Impacts of climate change on the hydrological regime of the Koshi river basin in the Himalayan region

AbstractUnderstanding the potential impact of climate change on the hydrological regime in the Himalayan region is of great importance for sustainable water resources management. This study assessed the historic and projected climate trends in the Koshi river basin using statistical analysis. The hydrological characteristics and the contribution of different runoff components under present and projected future conditions were investigated in the Dudh Koshi sub-basin using the J2000 model. Data for 1995 to 2096 from the Providing REgional Climates for Impacts Studies (PRECIS) regional climate model were used in the J2000 model to project the impact of climate change under the A1B climate scenario in mid-century (2040–2050) and late-century (2086–2096), compared to baseline (2000–2010). Present climate showed an increase in average temperature in the river basin at a rate of 0.058 °C/year for maximum temperature and 0.014 °C/year for minimum temperature over the past forty years. The model simulation of the hydrological regime from 1985 to1997 was satisfactory. The average annual contribution of snow and glacier melt to total discharge was about 34%, whereas it was 63% in the pre-monsoon season (March to May). The projected future results from the model indicate a 13% increase in annual discharge by mid-century followed by a slight decrease; and a 16% increase in evapotranspiration by the end of the century. Snowfall is projected to decrease substantially due to the rise in temperature, the basin will lose snow storage capacity, and there will be a marked decrease in snowmelt runoff from non-glaciated areas. In contrast, melt from glaciated areas will increase up to mid-century and start decreasing thereafter. The model results suggest that snowfall pattern, snowmelt, discharge, and evapotranspiration are all sensitive to the effects of climate change

Policy Workshop on Co-learning Opportunity for the Water, Energy, Food and Ecosystems (WEFE) Nexus in Nepal

Within Nepal, water, energy, food, and ecosystems (WEFE) are vital resources not merely for the current generation, but also for future ones, especially to satisfy the demands of a growing population and to respond to socio-economic changes. The WEFE nexus approach realizes that the management of water, energy, food, and ecosystems must be undertaken in a holistic way. Nevertheless, governments, investors, and other stakeholders face challenges in the management of WEFE resources, particularly in the face of climate change. Notably, a lack of coordination in utilizing such resources can be a source of potential conflict in many areas. On June 19 and 20, 2022, the International Water Management Institute (IWMI) and the Department of Water Resources and Irrigation (DWRI) co-organized a co-learning workshop to discuss the challenges and opportunities of integrated management of WEFE resources using the nexus thinking approach in Nepal

Evaluating upstream downstream linkages of Hydrological Dynamics in the Himalayan Region

The glacierised mountain catchments of the Himalayan region serve lives and livelihoods for millions of people living downstream. When water (or streamflow) flows from headwaters to floodplains, the water resources are widely utilised for many activities such as agriculture, drinking water, and hydropower. The activities and processes (such as land-use change and snow and glacier melt) in upstream areas affect the spatial and temporal distribution of water resources to downstream regions. In the context of climate change, the hydrological regime of the Himalayan river systems is likely to be affected which might change the water availability for downstream people. The understanding of the hydrological dynamics is crucial for sustainable planning and management of water resources of the Himalayan region. However, the lack of hydro-meteorological data in the region, especially in high-altitude areas, hinders the process of understanding the system dynamics. In this context, the present study is intended to analyse the upstream-downstream linkages of hydrological dynamics in the Kosi river basin of the Himalayan region. The study attempted to understand the hydrological system dynamics of the Kosi river basin using the process oriented and distributed hydrological model. Similarly, the model application also enables to understand the impact of land-use and climate change on hydrological regime. The understanding of process characteristics of precipitation and runoff generation derived from the modelling application was instrumental in recognising the upstream-downstream relationship

Influence of socio-economic attributes of farmers on the adoption of orchard management practices of mandarin in Myagdi district, Nepal

Mandarin is one of the major and highly commercialized fruit crops of Nepal. However, its productivity is widely varied throughout the country. The association of socio-economic characteristics of the farmers with the adoption of different orchard management practices and ultimately productivity is less known. Therefore, survey research was conducted in the Myagdi district to study the influence of socio-economic attributes on the adoption of different orchard management practices and their relation to the productivity of mandarin. A total sample size of 94 was selected by simple random sampling technique and interviewed with a pre-tested, semi-structured questionnaire. Data were entered and analyzed using MS Excel, Statistical Package for the Social Sciences (SPSS), and STATA, and the inferences were retrieved using the binary logistic regression model and multiple linear regression model. The study showed that the education level of the farmers has a positive influence on the adoption of mulching (p = 0.04) and pruning (p = 0.07). The secondary income source of the household has a positive impact on the adoption of chemical fertilizers (p = 0.08) and pruning (p = 0.03). Commercial mandarin farming in larger area has a positive influence on the adoption of Bordeaux mixture (p = 0.03) and insect management (p = 0.01). Extension services has great influence on the adoption of chemical fertilizers (p = 0.02), mulching (p = 0.03), Bordeaux mixture (p = 0.00) and insect management (p = 0.1). However, education level (p = 0.05), area under mandarin farm (p = 0.09), and extension services (p = 0.00) discourage the adoption of intercropping in the mandarin orchard. The productivity of mandarin orchards was significantly enhanced by FYM application, chemical fertilizers, irrigation, weeding, and Bordeaux application. This study shows that the farmers with better socio-economic conditions are more likely to adopt improved management practices in mandarin orchard which in turn enhance their productivity

Impacts of climate change on the flow of the transboundary Koshi River, with implications for local irrigation

This study assesses climate change impacts on the hydrological regime of a river basin and its implications for future irrigation water availability in the Koshi River basin using RCPs 4.5 and 8.5 over short-term (2016-2045), mid-century (2036-2065) and end-of-century (2071-2100) periods. Average flow in the Koshi River is projected to increase. Projections of average minimum monthly river flow suggest that the areas of winter wheat and monsoon paddy rice could be increased. However, the planting period of paddy rice should be delayed by one month (July to August) to capture the expected increased water availability in the river

Correlation of Anthropometric Measurements with Hamstring Graft Size in Anterior Cruciate Ligament Reconstruction in Nepalese Population: A Prospective Observational Study

Background: The use of autologous hamstring tendon for arthroscopic Anterior Cruciate ligament (ACL) reconstruction is very common. The size of hamstring tendons varies significantly between individuals, and graft diameter is unpredictable. Anthropometric measurements may be a simple way to estimate hamstring tendon length and diameter. This study aims to determine the correlation between anthropometric measurements of patients with length and diameter of harvested hamstring autograft during ACL reconstruction. Methods: A prospective observational study was carried out after ethical approval. All patients who underwent arthroscopic ACL reconstruction from 1 March 2022 to 30 April 2023 in Birat Medical College Teaching Hospital were included. Fourty seven patients’ age, sex, height, weight and thigh length were recorded preoperatively. Hamstring tendons were harvested and length of the semitendinosus tendon and diameter of the quadrupled graft (doubled semitendinosus and doubled gracilis) was measured intraoperatively. We used Pearson’s correlation coefficient to observe the relationship between anthropometric measurements and graft variables. Results: Mean length of harvested semitendinosus tendon was 27.4 ± 1.8 cm and mean quadrupled hamstring autograft diameter was 7.4 ± 0.8 mm. A significant positive correlation between graft variables (semitendinosus tendon length and quadrupled hamstring autograft diameter) and patients’ height and thigh length was found.Regression equations for predicting Semitendinosus tendon length and quadrupled hamstring autograft diameter from thigh length in males and females are also derived. Conclusion: Height and thigh length of patients are useful parameters for predicting semitendinosus tendon length and quadrupled hamstring graft diameter before ACL reconstruction

Ramp Tear among Patients Undergoing Arthroscopic Anterior Cruciate Ligament Reconstruction in a Tertiary Care Centre

Introduction: Ramp tear is a specific injury that affects the posterior horn of the medial meniscus and its meniscosynovial or meniscocapsular attachments. The actual prevalence of ramp lesion is unknown due to the high probability of misdiagnosis or underdiagnosis caused by the low sensitivity of imaging modalities and poor visualization during arthroscopy. This study aimed to find out the prevalence of ramp tear among patients undergoing arthroscopic anterior cruciate ligament reconstruction in a tertiary care centre. Methods: A descriptive cross-sectional study was conducted among patients undergoing arthroscopic anterior cruciate ligament reconstruction after getting ethical approval from the Institutional Review Committee. Data from 1 March 2019 to 31 December 2022 was collected between 1 May 2023 to 30 May 2023 from medical records. The study included all patients who underwent arthroscopic anterior cruciate ligament reconstruction. Patients with a previous history of medial meniscus injury or repair and undergoing revision anterior cruciate ligament reconstruction were excluded. Convenience sampling method was used. The point estimate was calculated at a 95% Confidence Interval. Results: Out of 412 patients who underwent arthroscopic anterior cruciate ligament reconstruction, 53 (12.86%) (9.63-16.09, 95% Confidence Interval) had ramp tears. The mean age of patients with ramp tears was 28.64±7.57 years. Among 53 patients, 42 (79.24%) were male and 11 (20.75%) were female. Conclusions: The prevalence of ramp tears in patients undergoing arthroscopic anterior cruciate ligament reconstruction in a tertiary care centre was found to be lower than other studies done in other international studies