Changes in hydrological extremes and climate variability in the Severn Uplands

Hydrological extremes within the UK have increased in intensity, frequency andpersistence over recent years and are predicted to increase in variability throughout the 21stcentury. Past and future changes in hydrological extremes relative to climate change wereinvestigated within Severn Uplands, a climate sensitive catchment. Using the Mann-Kendall trend detection test, time-series analysis over a 30-year period revealed asignificant increase in winter and autumn precipitation and a decrease in summerprecipitation. The analysis of flow time-series indicated an increase in winter and Julyflows and a decrease in spring flows. Changes in climate variability over the same periodshowed increases in air temperature and SST, and a reduction in snow cover. Climatevariables were found to largely correlate with hydrological extremes which werecharacteristic of certain weather types and largely influenced by the NAO.To model future flows within the Severn Uplands a hydrological model (HEC-HMS) wasused to simulate hydrological processes. The extreme hydrological event of November-December 2006 was used to calibrate the model. The difference between using radar andgauge precipitation data to drive the model was quantified. Radar data resulted in thesmallest prediction accuracy followed by gauge-corrected radar data (corrected using themean-field bias where gauge rainfall was interpolated using cokriging) and then gaugeprecipitation which had the largest prediction accuracy. Model accuracy was sufficientusing the gauge corrected radar and gauge precipitation data as inputs, so both were alteredfor future predictions to investigate the propagation of uncertainty. Predicted changes intemperature and precipitation by the UKCIP02 scenarios were used to alter the baselineextreme event to predict changes in peak flow and outflow volume. Both radar- and gaugedrivenhydrological modelling predicted large flow increases for the 21st century withincreases up to 8% by the 2020s, 18% by the 2050s and 30% by the 2080s. Discrepanciesbetween predictions were observed when using the different data inputs

Environmental Livelihood Security in Southeast Asia and Oceania: A Water-Energy-Food-Livelihoods Nexus Approach for Spatially Assessing Change

This document addresses the need for explicit inclusion of livelihoods within the environment nexus (water-energy-food security), not only responding to literature gaps but also addressing emerging dialogue from existing nexus consortia. We present the first conceptualization of ‘environmental livelihood security’, which combines the nexus perspective with sustainable livelihoods. The geographical focus of this paper is Southeast Asia and Oceania, a region currently wrought by the impacts of a changing climate. Climate change is the primary external forcing mechanism on the environmental livelihood security of communities in Southeast Asia and Oceania which, therefore, forms the applied crux of this paper. Finally, we provide a primer for using geospatial information to develop a spatial framework to enable geographical assessment of environmental livelihood security across the region. We conclude by linking the value of this research to ongoing sustainable development discussions, and for influencing policy agenda

Sustainable development and the water–energy–food nexus: A perspective on livelihoods

AbstractThe water–energy–food nexus is being promoted as a conceptual tool for achieving sustainable development. Frameworks for implementing nexus thinking, however, have failed to explicitly or adequately incorporate sustainable livelihoods perspectives. This is counterintuitive given that livelihoods are key to achieving sustainable development. In this paper we present a critical review of nexus approaches and identify potential linkages with sustainable livelihoods theory and practice, to deepen our understanding of the interrelated dynamics between human populations and the natural environment. Building upon this review, we explore the concept of ‘environmental livelihood security’ – which encompasses a balance between natural resource supply and human demand on the environment to promote sustainability – and develop an integrated nexus-livelihoods framework for examining the environmental livelihood security of a system. The outcome is an integrated framework with the capacity to measure and monitor environmental livelihood security of whole systems by accounting for the water, energy and food requisites for livelihoods at multiple spatial scales and institutional levels. We anticipate this holistic approach will not only provide a significant contribution to achieving national and regional sustainable development targets, but will also be effective for promoting equity amongst individuals and communities in local and global development agendas

Environmental livelihood security in Southeast Asia and Oceania

This policy brief integrates sustainable livelihoods thinking into discussions on environmental security and the water-food-energy nexus, responding both to a gap in the literature and to emerging policy discourse. We present the first conceptualization of ‘environmental livelihood security’, a concept which draws upon frameworks of water-energy-food security and sustainable livelihoods. The geographical focus is Southeast Asia and Oceania, a region where populations are particularly vulnerable and threatened by the impacts of a changing climate. Various socio-environmental pressures act as an external forcing mechanism on communities attaining environmental livelihood security in this region. We provide a primer for using geospatial information to enable the development of a framework to spatially assess environmental livelihood security. The value of this research is highlighted through linkages to ongoing sustainable development and climate-compatible discussions, and by identifying the relevance for influencing policy agendas

Monitoring socio-environmental change for sustainable development: developing a Multidimensional Livelihoods Index (MLI)

To enable more effective monitoring of sustainable development for meeting targets of the post-2015 agenda, assessment is required at the sub-national level to better understand the spatial variation in factors which contribute to sustaining livelihoods. In this research we take Nepal as a case study; a nation consistently ranked as one of the poorest in the world. To understand how sustainable development can effectively promote livelihood diversification, we advocate that a multidimensional spatial approach is essential for monitoring social and environmental change to aid decision-making processes. To achieve this, a multidimensional index was created to spatially explore the landscape of livelihoods across rural Nepal. A methodology was developed to quantify the livelihoods asset pentagon (human-physical-social-financial-natural) of the Sustainable Livelihoods Framework. 23 socio-environmental indicators were selected to map the multidimensionality of livelihoods at the eco-development area unit level and produce the Multidimensional Livelihoods Index (MLI). Results indicate considerable spatial variability in the factors affecting people's livelihoods across Nepal. In general, the MLI decreases as you move north and east, reflecting changes in the topographic landscape and distance from the Kathmandu Valley Outcomes suggest an effective method for monitoring change at a sub-national level; highlighting potential locations and/or livelihood strategies for improving the targeting of resources (e.g. investment of foreign aid) to facilitate more sustainable development for the future

Assessing the accuracy and applied use of satellite-derived precipitation estimates over Nepal

Accurate observational precipitation data supplied at a fine spatial resolution is vital for informing sustainable water resources management in Nepal. Livelihoods in Nepal are acutely impacted by precipitation. The amount of monsoon precipitation determines water available for drinking, hydropower and irrigation. Extreme precipitation events often result in landslides, flash flooding and crop damages. Freely available satellite-derived precipitation data products have the potential to substantially inform water policy. Such products could advocate sustainable use of water resources and enhance the adaptive capacity of rural populations in Nepal to future precipitation changes. In this research, statistical measures were used to assess the accuracy of Tropical Rainfall Measuring Mission satellite-derived precipitation estimates (TRMM 3B42) relative to ground-based precipitation data (APHRODITE), seasonally from 2001 to 2007. In all seasons the majority of satellite precipitation estimates were significantly correlated with ground-based precipitation. However, satellite precipitation estimates consistently overestimated the amount of precipitation, with error greatest in the monsoon season. The satellite precipitation product inaccurately detected extreme precipitation events, 'rainy days' and precipitation intensity in the monsoon season. Results suggest that precipitation estimates derived from this satellite product have limited use in agricultural planning, water resource management and developing mitigation measures to the impacts of extreme events in Nepal. Currently, ground-based precipitation measurements still provide the most accurate information for use in water resources management. Maintaining and developing precipitation gauge networks in Nepal, particularly in regions of high relief, is extremely important for increasing the accuracy of both ground-based and satellite-derived precipitation products

Observed run-off and suspended sediment dynamics from a minor glacierized basin in south-west Greenland

This study examined run-off and suspended sediment dynamics in a minor glacierized basin in south-west Greenland. A discharge (Q), turbidity (Tu) and air temperature (Tair) record was maintained for 26 days from 25 July 2009 to 19 August 2009 which was supplemented by 335 water samples analysed for suspended sediment concentration (SSC). Clear diurnal fluctuations in Tair, Q and SSC were observed. Mean Tair rose from 10.2 °C in a sunny clear Phase 1 (days 1–14) to 10.8 °C in a cloudy Phase 2 (days 15–25), mean Q increased from 3.4 m3/s in Phase 1 to 4.8 m3/s in Phase 2 and this significant increase in Q may be explained by fresh snowfall higher on the glaciers melting. Mean sampled SSC was 23 mg/l while mean predicted SSC increased from 34 mg/l in Phase 1 to 45 mg/l in Phase 2 and is assumed to be a direct result of the increased Q in Phase 2 entraining fine sediment from higher up channel banks and bars. The SSC, suspended sediment load and SSY estimated in this study are compared with a growing and updated database of sediment studies in Greenland (where data from sediment transport studies in 16 locations around Greenland are collated)

Spatio-temporal trends in precipitation and their implications for water resources management in climate-sensitive Nepal

As one of the world's most water-abundant countries Nepal has plenty of water, yet resources are unevenly distributed, both spatially and temporally. Limited accessibility and poorly managed water resources continue to inhibit socioeconomic development. Poverty levels are high across the nation (57% of the population lives below the international poverty line) and population expansion, coupled with rapid environmental change, is thought to be placing substantial pressure on water resources; an irrefutable asset for sustaining livelihoods and an essential contributing factor for alleviating poverty. Precipitation is a vital water resource for much of the rural population, 80% of which are dependent on rain-fed agriculture for their livelihoods, and fluctuations in which can give rise to changing states of poverty. Here we provide a comprehensive spatiotemporal analysis of precipitation time-series data for Nepal and discuss the contribution of precipitation change to water resources management for this land-locked Himalayan nation. We show that precipitation totals have predominantly remained stable; precipitation extremes and variability indicate widespread decrease; and no clear variation in monsoon onset date is reported. Based on these results, we suggest that water resources management needs to focus on population and environmental pressures, rather than specifically mitigating for precipitation change

Plenty of water, not enough strategy: How inadequate accessibility, poor governance and a volatile government can tip the balance against ensuring water security: the case of Nepal

Water security is arguably the single most important factor regarding the future sustainability of our planet. Without water we have no life, and with depleting freshwater resources conflict can easily ensue. The intersection between hydrology and politics requires a delicate balancing from decision-makers to ensure policy is well-informed and science is well communicated. In this paper, we discuss water issues currently faced by Nepal, a nation where freshwater resources are abundant yet political pressures are threatening future water security. We argue that despite adequate water supplies a nation may still experience severe water insecurity, particularly if effective governance and equitable access are not prioritised. We explore potential policy options necessary to achieve a holistic framework for water resources management, which we suggest, need to consider water resource reliability, accessibility and governance as fundamental pillars for ensuring water security