Global climate change has local implications. Focusing on datasets from the topographically-challenging Karnali river basin in Western Nepal, this research provides an overview of hydro-climatic parameters that have been observed during 1981–2012. The spatial and temporal variability of temperature and precipitation were analyzed in the basin considering the seven available climate stations and 20 precipitation stations distributed in the basin. The non-parametric Mann–Kendall test and Sen’s method were used to study the trends in climate data. Results show that the average precipitation in the basin is heterogeneous, and more of the stations trend are decreasing. The precipitation shows decreasing trend by 4.91 mm/year, i.e., around 10% on average. Though the increasing trends were observed in both minimum and maximum temperature, maximum temperature trend is higher than the minimum temperature and the maximum temperature trend during the pre-monsoon season is significantly higher (0.08 °C/year). River discharge and precipitation observations were analyzed to understand the rainfall-runoff relationship. The peak discharge (August) is found to be a month late than the peak precipitation (July) over the basin. Although the annual precipitation in most of the stations shows a decreasing trend, there is constant river discharge during the period 1981–2010.

It has long been recognized that there is a link between sustainable development, poverty and consistent access to useable water. Increased population is requiring more water and changing climate is altering the hydrological cycle making the water less accessible at the time when it is required. Combining the measurement of water availability and the socioeconomic capacity towards its access gives new insights in the fields of water resources management and poverty alleviation, which ultimately address the agenda of sustainable development. This paper customizes the water poverty index (WPI) indicators to encompass the climatic extremes and social settings to analyse the water stresses to the community people and their capacity to manage the water extremes focusing on the water availability in climatic variability condition in Karnali river basin in western Nepal. The indicators of the WPI were based on the multiple aspects of water focusing to water quantity and availability. The WPI is not only a useful tool to monitor progress; but it can even be used to identify areas of greatest need, thereby enabling prioritization of action in the water sector.

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Water and watershed resources have been degraded due to population growth combined with unplanned urbanization, industrial growth, and inappropriate farming systems worldwide. An effective, efficient, and holistic management system is crucial for reversing the degradation. In the Himalayan landscape, integrated river basin management (IRBM) could play an important role, especially due to the topographical challenges and governmental structures, and inconsistencies between hydro-physical boundaries and administrative boundaries. In Nepal, since early 2005 several studies have been carried out on basin-level management. However, the Government of Nepal adopted a basin-level management approach for implementing IRBM only after 2017, a few years after federal restructuring. This paper aims to review the progress made in the political, legislative, and institutional arenas for the implementation of IRBM in Nepal. The study is based on policy analysis and a literature review. It highlights that Nepal is in the preparatory phase of establishing a legal-institutional framework for IRBM and lacks proper institutional mechanisms for translating the principles of IRBM to actions on the ground. The chapter identifies the strengths and gaps in existing institutional arrangements and sheds light on the practical aspects of IRBM implementation, which would be useful learning for the countries aiming to implement IRBM in similar landscapes globally. Based on the study, it is concluded that an integrated approach based on collaboration among the different tiers and sectors of government is essential for implementing IRBM and ensuring the sustainability of water resources.

Increasing temperature and variability in precipitation are affecting different sectors in the Himalayan region. This study aims to quantify the future scenario and related extreme indices in the Kabul River Basin of the western Himalaya using high-resolution climate data sets. We selected the representative global climate model simulations for RCP4.5 and 8.5, based on their abilities to represent the historical climate cycle. By using a three-step methodology, we selected four models for RCP4.5 and four for RCP8.5. The analysis shows that, overall, precipitation will increase by 4 and 12 per cent for RCP4.5 and 8.5 respectively by the end of the 21st century, and the seasonal analysis shows decreasing pattern during the winter and pre-monsoon seasons. However, temperatures will increase consistently by 3^OC to 5^OC in RCP4.5 and 8.5 scenarios. The extreme indices were calculated based on the selected models. The extremes, like consecutive summer days, warm days, and heatwave will increase, whereas the frost days, cold nights, and cold waves will decrease towards the end of this century. Notably, more warm days and heatwaves than the baseline period are projected in future scenarios. Besides, the extremes are not homogenous in time and space. We also discussed the potential implications of these climatic extremes as related to human health, agricultural productivity, water availability, and the cryosphere. We strongly urge prompt climate actions in order to increase the adaptive capacity against these extreme changes and to build a resilient livelihood in the Kabul River Basin.