2016年 第26卷 第4期
2016, 26(4): 429-438.
doi: 10.1007/s11769-016-0819-9
摘要:
Land cover is recognized as one of the fundamental terrestrial datasets required in land system change and other ecosystem related researches across the globe. The regional differentiation and spatial-temporal variation of land cover has significant impact on regional natural environment and socio-economic sustainable development. Under this context, we reconstructed the history land cover data in Siberia to provide a comparable datasets to the land cover datasets in China and abroad. In this paper, the European Space Agency (ESA) Global Land Cover Map (GlobCover), Landsat Thematic Mapper (TM), Enhanced Thematic Mapper (ETM), Multispectral Scanner (MSS) images, Google Earth images and other additional data were used to produce the land cover datasets in 1975 and 2010 in Siberia. Data evaluation show that the total user's accuracy of land cover data in 2010 was 86.96%, which was higher than ESA GlobCover data in Siberia. The analysis on the land cover changes found that there were no big land cover changes in Siberia from 1975 to 2010 with only a few conversions between different natural forest types. The mainly changes are the conversion from deciduous needleleaf forest to deciduous broadleaf forest, deciduous needleleaf forest to mixed forest, savannas to deciduous needleleaf forest etc., indicating that the dominant driving factor of land cover changes in Siberia was natural element rather than human activities at some extent, which was very different from China. However, our purpose was not just to produce the land cover datasets at two time period or explore the driving factors of land cover changes in Siberia, we also paid attention on the significance and application of the datasets in various fields such as global climate change, geopolitics, cross-border cooperation and so on.
Land cover is recognized as one of the fundamental terrestrial datasets required in land system change and other ecosystem related researches across the globe. The regional differentiation and spatial-temporal variation of land cover has significant impact on regional natural environment and socio-economic sustainable development. Under this context, we reconstructed the history land cover data in Siberia to provide a comparable datasets to the land cover datasets in China and abroad. In this paper, the European Space Agency (ESA) Global Land Cover Map (GlobCover), Landsat Thematic Mapper (TM), Enhanced Thematic Mapper (ETM), Multispectral Scanner (MSS) images, Google Earth images and other additional data were used to produce the land cover datasets in 1975 and 2010 in Siberia. Data evaluation show that the total user's accuracy of land cover data in 2010 was 86.96%, which was higher than ESA GlobCover data in Siberia. The analysis on the land cover changes found that there were no big land cover changes in Siberia from 1975 to 2010 with only a few conversions between different natural forest types. The mainly changes are the conversion from deciduous needleleaf forest to deciduous broadleaf forest, deciduous needleleaf forest to mixed forest, savannas to deciduous needleleaf forest etc., indicating that the dominant driving factor of land cover changes in Siberia was natural element rather than human activities at some extent, which was very different from China. However, our purpose was not just to produce the land cover datasets at two time period or explore the driving factors of land cover changes in Siberia, we also paid attention on the significance and application of the datasets in various fields such as global climate change, geopolitics, cross-border cooperation and so on.
2016, 26(4): 439-455.
doi: 10.1007/s11769-016-0818-x
摘要:
The Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) and National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center (CPC) morphing technique (CMORPH) are two important multi-satellite precipitation products in TRMM-era and perform important functions in GPM-era. Both TMPA and CMORPH systems simultaneously upgraded their retrieval algorithms and released their latest version of precipitation data in 2013. In this study, the latest TMPA and CMORPH products (i.e., Version-7 real-time TMPA (T-rt) and gauge-adjusted TMPA (T-adj), and Version-1.0 real-time CMORPH (C-rt) and Version-1.0 gauge-adjusted CMORPH (C-adj)) are evaluated and intercompared by using independent rain gauge observations for a 12-year (2000-2011) period over two typical basins in China with different geographical and climate conditions. Results indicate that all TMPA and CMORPH products tend to overestimate precipitation for the high-latitude semiarid Laoha River Basin and underestimate it for the low-latitude humid Mishui Basin. Overall, the satellite precipitation products exhibit superior performance over Mishui Basin than that over Laoha River Basin. The C-adj presents the best performance over the high-latitude Laoha River Basin, whereas T-adj showed the best performance over the low-latitude Mishui Basin. The two gauge-adjusted products demonstrate potential in water resource management. However, the accuracy of two real-time satellite precipitation products demonstrates large variability in the two validation basins. The C-rt reaches a similar accuracy level with the gauge-adjusted satellite precipitation products in the high-latitude Laoha River Basin, and T-rt performs well in the low-latitude Mishui Basin. The study also reveals that all satellite precipitation products obviously overestimate light rain amounts and events over Laoha River Basin, whereas they underestimate the amount and events over Mishui Basin. The findings of the precision characteristics associated with the latest TMPA and CMORPH precipitation products at different basins will offer satellite precipitation users an enhanced understanding of the applicability of the latest TMPA and CMORPH for water resource management, hydrologic process simulation, and hydrometeorological disaster prediction in other similar regions in China. The findings will also be useful for IMERG algorithm development and update in GPM-era.
The Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) and National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center (CPC) morphing technique (CMORPH) are two important multi-satellite precipitation products in TRMM-era and perform important functions in GPM-era. Both TMPA and CMORPH systems simultaneously upgraded their retrieval algorithms and released their latest version of precipitation data in 2013. In this study, the latest TMPA and CMORPH products (i.e., Version-7 real-time TMPA (T-rt) and gauge-adjusted TMPA (T-adj), and Version-1.0 real-time CMORPH (C-rt) and Version-1.0 gauge-adjusted CMORPH (C-adj)) are evaluated and intercompared by using independent rain gauge observations for a 12-year (2000-2011) period over two typical basins in China with different geographical and climate conditions. Results indicate that all TMPA and CMORPH products tend to overestimate precipitation for the high-latitude semiarid Laoha River Basin and underestimate it for the low-latitude humid Mishui Basin. Overall, the satellite precipitation products exhibit superior performance over Mishui Basin than that over Laoha River Basin. The C-adj presents the best performance over the high-latitude Laoha River Basin, whereas T-adj showed the best performance over the low-latitude Mishui Basin. The two gauge-adjusted products demonstrate potential in water resource management. However, the accuracy of two real-time satellite precipitation products demonstrates large variability in the two validation basins. The C-rt reaches a similar accuracy level with the gauge-adjusted satellite precipitation products in the high-latitude Laoha River Basin, and T-rt performs well in the low-latitude Mishui Basin. The study also reveals that all satellite precipitation products obviously overestimate light rain amounts and events over Laoha River Basin, whereas they underestimate the amount and events over Mishui Basin. The findings of the precision characteristics associated with the latest TMPA and CMORPH precipitation products at different basins will offer satellite precipitation users an enhanced understanding of the applicability of the latest TMPA and CMORPH for water resource management, hydrologic process simulation, and hydrometeorological disaster prediction in other similar regions in China. The findings will also be useful for IMERG algorithm development and update in GPM-era.
2016, 26(4): 456-465.
doi: 10.1007/s11769-015-0760-3
摘要:
A riverhead is the demarcation point of continuous water channel and seasonal channel, which is characterized by a critical flow that can support a continuous water body. In this study, the critical support discharge (CSD) is defined as the critical steady flows required to form the origin of a stream. The CSD is used as the criterion to determine the beginning of the riverhead, which can be controlled by hydro-climate factors (e.g., annual precipitation, annual evaporation, or minimum stream flow in arid season). The CSD has a close correlation with the critical support/source area (CSA) that largely affects the density of the river network and the division of sub-watersheds. In general, river density may vary with regional meteorological and hydrological conditions that have to be considered in the analysis. In this paper, a new model referring to the relationship of CSA and CSD is proposed, which is based on the physical mechanism for the origin of riverheads. The feasibility of the model was verified using two watersheds (Duilongqu Basin of the Lhasa River and Beishuiqu Basin of the Nyangqu River) in Tibet Autonomous Region to calculate the CSA and extract river networks. A series of CSAs based on different CSDs in derived equation were tested by comparing the extracted river networks with the reference network obtained from a digitized map of river network at large scales. Comparison results of river networks derived from digital elevation model with real ones indicate that the CSD (equal to criterion of flow quantity (Qc)) are 0.0028 m3/s in Duilongqu and 0.0085 m3/s in Beishuiqu. Results show that the Qc can vary with hydro-climate conditions. The Qc is high in humid region and low in arid region, and the optimal Qc of 0.0085 m3/s in Beishuiqu Basin (humid region) is higher than 0.0028 m3/s in Duilongqu Basin (semi-arid region). The suggested method provides a new application approach that can be used to determine the Qc of a riverhead in complex geographical regions, which can also reflect the effect of hydro-climate change on rivers supply in different regions.
A riverhead is the demarcation point of continuous water channel and seasonal channel, which is characterized by a critical flow that can support a continuous water body. In this study, the critical support discharge (CSD) is defined as the critical steady flows required to form the origin of a stream. The CSD is used as the criterion to determine the beginning of the riverhead, which can be controlled by hydro-climate factors (e.g., annual precipitation, annual evaporation, or minimum stream flow in arid season). The CSD has a close correlation with the critical support/source area (CSA) that largely affects the density of the river network and the division of sub-watersheds. In general, river density may vary with regional meteorological and hydrological conditions that have to be considered in the analysis. In this paper, a new model referring to the relationship of CSA and CSD is proposed, which is based on the physical mechanism for the origin of riverheads. The feasibility of the model was verified using two watersheds (Duilongqu Basin of the Lhasa River and Beishuiqu Basin of the Nyangqu River) in Tibet Autonomous Region to calculate the CSA and extract river networks. A series of CSAs based on different CSDs in derived equation were tested by comparing the extracted river networks with the reference network obtained from a digitized map of river network at large scales. Comparison results of river networks derived from digital elevation model with real ones indicate that the CSD (equal to criterion of flow quantity (Qc)) are 0.0028 m3/s in Duilongqu and 0.0085 m3/s in Beishuiqu. Results show that the Qc can vary with hydro-climate conditions. The Qc is high in humid region and low in arid region, and the optimal Qc of 0.0085 m3/s in Beishuiqu Basin (humid region) is higher than 0.0028 m3/s in Duilongqu Basin (semi-arid region). The suggested method provides a new application approach that can be used to determine the Qc of a riverhead in complex geographical regions, which can also reflect the effect of hydro-climate change on rivers supply in different regions.
2016, 26(4): 466-477.
doi: 10.1007/s11769-016-0816-z
摘要:
Although the quantification and valuation of ecosystem services have been studied for a long time, few studies have specifically focused on the quantification of tradeoffs between ecosystem services and tradeoff hotspots. Based on previous studies of ecosystem service assessment, we proposed a feasible method to analyze the tradeoffs between ecosystem services, including determination of their relationship, quantification of tradeoffs, and identification of tradeoff hotspots. Potential influencing factors were then further analyzed. The Yanhe Basin in the Loess Plateau was selected as an example to demonstrate the application process. Firstly, the amounts of net primary production (NPP) and water yield (WY) in 2000 and 2008 were estimated by using biophysical models. Secondly, correlation analysis was used to indicate the tradeoffs between NPP and WY. Thirdly, tradeoff index (TINPP/WY) was established to quantify the extent of tradeoffs between NPP and WY, and the average value of TINPP/WY is 24.4 g/(mm·m2) for the Yanhe Basin between 2000 and 2008. Finally, the tradeoff hotspots were identified. The results indicated that the area of lowest tradeoff index concentrated in the middle part of the Yanhe Basin and marginal areas of the southern basin. Map overlapping was used for preliminary analysis to seek potential influencing factors, and the results showed that shrub was the best suited for growing in the Yanhe Basin, but also was a potential influencing factor for formulation of the tradeoff hotspots. The concept of tradeoff index could also be used to quantify the degree of synergy between different ecosystem services. The method to identify the tradeoff hotspots could help us to narrow the scope of study area for further research on the relationship among ecosystem services and concentrate on the potential factors for formation of tradeoff between ecosystem services, enhance the capacity to maintain the sustainability of ecosystem.
Although the quantification and valuation of ecosystem services have been studied for a long time, few studies have specifically focused on the quantification of tradeoffs between ecosystem services and tradeoff hotspots. Based on previous studies of ecosystem service assessment, we proposed a feasible method to analyze the tradeoffs between ecosystem services, including determination of their relationship, quantification of tradeoffs, and identification of tradeoff hotspots. Potential influencing factors were then further analyzed. The Yanhe Basin in the Loess Plateau was selected as an example to demonstrate the application process. Firstly, the amounts of net primary production (NPP) and water yield (WY) in 2000 and 2008 were estimated by using biophysical models. Secondly, correlation analysis was used to indicate the tradeoffs between NPP and WY. Thirdly, tradeoff index (TINPP/WY) was established to quantify the extent of tradeoffs between NPP and WY, and the average value of TINPP/WY is 24.4 g/(mm·m2) for the Yanhe Basin between 2000 and 2008. Finally, the tradeoff hotspots were identified. The results indicated that the area of lowest tradeoff index concentrated in the middle part of the Yanhe Basin and marginal areas of the southern basin. Map overlapping was used for preliminary analysis to seek potential influencing factors, and the results showed that shrub was the best suited for growing in the Yanhe Basin, but also was a potential influencing factor for formulation of the tradeoff hotspots. The concept of tradeoff index could also be used to quantify the degree of synergy between different ecosystem services. The method to identify the tradeoff hotspots could help us to narrow the scope of study area for further research on the relationship among ecosystem services and concentrate on the potential factors for formation of tradeoff between ecosystem services, enhance the capacity to maintain the sustainability of ecosystem.
2016, 26(4): 478-494.
doi: 10.1007/s11769-016-0807-0
摘要:
Examining the direct and indirect effects of climatic factors on vegetation growth is critical to understand the complex linkage between climate change and vegetation dynamics. Based on the Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data and meteorological data (temperature and precipitation) from 2001 to 2012, the trend of vegetation dynamics were examined in the Ziya-Daqing basins, China. The path analysis was used to obtain the information on the relationships among climatic factors and their effects on vegetation growth. It was found that the trends of growing season NDVI were insignificant in most plain dry land, while the upward trends were significant in forest, grass and dry land in Taihang Mountains. According to the path analysis, in 23% of the basins the inter-annual NDVI variation was dominated by the direct effect of precipitation, in 5% by the direct effects of precipitation and temperature, and in less than 1% by the direct effect of temperature or indirect effects of these two climatic factors. It indicated that precipitation significantly affected the vegetation growth in the whole basins, and this effect was not regulated by temperature. Precipitation increase (especially in July, August and September) was favorable to greenness enhancement. Summer temperature rising showed negative effect on plant productivity enhancement, but temperature rise in April was beneficial for the vegetation growth. When April temperature increases by 1℃, the onset date of greenness for natural vegetation will be 2 days in advance. There was a lag-time effect of precipitation or temperature on monthly NDVI for all land use types except grass.
Examining the direct and indirect effects of climatic factors on vegetation growth is critical to understand the complex linkage between climate change and vegetation dynamics. Based on the Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data and meteorological data (temperature and precipitation) from 2001 to 2012, the trend of vegetation dynamics were examined in the Ziya-Daqing basins, China. The path analysis was used to obtain the information on the relationships among climatic factors and their effects on vegetation growth. It was found that the trends of growing season NDVI were insignificant in most plain dry land, while the upward trends were significant in forest, grass and dry land in Taihang Mountains. According to the path analysis, in 23% of the basins the inter-annual NDVI variation was dominated by the direct effect of precipitation, in 5% by the direct effects of precipitation and temperature, and in less than 1% by the direct effect of temperature or indirect effects of these two climatic factors. It indicated that precipitation significantly affected the vegetation growth in the whole basins, and this effect was not regulated by temperature. Precipitation increase (especially in July, August and September) was favorable to greenness enhancement. Summer temperature rising showed negative effect on plant productivity enhancement, but temperature rise in April was beneficial for the vegetation growth. When April temperature increases by 1℃, the onset date of greenness for natural vegetation will be 2 days in advance. There was a lag-time effect of precipitation or temperature on monthly NDVI for all land use types except grass.
2016, 26(4): 495-507.
doi: 10.1007/s11769-015-0763-0
摘要:
The effects of acid deposition on pine forest ecosystems in Longli of Guizhou Province, southwestern China are studied using indoor experiments and model simulations. Indoor experiments are designed to explore the aluminum toxicity on pine seedlings, and the long-term soil acidification model (LTSAM) and a terrestrial biogeochemistry model (CENTURY) are used to simulate the influences of acid deposition on pine forest ecosystems. The indoor experiment results of aluminum toxicity show that aluminum ions in solution limit plant growth and acid deposition enhances this effect by facilitating the release of aluminum ions from the soil. Pine seedling biomass and root elongation decrease as the aluminum concentration increases. The results of model simulations show that the soil chemistry varies significantly with different changes in acid deposition. When the acid deposition increases, the pH value in the soil solution decreases and the soil Al3+ concentration increases. The increased acid deposition also has negative impacts on the forest ecosystem, i.e., decreases plant biomass, net primary productivity (NPP) and net CO2 uptake. As a result, the soil organic carbon (SOC) decreases because of the limited supply of decomposition material. Thus acid deposition need be reduced to help protect the forest ecosystems.
The effects of acid deposition on pine forest ecosystems in Longli of Guizhou Province, southwestern China are studied using indoor experiments and model simulations. Indoor experiments are designed to explore the aluminum toxicity on pine seedlings, and the long-term soil acidification model (LTSAM) and a terrestrial biogeochemistry model (CENTURY) are used to simulate the influences of acid deposition on pine forest ecosystems. The indoor experiment results of aluminum toxicity show that aluminum ions in solution limit plant growth and acid deposition enhances this effect by facilitating the release of aluminum ions from the soil. Pine seedling biomass and root elongation decrease as the aluminum concentration increases. The results of model simulations show that the soil chemistry varies significantly with different changes in acid deposition. When the acid deposition increases, the pH value in the soil solution decreases and the soil Al3+ concentration increases. The increased acid deposition also has negative impacts on the forest ecosystem, i.e., decreases plant biomass, net primary productivity (NPP) and net CO2 uptake. As a result, the soil organic carbon (SOC) decreases because of the limited supply of decomposition material. Thus acid deposition need be reduced to help protect the forest ecosystems.
2016, 26(4): 508-517.
doi: 10.1007/s11769-015-0737-2
摘要:
In order to generate scientifically-based comparative information to improve fertilization efficiency and reduce nutrient loss, 610 samples of 122 soil profiles were collected at the 0-60 cm depth to compare soil nutrient contents including soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), available phosphorus (AP), and available potassium (AK) among different slope positions in a Mollisol farmland area of Northeast China. The contents of SOM and TN typically decreased with increased soil depth at back and bottom slope. Soil loss and deposition tended to decrease SOM and TN at the 0-20 cm soil depth on both the back slope and the slope bottom. The TP firstly decreased from 0-20 cm to 30-40 cm, and then not constantly increased at the back slope and the bottom slope. Due to the characteristics of soil nutrients and crop absorption, the contents of both AP and AK were typically the highest at the summit, followed by the slope bottom and the back slope in the 0-20 cm layer. Generally, in order to sustain the high soil productivity and protect the environment, attention should be paid to soil conservation on back slope; in addition, additional N and P fertilizer is necessary on the back slope.
In order to generate scientifically-based comparative information to improve fertilization efficiency and reduce nutrient loss, 610 samples of 122 soil profiles were collected at the 0-60 cm depth to compare soil nutrient contents including soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), available phosphorus (AP), and available potassium (AK) among different slope positions in a Mollisol farmland area of Northeast China. The contents of SOM and TN typically decreased with increased soil depth at back and bottom slope. Soil loss and deposition tended to decrease SOM and TN at the 0-20 cm soil depth on both the back slope and the slope bottom. The TP firstly decreased from 0-20 cm to 30-40 cm, and then not constantly increased at the back slope and the bottom slope. Due to the characteristics of soil nutrients and crop absorption, the contents of both AP and AK were typically the highest at the summit, followed by the slope bottom and the back slope in the 0-20 cm layer. Generally, in order to sustain the high soil productivity and protect the environment, attention should be paid to soil conservation on back slope; in addition, additional N and P fertilizer is necessary on the back slope.
2016, 26(4): 518-526.
doi: 10.1007/s11769-016-0824-z
摘要:
In order to study the diurnal variation of soil CO2 efflux from temperate meadow steppes in Northeast China, and determine the best time for observation, a field experiment was conducted with a LI-6400 soil CO2 flux system under five typical plant communities (Suaeda glauca (Sg), Chloris virgata (Cv), Puccinellia distans (Pd), Leymus chinensis (Lc) and Phragmites australis (Pa)) and an alkali-spot land (As) at the meadow steppe of western Songnen Plain. The results showed that the diurnal variation of soil CO2 efflux exhibited a single peak curve in the growing season. Diurnal maximum soil respiration (Rs) often appeared between 11:00 and 13:00, while the minimum occurred at 21:00-23:00 or before dawn. Air temperature near the soil surface (Ta) and soil temperature at 10 cm depth (T10) exerted dominant control on the diurnal variations of soil respiration. The time-windows 7:00-9:00 could be used as the optimal measuring time to represent the daily mean soil CO2 efflux at the Cv, Pd, Lc and Pa sites. The daily mean soil CO2 efflux was close to the soil CO2 efflux from 15:00 to 17:00 and the mean of 2 individual soil CO2 efflux from 15:00 to 19:00 at the As and Sg sites, respectively. During nocturnal hours, negative soil CO2 fluxes (CO2 downwards into the soil) were frequently observed at the As and Sg sites, the magnitude of the negative CO2 fluxes were 0.10-1.55 μmol/(m2·s) and 0.10-0.69 μmol/(m2·s) at the two sites. The results implied that alkaline soils could absorb CO2 under natural condition, which might have significant implications to the global carbon budget accounting.
In order to study the diurnal variation of soil CO2 efflux from temperate meadow steppes in Northeast China, and determine the best time for observation, a field experiment was conducted with a LI-6400 soil CO2 flux system under five typical plant communities (Suaeda glauca (Sg), Chloris virgata (Cv), Puccinellia distans (Pd), Leymus chinensis (Lc) and Phragmites australis (Pa)) and an alkali-spot land (As) at the meadow steppe of western Songnen Plain. The results showed that the diurnal variation of soil CO2 efflux exhibited a single peak curve in the growing season. Diurnal maximum soil respiration (Rs) often appeared between 11:00 and 13:00, while the minimum occurred at 21:00-23:00 or before dawn. Air temperature near the soil surface (Ta) and soil temperature at 10 cm depth (T10) exerted dominant control on the diurnal variations of soil respiration. The time-windows 7:00-9:00 could be used as the optimal measuring time to represent the daily mean soil CO2 efflux at the Cv, Pd, Lc and Pa sites. The daily mean soil CO2 efflux was close to the soil CO2 efflux from 15:00 to 17:00 and the mean of 2 individual soil CO2 efflux from 15:00 to 19:00 at the As and Sg sites, respectively. During nocturnal hours, negative soil CO2 fluxes (CO2 downwards into the soil) were frequently observed at the As and Sg sites, the magnitude of the negative CO2 fluxes were 0.10-1.55 μmol/(m2·s) and 0.10-0.69 μmol/(m2·s) at the two sites. The results implied that alkaline soils could absorb CO2 under natural condition, which might have significant implications to the global carbon budget accounting.
2016, 26(4): 527-538.
doi: 10.1007/s11769-016-0825-y
摘要:
The important effects of snow cover to ground thermal regime has received much attention of scholars during the past few decades. In the most of previous research, the effects were usually evaluated through the numerical models and many important results are found. However, less examples and insufficient data based on field measurements are available to show natural cases. In the present work, a typical case study in Mohe and Beijicun meteorological stations, which both are located in the most northern tip of China, is given to show the effects of snow cover on the ground thermal regime. The spatial (the ground profile) and time series analysis in the extremely snowy winter of 2012-2013 in Heilongjiang Province are also performed by contrast with those in the winter of 2011-2012 based on the measured data collected by 63 meteorological stations. Our results illustrate the positive (warmer) effect of snow cover on the ground temperature (GT) on the daily basis, the highest difference between GT and daily mean air temperature (DGAT) is as high as 32.35℃. Moreover, by the lag time analysis method it is found that the response time of GT from 0 cm to 20 cm ground depth to the alternate change of snow depth has 10 days lag, while at 40 cm depth the response of DGAT is not significant. This result is different from the previous research by modeling, in which the response depth of ground to the alteration of snow depth is far more than 40 cm.
The important effects of snow cover to ground thermal regime has received much attention of scholars during the past few decades. In the most of previous research, the effects were usually evaluated through the numerical models and many important results are found. However, less examples and insufficient data based on field measurements are available to show natural cases. In the present work, a typical case study in Mohe and Beijicun meteorological stations, which both are located in the most northern tip of China, is given to show the effects of snow cover on the ground thermal regime. The spatial (the ground profile) and time series analysis in the extremely snowy winter of 2012-2013 in Heilongjiang Province are also performed by contrast with those in the winter of 2011-2012 based on the measured data collected by 63 meteorological stations. Our results illustrate the positive (warmer) effect of snow cover on the ground temperature (GT) on the daily basis, the highest difference between GT and daily mean air temperature (DGAT) is as high as 32.35℃. Moreover, by the lag time analysis method it is found that the response time of GT from 0 cm to 20 cm ground depth to the alternate change of snow depth has 10 days lag, while at 40 cm depth the response of DGAT is not significant. This result is different from the previous research by modeling, in which the response depth of ground to the alteration of snow depth is far more than 40 cm.
2016, 26(4): 539-549.
doi: 10.1007/s11769-015-0794-6
摘要:
Resources and environment carrying capacity is central to not only regional sustainable development but also major function-oriented zoning. This paper presents an evaluation index system for resources and environment carrying capacity based on four aspects of carrying capacity (i.e., water resources, land resources, the environment, and ecosystems) by using a square deviation decision-making method, and on the basis of above effort evaluates the resources and environment carrying capacity across 31 provincial regions in China (not including Hong Kong, Macau and Taiwan regions of China). In addition, this paper evaluates the current state of socio-economic development, and analyzes the spatial distribution of resources and environment pressure. The results showed that distinct spatial differences in resources and environment carrying capacity and pressure across provincial regions. Resources and environment pressure is affected by both comprehensive resources and environment carrying capacity and socio-economic development. Regions subjected to lower degrees of resources and environment pressure will be restricted by resources and environmental problems through future courses of development owing to excessively low carrying capacities. By contrast, regions with higher comprehensive resources and environment carrying capacity will be subjected to excessively high levels of resources and environment pressure because of rapid socio-economic development. Both of resources and environment carrying capacity and pressure must therefore be considered in the allocation of country-binding targets to provincial regions.
Resources and environment carrying capacity is central to not only regional sustainable development but also major function-oriented zoning. This paper presents an evaluation index system for resources and environment carrying capacity based on four aspects of carrying capacity (i.e., water resources, land resources, the environment, and ecosystems) by using a square deviation decision-making method, and on the basis of above effort evaluates the resources and environment carrying capacity across 31 provincial regions in China (not including Hong Kong, Macau and Taiwan regions of China). In addition, this paper evaluates the current state of socio-economic development, and analyzes the spatial distribution of resources and environment pressure. The results showed that distinct spatial differences in resources and environment carrying capacity and pressure across provincial regions. Resources and environment pressure is affected by both comprehensive resources and environment carrying capacity and socio-economic development. Regions subjected to lower degrees of resources and environment pressure will be restricted by resources and environmental problems through future courses of development owing to excessively low carrying capacities. By contrast, regions with higher comprehensive resources and environment carrying capacity will be subjected to excessively high levels of resources and environment pressure because of rapid socio-economic development. Both of resources and environment carrying capacity and pressure must therefore be considered in the allocation of country-binding targets to provincial regions.
2016, 26(4): 550-565.
doi: 10.1007/s11769-015-0771-0
摘要:
Rural settlements are the main carriers of agriculture, rural areas and farmers; thus, optimizing the production and living space of rural settlements is highly significant to rural development. Taking the effective allocation of resources as the starting point, a suitability evaluation system of rural settlements, based on accessibility of production and living, was proposed in this study to provide scientific basis for the optimization of production and living space. The accessibility of production and living was measured by an improved two-step floating catchment area method, which considered proximity and availability based on the inclination of rural residents. The suitability evaluation system consisted of traditional suitability evaluation and newly proposed limiting factor identification based on the loss score proportion of suitability. Tingzu Town of Hubei Province, China, was chosen as the case study area. Based on the results of the suitability evaluation system, corresponding suggestions on rural land consolidation, industry division, as well as the layout of health care and education facilities were proposed to optimize the production and living space of rural settlements in Tingzu Town. It is found that the suitability evaluation based on accessibility of production and living is more scientific and accurate than the traditional ones which significantly overestimate production and living convenience. Moreover, the limiting factor identification can help us put forward suggestions according to local conditions and bring about the highly targeted optimization of production and living space of rural settlements.
Rural settlements are the main carriers of agriculture, rural areas and farmers; thus, optimizing the production and living space of rural settlements is highly significant to rural development. Taking the effective allocation of resources as the starting point, a suitability evaluation system of rural settlements, based on accessibility of production and living, was proposed in this study to provide scientific basis for the optimization of production and living space. The accessibility of production and living was measured by an improved two-step floating catchment area method, which considered proximity and availability based on the inclination of rural residents. The suitability evaluation system consisted of traditional suitability evaluation and newly proposed limiting factor identification based on the loss score proportion of suitability. Tingzu Town of Hubei Province, China, was chosen as the case study area. Based on the results of the suitability evaluation system, corresponding suggestions on rural land consolidation, industry division, as well as the layout of health care and education facilities were proposed to optimize the production and living space of rural settlements in Tingzu Town. It is found that the suitability evaluation based on accessibility of production and living is more scientific and accurate than the traditional ones which significantly overestimate production and living convenience. Moreover, the limiting factor identification can help us put forward suggestions according to local conditions and bring about the highly targeted optimization of production and living space of rural settlements.
2016, 26(4): 566-576.
doi: 10.1007/s11769-016-0826-x
摘要:
Based on SPOT5 satellite remote sensing images and land use data in five time phases covering the period 1988-2012, the distribution characteristics, spatial differentiation processes, and driving mechanisms affecting the residential land of the Jinshitan Tourist Resort were studied. The work included a combination of GIS technology, adoption of the differentiation index D, and the multi-group differentiation-measure model D (m). The results provided a basis for the following conclusions:1) From 1988 to 2012, the degree of differentiation of the rural residential land first decreased, and then increased. The general residential, commercial residential and garden-house land-types all showed declining trends, of which the garden-house type presented the most intense volatility. 2) The overall background of the traditional residential land type was gradually replaced by a new residential land type, and the total area of residential land increased year by year, significantly improving the overall residential conditions. The areas of the new residential land type showed growth, and were increasingly widely distributed in the coastal tourist resorts, transportation corridors, and scenic areas. 3) Government policy, social differentiation, market mechanisms, and individual choices (along with other factors) were mutually promoted, although still restrained. However, all of these factors interacted to constrain the developmental direction and the processes affecting tourism real estate in the Dalian Jinshitan Tourist Resort.
Based on SPOT5 satellite remote sensing images and land use data in five time phases covering the period 1988-2012, the distribution characteristics, spatial differentiation processes, and driving mechanisms affecting the residential land of the Jinshitan Tourist Resort were studied. The work included a combination of GIS technology, adoption of the differentiation index D, and the multi-group differentiation-measure model D (m). The results provided a basis for the following conclusions:1) From 1988 to 2012, the degree of differentiation of the rural residential land first decreased, and then increased. The general residential, commercial residential and garden-house land-types all showed declining trends, of which the garden-house type presented the most intense volatility. 2) The overall background of the traditional residential land type was gradually replaced by a new residential land type, and the total area of residential land increased year by year, significantly improving the overall residential conditions. The areas of the new residential land type showed growth, and were increasingly widely distributed in the coastal tourist resorts, transportation corridors, and scenic areas. 3) Government policy, social differentiation, market mechanisms, and individual choices (along with other factors) were mutually promoted, although still restrained. However, all of these factors interacted to constrain the developmental direction and the processes affecting tourism real estate in the Dalian Jinshitan Tourist Resort.
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