Event mean concentration and first flush from residential catchments in different climate zones.

Most studies on EMC (Event mean concentration) and first flush are reported as local studies; however variations of EMC and first flush across catchments in different climate zones has not been studied. This research collected continuous flow and discrete water quality data and rainfall measurements from 17 catchments, EMC and rainfall data from 14 catchments, and an additional dataset where only average EMC values are reported (19 catchments). The data are from residential sites across temperate, tropical, dry, and continental climate zones and include water quality parameters in particulate (total suspended solids), mixed (total nitrogen and total phosphorus) and dissolved (orthophosphate and ammonium nitrogen) forms. Our study shows that EMC differs significantly between climate zones. The average EMC is highest in dry followed by continental and temperate, with lowest in the tropical zone. Pearson's correlation analysis revealed that the rainfall depth is negatively correlated with EMC for particulate and mixed form parameters for the tropical, temperate and dry zones, but positively correlated for the continental zone. The discrete time-series data from the 17 catchments were used to evaluate first flush and it was found that catchments in the tropics exhibit stronger first flush than temperate zone catchments, for all the water quality parameters with particulate showing a stronger first flush compared to dissolved forms. Based on the distribution of the data, new limits for very strong, strong, moderate, and very weak to no first flush are suggested for TSS for different climate zones. The new limits were quantified by fitting the function L^=V^bwhere L^and V^are the normalized cumulative runoff load and volume, respectively. For catchments in the tropics, this corresponds to b < 0.47, 0.6 > b > 0.47, 0.76 > b > 0.6 and b > 0.76, respectively. For the temperate zone, b < 0.5, 0.67 > b > 0.5, 0.85 > b > 0.67 and b > 0.85, are appropriate. From a design perspective, the FF20 concept defined as the load corresponding to 20% runoff volume, is often used. The ranges FF20 < 0.27, 0.36 > FF20 > 0.27, 0.45 > FF20 > 0.36 and FF20 > 0.45 and FF20 < 0.24, 0.31 > FF20 > 0.24, 0.31 > FF20 > 0.39 and FF20 > 0.39 are proposed for tropical and temperate catchments, respectively. Other limits for TP, TN, OP and NH4-N are also suggested. This is the first study of its kind and an expended dataset especially for continental and dry regions is needed to further validate the findings.

Achieving water security in rural Indian Himalayas: A participatory account of challenges and potential solutions.

The complex and diverse factors that influence water security in the Indian Himalayan Region were examined using problem and solution tree (PAST) mapping together with a field study. Five PASTs, each constructed by a different group of stakeholders, namely the state government, the local government, researchers, development agencies, and the local community, were analysed to obtain a holistic and multi-sectoral understanding of water security in the region, and the analysis was supplemented with field data. The systematic study helped in (1) identifying many factors - climatic, geographical, cultural, and socio-economic - that influence water security, (2) assessing their impacts on mountain livelihoods, and (3) documenting thirty-two potential interventions in the form of adaptations (e.g. springshed management programme) and coping strategies (e.g. buying water from informal water markets) to strengthen water security. These strategies followed three main themes namely conserving water resources, improving rural livelihood and sustainable infrastructure development and risk management. The study also helped in building a shared sense of understanding, purpose, and action between the diverse groups of stakeholders. The study suggests that ensuring water security in rural mountain areas requires holistic and multi-sectoral policies, which should be developed by including all actors in the network of stakeholders; that local conditions be given utmost importance in the policy planning cycle (e.g. focus on springs in mountains); and that cultural landscape and local identities be closely examined to reduce the inequalities in access to resources.

Assessing national vulnerability to phosphorus scarcity to build food system resilience: The case of India.

The scarcity of phosphorus worldwide led researchers to develop indicators of national vulnerability to phosphorus scarcity, however this has not been applied at a national level so far. A systematic approach is described here to identify country-specific indicators of such vulnerability, in this case for India, based on literature and stakeholder engagement. The indicators are then aggregated to compute a phosphorus vulnerability index (PVI) to help policymakers formulate strategies towards building national resilience towards scarcity of phosphorus. For India, the key indicators include import dependence, soil fertility, purchasing power of farmers, and their access to credit. A PVI of 37.29 puts India in the 'highly vulnerable' category. Existing schemes targeted for agricultural sector in India are assessed for their ability to manage phosphorus vulnerability and for building resilience. Other developing countries with similar challenges can easily replicate the approach.

Analyzing Social Networks to Examine the Changing Governance Structure of Springsheds: A Case Study of Sikkim in the Indian Himalayas.

The governance of natural resources now attracts greater participation of different stakeholders, ushering in a shift from conventional governance by the state to that by a network of stakeholders-a form of governance marked by a growing role of non-state and local actors. These changing dynamics are highlighted through a study of the governance network for springsheds in the Indian Himalayas by empirically mapping the changes in the Dhara Vikas Yojna, a plan or scheme (yojana) by the state for the development (vikas) of springs (dhara) in Sikkim, India, from policy planning to policy implementation. The study highlights the diverse existing and emerging roles of different stakeholders, the complex relationships between them, and the power dynamics that influence the management of springsheds. The study (1) identified some new but missing actors/actor groups that were critical to managing springs; (2) showed that although state governments continue to play a dominant role, decision making is shifting to non-state and local actors; and (3) highlighted the importance of exchanging knowledge and information in implementing a policy more effectively. Understanding the characteristics of the governance network helped in drawing lessons to make the plan more sustainable and replicable, which include considering the policy in the wider context of policies for other sectors such as sanitation and hydropower development, incentivising the emerging actors, and building a stronger interdisciplinary and inclusive knowledge network. Such an integrated approach to policymaking can also be adopted to analyze governance networks related to natural resources other than water.

Energy and carbon footprints of sewage treatment methods.

The paper presents energy and carbon footprints of sewage treatment plants (STPs) operating at different scales and using different technology options based on primary data from 50 STPs operating in India and the UK. The study used a combination of fundamental mass-balance approach for energy consumption and the methodology defined by IPCC for the carbon emissions. Small-scale institutional STPs consume twelve times the energy consumed by large-scale municipal STPs, the corresponding energy intensities being 4.87 kWh/m(3) and 0.40 kWh/m(3) respectively. Embodied energy from construction material and chemicals accounted for 46% and 33% of the total energy intensity of the municipal and institutional STPs respectively. The average carbon footprint of large-scale STPs is 0.78 kgCO2eq/m(3) and for small-scale STPs it is 3.04 kgCO2eq/m(3). However, fugitive emissions from large-scale STPs constituted 74% of the total carbon emissions whereas the figure was only 0.05% for small-scale STPs. Average electrical energy intensity in STPs in India is much lower (0.14 kWh/m(3)) than that in the UK (0.46 kWh/m(3)). This is due to the reason that STPs in India do not have resource recovery processes and use solar heat for sludge drying. The paper offers information and insights for designing low carbon strategies for urban waste infrastructure.

Energy and material flows of megacities.

Understanding the drivers of energy and material flows of cities is important for addressing global environmental challenges. Accessing, sharing, and managing energy and material resources is particularly critical for megacities, which face enormous social stresses because of their sheer size and complexity. Here we quantify the energy and material flows through the world's 27 megacities with populations greater than 10 million people as of 2010. Collectively the resource flows through megacities are largely consistent with scaling laws established in the emerging science of cities. Correlations are established for electricity consumption, heating and industrial fuel use, ground transportation energy use, water consumption, waste generation, and steel production in terms of heating-degree-days, urban form, economic activity, and population growth. The results help identify megacities exhibiting high and low levels of consumption and those making efficient use of resources. The correlation between per capita electricity use and urbanized area per capita is shown to be a consequence of gross building floor area per capita, which is found to increase for lower-density cities. Many of the megacities are growing rapidly in population but are growing even faster in terms of gross domestic product (GDP) and energy use. In the decade from 2001-2011, electricity use and ground transportation fuel use in megacities grew at approximately half the rate of GDP growth.

Ecobiotechnological strategy to enhance efficiency of bioconversion of wastes into hydrogen and methane.

Vegetable wastes (VW) and food wastes (FW) are generated in large quantities by municipal markets, restaurants and hotels. Waste slurries (250 ml) in 300 ml BOD bottles, containing 3, 5 and 7 % total solids (TS) were hydrolyzed with bacterial mixtures composed of: Bacillus, Acinetobacter, Exiguobacterium, Pseudomonas, Stenotrophomonas and Sphingobacterium species. Each of these bacteria had high activities for the hydrolytic enzymes: amylase, protease and lipase. Hydrolysate of biowaste slurries were subjected to defined mixture of H2 producers and culture enriched for methanogens. The impact of hydrolysis of VW and FW was observed as 2.6- and 2.8-fold enhancement in H2 yield, respectively. Direct biomethanation of hydrolysates of VW and FW resulted in 3.0- and 1.15-fold improvement in CH4 yield, respectively. A positive effect of hydrolysis was also observed with biomethanation of effluent of H2 production stage, to the extent of 1.2- and 3.5-fold with FW and VW, respectively. The effective H2 yields were 17 and 85 l/kg TS fed, whereas effective CH4 yields were 61.7 and 63.3 l/kg TS fed, from VW and FW, respectively. This ecobiotechnological strategy can help to improve the conversion efficiency of biowastes to biofuels.

Water quality modelling of the river Yamuna (India) using QUAL2E-UNCAS.

This paper describes the utility of QUAL2E as a modelling package in the evaluation of a water quality improvement programme. In this study, QUAL2E was applied to determine the pollution loads in the river Yamuna during its course through the national capital territory of Delhi, India. The study aimed at examining the influence of different scenarios on river water quality. Four different pollution scenarios were analysed besides the 'business as usual' situation. The study revealed that it was necessary to treat the discharge from drains to the river Yamuna and diversion of a substantial load to the Agra canal for further treatment was also essential. It was also established through this study that maintaining a flow rate of more than 10 m(3)/s in the river could also help preserve the river's water quality. To clearly display the model outcomes and demarcate polluted zones in the river stretch, model results were interfaced with a Geographical Information System (GIS) to produce cartographic outputs. In addition, uncertainty analysis in the form of first-order error analysis and Monte Carlo analysis was performed, to realise the effect of each model parameter on DO and BOD predictions. The uncertainty analysis gave satisfactory results on simulated data.