Spanning a vast territory of approximately 13 million km 2 , Asian Russia was home to 38 million ... more Spanning a vast territory of approximately 13 million km 2 , Asian Russia was home to 38 million people in 2016. In an effort to synthesize data and knowledge regarding urbanization and sustainable development in Asian Russia in the context of socioeconomic transformation following the breakup of the Soviet Union in 1990, we quantified the spatiotemporal changes of urban dynamics using satellite imagery and explored the interrelationships between urbanization and sustainability. We then developed a sustainability index, complemented with structural equation modeling, for a comprehensive analysis of their dynamics. We chose six case cities, i.e., Yekaterinburg, Novosibirsk, Krasnoyarsk, Omsk, Irkutsk, and Khabarovsk, as representatives of large cities to investigate whether large cities are in sync with the region in terms of population dynamics, urbanization, and sustainability. Our major findings include the following. First, Asian Russia experienced enhanced economic growth despite the declining population. Furthermore, our case cities showed a general positive trend for population dynamics and urbanization as all except Irkutsk experienced population increases and all expanded their urban built-up areas, ranging from 13% to 16% from 1990 to 2014. Second, Asian Russia and its three federal districts have improved their sustainability and levels of economic development, environmental conditions, and social development. Although both regional sustainability and economic development experienced a serious dip in the 1990s, environmental conditions and social development continuously improved from 1990 to 2014, with social development particularly improving after 1995. Third, in terms of the relationships between urbanization and sustainability, economic development appeared as an important driver of urbanization, social development, and environmental degradation in Asian Russia, with economic development having a stronger influence on urbanization than on social development or environmental degradation.
International Journal of Remote Sensing, Nov 27, 2017
ABSTRACT Remote sensing of chlorophyll-a is challenging in water containing inorganic suspended s... more ABSTRACT Remote sensing of chlorophyll-a is challenging in water containing inorganic suspended sediments (i.e. non-volatile suspended solids, NVSS) and coloured dissolved organic matter (CDOM). The effects of NVSS and CDOM on empirical remote-sensing estimates of chlorophyll-a in inland waters have not been determined on a broad spatial and temporal scale. This study evaluated these effects using a long-term (1989–2012) data set that included chlorophyll-a, NVSS, and CDOM from 39 reservoirs across Missouri (USA). Model comparisons indicated that the machine-learning algorithm BRT (boosted regression trees, validation Nash–Sutcliffe coefficient = 0.350) was better than linear regression (validation Nash–Sutcliffe coefficient = 0.214) for chlorophyll-a estimate using Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) imagery. Only a small proportion of BRT model residuals could be explained by sediments or CDOM, and the observed trends in BRT residuals were different from the theoretical effects expected from NVSS and CDOM. Our results also indicated a small systematic bias by the BRT model, but it was not likely caused by NVSS or CDOM.
Abstract. Accumulating remotely sensed and ground-measured data and improvements in data mining s... more Abstract. Accumulating remotely sensed and ground-measured data and improvements in data mining such as machine-learning techniques open new opportunities for monitoring and managing algal blooms over large spatial scales. The goal of this study was to test the accuracy of remotely sensed algal biomass determined with machine-learning algorithms and Landsat TM/ETM+ imagery. We used chlorophyll-a concentration data from the 2007 National Lake Assessment (NLA) (lake N = 1157) by the US Environmental Protection Agency to train and test Landsat TM/ETM+ algorithms. Results showed significant improvements in chlorophyll-a retrieval accuracy using machine-learning algorithms compared with traditional empirical models using linear regression. Specifically, the results from boosted regression trees and random forest explained, respectively, 45.8% and 44.5% of chlorophyll-a variation. Multiple linear regression could only explain 39.8% of chlorophyll-a variation. The chlorophyll-a concentration derived from Landsat TM/ETM+ and a simple to use Google Earth Engine application, accurately characterized a 2009 algal bloom in western Lake Erie to show the model worked well for the analysis of temporal changes in algal conditions. Compared with chlorophyll-a data from the NLA, chlorophyll-a measurements with our Landsat TM/ETM+ model had almost the same correlation with lake’s total phosphorus concentrations, especially when using multiple Landsat images. Therefore, Landsat measurements of chlorophyll-a have value for ecological assessments and managing algal problems in lakes.
Journal of Arid Land Resources and Environment, 2009
This paper presents the evaluation of the Sloping Land Conversion Program(SLCP) implementation in... more This paper presents the evaluation of the Sloping Land Conversion Program(SLCP) implementation in a study region which is situated in the middle and upper reaches of Yellow River.The area is one of four appraisal areas chosen by a project named "An Integrative Impact Evaluation of China's Ecological Restoration Programs" funded by American National Science Foundation.Satellite remote sensing images covered the region are interpreted in order to get LUCC(land use and land cover change) data within 20 years,specially data on sloping land bigger than 25° and data around the start time of SLCP.The LUCC data is applied to evaluation and effect analysis of SLCP implementation.Interpreted data tells the fact that SLCP effect is good in the study area.In the research,24 Satellite remote sensing images are used to trace historical transition on LUCC to the year 1978.
Determining if the vast soil health degradations across the seven major soil groups (orders) of S... more Determining if the vast soil health degradations across the seven major soil groups (orders) of Sub-Saharan Africa (SSA) can be managed on the basis of a one-size-fits-all or location-specific approach is limited by a lack of soil group-based understanding of soil health degradations. We used the relationship between changes in nematode population dynamics relative to food and reproduction (enrichment, EI) and resistance to disturbance (structure, SI) indices to characterize the soil food web (SFW) and soil health conditions of Ferralsol, Lithosol and Nitosol soil groups in Ghana, Kenya and Malawi. We applied bivariate correlations of EI, SI, soil pH, soil organic carbon (SOC), and texture (sand, silt and clay) to identify integrated indicator parameters, and principal component analysis (PCA) to determine how all measured parameters, soil groups, and countries align. A total of 512 georeferenced soil samples from disturbed (agricultural) and undisturbed (natural vegetation) landsca...
The USDA Agricultural Research Service, Southwest Watershed Research Center, Walnut Gulch Experim... more The USDA Agricultural Research Service, Southwest Watershed Research Center, Walnut Gulch Experimental Watershed (WGEW), is located in the San Pedro Valley of southeastern Arizona. It is one of the most highly instrumented semiarid experimental watersheds in the world and has one of the largest published collections of spectral imagery with coordinated ground observations. The WGEW Image and Ground Data Archive produced in 2006 (WIDGA06) is a collection of images from satellite‐ and aircraft‐based sensors dating back to 1990 with ancillary ground‐based measurements archived with each image. This report provides background information on the collection and archiving of this data set and contact information for obtaining copies of the image and data files. Many images are available in the University of Arizona, Arizona Regional Image Archive (ARIA) (http://aria.arizona.edu). Metadata are available via the U.S. Department of Agriculture, Agricultural Research Service, Southwest Watersh...
Bulletin of the American Meteorological Society, 1991
Arid and semiarid rangelands comprise a significant portion of the earth's land surface. Yet litt... more Arid and semiarid rangelands comprise a significant portion of the earth's land surface. Yet little is known about the effects of temporal and spatial changes in surface soil moisture on the hydrologic cycle, energy balance, and the feedbacks to the atmosphere via thermal forcing over such environments. Understanding this interrelationship is crucial for evaluating the role of the hydrologic cycle in surface-atmosphere interactions. This study focuses on the utility of remote sensing to provide measurements of surface soil moisture, surface albedo, vegetation
The Mekong River basin (MRB) is a transboundary basin that supports livelihoods of over 70 millio... more The Mekong River basin (MRB) is a transboundary basin that supports livelihoods of over 70 million inhabitants and diverse terrestrial-aquatic ecosystems. This critical lifeline for people and ecosystems is under transformation due to climatic stressors and human activities (e.g., land use change and dam construction). Thus, there is an urgent need to better understand the changing hydrological and ecological systems in the MRB and develop improved adaptation strategies. This, however, is hampered partly by lack of sufficient, reliable, and accessible observational data across the basin. Here, we fill this long-standing gap for MRB by synthesizing climate, hydrological, ecological, and socioeconomic data from various disparate sources. The data— including groundwater records digitized from the literature—provide crucial insights into surface water systems, groundwater dynamics, land use patterns, and socioeconomic changes. The analyses presented also shed light on uncertainties asso...
We examine Land Use Land Cover Change (LULCC) in the Dedza and Ntcheu districts of Central Malawi... more We examine Land Use Land Cover Change (LULCC) in the Dedza and Ntcheu districts of Central Malawi and model anthropogenic and environmental drivers. We present an integrative approach to understanding heterogenous landscape interactions and short- to long-term shocks and how they inform future land management and policy in Malawi. Landsat 30-m satellite imagery for 2001, 2009, and 2019 was used to identify and quantify LULCC outcomes based on eight input classes: agriculture, built-up areas, barren, water, wetlands, forest-mixed vegetation, shrub-woodland, and other. A Multilayer Perceptron (MLP) neural network was developed to examine land-cover transitions based on the drivers; elevation, slope, soil texture, population density and distance from roads and rivers. Agriculture is projected to dominate the landscape by 2050. Dedza has a higher probability of future land conversion to agriculture (0.45 to 0.70) than Ntcheu (0.30 to 0.45). These findings suggest that future land manage...
Aims: Livestock grazing, one of the principal utilization patterns, usually exerts a substantial ... more Aims: Livestock grazing, one of the principal utilization patterns, usually exerts a substantial effect on the carbon allocations between the above- and belowground components of a grassland ecosystem. The major aims of this study were to evaluate the proportions of 13C allocation to various C pools of the plant-soil system of a meadow steppe ecosystem in response to livestock grazing intensity.Methods: In situ stable 13C isotope pulse labeling was conducted in the plots of a long-term grazing experiment with 4 levels of grazing intensities. Plant and soil materials were sampled at on eight occasions (0, 3, 10, 18, 31, 56 and 100 days after labeling) to analyze the decline in 13C over time, and their composition signature of 13C were analyzed by the isotope ratio mass spectrometer technique.Results: We found a significantly larger decline in assimilated 13C for the heavily grazed swards compared to other grazing intensities, with the relocation rate of 13C from shoots to belowground...
Temperate and semiarid grasslands comprise 80% of the land area on the Mongolian Plateau and envi... more Temperate and semiarid grasslands comprise 80% of the land area on the Mongolian Plateau and environs, which includes Mongolia (MG), and the province of Inner Mongolia (IM), China. Substantial land cover/use change in the last few decades, driven by a combination of post-liberalization socioeconomic changes and extreme climatic events, has degraded these water-limited grassland's structure and function. Hence, a precise estimation of canopy cover (CC, %) and aboveground biomass (AGB, g m −2) is needed. In this study, we ana
During the past several decades, the Earth system has changed significantly, especially across No... more During the past several decades, the Earth system has changed significantly, especially across Northern Eurasia. Changes in the socioeconomic conditions of the larger countries in the region have also resulted in a variety of regional environmental changes that can have global consequences. The Northern Eurasia Future Initiative (NEFI) has been designed as an essential continuation of the Northern Eurasia Earth Science Partnership Initiative (NEESPI), which was launched in 2004. NEESPI sought to elucidate all aspects of ongoing environmental change, to inform societies and, thus, to better prepare societies for future developments. A key principle of NEFI is that these developments must now be secured through science-based strategies codesigned with regional decision-makers to lead their societies to prosperity in the face of environmental and institutional challenges. NEESPI scientific research, data, and models have created a solid knowledge base to support the NEFI program. This paper presents the NEFI research vision consensus based on that knowledge. It provides the reader with samples of recent accomplishments in regional studies and formulates new NEFI science questions. To address these questions, nine research foci are identified and their selections are briefly justified. These foci include warming of the Arctic; changing frequency, pattern, and intensity of extreme and inclement environmental conditions; retreat of the cryosphere; changes in terrestrial water cycles; changes in the biosphere; pressures on land use; changes in infrastructure; societal actions in response to environmental change; and quantification of Northern Eurasia's role in the global Earth system. Powerful feedbacks between the Earth and human systems in Northern Eurasia (e.g., mega-fires, droughts, depletion of the cryosphere essential for water supply, retreat of sea ice) result from past and current human activities (e.g., large-scale water withdrawals, land use, and governance change) and potentially restrict or provide new opportunities for future human activities. Therefore, we propose that integrated assessment models are needed as the final stage of global change assessment. The overarching goal of this NEFI modeling effort will enable evaluation
Quantifying carbon (C) dioxide exchanges between ecosystems and the atmosphere and the underlying... more Quantifying carbon (C) dioxide exchanges between ecosystems and the atmosphere and the underlying mechanism of biophysical regulations under similar environmental conditions is critical for an accurate understanding of C budgets and ecosystem functions. For the first time, a cluster of four eddy covariance towers were set up to answer how C fluxes shift among four dominant ecosystems in Mongolia - meadow steppe (MDW), typical steppe (TPL), dry typical steppe (DRT) and shrubland (SHB) during two growing seasons (2014 and 2015). Large variations were observed for the annual net ecosystem exchange (NEE) from 59 to 193gCm(- 2), though all four sites acted as a C source. During the two growing seasons, MDW acted as a C sink, TPL and DRT were C neutral, while SHB acted as a C source. MDW to SHB and TPL conversions resulted in a 2.6- and 2.2-fold increase in C release, respectively, whereas the TPL to SHB conversion resulted in a 1.1-fold increase at the annual scale. C assimilation was hi...
The spatio-temporal characteristics of remote sensing are considered to be the primary advantage ... more The spatio-temporal characteristics of remote sensing are considered to be the primary advantage in environmental studies. With long-term and frequent satellite observations, it is possible to monitor changes in key biophysical attributes such as phenological characteristics, and relate them to climate change by examining their correlations. Although a number of remote sensing methods have been developed to quantify vegetation seasonal cycles using time-series of vegetation indices, there is limited effort to explore and monitor changes and trends of vegetation phenology in the Monsoon Southeast Asia, which is adversely affected by changes in the Asian monsoon climate. In this study, MODIS EVI and TRMM time series data, along with field survey data, were analyzed to quantify phenological patterns and trends in the Monsoon Southeast Asia during 2001-2010 period and assess their relationship with climate change in the region. The results revealed a great regional variability and inter...
... 200438. Olson, J., Misana, S., Campbell, D., Mbonile, M. and Mugisha, S. 2004. ... Sci. Paper... more ... 200438. Olson, J., Misana, S., Campbell, D., Mbonile, M. and Mugisha, S. 2004. ... Sci. Paper No. 465, Department of Atmospheric Science, Colorado State University, Fort Collins, CO View all references) and a sea breeze model (Mahrer and Pielke 197727. ...
Spanning a vast territory of approximately 13 million km 2 , Asian Russia was home to 38 million ... more Spanning a vast territory of approximately 13 million km 2 , Asian Russia was home to 38 million people in 2016. In an effort to synthesize data and knowledge regarding urbanization and sustainable development in Asian Russia in the context of socioeconomic transformation following the breakup of the Soviet Union in 1990, we quantified the spatiotemporal changes of urban dynamics using satellite imagery and explored the interrelationships between urbanization and sustainability. We then developed a sustainability index, complemented with structural equation modeling, for a comprehensive analysis of their dynamics. We chose six case cities, i.e., Yekaterinburg, Novosibirsk, Krasnoyarsk, Omsk, Irkutsk, and Khabarovsk, as representatives of large cities to investigate whether large cities are in sync with the region in terms of population dynamics, urbanization, and sustainability. Our major findings include the following. First, Asian Russia experienced enhanced economic growth despite the declining population. Furthermore, our case cities showed a general positive trend for population dynamics and urbanization as all except Irkutsk experienced population increases and all expanded their urban built-up areas, ranging from 13% to 16% from 1990 to 2014. Second, Asian Russia and its three federal districts have improved their sustainability and levels of economic development, environmental conditions, and social development. Although both regional sustainability and economic development experienced a serious dip in the 1990s, environmental conditions and social development continuously improved from 1990 to 2014, with social development particularly improving after 1995. Third, in terms of the relationships between urbanization and sustainability, economic development appeared as an important driver of urbanization, social development, and environmental degradation in Asian Russia, with economic development having a stronger influence on urbanization than on social development or environmental degradation.
International Journal of Remote Sensing, Nov 27, 2017
ABSTRACT Remote sensing of chlorophyll-a is challenging in water containing inorganic suspended s... more ABSTRACT Remote sensing of chlorophyll-a is challenging in water containing inorganic suspended sediments (i.e. non-volatile suspended solids, NVSS) and coloured dissolved organic matter (CDOM). The effects of NVSS and CDOM on empirical remote-sensing estimates of chlorophyll-a in inland waters have not been determined on a broad spatial and temporal scale. This study evaluated these effects using a long-term (1989–2012) data set that included chlorophyll-a, NVSS, and CDOM from 39 reservoirs across Missouri (USA). Model comparisons indicated that the machine-learning algorithm BRT (boosted regression trees, validation Nash–Sutcliffe coefficient = 0.350) was better than linear regression (validation Nash–Sutcliffe coefficient = 0.214) for chlorophyll-a estimate using Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) imagery. Only a small proportion of BRT model residuals could be explained by sediments or CDOM, and the observed trends in BRT residuals were different from the theoretical effects expected from NVSS and CDOM. Our results also indicated a small systematic bias by the BRT model, but it was not likely caused by NVSS or CDOM.
Abstract. Accumulating remotely sensed and ground-measured data and improvements in data mining s... more Abstract. Accumulating remotely sensed and ground-measured data and improvements in data mining such as machine-learning techniques open new opportunities for monitoring and managing algal blooms over large spatial scales. The goal of this study was to test the accuracy of remotely sensed algal biomass determined with machine-learning algorithms and Landsat TM/ETM+ imagery. We used chlorophyll-a concentration data from the 2007 National Lake Assessment (NLA) (lake N = 1157) by the US Environmental Protection Agency to train and test Landsat TM/ETM+ algorithms. Results showed significant improvements in chlorophyll-a retrieval accuracy using machine-learning algorithms compared with traditional empirical models using linear regression. Specifically, the results from boosted regression trees and random forest explained, respectively, 45.8% and 44.5% of chlorophyll-a variation. Multiple linear regression could only explain 39.8% of chlorophyll-a variation. The chlorophyll-a concentration derived from Landsat TM/ETM+ and a simple to use Google Earth Engine application, accurately characterized a 2009 algal bloom in western Lake Erie to show the model worked well for the analysis of temporal changes in algal conditions. Compared with chlorophyll-a data from the NLA, chlorophyll-a measurements with our Landsat TM/ETM+ model had almost the same correlation with lake’s total phosphorus concentrations, especially when using multiple Landsat images. Therefore, Landsat measurements of chlorophyll-a have value for ecological assessments and managing algal problems in lakes.
Journal of Arid Land Resources and Environment, 2009
This paper presents the evaluation of the Sloping Land Conversion Program(SLCP) implementation in... more This paper presents the evaluation of the Sloping Land Conversion Program(SLCP) implementation in a study region which is situated in the middle and upper reaches of Yellow River.The area is one of four appraisal areas chosen by a project named "An Integrative Impact Evaluation of China's Ecological Restoration Programs" funded by American National Science Foundation.Satellite remote sensing images covered the region are interpreted in order to get LUCC(land use and land cover change) data within 20 years,specially data on sloping land bigger than 25° and data around the start time of SLCP.The LUCC data is applied to evaluation and effect analysis of SLCP implementation.Interpreted data tells the fact that SLCP effect is good in the study area.In the research,24 Satellite remote sensing images are used to trace historical transition on LUCC to the year 1978.
Determining if the vast soil health degradations across the seven major soil groups (orders) of S... more Determining if the vast soil health degradations across the seven major soil groups (orders) of Sub-Saharan Africa (SSA) can be managed on the basis of a one-size-fits-all or location-specific approach is limited by a lack of soil group-based understanding of soil health degradations. We used the relationship between changes in nematode population dynamics relative to food and reproduction (enrichment, EI) and resistance to disturbance (structure, SI) indices to characterize the soil food web (SFW) and soil health conditions of Ferralsol, Lithosol and Nitosol soil groups in Ghana, Kenya and Malawi. We applied bivariate correlations of EI, SI, soil pH, soil organic carbon (SOC), and texture (sand, silt and clay) to identify integrated indicator parameters, and principal component analysis (PCA) to determine how all measured parameters, soil groups, and countries align. A total of 512 georeferenced soil samples from disturbed (agricultural) and undisturbed (natural vegetation) landsca...
The USDA Agricultural Research Service, Southwest Watershed Research Center, Walnut Gulch Experim... more The USDA Agricultural Research Service, Southwest Watershed Research Center, Walnut Gulch Experimental Watershed (WGEW), is located in the San Pedro Valley of southeastern Arizona. It is one of the most highly instrumented semiarid experimental watersheds in the world and has one of the largest published collections of spectral imagery with coordinated ground observations. The WGEW Image and Ground Data Archive produced in 2006 (WIDGA06) is a collection of images from satellite‐ and aircraft‐based sensors dating back to 1990 with ancillary ground‐based measurements archived with each image. This report provides background information on the collection and archiving of this data set and contact information for obtaining copies of the image and data files. Many images are available in the University of Arizona, Arizona Regional Image Archive (ARIA) (http://aria.arizona.edu). Metadata are available via the U.S. Department of Agriculture, Agricultural Research Service, Southwest Watersh...
Bulletin of the American Meteorological Society, 1991
Arid and semiarid rangelands comprise a significant portion of the earth's land surface. Yet litt... more Arid and semiarid rangelands comprise a significant portion of the earth's land surface. Yet little is known about the effects of temporal and spatial changes in surface soil moisture on the hydrologic cycle, energy balance, and the feedbacks to the atmosphere via thermal forcing over such environments. Understanding this interrelationship is crucial for evaluating the role of the hydrologic cycle in surface-atmosphere interactions. This study focuses on the utility of remote sensing to provide measurements of surface soil moisture, surface albedo, vegetation
The Mekong River basin (MRB) is a transboundary basin that supports livelihoods of over 70 millio... more The Mekong River basin (MRB) is a transboundary basin that supports livelihoods of over 70 million inhabitants and diverse terrestrial-aquatic ecosystems. This critical lifeline for people and ecosystems is under transformation due to climatic stressors and human activities (e.g., land use change and dam construction). Thus, there is an urgent need to better understand the changing hydrological and ecological systems in the MRB and develop improved adaptation strategies. This, however, is hampered partly by lack of sufficient, reliable, and accessible observational data across the basin. Here, we fill this long-standing gap for MRB by synthesizing climate, hydrological, ecological, and socioeconomic data from various disparate sources. The data— including groundwater records digitized from the literature—provide crucial insights into surface water systems, groundwater dynamics, land use patterns, and socioeconomic changes. The analyses presented also shed light on uncertainties asso...
We examine Land Use Land Cover Change (LULCC) in the Dedza and Ntcheu districts of Central Malawi... more We examine Land Use Land Cover Change (LULCC) in the Dedza and Ntcheu districts of Central Malawi and model anthropogenic and environmental drivers. We present an integrative approach to understanding heterogenous landscape interactions and short- to long-term shocks and how they inform future land management and policy in Malawi. Landsat 30-m satellite imagery for 2001, 2009, and 2019 was used to identify and quantify LULCC outcomes based on eight input classes: agriculture, built-up areas, barren, water, wetlands, forest-mixed vegetation, shrub-woodland, and other. A Multilayer Perceptron (MLP) neural network was developed to examine land-cover transitions based on the drivers; elevation, slope, soil texture, population density and distance from roads and rivers. Agriculture is projected to dominate the landscape by 2050. Dedza has a higher probability of future land conversion to agriculture (0.45 to 0.70) than Ntcheu (0.30 to 0.45). These findings suggest that future land manage...
Aims: Livestock grazing, one of the principal utilization patterns, usually exerts a substantial ... more Aims: Livestock grazing, one of the principal utilization patterns, usually exerts a substantial effect on the carbon allocations between the above- and belowground components of a grassland ecosystem. The major aims of this study were to evaluate the proportions of 13C allocation to various C pools of the plant-soil system of a meadow steppe ecosystem in response to livestock grazing intensity.Methods: In situ stable 13C isotope pulse labeling was conducted in the plots of a long-term grazing experiment with 4 levels of grazing intensities. Plant and soil materials were sampled at on eight occasions (0, 3, 10, 18, 31, 56 and 100 days after labeling) to analyze the decline in 13C over time, and their composition signature of 13C were analyzed by the isotope ratio mass spectrometer technique.Results: We found a significantly larger decline in assimilated 13C for the heavily grazed swards compared to other grazing intensities, with the relocation rate of 13C from shoots to belowground...
Temperate and semiarid grasslands comprise 80% of the land area on the Mongolian Plateau and envi... more Temperate and semiarid grasslands comprise 80% of the land area on the Mongolian Plateau and environs, which includes Mongolia (MG), and the province of Inner Mongolia (IM), China. Substantial land cover/use change in the last few decades, driven by a combination of post-liberalization socioeconomic changes and extreme climatic events, has degraded these water-limited grassland's structure and function. Hence, a precise estimation of canopy cover (CC, %) and aboveground biomass (AGB, g m −2) is needed. In this study, we ana
During the past several decades, the Earth system has changed significantly, especially across No... more During the past several decades, the Earth system has changed significantly, especially across Northern Eurasia. Changes in the socioeconomic conditions of the larger countries in the region have also resulted in a variety of regional environmental changes that can have global consequences. The Northern Eurasia Future Initiative (NEFI) has been designed as an essential continuation of the Northern Eurasia Earth Science Partnership Initiative (NEESPI), which was launched in 2004. NEESPI sought to elucidate all aspects of ongoing environmental change, to inform societies and, thus, to better prepare societies for future developments. A key principle of NEFI is that these developments must now be secured through science-based strategies codesigned with regional decision-makers to lead their societies to prosperity in the face of environmental and institutional challenges. NEESPI scientific research, data, and models have created a solid knowledge base to support the NEFI program. This paper presents the NEFI research vision consensus based on that knowledge. It provides the reader with samples of recent accomplishments in regional studies and formulates new NEFI science questions. To address these questions, nine research foci are identified and their selections are briefly justified. These foci include warming of the Arctic; changing frequency, pattern, and intensity of extreme and inclement environmental conditions; retreat of the cryosphere; changes in terrestrial water cycles; changes in the biosphere; pressures on land use; changes in infrastructure; societal actions in response to environmental change; and quantification of Northern Eurasia's role in the global Earth system. Powerful feedbacks between the Earth and human systems in Northern Eurasia (e.g., mega-fires, droughts, depletion of the cryosphere essential for water supply, retreat of sea ice) result from past and current human activities (e.g., large-scale water withdrawals, land use, and governance change) and potentially restrict or provide new opportunities for future human activities. Therefore, we propose that integrated assessment models are needed as the final stage of global change assessment. The overarching goal of this NEFI modeling effort will enable evaluation
Quantifying carbon (C) dioxide exchanges between ecosystems and the atmosphere and the underlying... more Quantifying carbon (C) dioxide exchanges between ecosystems and the atmosphere and the underlying mechanism of biophysical regulations under similar environmental conditions is critical for an accurate understanding of C budgets and ecosystem functions. For the first time, a cluster of four eddy covariance towers were set up to answer how C fluxes shift among four dominant ecosystems in Mongolia - meadow steppe (MDW), typical steppe (TPL), dry typical steppe (DRT) and shrubland (SHB) during two growing seasons (2014 and 2015). Large variations were observed for the annual net ecosystem exchange (NEE) from 59 to 193gCm(- 2), though all four sites acted as a C source. During the two growing seasons, MDW acted as a C sink, TPL and DRT were C neutral, while SHB acted as a C source. MDW to SHB and TPL conversions resulted in a 2.6- and 2.2-fold increase in C release, respectively, whereas the TPL to SHB conversion resulted in a 1.1-fold increase at the annual scale. C assimilation was hi...
The spatio-temporal characteristics of remote sensing are considered to be the primary advantage ... more The spatio-temporal characteristics of remote sensing are considered to be the primary advantage in environmental studies. With long-term and frequent satellite observations, it is possible to monitor changes in key biophysical attributes such as phenological characteristics, and relate them to climate change by examining their correlations. Although a number of remote sensing methods have been developed to quantify vegetation seasonal cycles using time-series of vegetation indices, there is limited effort to explore and monitor changes and trends of vegetation phenology in the Monsoon Southeast Asia, which is adversely affected by changes in the Asian monsoon climate. In this study, MODIS EVI and TRMM time series data, along with field survey data, were analyzed to quantify phenological patterns and trends in the Monsoon Southeast Asia during 2001-2010 period and assess their relationship with climate change in the region. The results revealed a great regional variability and inter...
... 200438. Olson, J., Misana, S., Campbell, D., Mbonile, M. and Mugisha, S. 2004. ... Sci. Paper... more ... 200438. Olson, J., Misana, S., Campbell, D., Mbonile, M. and Mugisha, S. 2004. ... Sci. Paper No. 465, Department of Atmospheric Science, Colorado State University, Fort Collins, CO View all references) and a sea breeze model (Mahrer and Pielke 197727. ...
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