Multi-Objective Optimization for Analysis of Changing Trade-Offs in the Nepalese Water-Energy-Food Nexus with Hydropower Development

While the water–energy–food nexus approach is becoming increasingly important for more efficient resource utilization and economic development, limited quantitative tools are available to incorporate the approach in decision-making. We propose a spatially explicit framework that couples two well-established water and power system models to develop a decision support tool combining multiple nexus objectives in a linear objective function. To demonstrate our framework, we compare eight Nepalese power development scenarios based on five nexus objectives: minimization of power deficit, maintenance of water availability for irrigation to support food self-sufficiency, reduction in flood risk, maintenance of environmental flows, and maximization of power export. The deterministic multi-objective optimization model is spatially resolved to enable realistic representation of the nexus linkages and accounts for power transmission constraints using an optimal power flow approach. Basin inflows, hydropower plant specifications, reservoir characteristics, reservoir rules, irrigation water demand, environmental flow requirements, power demand, and transmission line properties are provided as model inputs. The trade-offs and synergies among these objectives were visualized for each scenario under multiple environmental flow and power demand requirements. Spatially disaggregated model outputs allowed for the comparison of scenarios not only based on fulfillment of nexus objectives but also scenario compatibility with existing infrastructure, supporting the identification of projects that enhance overall system efficiency. Though the model is applied to the Nepalese nexus from a power development perspective here, it can be extended and adapted for other problems

Tracing recharge zones for spring sources in the mid-hills of Western Nepal using stable isotopes

Springs, a major source of water in the hills and mountains of Nepal, are drying up. Since 2014, with funding from the Asian Development Bank and the Nordic Development Fund, the “Building Climate Resilience of Watersheds in Mountain Eco-Regions” (BCRWME) project is working to provide 45,000 households in vulnerable mountain communities with access to more reliable water resources via spring or surface water sources. Despite the recognition of springs as a livelihood driver in these communities and the observed alarming trends in the drying up of springs, a scientific understanding of mountain springs in Nepal has not been established. Under BCRWME, the International Water Management Institute (IWMI) is leading comprehensive research characterizing mountain springs and identifying science-based interventions that can increase reliability and water availability in springs. IWMI is conducting isotope analysis in Banlek and Shikarpur in western Nepal to investigate hydrological processes in mountain springs and identify recharge zones for these springs

Isotope analysis for understanding mountain springs in western Nepal

Springs are a major source of water in the hills and mountains of Nepal. Since 2014, with funding from the Asian Development Bank and the Nordic Development Fund, the “Building Climate Resilience of Watersheds in Mountain Eco-Regions” (BCRWME) project is working to provide 45,000 households in vulnerable mountain communities with access to more reliable water resources via spring or surface water sources. Despite the recognition of springs as a livelihood driver in these communities and the observed alarming trends in the drying up of springs, a scientific understanding of mountain springs in Nepal has not been established. Under BCRWME, the International Water Management Institute (IWMI) is leading comprehensive research into characterizing mountain springs and identifying science-based interventions that can increase reliability and water availability in these sources. IWMI is conducting isotope analysis to investigate hydrological processes in mountain springs and identifying recharge zones in order to sustain springs in Banlek and Shikarpur in western Nepal

Quantification of run-of-river hydropower potential in the Upper Indus basin under climate change

IntroductionDespite ambitious plans to quadruple hydropower generation in the Indus basin, a quantitative assessment of the impact of climate change on hydropower availability in the basin is missing. To address this gap, we combine downscaled CMIP6 projections with the Hydropower Potential Exploration (HyPE) model to quantify future hydropower potential available in the upper Indus basin.MethodsHyPE uses a spatial cost-minimization framework to evaluate four classes of hydropower potential, namely theoretical, technical, financial and sustainable, considering various constraints on the siting and sizing of two run-of-river hydropower plant configurations.ResultsUnder future discharge projections, all classes of potential increase while subbasin changes align with the spatial patterns projected in hydro-climatology. Theoretical potential changes by 3.9–56 %, technical potential by −2.3–46.8 %, financial potential by −8.8–50.4 % and sustainable potential by −6.1–49.7 %. A small decline is observed in the northwestern subbasins where increase in potential is lower than in the southeast. In contrast, with increasing variability in the Indian Summer Monsoon in the future, the southeastern subbasins have the strongest increase in sustainable potential accompanied by higher increase in plant size, decrease in costs and higher variability. The southeastern Satluj subbasin is the hotspot where sustainable potential has the highest increase of up to 145 %. The northwestern Kabul subbasin has the highest decrease of up to −27 %. The Swat subbasin has the lowest variability in sustainable potential while the Jhelum and Indus main subbasins remain the subbasins with the cheapest potential into the future. The performance of future sustainable portfolios differ from the performance of historical portfolios by −11.1–39.9 %.DiscussionHence, considering future climate in the present-day planning of hydropower will lead to improved performance under a majority of scenarios. The sufficiency of hydropower potential to fulfill energy security depends on future population growth. Energy availability is projected to decline in the northwest as population increases faster than hydropower potential. The per capita sustainable potential In the Kabul subbasin reduces to a third of the historical value. A socio-hydrological approach is necessary to address the complexity of achieving sustainable and equitable hydropower development in the Indus basin under such spatial mismatch between hydropower availability and energy demand in a resource-limited world

EviAtlas : a tool for visualising evidence synthesis databases

Abstract: Systematic mapping assesses the nature of an evidence base, answering how much evidence exists on a particular topic. Perhaps the most useful outputs of a systematic map are an interactive database of studies and their meta-data, along with visualisations of this database. Despite the rapid increase in systematic mapping as an evidence synthesis method, there is currently a lack of Open Source software for producing interactive visualisations of systematic map databases. In April 2018, as attendees at and coordinators of the first ever Evidence Synthesis Hackathon in Stockholm, we decided to address this issue by developing an R-based tool called EviAtlas, an Open Access (i.e. free to use) and Open Source (i.e. software code is freely accessible and reproducible) tool for producing interactive, attractive tables and figures that summarise the evidence base. Here, we present our tool which includes the ability to generate vital visualisations for systematic maps and reviews as follows: a complete data table; a spatially explicit geographical information system (Evidence Atlas); Heat Maps that cross-tabulate two or more variables and display the number of studies belonging to multiple categories; and standard descriptive plots showing the nature of the evidence base, for example the number of studies published per year or number of studies per country. We believe that EviAtlas will provide a stimulus for the development of other exciting tools to facilitate evidence synthesis

Pulling up new chairs to the table: experiences of organising diversity and inclusion events during a pandemic

Young Women of Geosciences (YWOG) is a group at Utrecht University (the Netherlands) which aims to create an equal and inclusive working environment for all employees in the faculty of Geosciences. Now in our fourth year, with an expanding committee and increasing support from the faculty, we share some details and insights from events held during the pandemic. After several years of having primarily the same small group of people attending our events (i.e. “preaching to the choir”) our aim was to engage with more people in our faculty. We wanted to pull up new chairs to the table and hear new opinions and thoughts and so, our events were planned with this primary goal in mind. However, under changing and variable conditions due to the pandemic, the planning of events to promote diversity and inclusion became more of a challenge. We had to devise strategies to keep people engaged in diversity and inclusion topics while people became tired of online events, and were busy just dealing with the pandemic. Our primary success was a book giveaway and discussion where three books related to diversity and inclusion (some also with climate and environmental aspects) were given for free to 30 staff members. This was followed by an open online discussion about topics that arose in the books and how these issues were experienced in our own faculty. This session had the greatest number of male participants we have ever had at one of our events (despite all sessions always being open to all genders) and this led to great information sharing and discussions. We also organised two Wikipedia hackathons which aimed to improve information on Wikipedia about female and minority scientists. This event required a great deal of time and skill development which unfortunately many people were not able to commit to, which led to smaller numbers and less engagement than our book event. Overall, we managed to introduce new groups of people to our discussions and engage with a broader audience than in previous years, within a virtual environment. We attribute this in large part to attractive events and hard work on our communication strategy. We found that engagement in activities, particularly for new attendees, was highly dependent on time availability and concrete communication of details of the event. We frequently used social media to communicate about our events and significant growth of these channels in the virtual-only environment of lockdowns led to overall increased engagement. This was particularly the case on Twitter, where we have found active and supportive fellow networks to engage with, be inspired by, and inspire

Spatial adaptation pathways to reconcile future water and food security in the Indus River basin

Irrigated wheat production is critical for food security in the Indus basin. Changing climatic and socio-economic conditions are expected to increase wheat demand and reduce irrigation water availability. Therefore, adaptation of irrigated wheat production is essential to achieve the interlinked Sustainable Development Goals for both water and food security. Here, we developed a spatial adaptation pathways methodology that integrates water and food objectives under future climate change and population growth. The results show that strategic combinations between production intensification, laser land leveling, and targeted expansion of irrigated areas can ensure wheat production increases and irrigation water savings in the short term. However, no adaptation pathways can ensure long-term wheat production within the existing irrigation water budget under rapid population growth. Adaptation planning for the Sustainable Development Goals in the Indus basin must therefore address both climatic and population changes, and anticipate that current food production practices may be unsustainable

From theoretical to sustainable potential for run-of-river hydropower development in the upper Indus basin

A comprehensive assessment of hydropower resource potential considering factors beyond technical and financial parameters is missing for the upper Indus basin (UIB). Our framework takes a systems approach to quantify the theoretical to sustainable hydropower potential by successively considering natural, technical, financial, anthropogenic, environmental, and geo-hazard risk constraints on hydropower at individual sites as well as at the basin-scale. Theoretical potential of the UIB is 1564 TWh/yr at 500-m resolution. Across three energy focus and three geo-hazard risk scenarios, our cost-minimization model finds that technical (12%–19%), financial (6%–17%) and sustainable (2%–10%) potential are a small portion of the theoretical value. Mixed development combining plants of various size, cost and configuration provides the highest potential with the best spatial coverage. Alongside, our review of 20 datasets reveals a visualized potential exceeding 300 TWh/yr from 447 hydropower plants across the UIB, with only a quarter of the potential materialized by mostly large plants in the mainstreams. Hydropower cost curves show that Swat and Kabul sub-basins have a larger proportion of cost-effective and sustainable potential untapped by the visualized potential. Water use for other sectors represents the strongest constraints, reducing a third of the technical potential when evaluating sustainable potential. Ultimately, human decisions regarding scale, configuration and sustainability have a larger influence on hydropower potential than model parameter assumptions. In quantifying hydropower potential under many policy scenarios, we demonstrate the need for defining hydropower sustainability from a basin-scale perspective towards energy justice and balanced fulfilment of Sustainable Development Goals for water and energy across the Indus

Quantification of run-of-river hydropower potential in the Upper Indus basin under climate change

Introduction: Despite ambitious plans to quadruple hydropower generation in the Indus basin, a quantitative assessment of the impact of climate change on hydropower availability in the basin is missing. To address this gap, we combine downscaled CMIP6 projections with the Hydropower Potential Exploration (HyPE) model to quantify future hydropower potential available in the upper Indus basin. Methods: HyPE uses a spatial cost-minimization framework to evaluate four classes of hydropower potential, namely theoretical, technical, financial and sustainable, considering various constraints on the siting and sizing of two run-of-river hydropower plant configurations. Results: Under future discharge projections, all classes of potential increase while subbasin changes align with the spatial patterns projected in hydro-climatology. Theoretical potential changes by 3.9–56 %, technical potential by −2.3–46.8 %, financial potential by −8.8–50.4 % and sustainable potential by −6.1–49.7 %. A small decline is observed in the northwestern subbasins where increase in potential is lower than in the southeast. In contrast, with increasing variability in the Indian Summer Monsoon in the future, the southeastern subbasins have the strongest increase in sustainable potential accompanied by higher increase in plant size, decrease in costs and higher variability. The southeastern Satluj subbasin is the hotspot where sustainable potential has the highest increase of up to 145 %. The northwestern Kabul subbasin has the highest decrease of up to −27 %. The Swat subbasin has the lowest variability in sustainable potential while the Jhelum and Indus main subbasins remain the subbasins with the cheapest potential into the future. The performance of future sustainable portfolios differ from the performance of historical portfolios by −11.1–39.9 %. Discussion: Hence, considering future climate in the present-day planning of hydropower will lead to improved performance under a majority of scenarios. The sufficiency of hydropower potential to fulfill energy security depends on future population growth. Energy availability is projected to decline in the northwest as population increases faster than hydropower potential. The per capita sustainable potential In the Kabul subbasin reduces to a third of the historical value. A socio-hydrological approach is necessary to address the complexity of achieving sustainable and equitable hydropower development in the Indus basin under such spatial mismatch between hydropower availability and energy demand in a resource-limited world

Knowledge priorities on climate change and water in the Upper Indus Basin: a horizon scanning exercise to identify the top 100 research questions in social and natural sciences

River systems originating from the Upper Indus Basin (UIB) are dominated by runoff from snow and glacier melt and summer monsoonal rainfall. These water resources are highly stressed as huge populations of people living in this region depend on them, including for agriculture, domestic use, and energy production. Projections suggest that the UIB region will be affected by considerable (yet poorly quantified) changes to the seasonality and composition of runoff in the future, which are likely to have considerable impacts on these supplies. Given how directly and indirectly communities and ecosystems are dependent on these resources and the growing pressure on them due to ever-increasing demands, the impacts of climate change pose considerable adaptation challenges. The strong linkages between hydroclimate, cryosphere, water resources, and human activities within the UIB suggest that a multi- and inter-disciplinary research approach integrating the social and natural/environmental sciences is critical for successful adaptation to ongoing and future hydrological and climate change. Here we use a horizon scanning technique to identify the Top 100 questions related to the most pressing knowledge gaps and research priorities in social and natural sciences on climate change and water in the UIB. These questions are on the margins of current thinking and investigation and are clustered into 14 themes, covering three overarching topics of “governance, policy, and sustainable solutions”, “socioeconomic processes and livelihoods”, and “integrated Earth System processes”. Raising awareness of these cutting-edge knowledge gaps and opportunities will hopefully encourage researchers, funding bodies, practitioners, and policy makers to address them