Your search found 24 records
1 Thapa, B. R.; Ishidaira, H.; Pandey, Vishnu Prasad; Shakya, N. M. 2017. A multi-model approach for analyzing water balance dynamics in Kathmandu Valley, Nepal. Journal of Hydrology: Regional Studies, 9:149-162. [doi: https://doi.org/10.1016/j.ejrh.2016.12.080]
Water balance ; Hydrological cycle ; Models ; Water resources ; Water security ; Water storage ; Watersheds ; Runoff ; Precipitation ; Rain ; Evapotranspiration ; Calibration ; Strategies ; Performance indexes ; Forecasting ; Meteorological stations ; Valleys / Nepal / Kathmandu Valley
(Location: IWMI HQ Call no: e-copy only Record No: H048050)
http://www.sciencedirect.com/science/article/pii/S2214581816303342/pdfft?md5=dfb49d8448e61d96f0bca2947f34951d&pid=1-s2.0-S2214581816303342-main.pdf
https://vlibrary.iwmi.org/pdf/H048050.pdf
https://vlibrary.iwmi.org/pdf/H048050.pdf
(1.35 MB) (1.35 MB)
Study region: Kathmandu Valley, Capital city of Nepal.
Study focus: This study applied three hydrological models (i.e., SWAT, HBV, and BTOPMC) to analyze the water balance components and their temporal and seasonal variations in the Kathmandu Valley, Nepal. The water balance components were investigated using the same precipitation, climatic data, and potential evapotranspiration (PET) as input variables for each model. The yearly and seasonal variations in each component and the interactions among them were analyzed. There was a close agreement between the monthly observed and calibrated runoff at the watershed scale, and all the three models captured well the flow patterns for most of the seasons.
New hydrological insights for the region: The average annual runoff in the study watershed calculated by the SWAT, HBV, and BTOPMC models was 887, 834, and 865 mm, corresponding to 59%, 55%, and 57% of the annual precipitation, respectively. The average annual evapotranspiration (ET) was 625, 623, and 718 mm, and the estimated yearly average total water storage (TWS) was 5, -35, and 29 mm, respectively. The long-term average TWS component was similar in all three models. ET had the lowest inter-annual variation and runoff had the greatest inter-annual variation in all models. Predictive analysis using the three models suggested a reasonable range for estimates of runoff, ET, and TWS. Although there was variation in the estimates among the different models, our results indicate a possible range of variation for those values, which is a useful finding for the short- and long-term planning of water resource development projects in the study area. The effects of historical water use, water stress, and climatic projections using multi-model water balance approaches offer a useful direction for future studies to enhance our understanding of anthropogenic effects in the Kathmandu Valley.
Study focus: This study applied three hydrological models (i.e., SWAT, HBV, and BTOPMC) to analyze the water balance components and their temporal and seasonal variations in the Kathmandu Valley, Nepal. The water balance components were investigated using the same precipitation, climatic data, and potential evapotranspiration (PET) as input variables for each model. The yearly and seasonal variations in each component and the interactions among them were analyzed. There was a close agreement between the monthly observed and calibrated runoff at the watershed scale, and all the three models captured well the flow patterns for most of the seasons.
New hydrological insights for the region: The average annual runoff in the study watershed calculated by the SWAT, HBV, and BTOPMC models was 887, 834, and 865 mm, corresponding to 59%, 55%, and 57% of the annual precipitation, respectively. The average annual evapotranspiration (ET) was 625, 623, and 718 mm, and the estimated yearly average total water storage (TWS) was 5, -35, and 29 mm, respectively. The long-term average TWS component was similar in all three models. ET had the lowest inter-annual variation and runoff had the greatest inter-annual variation in all models. Predictive analysis using the three models suggested a reasonable range for estimates of runoff, ET, and TWS. Although there was variation in the estimates among the different models, our results indicate a possible range of variation for those values, which is a useful finding for the short- and long-term planning of water resource development projects in the study area. The effects of historical water use, water stress, and climatic projections using multi-model water balance approaches offer a useful direction for future studies to enhance our understanding of anthropogenic effects in the Kathmandu Valley.
2 Salam, P. A.; Pandey, Vishnu Prasad; Shrestha, S.; Anal, A. K. 2017. The need for the nexus approach. In Salam, P. A.; Shrestha, S.; Pandey, V. P.; Anal, A. K. (Eds.). Water-energy-food nexus: principles and practices. Indianapolis, IN, USA: Wiley. pp.3-10.
Sustainable Development Goals ; Water resources ; Water availability ; Water use ; Energy consumption ; Energy resources ; Food consumption ; Economic development ; Renewable energy ; Household consumption ; Fossil fuels
(Location: IWMI HQ Call no: IWMI Record No: H048456)
The water, energy, and food resources share a lot in common; they have strong interdependencies and are inadvertently affected by action in any one of them. Therefore, the nexus approach (integrated policies related to water, energy, and food) is required in the face of growing concerns over the future availability and sustainability of these resources. The nexus approach can help achieve at least some of the “Sustainable Development Goals (SDGs)” (e.g., SDG 2, 6, 7, 12, 13, 15). This chapter discusses trends in availability and consumption of the three key resources (i.e., water, energy, and food) and interactions between them, and finally provides some reasons why the nexus approach can help achieve social and economic development goals.
3 Pandey, Vishnu Prasad; Shrestha, S. 2017. Evolution of the nexus as a policy and development discourse. In Salam, P. A.; Shrestha, S.; Pandey, V. P.; Anal, A. K. (Eds.). Water-energy-food nexus: principles and practices. Indianapolis, IN, USA: Wiley. pp.11-20.
Ecosystems ; Policy making ; Development ; Integrated management ; Water resources ; Water management ; Environmental protection ; Food security
(Location: IWMI HQ Call no: IWMI Record No: H048457)
The key resources that sustain life and the ecosystem (e.g., water, food, energy, and others) are linked in many ways. Action in one sector might have impacts on others, thus forming a policy nexus among them. The relationships between the resources were realized long back; however, the nexus concept is still evolving as a policy and development discourse with the involvement of many actors. It is generally considered as a “multicentric” approach, the advancement of “water centric” Integrated Water Resources Management (IWRM). This chapter presents a systematic review on how the nexus concept emerged and is now spreading to cover wider sectors; it then discusses key actors involved in raising the profile of the nexus as a policy and development discourse.
4 Salam, P. A.; Shrestha, S.; Pandey, Vishnu Prasad; Anal, A. K. (Eds.) 2017. Water-energy-food nexus: principles and practices. NJ, USA: Wiley; Washington, USA: American Geophysical Union (AGU). 252p.
Water resources ; Water management ; Energy resources ; Food resources ; Food security ; Nexus ; Development policy ; Policy making ; Sustainable Development Goals ; Developing countries ; International cooperation ; International waters ; River basins ; Rural areas ; Climate change ; Carbon footprint ; Crop production ; Rice ; Cultivation ; Research institutions ; Riverbanks ; Filtration ; Case studies / South Asia / South Africa / Western Asia / USA / Southeast Nepal / Tanzania / Uganda / Rwanda / Burundi / Democratic Republic of the Congo / Kenya / Ethiopia / Eritrea / South Sudan / Republic of the Sudan / Egypt / Bangladesh / California / Nile Basin
(Location: IWMI HQ Call no: IWMI Record No: H048731)
5 Shrestha, P. K.; Shakya, N. M.; Pandey, Vishnu Prasad; Birkinshaw, S. J.; Shrestha, S. 2017. Model-based estimation of land subsidence in Kathmandu Valley, Nepal. Geomatics, Natural Hazards and Risk, 8(2):974-996. [doi: https://doi.org/10.1080/19475705.2017.1289985]
Land cover ; Subsidence ; Estimation ; Groundwater extraction ; Aquifers ; Water supply ; Development projects ; Hydrology ; Models ; Calibration ; Meteorology ; Forecasting ; Flow discharge ; Recharge ; Valleys ; Population growth ; Urban areas / Nepal / Kathmandu Valley
(Location: IWMI HQ Call no: e-copy only Record No: H048977)
https://www.tandfonline.com/doi/pdf/10.1080/19475705.2017.1289985?needAccess=true
https://vlibrary.iwmi.org/pdf/H048977.pdf
https://vlibrary.iwmi.org/pdf/H048977.pdf
(2.21 MB) (2.21 MB)
This study is the first to assess land subsidence in the Kathmandu Valley, Nepal. Land subsidence simulations were based on a fully calibrated groundwater (GW) flow model developed using a coupled surface–subsurface modelling system. Subsidence is predicted to occur as a result of deep aquifer compaction due to excessive GW abstraction. The north and north-east areas at the periphery of the GW basin are hotspots for this subsidence. The estimated subsidence is most sensitive to changes in land cover within the recharge areas. The model shows the Melamchi water supply project assists in the control of subsidence to some extent. In the absence of land subsidence measurements, this paper highlights the location and the potential levels of the subsidence hazard which will be useful for hazard prevention management. Additionally, this work provides a basis to design field investigations, monitoring networks for land subsidence and upgrading the present GW monitoring network. Although the study has presented a preliminary analysis, a more comprehensive model inclusive of clay subsidence is required to address the subsidence vulnerability of the central densely populated core of the valley, which reflects the need for a comprehensive database of the hydrogeology in the valley.
6 Thapa, Bhesh Raj; Ishidaira, H.; Pandey, Vishnu Prasad; Bhandari, T. M.; Shakya, N. M. 2018. Evaluation of water security in Kathmandu Valley before and after water transfer from another basin. Water, 10(2):1-12. [doi: https://doi.org/10.3390/w10020224]
Water security ; Evaluation ; Water supply ; Development projects ; Water transfer ; Drinking water ; Water demand ; Estimation ; Freshwater ; Reservoirs ; Water distribution ; Population growth ; Households ; Valleys ; River basins / Nepal / Kathmandu Valley / Melamchi Water Supply Project
(Location: IWMI HQ Call no: e-copy only Record No: H048978)
(2.98 MB) (2.98 MB)
Kathmandu Upatyaka Khanepani Limited (KUKL) has planned to harness water from outside the valley from Melamchi as an inter-basin project to supply water inside the ring road (core valley area) of the Kathmandu Valley (KV). The project, called the “Melamchi Water Supply Project (MWSP)”, is expected to have its first phase completed by the end of September 2018 and its second phase completed by the end of 2023 to supply 170 MLD (million liters a day) through the first phase and an additional 340 MLD through the second phase. The area has recently faced a severe water deficit and KUKL’s existing infrastructure has had a limited capability, supplying only 19% of the water that is demanded in its service areas during the dry season and 31% during the wet season. In this context, this study aims to assess the temporal trends and spatial distribution of household water security index (WSI), defined as a ratio of supply to demand for domestic water use for basic human water requirements (50 L per capita per day (lpcd)) and economic growth (135 lpcd) as demand in pre and post-MWSP scenarios. For this purpose, data on water demand and supply with infrastructure were used to map the spatial distribution of WSI and per capita water supply using ArcMap. Results show a severe water insecurity condition in the year 2017 in all KUKL service areas (SAs), which is likely to improve after completion of the MWSP. It is likely that recent distribution network and strategies may lead to inequality in water distribution within the SAs. This can possibly be addressed by expanding existing distribution networks and redistributing potable water, which can serve an additional 1.21 million people in the area. Service providers may have to develop strategies to strengthen a set of measures including improving water supply infrastructures, optimizing water loss, harnessing additional water from hills, and managing water within and outside the KUKL SAs in the long run to cover the entire KV.
7 Aslam, R. A.; Shrestha, S.; Pandey, Vishnu Prasad. 2018. Groundwater vulnerability to climate change: a review of the assessment methodology. Science of the Total Environment, 612:853-875. [doi: https://doi.org/10.1016/j.scitotenv.2017.08.237]
Water resources ; Groundwater recharge ; Climate change adaptation ; Assessment ; Indicators ; Aquifers ; Contamination ; Rain ; Sea level ; Soils ; Sensitivity analysis ; Models ; Social aspects / USA / Egypt / Thailand / Timor-Leste / Dauphin Island / Nile Delta Aquifer
(Location: IWMI HQ Call no: e-copy only Record No: H048979)
(5.02 MB)
Impacts of climate change on water resources, especially groundwater, can no longer be hidden. These impacts are further exacerbated under the integrated influence of climate variability, climate change and anthropogenic activities. The degree of impact varies according to geographical location and other factors leading systems and regions towards different levels of vulnerability. In the recent past, several attempts have been made in various regions across the globe to quantify the impacts and consequences of climate and non-climate factors in terms of vulnerability to groundwater resources. Firstly, this paper provides a structured review of the available literature, aiming to critically analyse and highlight the limitations and knowledge gaps involved in vulnerability (of groundwater to climate change) assessment methodologies. The effects of indicator choice and the importance of including composite indicators are then emphasised. A new integrated approach for the assessment of groundwater vulnerability to climate change is proposed to successfully address those limitations. This review concludes that the choice of indicator has a significant role in defining the reliability of computed results. The effect of an individual indicator is also apparent but the consideration of a combination (variety) of indicators may give more realistic results. Therefore, in future, depending upon the local conditions and scale of the study, indicators from various groups should be chosen. Furthermore, there are various assumptions involved in previous methodologies, which limit their scope by introducing uncertainty in the calculated results. These limitations can be overcome by implementing the proposed approach.
8 Pandey, Vishnu Prasad; Dhaubanjar, Sanita; Bharati, Luna; Thapa, Bhesh Raj. 2019. Hydrological response of Chamelia Watershed in Mahakali Basin to climate change. Science of the Total Environment, 650(Part 1):365-383. [doi: https://doi.org/10.1016/j.scitotenv.2018.09.053]
Water resources ; Watersheds ; Climate change ; Hydrological factors ; Water availability ; Water balance ; Stream flow ; Groundwater ; Temperature ; Precipitation ; Forecasting ; River basins ; Soil types ; Spatial distribution ; Models ; Uncertainty ; Hydrometeorology / Nepal / Mahakali Basin / Chamelia Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H048982)
(6.23 MB)
Chamelia (catchment area = 1603 km2 ), a tributary of Mahakali, is a snow-fed watershed in Western Nepal. The watershed has 14 hydropower projects at various stages of development. This study simulated the current and future hydrological system of Chamelia using the Soil and Water Assessment Tool (SWAT). The model was calibrated for 2001–2007; validated for 2008–2013; and then applied to assess streamflow response to projected future climate scenarios. Multi-site calibration ensures that the model is capable of reproducing hydrological heterogeneity within the watershed. Current water balance above the Q120 hydrological station in the forms of precipitation, actual evapotranspiration (AET), and net water yield are 2469 mm, 381 mm and 1946 mm, respectively. Outputs of five Regional Climate Models (RCMs) under two representative concentration pathways (RCPs) for three future periods were considered for assessing climate change impacts. An ensemble of bias-corrected RCM projections showed that maximum temperature under RCP4.5 (RCP8.5) scenario for near-, mid-, and far-futures is projected to increase from the baseline by 0.9 °C (1.1 °C), 1.4 °C (2.1 °C), and 1.6 °C (3.4 °C), respectively. Minimum temperature for the same scenarios and future periods are projected to increase by 0.9 °C (1.2 °C), 1.6 °C (2.5 °C), and 2.0 °C (3.9 °C), respectively. Average annual precipitation under RCP4.5 (RCP8.5) scenario for near-, mid-, and far-futures are projected to increase by 10% (11%), 10% (15%), and 13% (15%), respectively. Based on the five RCMs considered, there is a high consensus for increase in temperature but higher uncertainty with respect to precipitations. Under these projected changes, average annual streamflow was simulated to increase gradually from the near to far future under both RCPs; for instance, by 8.2% in near-, 12.2% in mid-, and 15.0% in far-future under RCP4.5 scenarios. The results are useful for planning water infrastructure projects, in Chamelia and throughout the Mahakali basin, to ensure long-term sustainability under climate change.
9 Pakhtigian, E. L.; Jeuland, M.; Dhaubanjar, Sanita; Pandey, Vishnu Prasad. 2020. Balancing intersectoral demands in basin-scale planning: the case of Nepal’s western river basins. Water Resources and Economics, 30:100152. [doi: https://doi.org/10.1016/j.wre.2019.100152]
River basins ; Water resources development ; Planning ; Economic development ; Prioritization ; Ecosystems ; Economic value ; Energy generation ; Hydropower ; Irrigation programs ; Agricultural sector ; Infrastructure ; Costs ; Water allocation ; Hydrology ; Models ; Sensitivity analysis ; Environmental effects / Nepal / Karnali-Mohana River Basin / Mahakali River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H049415)
(1.98 MB)
Basin-wide planning requires tools and strategies that allow comparison of alternative pathways and priorities at relevant spatial and temporal scales. In this paper, we apply a hydroeconomic model–the Western Nepal Energy Water Model–that better accounts for feedbacks between water and energy markets, to optimize water allocations across energy, agriculture, municipal, and environmental sectors. The model maximizes total economic benefits, accounting for trade-offs both within and across sectors. In Western Nepal, we find that surface water availability is generally sufficient to meet existing and growing demands in energy and agricultural sectors; however, expansion of water storage and irrigation infrastructure may limit environmental flows below levels needed to maintain the full integrity of important aquatic ecosystems. We also find substantial trade-offs between irrigation in Nepal and satisfaction of the institutional requirements implied by international water-use agreements with the downstream riparian India. Similar trade-offs do not exist with hydropower, however. Model results and allocations are sensitive to future domestic and international energy demands and valuations.
10 Pakhtigian, E. L.; Jeuland, M.; Bharati, Luna; Pandey, Vishnu Prasad. 2021. The role of hydropower in visions of water resources development for rivers of western Nepal. International Journal of Water Resources Development, 37(3):531-558. (Special issue: Hydropower-based Collaboration in South Asia: Socio-economic Development and the Electricity Trade) [doi: https://doi.org/10.1080/07900627.2019.1600474]
Water resources development ; Planning ; Hydropower ; River basins ; Energy generation ; Hydroelectric power ; Water management ; Sustainability ; Water use ; Stakeholders ; Prioritization ; State intervention ; Natural resources ; Ecosystems ; Households / Nepal / Karnali River Basin / Mahakali River basin / Mohana River basin
(Location: IWMI HQ Call no: e-copy only Record No: H049416)
(2.88 MB)
Water resources can play significant roles in development pathways for water-endowed, low-income countries like Nepal. This article describes three visions for water resource development in the Karnali and Mahakali Basins of Western Nepal: state-led development, demand-driven development and preservation of ecosystem integrity. The analysis calls attention to water use trade-offs, including those resulting from national priorities such as infrastructure-based hydropower and irrigation, from local drinking water demand, and from environmental conservation concerns. While these visions of water resources development do diverge, common trends appear, including acknowledgment of water management’s role in expanding energy access and increasing agricultural productivity.
11 Dhaubanjar, Sanita; Pandey, Vishnu Prasad; Bharati, Luna. 2020. Climate futures for western Nepal based on regional climate models in the CORDEX-SA [Coordinated Regional Downscaling Experiment for South Asia]. International Journal of Climatology, 40(4):2201-2225. [doi: https://doi.org/10.1002/joc.6327]
Climate change ; Forecasting ; Models ; Water resources ; Impact assessment ; Precipitation ; Temperature ; Uncertainty ; Risk assessment ; Meteorological stations ; Decision support ; Mountains / South Asia / Nepal / Karnali
(Location: IWMI HQ Call no: e-copy only Record No: H049417)
(20.90 MB)
With the objective to provide a basis for regional climate models (RCMs) selection and ensemble generation for climate impact assessments, we perform the first ever analysis of climate projections for Western Nepal from 19 RCMs in the Coordinated Regional Downscaling Experiment for South Asia (CORDEX-SA). Using the climate futures (CF) framework, projected changes in annual total precipitation and average minimum/maximum temperature from the RCMs are classified into 18 CF matrices for two representative concentration pathways (RCPs: 4.5/8.5), three future time frames (2021–2045/2046–2070/2071–2095), three geographic regions (mountains/hills/plains) and three representative CF (low-risk/consensus/ high-risk). Ten plausible CF scenario ensembles were identified to assess future water availability in Karnali basin, the headwaters of the Ganges. Comparison of projections for the three regions with literature shows that spatial disaggregation possible using RCMs is important, as local values are often higher with higher variability than values for South Asia. Characterization of future climate using raw and bias-corrected data shows that RCM projections vary most between mountain and Tarai plains with increasing divergence for higher future and RCPs. Warmer temperatures, prolonged monsoon and sporadic rain events even in drier months are likely across all regions. Highest fluctuations in precipitation are projected for the hills and plains while highest changes in temperature are projected for the mountains. Trends in change in annual average discharge for the scenarios vary across the basin with both precipitation and temperature change influencing the hydrological cycle. CF matrices provide an accessible and simplified basis to systematically generate application-specific plausible climate scenario ensembles from all available RCMs for a rigorous impact assessment.
12 Pandey, Vishnu Prasad; Sharma, Akriti; Dhaubanjar, Sanita; Bharati, Luna; Joshi, I. R. 2019. Climate shocks and responses in Karnali-Mahakali basins, western Nepal. Climate, 7(7):1-24. (Special issue: Social-Ecological Systems, Climate and Global Change Impacts) [doi: https://doi.org/10.3390/cli7070092]
Climate change adaptation ; Risk analysis ; River basins ; Climatology ; Weather hazards ; Drought ; Rain ; Flooding ; Hailstorms ; Crop losses ; Strategies ; Mountains ; Households ; Animal diseases / Nepal / Karnali River Basin / Mahakali River Basin / Mohana River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H049418)
(2.29 MB) (2.29 MB)
The Himalayas are highly susceptible to the impacts of climate change, as it consequently increases the vulnerability of downstream communities, livelihoods and ecosystems. Western Nepal currently holds significant potential as multiple opportunities for water development within the country are underway. However, it is also identified as one of the most vulnerable regions to climate change, with both an increase in the occurrence of natural disasters and exacerbated severity and impacts levels. Regional climate model (RCM) projections indicate warmer weather with higher variability in rainfall for this region. This paper combines bio-physical and social approaches to further study and understand the current climate shocks and responses present in Western Nepal. Data was collected from 3660 households across 122 primary sampling units across the Karnali, Mahakali and Mohana River basins along with focus group discussions, which provided a rich understanding of the currently perceived climatic shocks and related events. Further analysis of climatology was carried out through nine indices of precipitation and temperature that were found to be relevant to the discussed climate shocks. Results show that 79% of households reported experiencing at least one type of climate shock in the five-year period and the most common occurrence was droughts, which is also supported by the climate data. Disaggregated results show that perception varies with the region and among the basins. Analysis of climatic trends further show that irregular weather is most common in the hill region, although average reported frequency of irregular weather is higher in the mountain. Further analysis into the severity and response to climatic shocks suggest an imminent need for better adaptation strategies. This study’s results show that a vast majority of respondents lack proper access to knowledge and that successful adaptation strategies must be adapted to specific regions to meet communities’ local needs.
13 Khatiwada, K. R.; Pandey, Vishnu Prasad. 2019. Characterization of hydro-meteorological drought in Nepal Himalaya: a case of Karnali River Basin. Weather and Climate Extremes, 26:100239. [doi: https://doi.org/10.1016/j.wace.2019.100239]
Drought ; Hydrometeorology ; Climate change ; River basins ; Precipitation ; Crop production ; Crop yield ; Extreme weather events ; Monsoon climate ; Temperature ; Meteorological stations / Nepal / Himalaya / Karnali River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H049419)
https://www.sciencedirect.com/science/article/pii/S2212094718302044/pdfft?md5=91d9ccaec12e6fa60b214db2656e3a73&pid=1-s2.0-S2212094718302044-main.pdf
https://vlibrary.iwmi.org/pdf/H049419.pdf
https://vlibrary.iwmi.org/pdf/H049419.pdf
(3.34 MB) (3.34 MB)
Himalayan river basin is marked by a complex topography with limited observational data. In the context of increasing extreme events, this study aims to characterize drought events in the Karnali River Basin (KRB). Firstly, historical data for 34-years (1981–2014) from ten different stations were analyzed to compute following drought indices: Standardized Precipitation Index (SPI), Standardized Precipitation Evapotranspiration Index (SPEI), Reconnaissance Drought Index (RDI), Self-Calibrated Palmer Drought Severity Index (sc-PDSI), Standardized Streamflow Index (SFI), and Palmer Hydrological Drought Severity Index (PHDI). Among them, SPI is able to capture the drought duration and intensity fairly well with the others. Secondly, SPI was used to analyse the drought of the entire basin. The SPI analysis showed occurrence of major drought events in the recent years: 1984–85, 1987–88, 1992–93, 1994–95, 2004–09, and 2012. The winter drought of 1999, 2006, 2008–09 were widespread and the monsoon drought is increasing its frequency. No particular pattern of drought was observed from the historical data; however, yield sensitivity index revealed that precipitation pattern and anomaly is influencing crop yield in the area. Being the first study revealing prevalence of the drought in KRB, it can provide a basis for prioritizing interventions focused on drought management in the region.
14 Pandey, Vishnu Prasad; Dhaubanjar, Sanita; Bharati, Luna; Thapa, Bhesh Raj. 2018. Climate change and water availability in western Nepal. In Nepal Academy of Science and Technology (NAST). Proceedings of the Seminar on Nature for Water, Kanchanpur, Nepal, 28 March 2018. Kathmandu, Nepal: Nepal Academy of Science and Technology (NAST) pp.8-19.
Climate change ; Water availability ; Hydrology ; Models ; Watersheds ; Precipitation ; Temperature ; Forecasting ; Water resources ; River basins ; Projects / Nepal / Mahakali Basin / Chamelia Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H049463)
http://www.nast.gov.np/documentfile/proceedings_theSeminar_Water.pdf
https://vlibrary.iwmi.org/pdf/H049463.pdf
https://vlibrary.iwmi.org/pdf/H049463.pdf
(0.84 MB) (6.21 MB)
The response of any hydrological system to climate change may differ depending on characteristics of the system. Such studies are lacking for basins in Western Nepal. This paper, therefore, argues for a need to re-phrase the context of Western Nepal in more positive light and then analyses how a projected change in climate may impact on water availability of the region with a case of Chamelia watershed. A hydrological model in SWAT (Soil and Water Assessment Tool) environment is developed for the purpose. Future climate is projected using a set of fi ve Regional Circulation Models (RCMs). Then response of streamfl ow with projected change in climate is assessed. Results show the developed model performance is adequate to represent hydrological characteristics of the watershed. Future is projected to be warmer (high model consensus) and slightly wetter (more uncertainty), with winter and premonsoon season receiving more rainfall. Under the projected future changes, simulated stream fl ow is projected to change across future periods and seasons. The results are expected to be useful for future water resource and water infrastructure planning in the area.
15 Thapa, Bhesh Raj; Ishidaira, H.; Gusyev, M.; Pandey, Vishnu Prasad; Udmale, P.; Hayashi, M.; Shakya, N. M. 2019. Implications of the Melamchi water supply project for the Kathmandu Valley groundwater system. Water Policy, 21(S1):120-137. [doi: https://doi.org/10.2166/wp.2019.084]
Water supply ; Groundwater management ; Groundwater flow ; Models ; Groundwater extraction ; Pumping ; Wells ; Water resources ; Water deficit ; Water demand ; Watersheds ; Aquifers ; Valleys / Nepal / Kathmandu Valley / Melamchi Water Supply Project
(Location: IWMI HQ Call no: e-copy only Record No: H049465)
https://iwaponline.com/wp/article-pdf/21/S1/120/632511/021000120.pdf
https://vlibrary.iwmi.org/pdf/H049465.pdf
https://vlibrary.iwmi.org/pdf/H049465.pdf
(0.89 MB) (912 KB)
To meet the demand deficit in Kathmandu Valley, the Government of Nepal has planned to supply an additional 510 million liters per day (mld) of water by implementing the Melamchi Water Supply Project (MWSP) in the near future. In this study, we aim to assess the spatial distribution of groundwater availability and pumping under five scenarios for before and after the implementation of the MWSP using a numerical groundwater flow model. The data on water demand, supply infrastructure, changes in hydraulic head, groundwater pumping rates, and aquifer characteristics were analyzed. Results showed that groundwater pumping from individual wells ranges from 0.0018 to 2.8 mld and the average hydraulic head declined from 2.57 m below ground level (bgl) (0.23 m/year) to 21.58 m bgl (1.96 m/year). Model simulations showed that changes in average hydraulic head ranged from þ2.83 m to þ5.48 m at various stages of the MWSP implementation, and 2.97 m for increased pumping rates with no implementation of the MWSP. Regulation in pumping such as monetary instruments (groundwater pricing) on the use of groundwater along with appropriate metering and monitoring of pumping amounts depending on the availability of new and existing public water supply could be interventions in the near future.
16 Pandey, Vishnu Prasad; Dhaubanjar, Sanita; Bharati, Luna. 2017. Sustainable irrigation development: knowledge generation for Karnali-Mohana River Basin. In Nepal. Department of Irrigation. Proceedings of the 10th National Irrigation Seminar on Climate Smart Innovation for the Sustainable Irrigation Development, Nagarkot, Kathmandu, 1-2 June 2017. Lalitpur, Nepal: Department of Irrigation. pp.39-50.
Irrigation management ; Sustainable development ; Irrigation programs ; Water resources ; Water availability ; River basins ; Knowledge based systems ; Irrigation systems ; Water governance ; Water management ; Environmental flows / Nepal / Karnali-Mohana River Basin / Digo Jal Bikas Project
(Location: IWMI HQ Call no: e-copy only Record No: H049464)
(1.24 MB)
Water resources planning and management requires technical knowledge as well as social and environmental considerations and enabling environment for sustainable and equitable development. In this context, this paper highlights the Digo Jal Bikas project which is using a multi-disciplinary framework to generate science-based understanding required for sustainable irrigation development. The project is creating a knowledgebase including an inventory of irrigation and hydropower projects; water availability under current and future climatic conditions; environmental flows requirements for various types of river systems; tradeoff analysis of various water resources development scenarios; and water governance analysis. We present here how the project is generating such a multi-disciplinary knowledgebase that is key for promoting sustainable irrigation development in the Karnali-Mohana basin in the western Nepal.
17 Nepal, S.; Neupane, N.; Belbase, D.; Pandey, Vishnu Prasad; Mukherji, Aditi. 2021. Achieving water security in Nepal through unravelling the water-energy-agriculture nexus. International Journal of Water Resources Development, 37(1):67-93. [doi: https://doi.org/10.1080/07900627.2019.1694867]
Water security ; Energy sources ; Food security ; Nexus ; Water availability ; Surface water ; Groundwater ; Integrated management ; Water resources ; Water management ; Water governance ; Agricultural water use ; Industrial uses ; Domestic water ; Hydropower ; Water supply ; Irrigation systems ; Climate change ; Environmental sustainability ; Irrigated land ; Urban areas ; Rural areas ; Population growth / Nepal / Terai Region
(Location: IWMI HQ Call no: e-copy only Record No: H049496)
https://www.tandfonline.com/doi/abs/10.1080/07900627.2019.1694867?needAccess=true#aHR0cHM6Ly93d3cudGFuZGZvbmxpbmUuY29tL2RvaS9wZGYvMTAuMTA4MC8wNzkwMDYyNy4yMDE5LjE2OTQ4Njc/bmVlZEFjY2Vzcz10cnVlQEBAMA==
https://vlibrary.iwmi.org/pdf/H049496.pdf
https://vlibrary.iwmi.org/pdf/H049496.pdf
(2.65 MB) (2.65 MB)
This article investigates water security in Nepal from the perspective of the water-energy-agriculture (food) nexus, focusing on pathways to water security that originate in actions and policies related to other sectors. It identifies promoting development of Nepal’s hydropower potential to provide energy for pumping as way to improve water security in agriculture. Renewable groundwater reserves of 1.4 billion cubic meters (BCM), from an estimated available balance of 6.9 BCM, could be pumped to irrigate 613,000 ha of rainfed agricultural land in the Terai plains, with a potential direct economic gain of USD 1.1 billion annually and associated benefits including promotion of energy-based industry, food security and local employment. Governance also plays an important role in addressing water security. We conclude that a nexus-based approach is required for effective water management and governance.
18 Pandey, Vishnu Prasad; Shrestha, Dibesh; Adhikari, M.; Shakya, S. 2020. Streamflow alterations, attributions, and implications in extended East Rapti Watershed, central-southern Nepal. Sustainability, 12(9):3829. (Special issue: Implications of Climate Change for Ecosystems and Society) [doi: https://doi.org/10.3390/su12093829]
Watersheds ; Stream flow ; Climate change ; Anthropogenic factors ; Rainfall patterns ; Precipitation ; Temperature ; Population density ; Social aspects ; Environmental effects ; Groundwater extraction ; Meteorological stations ; River basins ; Runoff ; Hydrological factors ; Aquatic ecology ; Food security ; Land use change ; Land cover change / Nepal / East Rapti Watershed / Chitwan / Makwanpur
(Location: IWMI HQ Call no: e-copy only Record No: H049715)
(3.08 MB) (3.08 MB)
Streamflow alteration and subsequent change in long-term average, seasonality, and extremes (e.g., floods and droughts) may affect water security, which is a major concern in many watersheds across the globe. Both climatic and anthropogenic activities may contribute to such changes. Therefore, this study assesses: (i) Streamflow and precipitation trends to identify streamflow alterations in the Extended East Rapti (EER) watershed in central-southern Nepal; (ii) relationship of the alterations to climatic and anthropogenic sources; and (iii) implications of streamflow changes to the socio-environmental system. The trends in streamflow were analyzed for pre-and post-1990 periods considering the abrupt shift in temperature trend in 1990. Results showed a general decreasing trends in discharge post-1990 in the EER watershed. Human activities have significantly contributed in altering streamflow in the EER. Human-induced streamflow alterations have affected the water availability, food security, river health, aquatic biodiversity, and groundwater abstraction in the EER watershed.
19 Pandey, Vishnu Prasad; Dhaubanjar, Sanita; Bharati, Luna; Thapa, Bhesh Raj. 2020. Spatio-temporal distribution of water availability in Karnali-Mohana Basin, western Nepal: hydrological model development using multi-site calibration approach (Part-A). Journal of Hydrology: Regional Studies, 29:100690. [doi: https://doi.org/10.1016/j.ejrh.2020.100690]
Water availability ; Spatial distribution ; Hydrology ; Models ; Calibration ; River basins ; Water resources ; Precipitation ; Evapotranspiration ; Water yield ; Water balance ; Groundwater ; Land use ; Land cover ; Meteorological stations ; Monsoon climate ; Soil types / Nepal / Karnali-Mohana River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H049721)
https://www.sciencedirect.com/science/article/pii/S2214581820301646/pdfft?md5=982f21101d159ac4aa2a890bfe048505&pid=1-s2.0-S2214581820301646-main.pdf
https://vlibrary.iwmi.org/pdf/H049721.pdf
https://vlibrary.iwmi.org/pdf/H049721.pdf
(4.54 MB) (4.54 MB)
Study region: Karnali-Mohana (KarMo) river basin, Western Nepal.
Study focus: This study has developed a hydrological model using multi-site calibration approach for a large basin, the Karnali-Mohana (KarMo) in Western Nepal, which has a lot of potential for water resources development and contribute to the national prosperity. It further applies the model to characterize hydrology and water resources availability across spatio-temporal scales to enhance understanding on water availability and potential uses. The newly developed hydrological model in Soil and Water Assessment Tool (SWAT) is capable of reproducing the hydrological pattern, the average flows, and the flow duration curve at the outlet of the basin and five major sub-basins.
New hydrological insights for this region: The model simulated results showed that about 34 % of average annual precipitation in the KarMo basin is lost as evapotranspiration, but with a large spatio-temporal heterogeneity. The Hills and Tarai are relatively wetter than the Mountains. The average annual flow volume at the basin outlet is estimated as 46,250 million-cubic-meters (MCM). The hydrological characterization made in this study are further used for climate change impact assessment (Part-B in the same journal), environmental flows assessment and evaluating trade-offs among various water development pathways, which are published elsewhere. This model, therefore, has potential to contribute for strategic planning and sustainable management of water resources to fuel the country’s prosperity.
Study focus: This study has developed a hydrological model using multi-site calibration approach for a large basin, the Karnali-Mohana (KarMo) in Western Nepal, which has a lot of potential for water resources development and contribute to the national prosperity. It further applies the model to characterize hydrology and water resources availability across spatio-temporal scales to enhance understanding on water availability and potential uses. The newly developed hydrological model in Soil and Water Assessment Tool (SWAT) is capable of reproducing the hydrological pattern, the average flows, and the flow duration curve at the outlet of the basin and five major sub-basins.
New hydrological insights for this region: The model simulated results showed that about 34 % of average annual precipitation in the KarMo basin is lost as evapotranspiration, but with a large spatio-temporal heterogeneity. The Hills and Tarai are relatively wetter than the Mountains. The average annual flow volume at the basin outlet is estimated as 46,250 million-cubic-meters (MCM). The hydrological characterization made in this study are further used for climate change impact assessment (Part-B in the same journal), environmental flows assessment and evaluating trade-offs among various water development pathways, which are published elsewhere. This model, therefore, has potential to contribute for strategic planning and sustainable management of water resources to fuel the country’s prosperity.
20 Pandey, Vishnu Prasad; Dhaubanjar, Sanita; Bharati, Luna; Thapa, Bhesh Raj. 2020. Spatio-temporal distribution of water availability in Karnali-Mohana Basin, western Nepal: climate change impact assessment (Part-B). Journal of Hydrology: Regional Studies, 29:100691. [doi: https://doi.org/10.1016/j.ejrh.2020.100691]
Water availability ; Spatial distribution ; River basins ; Climate change ; Impact assessment ; Forecasting ; Water resources ; Hydrology ; Models ; Precipitation ; Temperature ; Monsoon climate ; Meteorological stations / Nepal / Karnali-Mohana River Basin / Bheri River Basin / Seti River Basin / Tila River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H049744)
https://www.sciencedirect.com/science/article/pii/S2214581820301658/pdfft?md5=ff42bea00d5ed47036d646dc01e141b2&pid=1-s2.0-S2214581820301658-main.pdf
https://vlibrary.iwmi.org/pdf/H049744.pdf
https://vlibrary.iwmi.org/pdf/H049744.pdf
(4.12 MB) (4.12 MB)
Study region: Karnali-Mohana river basin, Western Nepal.
Study focus: This study aims to project future climate and assess impacts of climate change (CC) on water availability in the Karnali-Mohana (KarMo) basin. Bias-corrected future climate was projected based on ensembles of multiple models selected from a set of 19 regional climate models (RCMs). The impacts on water availability were then assessed by forcing a well calibrated and validated hydrological model with projected future precipitation (P) and temperature (T) for various climatic scenarios.
New hydrological insights for this region: Results showed that future T is projected to increase spatio-temporally with higher rate for the mountain stations in the winter season; whereas future P has no distinct spatio-temporal trend but increase in dry season precipitation for future periods. The projected changes in P, T and evapotranspiration are expected to alter average annual flow at the outlets of the KarMo and its sub-basins, albeit with varying rate. The simulated results showed higher impacts in water availability at higher altitudes, thus indicating higher vulnerability of northern mountainous region to CC than the southern flatlands. Being the first ever study of such nature in the study area, these results will be useful for planning and development of climate-resilient water development projects in the region.
Study focus: This study aims to project future climate and assess impacts of climate change (CC) on water availability in the Karnali-Mohana (KarMo) basin. Bias-corrected future climate was projected based on ensembles of multiple models selected from a set of 19 regional climate models (RCMs). The impacts on water availability were then assessed by forcing a well calibrated and validated hydrological model with projected future precipitation (P) and temperature (T) for various climatic scenarios.
New hydrological insights for this region: Results showed that future T is projected to increase spatio-temporally with higher rate for the mountain stations in the winter season; whereas future P has no distinct spatio-temporal trend but increase in dry season precipitation for future periods. The projected changes in P, T and evapotranspiration are expected to alter average annual flow at the outlets of the KarMo and its sub-basins, albeit with varying rate. The simulated results showed higher impacts in water availability at higher altitudes, thus indicating higher vulnerability of northern mountainous region to CC than the southern flatlands. Being the first ever study of such nature in the study area, these results will be useful for planning and development of climate-resilient water development projects in the region.
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