system and improve China's natural resource governance capacity. At present, in the theory of natural resources accounting, there is still a lack of unified understanding of the accounting framework and method, and in practice, there is also a lack of an effective accounting system. Therefore, it is necessary to systematically analyze the theoretical results of current natural resources accounting and establish the natural resources accounting system in China to guide the practice of natural resources accounting. Based on WSR methodology, this paper studies the theory and literature of natural resources accounting, and considers the establishment of China's natural resources accounting system. The main conclusions of this study are as follows: The natural resources accounting system should systematically analyze the "WSR" of natural resources accounting; based on the "WSR" analysis, the natural resources accounting consists of the national economic accounting of natural resources, the government asset management accounting of natural resources and the enterprise operation asset accounting of natural resources. The national economic accounting of natural resources is helpful for making macro-economic plan and economic decision-making, government asset management accounting of natural resources is helpful for government asset management, and enterprise asset accounting of natural resources is helpful for enterprise natural resource asset management and market element allocation. Based on WSR method, the natural resources accounting system can make wiser choices for accounting purpose, accounting framework, way of realization and accounting method. After a systematic analysis, the construction of accounting theoretical structure of natural resources accounting is helpful to improve the theory and practice, and to solve the divergence in the field of natural resources accounting research.
- May. 08, 2021
- Journal of Natural Resources
- Vol. 35, Issue 12, 2968 (2020)
- DOI：10.31497/zrzyxb.20201212
Optics
Physics
Geography
All Subjects
Journal
Harnessing plasmon-exciton energy exchange for flexible organic solar cells with efficiency of 19.5%
May. 11, 2025
Journal
Sub-pA dark current infrared photodetection enabled by polarized water-intercalated heterojunctions
May. 11, 2025
Structured light: fundamentals and applications (2025)
Call for Papers
Editor (s): Yuanjie Yang, Yangjian Cai, Qiwen Zhan
Innovative Optical Sensor Systems (2025)
Submission Open:15 January 2025; Submission Deadline: 30 April 2025
Editor (s): Nunzio Cennamo, Olivier Soppera, Giuseppe D’Aguanno, Yang Zhao
Emerging Coding Method for Computational Imaging (2025)
Submission Open:1 April 2025; Submission Deadline: 1 August 2025
Editor (s): Xin Yuan, David Brady, Enrique Tajahuerce, Jinli Suo... Liang Gao and Ni Chen|Show fewer author(s)
© Copyright 2018-2021 | Chinese Laser Press. All Rights Reserved 沪ICP备15018463号-20