Myanmar is the largest country in mainland Southeast Asia. Since the reforms of 2011, the tempo o... more Myanmar is the largest country in mainland Southeast Asia. Since the reforms of 2011, the tempo of archaeological research has increased, and, in 2014, three Pyu cities (Sri Ksetra, Halin and Beikthano) were awarded World Heritage status. The ERC Project shows that Pyu cities present early, regionally important examples of settlements evolving from the late Iron Age into early urbanism in a context of spatial continuity. Sri Ksetra is the prototype of the type of urbanism found at Angkor and Pagan centuries later, where water management was imbedded in extended urban space.
The major threat to human societies posed by undernutrition has been recognised for millennia. De... more The major threat to human societies posed by undernutrition has been recognised for millennia. Despite substantial economic development and scientific innovation, however, progress in addressing this global challenge has been inadequate. Paradoxically, the last half-century also saw the rapid emergence of obesity, first in high-income countries but now also in low- and middle-income countries. Traditionally, these problems were approached separately, but there is increasing recognition that they have common drivers and need integrated responses. The new nutrition reality comprises a global ‘double burden’ of malnutrition, where the challenges of food insecurity, nutritional deficiencies and undernutrition coexist and interact with obesity, sedentary behaviour, unhealthy diets and environments that foster unhealthy behaviour. Beyond immediate efforts to prevent and treat malnutrition, what must change in order to reduce the future burden? Here, we present a conceptual framework that ...
This paper investigates how educational and geographic capital are assorted among households in r... more This paper investigates how educational and geographic capital are assorted among households in rural Nepal, and how women's marital age may shape this distribution. Our focus on the timing of marriage adds a new dimension to studies of geographies of youth and marital assortment, while our emphasis on the physical and spatial attributes of households leads us to propose the concept of geographic capital, operationalised here as agrarian landholding and access to rural markets. Using data on 17,284 women from rural lowland Nepal, heat tables showed substantial pairing among uneducated spouses, whereas educated men married women with varying levels of schooling, partly because fewer women were educated. Multivariable logistic regression models showed that the odds of marrying an educated man increased substantially for women with secondary education, and vice versa. Educated women were also more likely to marry into households with geographic capital. However, landowning husbands tended to marry younger wives, perhaps because the natal home was prepared to marry daughters earlier in order to access this geographic capital. The youngest-marrying women were least likely to marry into households with accessibility to markets. Our findings may help understand the decisions of both a woman's natal and marital household over the timing of her marriage, and the investment in her formal education. These patterns have implications for both spouses because capital not only shapes marital pairing, but also the spatial niche of the household within which women and their children will experience their life-course.
Background: Early childbirth is associated with adverse maternal and child health outcomes. In So... more Background: Early childbirth is associated with adverse maternal and child health outcomes. In South Asia, where women generally marry before having children, public health efforts need to focus on delaying marriage. Female education is widely considered the primary means to achieve this. However, it remains unclear how much education is required to delay marriage to the universal minimum age of 18 years, or what predicts marriage age in women lacking any education. This is crucial to address in the Terai region of Nepal which has the highest proportion of children out of school and where girls marry and have their first pregnancy early. Methods: We analyzed data from 6,406 women aged 23-30 years from a cluster-randomized trial in lowland Terai Nepal. Using Kaplan-Meier survival analysis, multivariable logistic and Cox proportional hazards regression models, we investigated associations between women's education level and age at marriage and first pregnancy, and the interval between these events. Among the uneducated women, we investigated associations of husband's education level with the same outcomes. Results: Compared to uneducated women, educated women had a greater probability of delaying marriage until the age of 18 years and of pregnancy until 20 years. Women needed to complete grade 9, and ideally 11, to substantially increase their odds of marrying after 18 years. Delaying first pregnancy to 20 years was largely due to marrying later; education had little extra effect. The association of marriage with first pregnancy age worked independently of education. However, later-marrying women, who generally had completed more education, had their first pregnancy sooner after marriage than earlier marrying women. Most uneducated women, regardless of their husbands' level of education, still married under the legal age of marriage. Conclusion: Delaying marriage to majority age requires greater efforts to ensure girls get to school in the first place, and complete secondary education. Since currently only 36% of girls in the Terai attend secondary school, parallel efforts to delay marriage are crucial to prevent early childbearing. Sexual and reproductive health programmes in school and in women's groups for married and uneducated adolescents may help prepare for marriage and pregnancy.
Land suitability analysis is an important step in land use planning for livestock development bec... more Land suitability analysis is an important step in land use planning for livestock development because of its high efficiency to allocate livestock farms to the most suitable land areas and minimize adverse effects on environment. This study aimed to use two multi-criteria analysis approaches: Weighted Linear Combination (WLC) and Ordered Weighted Averaging (OWA), to comparatively evaluate and map land use suitability for livestock production in Hangzhou metropolitan area, China. The evaluation used eight factors as suitability criteria, relating to topographic, environmental, human factors, and socioeconomic data. The analytic hierarchy process (AHP) method and GIS techniques were integrated into the evaluation models to create the land suitability map. The results of WLC approach showed that 11.4% of the total area was highly suitable for livestock production while 48.6% was unsuitable. Of these, areas located far from central city had higher suitability, while areas close to the urban district, drinking water source area, ecological and natural conservation area, had lower suitability. Sensitivity analysis indicated this expert suitability results for livestock production were robust. Indirect validations conducted by mutual comparisons of suitability maps computed using the WLC and OWA approaches demonstrated 90.4% of the overall agreement with a kappa coefficient of 0.857, indicating that both methods provide very similar spatial land use suitability distributions. Ecological fitness was evaluated by comparing the suitability analysis result with a previous livestock development planning and several recommendations aimed at improving the long-term livestock development plans were made for Hangzhou.
International Journal of Applied Earth Observation and Geoinformation, 2004
Widespread development and use of object-based GIS in the environmental sciences has stimulated a... more Widespread development and use of object-based GIS in the environmental sciences has stimulated a rapid growth in demand for parcel-based land cover data. Despite the fact that image segmentation techniques applied to remotely sensed data offer the most effective and direct approach to generating such data their use is still restricted to specialist applications. This paper describes a general purpose segmentation algorithm capable of creating parcel boundaries from a wide range of image types. A brief review of image segmentation in a range of disciplines identifies key elements of a successful segmentation algorithm. The structure and implementation of the algorithm is then described and its performance is illustrated using Landsat ETM imagery of Eastern England. Comparison of the segmentation product generated by the algorithm with those generated by independent human analysts demonstrates that the computer algorithm and the manually derived products have just less than eighty percent correspondence. Most of the differences stem from the more detailed results achieved by the segmentation algorithm.
The development of lidar opens a new era in archaeological survey. Working with Forest Research, ... more The development of lidar opens a new era in archaeological survey. Working with Forest Research, staff of the Unit for Landscape Modelling here explain the technique, and demonstrate its application to woodland, showing how it can be used to see through the trees. The article by Bewley et al. (pages 636-647 of this volume) shows the technique applied to the Stonehenge landscape.
Tropical forests currently play a key role in regulating the terrestrial carbon cycle and abating... more Tropical forests currently play a key role in regulating the terrestrial carbon cycle and abating climate change by storing carbon in wood. However, there remains considerable uncertainty as to whether tropical forests will continue to act as carbon sinks in the face of increased pressure from expanding human activities. Consequently, understanding what drives productivity in tropical forests is critical. We used permanent forest plot data from the Gola Rainforest National Park (Sierra Leone)one of the largest tracts of intact tropical moist forest in West Africato explore how (1) stand basal area and tree diversity, (2) past disturbance associated with past logging, and (3) underlying soil nutrient gradients interact to determine rates of aboveground wood production (AWP). We started by statistically modeling the diameter growth of individual trees and used these models to estimate AWP for 142 permanent forest plots. We then used structural equation modeling to explore the direct and indirect pathways which shape rates of AWP. Across the plot network, stand basal area emerged as the strongest determinant of AWP, with densely packed stands exhibiting the fastest rates of AWP. In addition to stand packing density, both tree diversity and soil phosphorus content were also positively related to productivity. By contrast, historical logging activities negatively impacted AWP through the removal of large trees, which contributed disproportionately to productivity. Understanding what determines variation in wood production across tropical forest landscapes requires accounting for multiple interacting driverswith stand structure, tree diversity, and soil nutrients all playing a key role. Importantly, our results also indicate that logging activities can have a long-lasting impact on a forest's ability to sequester and store carbon, emphasizing the importance of safeguarding old-growth tropical forests.
Soil cadmium (Cd) contamination has attracted a great deal of attention because of its detrimenta... more Soil cadmium (Cd) contamination has attracted a great deal of attention because of its detrimental effects on animals and humans. This study aimed to develop and compare the performances of stepwise linear regression (SLR), classification and regression tree (CART) and random forest (RF) models in the prediction and mapping of the spatial distribution of soil Cd and to identify likely sources of Cd accumulation in Fuyang County, eastern China. Soil Cd data from 276 topsoil (0-20 cm) samples were collected and randomly divided into calibration (222 samples) and validation datasets (54 samples). Auxiliary data, including detailed land use information, soil organic matter, soil pH, and topographic data, were incorporated into the models to simulate the soil Cd concentrations and further identify the main factors influencing soil Cd variation. The predictive models for soil Cd concentration exhibited acceptable overall accuracies (72.22% for SLR, 70.37% for CART, and 75.93% for RF). The...
This paper demonstrates an integrated method for studying cropland loss dynamics and the resultan... more This paper demonstrates an integrated method for studying cropland loss dynamics and the resultant impacts on sustainable development spanning the past 10 years (1996-2006) in response to rampant urban growth. This study deploys remote sensing to obtain accurate measures of cropland change information and applies GIS to examine the spatio-temporal trajectory of cropland loss. Coupled with landscape metrics and soil quality assessment approach, this paper also explores the impacts on fragmentation of cropland landscape and soil resource in detail. The case study concludes that cropland has undergone considerable loss from 1996 to 2006 and exhibited distinct variation of change dynamics
ABSTRACT We present the results of an investigation into the capabilities of high‐resolution airb... more ABSTRACT We present the results of an investigation into the capabilities of high‐resolution airborne Light Detection And Ranging (LiDAR) for the study of a small glacier in Svalbard. The data are shown to be capable of producing a digital elevation model (DEM) with a horizontal resolution of 1–2 m and a vertical resolution of 5–15 cm. This degree of resolution is suitable for mass‐balance estimation using repeat data on an annual or semi‐annual basis, but it is also reveals linear surface features such as meltwater channels and crevasses. These have potential for tracking in repeat imagery to deduce the surface flow of the glacier. The intensity of the returned LiDAR pulse can also be used to discriminate snow‐covered parts of the glacier from bare ice.
ABSTRACT LiDAR is developing into a formidable instrument of aerial survey. Here the author shows... more ABSTRACT LiDAR is developing into a formidable instrument of aerial survey. Here the author shows how the LiDAR picture can be enhanced so that features picked up by illumination from different directions can be combined in one comprehensive survey.
Myanmar is the largest country in mainland Southeast Asia. Since the reforms of 2011, the tempo o... more Myanmar is the largest country in mainland Southeast Asia. Since the reforms of 2011, the tempo of archaeological research has increased, and, in 2014, three Pyu cities (Sri Ksetra, Halin and Beikthano) were awarded World Heritage status. The ERC Project shows that Pyu cities present early, regionally important examples of settlements evolving from the late Iron Age into early urbanism in a context of spatial continuity. Sri Ksetra is the prototype of the type of urbanism found at Angkor and Pagan centuries later, where water management was imbedded in extended urban space.
The major threat to human societies posed by undernutrition has been recognised for millennia. De... more The major threat to human societies posed by undernutrition has been recognised for millennia. Despite substantial economic development and scientific innovation, however, progress in addressing this global challenge has been inadequate. Paradoxically, the last half-century also saw the rapid emergence of obesity, first in high-income countries but now also in low- and middle-income countries. Traditionally, these problems were approached separately, but there is increasing recognition that they have common drivers and need integrated responses. The new nutrition reality comprises a global ‘double burden’ of malnutrition, where the challenges of food insecurity, nutritional deficiencies and undernutrition coexist and interact with obesity, sedentary behaviour, unhealthy diets and environments that foster unhealthy behaviour. Beyond immediate efforts to prevent and treat malnutrition, what must change in order to reduce the future burden? Here, we present a conceptual framework that ...
This paper investigates how educational and geographic capital are assorted among households in r... more This paper investigates how educational and geographic capital are assorted among households in rural Nepal, and how women's marital age may shape this distribution. Our focus on the timing of marriage adds a new dimension to studies of geographies of youth and marital assortment, while our emphasis on the physical and spatial attributes of households leads us to propose the concept of geographic capital, operationalised here as agrarian landholding and access to rural markets. Using data on 17,284 women from rural lowland Nepal, heat tables showed substantial pairing among uneducated spouses, whereas educated men married women with varying levels of schooling, partly because fewer women were educated. Multivariable logistic regression models showed that the odds of marrying an educated man increased substantially for women with secondary education, and vice versa. Educated women were also more likely to marry into households with geographic capital. However, landowning husbands tended to marry younger wives, perhaps because the natal home was prepared to marry daughters earlier in order to access this geographic capital. The youngest-marrying women were least likely to marry into households with accessibility to markets. Our findings may help understand the decisions of both a woman's natal and marital household over the timing of her marriage, and the investment in her formal education. These patterns have implications for both spouses because capital not only shapes marital pairing, but also the spatial niche of the household within which women and their children will experience their life-course.
Background: Early childbirth is associated with adverse maternal and child health outcomes. In So... more Background: Early childbirth is associated with adverse maternal and child health outcomes. In South Asia, where women generally marry before having children, public health efforts need to focus on delaying marriage. Female education is widely considered the primary means to achieve this. However, it remains unclear how much education is required to delay marriage to the universal minimum age of 18 years, or what predicts marriage age in women lacking any education. This is crucial to address in the Terai region of Nepal which has the highest proportion of children out of school and where girls marry and have their first pregnancy early. Methods: We analyzed data from 6,406 women aged 23-30 years from a cluster-randomized trial in lowland Terai Nepal. Using Kaplan-Meier survival analysis, multivariable logistic and Cox proportional hazards regression models, we investigated associations between women's education level and age at marriage and first pregnancy, and the interval between these events. Among the uneducated women, we investigated associations of husband's education level with the same outcomes. Results: Compared to uneducated women, educated women had a greater probability of delaying marriage until the age of 18 years and of pregnancy until 20 years. Women needed to complete grade 9, and ideally 11, to substantially increase their odds of marrying after 18 years. Delaying first pregnancy to 20 years was largely due to marrying later; education had little extra effect. The association of marriage with first pregnancy age worked independently of education. However, later-marrying women, who generally had completed more education, had their first pregnancy sooner after marriage than earlier marrying women. Most uneducated women, regardless of their husbands' level of education, still married under the legal age of marriage. Conclusion: Delaying marriage to majority age requires greater efforts to ensure girls get to school in the first place, and complete secondary education. Since currently only 36% of girls in the Terai attend secondary school, parallel efforts to delay marriage are crucial to prevent early childbearing. Sexual and reproductive health programmes in school and in women's groups for married and uneducated adolescents may help prepare for marriage and pregnancy.
Land suitability analysis is an important step in land use planning for livestock development bec... more Land suitability analysis is an important step in land use planning for livestock development because of its high efficiency to allocate livestock farms to the most suitable land areas and minimize adverse effects on environment. This study aimed to use two multi-criteria analysis approaches: Weighted Linear Combination (WLC) and Ordered Weighted Averaging (OWA), to comparatively evaluate and map land use suitability for livestock production in Hangzhou metropolitan area, China. The evaluation used eight factors as suitability criteria, relating to topographic, environmental, human factors, and socioeconomic data. The analytic hierarchy process (AHP) method and GIS techniques were integrated into the evaluation models to create the land suitability map. The results of WLC approach showed that 11.4% of the total area was highly suitable for livestock production while 48.6% was unsuitable. Of these, areas located far from central city had higher suitability, while areas close to the urban district, drinking water source area, ecological and natural conservation area, had lower suitability. Sensitivity analysis indicated this expert suitability results for livestock production were robust. Indirect validations conducted by mutual comparisons of suitability maps computed using the WLC and OWA approaches demonstrated 90.4% of the overall agreement with a kappa coefficient of 0.857, indicating that both methods provide very similar spatial land use suitability distributions. Ecological fitness was evaluated by comparing the suitability analysis result with a previous livestock development planning and several recommendations aimed at improving the long-term livestock development plans were made for Hangzhou.
International Journal of Applied Earth Observation and Geoinformation, 2004
Widespread development and use of object-based GIS in the environmental sciences has stimulated a... more Widespread development and use of object-based GIS in the environmental sciences has stimulated a rapid growth in demand for parcel-based land cover data. Despite the fact that image segmentation techniques applied to remotely sensed data offer the most effective and direct approach to generating such data their use is still restricted to specialist applications. This paper describes a general purpose segmentation algorithm capable of creating parcel boundaries from a wide range of image types. A brief review of image segmentation in a range of disciplines identifies key elements of a successful segmentation algorithm. The structure and implementation of the algorithm is then described and its performance is illustrated using Landsat ETM imagery of Eastern England. Comparison of the segmentation product generated by the algorithm with those generated by independent human analysts demonstrates that the computer algorithm and the manually derived products have just less than eighty percent correspondence. Most of the differences stem from the more detailed results achieved by the segmentation algorithm.
The development of lidar opens a new era in archaeological survey. Working with Forest Research, ... more The development of lidar opens a new era in archaeological survey. Working with Forest Research, staff of the Unit for Landscape Modelling here explain the technique, and demonstrate its application to woodland, showing how it can be used to see through the trees. The article by Bewley et al. (pages 636-647 of this volume) shows the technique applied to the Stonehenge landscape.
Tropical forests currently play a key role in regulating the terrestrial carbon cycle and abating... more Tropical forests currently play a key role in regulating the terrestrial carbon cycle and abating climate change by storing carbon in wood. However, there remains considerable uncertainty as to whether tropical forests will continue to act as carbon sinks in the face of increased pressure from expanding human activities. Consequently, understanding what drives productivity in tropical forests is critical. We used permanent forest plot data from the Gola Rainforest National Park (Sierra Leone)one of the largest tracts of intact tropical moist forest in West Africato explore how (1) stand basal area and tree diversity, (2) past disturbance associated with past logging, and (3) underlying soil nutrient gradients interact to determine rates of aboveground wood production (AWP). We started by statistically modeling the diameter growth of individual trees and used these models to estimate AWP for 142 permanent forest plots. We then used structural equation modeling to explore the direct and indirect pathways which shape rates of AWP. Across the plot network, stand basal area emerged as the strongest determinant of AWP, with densely packed stands exhibiting the fastest rates of AWP. In addition to stand packing density, both tree diversity and soil phosphorus content were also positively related to productivity. By contrast, historical logging activities negatively impacted AWP through the removal of large trees, which contributed disproportionately to productivity. Understanding what determines variation in wood production across tropical forest landscapes requires accounting for multiple interacting driverswith stand structure, tree diversity, and soil nutrients all playing a key role. Importantly, our results also indicate that logging activities can have a long-lasting impact on a forest's ability to sequester and store carbon, emphasizing the importance of safeguarding old-growth tropical forests.
Soil cadmium (Cd) contamination has attracted a great deal of attention because of its detrimenta... more Soil cadmium (Cd) contamination has attracted a great deal of attention because of its detrimental effects on animals and humans. This study aimed to develop and compare the performances of stepwise linear regression (SLR), classification and regression tree (CART) and random forest (RF) models in the prediction and mapping of the spatial distribution of soil Cd and to identify likely sources of Cd accumulation in Fuyang County, eastern China. Soil Cd data from 276 topsoil (0-20 cm) samples were collected and randomly divided into calibration (222 samples) and validation datasets (54 samples). Auxiliary data, including detailed land use information, soil organic matter, soil pH, and topographic data, were incorporated into the models to simulate the soil Cd concentrations and further identify the main factors influencing soil Cd variation. The predictive models for soil Cd concentration exhibited acceptable overall accuracies (72.22% for SLR, 70.37% for CART, and 75.93% for RF). The...
This paper demonstrates an integrated method for studying cropland loss dynamics and the resultan... more This paper demonstrates an integrated method for studying cropland loss dynamics and the resultant impacts on sustainable development spanning the past 10 years (1996-2006) in response to rampant urban growth. This study deploys remote sensing to obtain accurate measures of cropland change information and applies GIS to examine the spatio-temporal trajectory of cropland loss. Coupled with landscape metrics and soil quality assessment approach, this paper also explores the impacts on fragmentation of cropland landscape and soil resource in detail. The case study concludes that cropland has undergone considerable loss from 1996 to 2006 and exhibited distinct variation of change dynamics
ABSTRACT We present the results of an investigation into the capabilities of high‐resolution airb... more ABSTRACT We present the results of an investigation into the capabilities of high‐resolution airborne Light Detection And Ranging (LiDAR) for the study of a small glacier in Svalbard. The data are shown to be capable of producing a digital elevation model (DEM) with a horizontal resolution of 1–2 m and a vertical resolution of 5–15 cm. This degree of resolution is suitable for mass‐balance estimation using repeat data on an annual or semi‐annual basis, but it is also reveals linear surface features such as meltwater channels and crevasses. These have potential for tracking in repeat imagery to deduce the surface flow of the glacier. The intensity of the returned LiDAR pulse can also be used to discriminate snow‐covered parts of the glacier from bare ice.
ABSTRACT LiDAR is developing into a formidable instrument of aerial survey. Here the author shows... more ABSTRACT LiDAR is developing into a formidable instrument of aerial survey. Here the author shows how the LiDAR picture can be enhanced so that features picked up by illumination from different directions can be combined in one comprehensive survey.
Uploads
Papers by Gabriel Amable