Keith Richards | University of Cambridge (original) (raw)
Papers by Keith Richards
Purpose Students were given an interactive exercise based on a research model (Foreseer TM), deve... more Purpose Students were given an interactive exercise based on a research model (Foreseer TM), developed by an interdisciplinary research team, that explores the interconnectivity of water, energy and land resources. Two groups of students were involved, one of undergraduates and the other of graduates. The aim was to enhance and complement teaching about resource system feedbacks and environmental modelling. Methodology The Foreseer model represents physical flows of the three resources (water, energy and land) using an interactive visual interface. The exercise was set up by giving students short instructions about how to use the tool to create four scenarios, and an online questionnaire was used to capture their understanding, and their ability to extract information from the model. Findings The exercise proved to be a helpful way to connect research and teaching in higher education, to the benefit of both. For students, it was an interactive and engaging way to learn about these complex sustainability issues. At the same time, it provided tangible feedback to researchers working on the model about the clarity of its user interface, and its pedagogic value. Originality/value This exercise represents a novel use of a resource model as a teaching tool in the study of the water, energy and land nexus, and is relevant to sustainability educators as an example of a model centred learning approach on this topic.
Global Environmental Change, 2021
National consumption of goods and services is met by domestic production and international trade.... more National consumption of goods and services is met by domestic production and international trade. As a result, countries and sectors exert pressure on natural resources both within and beyond their national borders. Where this resource demand is imposed matters to the effective management of global resource insecurity. Although instructive, the 'resource footprint' of a country or sector-a common yardstick to assess the sustainability of consumption in relation to water, energy and land systems-does not distinguish its origin of production and associated resource risk. As a result, the source and severity of global resource insecurity remains poorly understood. To understand how resource use connects different actors within the global economy, the water, energy and land footprints of 189 countries and 14838 country sectors are partitioned by source (domestic, macro-regional and remote) and risk (high, medium and low). Linking national consumption to source reveals countries and sectors are highly exposed, directly (via domestic production) and indirectly (via imports), to over-exploited, insecure, and degraded water, energy, and land resources. However, countries and sectors exhibit greater exposure to resource risks via international trade (≈ 80-90%), mainly from remote production sources. Within this context, countries and sectors share the same sources of resource supply and risk, highlighting an opportunity to manage their resource security by intervening in upstream global supply chains. Nevertheless, our findings also invite critical reflection on whether globalisation is compatible with managing risks countries face and drive across the global water-energy-land system.
Journal of Glaciology, 1996
This paper describes the development and testing of a distributed surface energy-balance model us... more This paper describes the development and testing of a distributed surface energy-balance model used to calculate rates of surface melting at Haut Glacier d’Arolla, Valais, Switzerland. The model uses a digital elevation model (DEM) of the glacier surface and surrounding topography together with meterological data collected at a site in front of the glacier to determine hourly or daily totals of the energy-balance components and hence of melting over the entire surface of the glacier with a spatial resolution of 20 m. The model can also be used to determine temporal and spatial variations in snow depth, snow-line position and glacier surface albedo. Calculations from the model are compared with observations made along the glacier centre line 1990, and in general the model performs very well. The correlation coefficients between calculated and measured snow-line elevation, albedo and ablation are 0.99, 0.85 and 0.81, respectively. The main source of error between modelled and measured...
Global Environmental Change, 2015
Energy system pathways which are projected to deliver minimum possible deployment cost, combined ... more Energy system pathways which are projected to deliver minimum possible deployment cost, combined with low Greenhouse Gas (GHG) emissions, are usually considered as 'no-regrets' options. However, the question remains whether such energy pathways present 'no-regrets' when also considering the wider environmental resource impacts, in particular those on land and water resources. This paper aims to determine whether the energy pathways of the UK's Carbon Plan are environmental "no-regrets" options, defined in this study as simultaneously exhibiting low impact on land and water services resulting from resource appropriation for energy provision. This is accomplished by estimating the land area and water abstraction required by 2050 under the four pathways of the Carbon Plan with different scenarios for energy crop composition, yield, and power station locations. The outcomes are compared with defined limits for sustainable land appropriation and water abstraction. The results show that of the four Carbon Plan pathways, only the "Higher Renewables, more energy efficiency" pathway is an environmental "no-regrets" option, and that is only if deployment of power stations inland is limited. The study shows that policies for future low-carbon energy systems should be developed with awareness of wider environmental impacts. Failing to do this could lead to a setback in achieving GHG emission reductions goals, because of unforeseen additional competition between the energy sector and demand for land and water services in other sectors.
Water Resources Research, 2014
Alpine lakes on the Tibetan Plateau are minimally disturbed by human activities and are sensitive... more Alpine lakes on the Tibetan Plateau are minimally disturbed by human activities and are sensitive indicators of climate variability. Accelerated lake expansion in the 2000s has been confirmed by both dramatic lake-area increases (for 312 lakes larger than 10 km 2) derived from optical images, and rapid water-level rises (for 117 lakes with water-level data) measured by satellite altimetry. However, the underlying climate causes remain unclear. This paper analyzes the relationship between the water-level changes of lakes on the plateau and the potential driving factors, such as the glacier meltwater supply and a dependency on precipitation and runoff over the whole plateau and in each zone. The results show that the rates of change of non-glacier-fed lakes in the 2000s were as high as those of glacier-fed lakes across the whole plateau and the lake-level changes were closely associated with the lake supply coefficients (the basin/lake area ratio). The lake variations agreed well with the spatial pattern of precipitation changes. However, in different zones, especially at around 33 N north of the plateau, glacier-fed lakes did exhibit faster lake level increases than no-glacier-fed lakes, indicating that the presence of a glacier meltwater supply augmented the precipitation-driven lake expansions in these areas. Despite the absence of quantitative modeling due to limited data availability, this study provides qualitative support that the lake expansions on the Tibetan Plateau in the 2000s have been driven primarily by changes in precipitation and evapotranspiration and not solely by the effect of glacier wastage.
… scientific nature of geomorphology: proceedings of …, 1996
Unifying geography: common …, 2004
15 SPACE, TIME AND SCIENCE Individuals, emergence and geographies of space and place Keith Richar... more 15 SPACE, TIME AND SCIENCE Individuals, emergence and geographies of space and place Keith Richards, Michael Bithell and Michael Bravo When Stella contemplated her own progress through time and space, she saw linesblack lines that zig-zagged this way and that, ...
Journal of Rural Studies, 2017
Validation of scientific findings from satellite remote sensing against local ecological knowledg... more Validation of scientific findings from satellite remote sensing against local ecological knowledge could make the interpretation of forest cover patterns more robust. In this paper, we examine local perceptions of forest cover change in parishes around Budongo and Bugoma for a 30-year period (1985-2014), compare the results with those obtained from remote sensing (Twongyirwe et al., 2015), and interrogate whether the perceptions could be related to livelihood typologies.. First, we characterise household strategies for the entire landscape to place livelihood strategies of communities in deforestated areas in a broader local context. An in-depth questionnaire was administered to 706 households in 13 parishes situated in 4 Agro-Ecological Zones (AEZs). The data included household demographic characteristics, energy use, cropping and livestock husbandry, and seasonal time-and labour-budgets. Principal Components Analysis (PCA) and Cluster Analysis (CA) were employed to help identify dominant structures in the data. Secondly, the 375 households in 7 parishes around Budongo and Bugoma forests (part of the 706) responded to additional questions that sought their perceptions on the forest cover trend. The PCA results for the entire landscape show that significant variation amongst households is mainly related to the cultivation time input, on-farm income particularly from cropping activities, livestock husbandry, demographic characteristics, agricultural extension activities, and cultivation labour input. Hierarchical CA shows that households at the landscape level fall into about nine different types, with variation in spatial distribution. The analysis suggests that poor households do live near forested regions, and that the rural poor are more reliant on forest products than peri-urban populations. Regarding perceptions of forest cover change, the majority (70.1%: n=375) of the respondents in the parishes think that there has been a decline in forest cover, and this percentage is larger than the percentage of non-respondents (18.9%), those that thought it had increased (5.6%), not changed (3.7%), and those that did not know (1.6%). In addition, perceptions on forest change were significantly related to the household livelihood typologies (X 2 =623.4, df=4, p=0.000): respondents who perceived forest cover as having declined and those that provided no response belonged to cluster 2 ("low income mixed farming households"), which is also the dominant livelihood typology around these forests. While the data largely suggest that there is a remarkable agreement between remote sensing results and local knowledge on forest change, and that local people may play a big role in filling data gaps where a dearth of information is prevalent (or where remote sensing evidence is fuzzy), there is a clear signal that people in different social classes and age groups can have very different views on what the change in forest might be despite what Landsat data show. This might have policy implications if decision makers tend to come from the groups that are not likely to have perceived forest cover change, or base their judgement on views from certain social classes. This implies that it is important to have the remote sensing data available as a counter balance to local perception (and vice versa) and therefore these data should be considered concurrently.
Global Environmental Change, 2015
5-4 4 5 1 a n d Ric h a r d s , Keit h 2 0 1 5. Ap p r o a c h e s t o e v al u a ti n g m o d el... more 5-4 4 5 1 a n d Ric h a r d s , Keit h 2 0 1 5. Ap p r o a c h e s t o e v al u a ti n g m o d el q u ality a c r o s s diffe r e n t r e gi m e ty p e s in e nvi r o n m e n t al a n d p u blic h e al t h g ov e r n a n c e. Glo b al E nvi ro n m e n t al C h a n g e 3 3 , p p .
Journal of Glaciology, 1990
During the summers of 1987 and 1988, 15 dye-tracer tests from a total of eight injection points w... more During the summers of 1987 and 1988, 15 dye-tracer tests from a total of eight injection points were conducted in the ablation area of Midtdalsbreen, a northern outlet of Hardangerjokulen, southern Norway. The spatial and temporal patterns of water discharge, shapes of the dye-return curves, through-flow velocities, dye-recovery rates, dispersivities, and velocity/discharge relationships suggest the existence of distinct catchments beneath the eastern and western halves of the glacier which are characterized by different types of drainage sytem. Experiments on the eastern side were associated with high melt-water discharges and produced short-lived and highly peaked dye-return curves, fast through-flow velocities, high dye-recovery rates, low dispersivity values which decreased through the melt season, and a velocity/discharge relationship with an exponent of 1.0. Experiments on the western side were associated with low melt-water discharges and produced flat, extended dye-return cu...
Energy Policy, 2015
The Carbon Plan could result in significant land use change for bioenergy by 2050. Higher Nuclear... more The Carbon Plan could result in significant land use change for bioenergy by 2050. Higher Nuclear; less efficiency pathway has the highest land use change impact. Higher Renewables; more energy efficiency pathway has the lowest land use change impact. Transport decarbonisation via biofuels has the highest land use change impacts. At current deployment rate only Higher Renewables pathway projections is achievable.
Energy Policy, 2015
A whole systems analysis of current and future water used for energy is presented. The energy sec... more A whole systems analysis of current and future water used for energy is presented. The energy sector's compliance with the "3 Red Lines" water policies is assessed. Future energy plans could conflict with the "3 Red Lines" industrial water policy. Water used for energy is highly dependant on technology choices. Co-benefits and trade-offs between future energy and water plans are identified.
Land, 2014
Climate change and agriculture influence each other. The effects of climate change on agriculture... more Climate change and agriculture influence each other. The effects of climate change on agriculture seem to be predominantly negative, although studies show a large variation in impacts between crops and regions. To compensate for these effects, agriculture can either intensify or expand in area; both of these options increase greenhouse gas emissions. It is therefore likely that such negative effects will increase agriculture's contribution to climate change, making this feedback a positive, self-reinforcing one. We have previously used a data-driven model to examine greenhouse gas emissions in 2050 related to agricultural scenarios of increasing demand for food. Here, we extend this approach by introducing the impacts of climate change on agricultural yields. We estimate the additional losses of natural habitats and increases in greenhouse gas emissions resulting from agricultural expansion and relocation induced by the negative effects of climate change. We studied two climate change scenarios and different assumptions about trade. These additional impacts caused by climate change are found to be relatively moderate compared to demand-driven impact, but still significant. They increase greenhouse gas emissions from land use change by an additional 8%-13%. Climate change tends to aggravate the effects of demand drivers in critical regions. Current emission scenarios are underestimates in that they do not include these feedback effects.
ISPRS Journal of Photogrammetry and Remote Sensing, 2014
Alpine lakes on the Tibetan Plateau (TP) are key indicators of climate change and climate variabi... more Alpine lakes on the Tibetan Plateau (TP) are key indicators of climate change and climate variability. The increasing availability of remote sensing techniques with appropriate spatiotemporal resolutions, broad coverage and low costs allows for effective monitoring lake changes on the TP and surroundings and understanding climate change impacts, particularly in remote and inaccessible areas where there are lack of in situ observations. This paper firstly introduces characteristics of Tibetan lakes, and outlines available satellite observation platforms and different remote sensing water-body extraction algorithms. Then, this paper reviews advances in applying remote sensing methods for various lake environment monitoring, including lake surface extent and water level, glacial lake and potential outburst floods, lake ice phenology, geological or geomorphologic evidences of lake basins, with a focus on the trends and magnitudes of lake area and water-level change and their spatially and temporally heterogeneous patterns. Finally we discuss current uncertainties or accuracy of detecting lake area and water-level changes from multisource satellite data and ongoing challenges in mapping characteristics of glacial lakes using remote sensing. Based on previous studies on the relationship between lake variation and climate change, it is inferred that the climate-driven mechanisms of lake variations on the TP still remain unclear and require further research.
Hydrological Sciences Journal, 1995
Using a combination of laboratory and field experiments, the performance of a Partech Instruments... more Using a combination of laboratory and field experiments, the performance of a Partech Instruments Ltd IR40-C active head suspended solids sensor has been tested with respect to changing particle size distribution and rapid variation in suspended sediment transport rate. The sensor, which utilizes light attenuation in the infrared waveband, has several advantages both over visible light optical designs and over nuclear or optical back-scatter (OBS) devices. Three sets of laboratory tests are reported: calibration experiments using estuarine, pro-glacial and control media; flume simulations of pulsed sediment supply at a variety of frequencies, concentrations and ambient flow velocities; and simple tests for the effect of air bubbles within the sensor light path. The sensor was also deployed in the field, together with an electromagnetic current meter, to monitor flow and suspended sediment transport fluctuations in the turbulent frequency range. Although the sensor performed well with respect to drift, noise and stability of calibration, significant variation occurred with respect to suspensions of differing particle sizes. A simple correction procedure involving the weighting of sensor output by specific particle surface area may enable comparison of turbidity data from different locations and times, and with standard calibration solutions. At high frequencies, the sensor is capable of resolving fluctuations in the transport rate to c. 0.5 s, which appears to correspond well to field observations of significant velocity fluctuation and transport 'events' and is comparable with results obtained using OBS devices. However, the resolution of transport fluctuations is again dependent upon particle characteristics, and the presence of air bubbles in the flow whose size approximates the path width of the sensor may mimic a fluctuating transport process. Further interpretation of high frequency measurement awaits research into the fundamentals of rapidly varying flow and sediment transport characteristics. Evaluation sur le terrain et au laboratoire d'une sonde de turbidité infrarouge et sa sensibilité à la taille des particules et aux variations de la concentration des matières en suspension Résumé L'effet de variations de la distribution des tailles de particules et du flux de matières en suspension sur le fonctionnement d'une sonde de matières en suspension a été évalué, les essais ayant été réalisés sur le Open for discussion until I June 1996
Earth Surface Processes and Landforms, 1997
Fluvial geomorphology has witnessed a continuing reduction in the time-and space-scales of resear... more Fluvial geomorphology has witnessed a continuing reduction in the time-and space-scales of research, with increasing emphasis on the dynamics of small site-specific river reaches. This shift can be regarded as part of a trend towards the understanding and explanation rather than description of how rivers change, which raises important questions regarding the relevance of such short timescale and small space-scale research to understanding longer-term aspects of landform behaviour. The methodological challenges that arise from such intensive case study research are illustrated here using a detailed investigation of a river reach. Morphological changes within this reach are shown to be driven by: (i) catchmentscale processes associated with the interaction of discharge and sediment supply waves; and (ii) modification of these processes through morphological controls on erosion and deposition patterns and hence net channel change. The 'morphological conditioning' of channel response reflects the configurational aspects of channel change, and the importance of local characteristics in the understanding of system behaviour. Sensitivity to local conditions implies that short timescale and small space-scale processes may be critical to channel behaviour, particularly if the system is interpreted in non-linear terms. Although it may be possible to identify statistically averaged stable states, non-linear system behaviour implies that system trajectories are sensitively dependent upon instantaneous system states. Thus, changes between average states can only be understood through an understanding of the sequence of configurational states through which the system evolves.
Interest in the integrated restoration of managed river corridors has arisen in response to falli... more Interest in the integrated restoration of managed river corridors has arisen in response to falling levels of riparian and floodplain biodiversity due to flood control works including channalization and flow regulation by headwater impoundments. This decline is in part, a direct response to the impact of engineering works on the geomorphological dynamics of rivers and in particular, upon rates of
Clays and Clay Minerals, 1980
Purpose Students were given an interactive exercise based on a research model (Foreseer TM), deve... more Purpose Students were given an interactive exercise based on a research model (Foreseer TM), developed by an interdisciplinary research team, that explores the interconnectivity of water, energy and land resources. Two groups of students were involved, one of undergraduates and the other of graduates. The aim was to enhance and complement teaching about resource system feedbacks and environmental modelling. Methodology The Foreseer model represents physical flows of the three resources (water, energy and land) using an interactive visual interface. The exercise was set up by giving students short instructions about how to use the tool to create four scenarios, and an online questionnaire was used to capture their understanding, and their ability to extract information from the model. Findings The exercise proved to be a helpful way to connect research and teaching in higher education, to the benefit of both. For students, it was an interactive and engaging way to learn about these complex sustainability issues. At the same time, it provided tangible feedback to researchers working on the model about the clarity of its user interface, and its pedagogic value. Originality/value This exercise represents a novel use of a resource model as a teaching tool in the study of the water, energy and land nexus, and is relevant to sustainability educators as an example of a model centred learning approach on this topic.
Global Environmental Change, 2021
National consumption of goods and services is met by domestic production and international trade.... more National consumption of goods and services is met by domestic production and international trade. As a result, countries and sectors exert pressure on natural resources both within and beyond their national borders. Where this resource demand is imposed matters to the effective management of global resource insecurity. Although instructive, the 'resource footprint' of a country or sector-a common yardstick to assess the sustainability of consumption in relation to water, energy and land systems-does not distinguish its origin of production and associated resource risk. As a result, the source and severity of global resource insecurity remains poorly understood. To understand how resource use connects different actors within the global economy, the water, energy and land footprints of 189 countries and 14838 country sectors are partitioned by source (domestic, macro-regional and remote) and risk (high, medium and low). Linking national consumption to source reveals countries and sectors are highly exposed, directly (via domestic production) and indirectly (via imports), to over-exploited, insecure, and degraded water, energy, and land resources. However, countries and sectors exhibit greater exposure to resource risks via international trade (≈ 80-90%), mainly from remote production sources. Within this context, countries and sectors share the same sources of resource supply and risk, highlighting an opportunity to manage their resource security by intervening in upstream global supply chains. Nevertheless, our findings also invite critical reflection on whether globalisation is compatible with managing risks countries face and drive across the global water-energy-land system.
Journal of Glaciology, 1996
This paper describes the development and testing of a distributed surface energy-balance model us... more This paper describes the development and testing of a distributed surface energy-balance model used to calculate rates of surface melting at Haut Glacier d’Arolla, Valais, Switzerland. The model uses a digital elevation model (DEM) of the glacier surface and surrounding topography together with meterological data collected at a site in front of the glacier to determine hourly or daily totals of the energy-balance components and hence of melting over the entire surface of the glacier with a spatial resolution of 20 m. The model can also be used to determine temporal and spatial variations in snow depth, snow-line position and glacier surface albedo. Calculations from the model are compared with observations made along the glacier centre line 1990, and in general the model performs very well. The correlation coefficients between calculated and measured snow-line elevation, albedo and ablation are 0.99, 0.85 and 0.81, respectively. The main source of error between modelled and measured...
Global Environmental Change, 2015
Energy system pathways which are projected to deliver minimum possible deployment cost, combined ... more Energy system pathways which are projected to deliver minimum possible deployment cost, combined with low Greenhouse Gas (GHG) emissions, are usually considered as 'no-regrets' options. However, the question remains whether such energy pathways present 'no-regrets' when also considering the wider environmental resource impacts, in particular those on land and water resources. This paper aims to determine whether the energy pathways of the UK's Carbon Plan are environmental "no-regrets" options, defined in this study as simultaneously exhibiting low impact on land and water services resulting from resource appropriation for energy provision. This is accomplished by estimating the land area and water abstraction required by 2050 under the four pathways of the Carbon Plan with different scenarios for energy crop composition, yield, and power station locations. The outcomes are compared with defined limits for sustainable land appropriation and water abstraction. The results show that of the four Carbon Plan pathways, only the "Higher Renewables, more energy efficiency" pathway is an environmental "no-regrets" option, and that is only if deployment of power stations inland is limited. The study shows that policies for future low-carbon energy systems should be developed with awareness of wider environmental impacts. Failing to do this could lead to a setback in achieving GHG emission reductions goals, because of unforeseen additional competition between the energy sector and demand for land and water services in other sectors.
Water Resources Research, 2014
Alpine lakes on the Tibetan Plateau are minimally disturbed by human activities and are sensitive... more Alpine lakes on the Tibetan Plateau are minimally disturbed by human activities and are sensitive indicators of climate variability. Accelerated lake expansion in the 2000s has been confirmed by both dramatic lake-area increases (for 312 lakes larger than 10 km 2) derived from optical images, and rapid water-level rises (for 117 lakes with water-level data) measured by satellite altimetry. However, the underlying climate causes remain unclear. This paper analyzes the relationship between the water-level changes of lakes on the plateau and the potential driving factors, such as the glacier meltwater supply and a dependency on precipitation and runoff over the whole plateau and in each zone. The results show that the rates of change of non-glacier-fed lakes in the 2000s were as high as those of glacier-fed lakes across the whole plateau and the lake-level changes were closely associated with the lake supply coefficients (the basin/lake area ratio). The lake variations agreed well with the spatial pattern of precipitation changes. However, in different zones, especially at around 33 N north of the plateau, glacier-fed lakes did exhibit faster lake level increases than no-glacier-fed lakes, indicating that the presence of a glacier meltwater supply augmented the precipitation-driven lake expansions in these areas. Despite the absence of quantitative modeling due to limited data availability, this study provides qualitative support that the lake expansions on the Tibetan Plateau in the 2000s have been driven primarily by changes in precipitation and evapotranspiration and not solely by the effect of glacier wastage.
… scientific nature of geomorphology: proceedings of …, 1996
Unifying geography: common …, 2004
15 SPACE, TIME AND SCIENCE Individuals, emergence and geographies of space and place Keith Richar... more 15 SPACE, TIME AND SCIENCE Individuals, emergence and geographies of space and place Keith Richards, Michael Bithell and Michael Bravo When Stella contemplated her own progress through time and space, she saw linesblack lines that zig-zagged this way and that, ...
Journal of Rural Studies, 2017
Validation of scientific findings from satellite remote sensing against local ecological knowledg... more Validation of scientific findings from satellite remote sensing against local ecological knowledge could make the interpretation of forest cover patterns more robust. In this paper, we examine local perceptions of forest cover change in parishes around Budongo and Bugoma for a 30-year period (1985-2014), compare the results with those obtained from remote sensing (Twongyirwe et al., 2015), and interrogate whether the perceptions could be related to livelihood typologies.. First, we characterise household strategies for the entire landscape to place livelihood strategies of communities in deforestated areas in a broader local context. An in-depth questionnaire was administered to 706 households in 13 parishes situated in 4 Agro-Ecological Zones (AEZs). The data included household demographic characteristics, energy use, cropping and livestock husbandry, and seasonal time-and labour-budgets. Principal Components Analysis (PCA) and Cluster Analysis (CA) were employed to help identify dominant structures in the data. Secondly, the 375 households in 7 parishes around Budongo and Bugoma forests (part of the 706) responded to additional questions that sought their perceptions on the forest cover trend. The PCA results for the entire landscape show that significant variation amongst households is mainly related to the cultivation time input, on-farm income particularly from cropping activities, livestock husbandry, demographic characteristics, agricultural extension activities, and cultivation labour input. Hierarchical CA shows that households at the landscape level fall into about nine different types, with variation in spatial distribution. The analysis suggests that poor households do live near forested regions, and that the rural poor are more reliant on forest products than peri-urban populations. Regarding perceptions of forest cover change, the majority (70.1%: n=375) of the respondents in the parishes think that there has been a decline in forest cover, and this percentage is larger than the percentage of non-respondents (18.9%), those that thought it had increased (5.6%), not changed (3.7%), and those that did not know (1.6%). In addition, perceptions on forest change were significantly related to the household livelihood typologies (X 2 =623.4, df=4, p=0.000): respondents who perceived forest cover as having declined and those that provided no response belonged to cluster 2 ("low income mixed farming households"), which is also the dominant livelihood typology around these forests. While the data largely suggest that there is a remarkable agreement between remote sensing results and local knowledge on forest change, and that local people may play a big role in filling data gaps where a dearth of information is prevalent (or where remote sensing evidence is fuzzy), there is a clear signal that people in different social classes and age groups can have very different views on what the change in forest might be despite what Landsat data show. This might have policy implications if decision makers tend to come from the groups that are not likely to have perceived forest cover change, or base their judgement on views from certain social classes. This implies that it is important to have the remote sensing data available as a counter balance to local perception (and vice versa) and therefore these data should be considered concurrently.
Global Environmental Change, 2015
5-4 4 5 1 a n d Ric h a r d s , Keit h 2 0 1 5. Ap p r o a c h e s t o e v al u a ti n g m o d el... more 5-4 4 5 1 a n d Ric h a r d s , Keit h 2 0 1 5. Ap p r o a c h e s t o e v al u a ti n g m o d el q u ality a c r o s s diffe r e n t r e gi m e ty p e s in e nvi r o n m e n t al a n d p u blic h e al t h g ov e r n a n c e. Glo b al E nvi ro n m e n t al C h a n g e 3 3 , p p .
Journal of Glaciology, 1990
During the summers of 1987 and 1988, 15 dye-tracer tests from a total of eight injection points w... more During the summers of 1987 and 1988, 15 dye-tracer tests from a total of eight injection points were conducted in the ablation area of Midtdalsbreen, a northern outlet of Hardangerjokulen, southern Norway. The spatial and temporal patterns of water discharge, shapes of the dye-return curves, through-flow velocities, dye-recovery rates, dispersivities, and velocity/discharge relationships suggest the existence of distinct catchments beneath the eastern and western halves of the glacier which are characterized by different types of drainage sytem. Experiments on the eastern side were associated with high melt-water discharges and produced short-lived and highly peaked dye-return curves, fast through-flow velocities, high dye-recovery rates, low dispersivity values which decreased through the melt season, and a velocity/discharge relationship with an exponent of 1.0. Experiments on the western side were associated with low melt-water discharges and produced flat, extended dye-return cu...
Energy Policy, 2015
The Carbon Plan could result in significant land use change for bioenergy by 2050. Higher Nuclear... more The Carbon Plan could result in significant land use change for bioenergy by 2050. Higher Nuclear; less efficiency pathway has the highest land use change impact. Higher Renewables; more energy efficiency pathway has the lowest land use change impact. Transport decarbonisation via biofuels has the highest land use change impacts. At current deployment rate only Higher Renewables pathway projections is achievable.
Energy Policy, 2015
A whole systems analysis of current and future water used for energy is presented. The energy sec... more A whole systems analysis of current and future water used for energy is presented. The energy sector's compliance with the "3 Red Lines" water policies is assessed. Future energy plans could conflict with the "3 Red Lines" industrial water policy. Water used for energy is highly dependant on technology choices. Co-benefits and trade-offs between future energy and water plans are identified.
Land, 2014
Climate change and agriculture influence each other. The effects of climate change on agriculture... more Climate change and agriculture influence each other. The effects of climate change on agriculture seem to be predominantly negative, although studies show a large variation in impacts between crops and regions. To compensate for these effects, agriculture can either intensify or expand in area; both of these options increase greenhouse gas emissions. It is therefore likely that such negative effects will increase agriculture's contribution to climate change, making this feedback a positive, self-reinforcing one. We have previously used a data-driven model to examine greenhouse gas emissions in 2050 related to agricultural scenarios of increasing demand for food. Here, we extend this approach by introducing the impacts of climate change on agricultural yields. We estimate the additional losses of natural habitats and increases in greenhouse gas emissions resulting from agricultural expansion and relocation induced by the negative effects of climate change. We studied two climate change scenarios and different assumptions about trade. These additional impacts caused by climate change are found to be relatively moderate compared to demand-driven impact, but still significant. They increase greenhouse gas emissions from land use change by an additional 8%-13%. Climate change tends to aggravate the effects of demand drivers in critical regions. Current emission scenarios are underestimates in that they do not include these feedback effects.
ISPRS Journal of Photogrammetry and Remote Sensing, 2014
Alpine lakes on the Tibetan Plateau (TP) are key indicators of climate change and climate variabi... more Alpine lakes on the Tibetan Plateau (TP) are key indicators of climate change and climate variability. The increasing availability of remote sensing techniques with appropriate spatiotemporal resolutions, broad coverage and low costs allows for effective monitoring lake changes on the TP and surroundings and understanding climate change impacts, particularly in remote and inaccessible areas where there are lack of in situ observations. This paper firstly introduces characteristics of Tibetan lakes, and outlines available satellite observation platforms and different remote sensing water-body extraction algorithms. Then, this paper reviews advances in applying remote sensing methods for various lake environment monitoring, including lake surface extent and water level, glacial lake and potential outburst floods, lake ice phenology, geological or geomorphologic evidences of lake basins, with a focus on the trends and magnitudes of lake area and water-level change and their spatially and temporally heterogeneous patterns. Finally we discuss current uncertainties or accuracy of detecting lake area and water-level changes from multisource satellite data and ongoing challenges in mapping characteristics of glacial lakes using remote sensing. Based on previous studies on the relationship between lake variation and climate change, it is inferred that the climate-driven mechanisms of lake variations on the TP still remain unclear and require further research.
Hydrological Sciences Journal, 1995
Using a combination of laboratory and field experiments, the performance of a Partech Instruments... more Using a combination of laboratory and field experiments, the performance of a Partech Instruments Ltd IR40-C active head suspended solids sensor has been tested with respect to changing particle size distribution and rapid variation in suspended sediment transport rate. The sensor, which utilizes light attenuation in the infrared waveband, has several advantages both over visible light optical designs and over nuclear or optical back-scatter (OBS) devices. Three sets of laboratory tests are reported: calibration experiments using estuarine, pro-glacial and control media; flume simulations of pulsed sediment supply at a variety of frequencies, concentrations and ambient flow velocities; and simple tests for the effect of air bubbles within the sensor light path. The sensor was also deployed in the field, together with an electromagnetic current meter, to monitor flow and suspended sediment transport fluctuations in the turbulent frequency range. Although the sensor performed well with respect to drift, noise and stability of calibration, significant variation occurred with respect to suspensions of differing particle sizes. A simple correction procedure involving the weighting of sensor output by specific particle surface area may enable comparison of turbidity data from different locations and times, and with standard calibration solutions. At high frequencies, the sensor is capable of resolving fluctuations in the transport rate to c. 0.5 s, which appears to correspond well to field observations of significant velocity fluctuation and transport 'events' and is comparable with results obtained using OBS devices. However, the resolution of transport fluctuations is again dependent upon particle characteristics, and the presence of air bubbles in the flow whose size approximates the path width of the sensor may mimic a fluctuating transport process. Further interpretation of high frequency measurement awaits research into the fundamentals of rapidly varying flow and sediment transport characteristics. Evaluation sur le terrain et au laboratoire d'une sonde de turbidité infrarouge et sa sensibilité à la taille des particules et aux variations de la concentration des matières en suspension Résumé L'effet de variations de la distribution des tailles de particules et du flux de matières en suspension sur le fonctionnement d'une sonde de matières en suspension a été évalué, les essais ayant été réalisés sur le Open for discussion until I June 1996
Earth Surface Processes and Landforms, 1997
Fluvial geomorphology has witnessed a continuing reduction in the time-and space-scales of resear... more Fluvial geomorphology has witnessed a continuing reduction in the time-and space-scales of research, with increasing emphasis on the dynamics of small site-specific river reaches. This shift can be regarded as part of a trend towards the understanding and explanation rather than description of how rivers change, which raises important questions regarding the relevance of such short timescale and small space-scale research to understanding longer-term aspects of landform behaviour. The methodological challenges that arise from such intensive case study research are illustrated here using a detailed investigation of a river reach. Morphological changes within this reach are shown to be driven by: (i) catchmentscale processes associated with the interaction of discharge and sediment supply waves; and (ii) modification of these processes through morphological controls on erosion and deposition patterns and hence net channel change. The 'morphological conditioning' of channel response reflects the configurational aspects of channel change, and the importance of local characteristics in the understanding of system behaviour. Sensitivity to local conditions implies that short timescale and small space-scale processes may be critical to channel behaviour, particularly if the system is interpreted in non-linear terms. Although it may be possible to identify statistically averaged stable states, non-linear system behaviour implies that system trajectories are sensitively dependent upon instantaneous system states. Thus, changes between average states can only be understood through an understanding of the sequence of configurational states through which the system evolves.
Interest in the integrated restoration of managed river corridors has arisen in response to falli... more Interest in the integrated restoration of managed river corridors has arisen in response to falling levels of riparian and floodplain biodiversity due to flood control works including channalization and flow regulation by headwater impoundments. This decline is in part, a direct response to the impact of engineering works on the geomorphological dynamics of rivers and in particular, upon rates of
Clays and Clay Minerals, 1980