Vishnu Prasad Pandey

Assessment of groundwater vulnerability and risk to pollution in Kathmandu Valley, Nepal

Groundwater vulnerability and risk assessment is a useful tool for groundwater pollution prevention and control. In this study, GIS based DRASTIC model have been used to assess intrinsic aquifer vulnerability to pollution whereas Groundwater Risk Assessment Model (GRAM) was used to assess the risk to groundwater pollution in the groundwater basin of Kathmandu Valley. Seven hydrogeological factors were used in DRASTIC model to produce DRASTIC Index (DI) map which represent intrinsic groundwater vulnerability to pollution of the area. The seven hydrogeological factors used were depth to water, net recharge, aquifer media, soil media, topography, impact of vadose zone, and hydraulic conductivity of aquifer. GIS based GRAM was used to produce likelihood of release of hazards, likelihood of detection of hazards, consequence of hazards and residual risk of groundwater contamination in terms of nitrate in the groundwater basin. It was found that more than 50% of the groundwater basin area in the valley is susceptible to groundwater pollution and these areas are mostly in Northern groundwater district Low and very low vulnerable areas account for only 13% and are located in Central and Southern groundwater districts. However after taking into account the barriers to groundwater pollution and likelihood of hazards release and detection, it was observed that most areas i.e. about 87% of the groundwater basin are at moderate residual risk to groundwater pollution. The resultant groundwater vulnerability and risk map provides a basis for policy makers and planners ability to use information effectively for decision making at protecting the groundwater from pollutants.

Livelihood vulnerability approach to assessing climate change impacts on mixed agro-livestock smallholders around the Gandaki River Basin in Nepal

Abstract Climate change vulnerability depends upon various factors and differs between places, sectors and communities. People in developing countries whose subsistence livelihood depends mainly upon agriculture and livestock production are identified as particularly vulnerable. Nepal, where the majority of people are in a mixed agro-livestock system, is identified as the world’s fourth most vulnerable country to climate change. However, there is limited knowledge on how vulnerable mixed agro-livestock smallholders are and how their vulnerability differs across different ecological regions in Nepal. This study aims to test two vulnerability assessment indices, livelihood vulnerability index and IPCC vulnerability index, around the Gandaki River Basin of central Nepal. A total of 543 households practicing mixed agro-livestock were surveyed from three districts, namely Dhading, Syangja and Kapilvastu representing three major ecological zones: mountain, mid-hill and Terai (lowland). Data on socio-demographics, livelihood determinants, social networks, health, food and water security, natural disasters and climate variability were collected and combined into the indices. Both indices differed for mixed agro-livestock smallholders across the three districts, with Dhading scoring as the most vulnerable and Syangja the least. Substantial variation across the districts was observed in components, sub-components and three dimensions (exposure, sensitivity and adaptive capacity) of vulnerability. The findings help in designing site-specific intervention strategies to reduce vulnerability of mixed agro-livestock smallholders to climate change.

Evaluation of index-overlay methods for groundwater vulnerability and risk assessment in Kathmandu Valley, Nepal

This study aimed at evaluating three index-overlay methods of vulnerability assessment (i.e., DRASTIC, GOD, and SI) for estimating risk to pollution of shallow groundwater aquifer in the Kathmandu Valley, Nepal. The Groundwater Risk Assessment Model (GRAM) model was used to compute the risk to groundwater pollution. Results showed that DRASTIC and SI methods are comparable for vulnerability assessment as both methods delineate around 80% of the groundwater basin area under high vulnerable zone. From the perspective of risk to pollution results, DRASTIC and GOD methods are comparable. Nevertheless, all the three methods estimate that at least 60% of the groundwater basin is under moderate risk to NO3-N pollution, which goes up to 75% if DRASTIC or GOD-based vulnerabilities are considered as exposure pathways. Finally, based on strength and significance of correlation between the estimated risk and observed NO3-N concentrations, it was found that SI method is a better-suited one to assess the vulnerability and risk to groundwater pollution in the study area. Findings from this study are useful to design strategies and actions aimed to prevent nitrate pollution in groundwater of Kathmandu Valley in Nepal.

Green, Blue and Grey Water Footprints of Primary Crops Production in Nepal

This study aims to estimate the green, blue and grey water footprints (WFs) of nine primary crops production in 75 districts, 5 developmental regions and 3 physiographic divisions of Nepal using local meteorological, agronomical and irrigation data at high spatial resolution. The estimates are based on the framework prescribed by the guideline of the Water Footprint Network. The green and blue WFs are calculated using a water balance model whereas the grey WF is estimated as the volume of freshwater needed to dilute nitrate pollution to an acceptable level. WF varies across different crops considered, different districts, development regions and physiographic divisions. WF of potato and wheat in Nepal is comparable to the world average; but paddy, barley and pulses have higher while sugarcane and maize have lower values compared to the world average. WFs of paddy, maize, potato and wheat are lower in Terai than the Hills and Mountains due to the accessibility of irrigation system and higher crop yield. Millet, pulses, oilseeds and barley have lower WFs and are suitable for Mountains. Similarly, sugarcane is suitable for both Terai and Mountain divisions because of its lower WF. Crops in Far Western Development Region generally have higher WFs due to the low crop productivity, and higher fertilizer use.

Assessing climate change vulnerability of water at household level

The Climate Vulnerability Index for Water (CVIW) was developed and applied to assess the climate related water vulnerability of households in mountainous region. The CVIW provides a realistic approach to recognize social and natural factors contributing to climate change water vulnerability at the household level. CVIW comprises of three components—exposure (Exp.), sensitivity (Sen.) and adaptive capacity (Adap.Cap.)—and 14 sub-components: four for Exp., five for Sen. and five for Adap.Cap. An indicator-based approach was used to assess the components of the index whereas a composite-index approach to estimate the index value. The CVIW was then applied for mountainous households in Uttrakhand, India. The study area was classified under rural and urban areas. Random sampling was adopted to select the households. The CVIW value in urban areas was found to be higher (0.767) than in rural areas (0.686) suggesting less water vulnerability of urban households. This comparatively higher water vulnerability of rural, forest-dependent, households is attributed to the heightened sensitivity and exposure of the rural region in comparison to the urban region. The major contributor to water vulnerability of rural households is the low standard of health facilities, the existing water problems and agricultural issues. Along with remoteness, the edaphic factors of mountainous region coupled with infrastructural issues are responsible for the present condition, all of which are addressable if future programs and policies include and implement regulations to remedy attributive factors.

Empirical assessment of adaptation to climate change impacts of mountain households: development and application of an Adaptation Capability Index

The present study proposes an index to assess the potential for adaptation to climate change for households in the mountainous regions. The index provides a realistic approach to recognize social and natural factors which contribute to successful adaptation and addresses several household functions, such as social networking, livelihood strategy, adjustment strategies, resource availability and accessibility. The proposed Adaptation Capability Index (ACI) is analytically defined, mathematically formulated and field tested on mountainous households in urban and semi-urban regions of the Uttarakhand Himalaya in India. To gather data on the topic relevant to the ACI, a household scale questionnaire was developed and administered to 120 heads of households through face-to-face interviews. The results highlight higher adaptive capability of urban households and low adaptation capacity of rural households due to poor farm productivity, low accessibility and availability of resources and technological input. Future programs and policies must include and implement regulations to remedy attributive factors responsible for higher adaptation. This paper may be applicable to other mountainous regions and may provide insights for effective adaptation strategies to climate change.

Climate change and adaptation: an integrated framework linking social and physical aspects in poorly-gauged regions

Various frameworks related to climate change and adaptations that have been developed to date have notable benefits as well as significant limitations. It is not always practical to implement advanced climate change frameworks in situations with limited data availability. Social aspects, such as people’s experience and perception, are often under-prioritized. Therefore, this study introduces an integrated framework linking social and physical aspects of climate change to assess its impacts on water resources and to evaluate differing adaptation options in poorly gauged basins. A case study of the Kali Gandaki River Basin (KGRB) in western Nepal is presented to demonstrate the applicability of this framework. Results of the study show that people of the mountainous Mustang district in the KGRB have perceived climate change or climate variability, its impacts on water resources, as well as other water-related issues and potential adaptations or responses. Furthermore, evaluation of people’s perception using available physical data confirms the increase in temperature and average annual discharge in the Kali Gandaki River as well as poor water use, as a major problem at all levels in the basin. Despite increasing water availability, a concurrent increase in water use is difficult due to topographic constraints on irrigation development. However, the impacts of climate change are particularly severe in Mustang, owing to the fact that a large proportion of the population depends on a climate-sensitive livelihood like agriculture. Therefore, various adaptation options are identified in the agricultural sector, and one relevant option is further evaluated. The framework developed in this study has the potential to be further applied to other poorly gauged basins.

Climate change and adaptation strategies in Budhi Gandaki River Basin, Nepal: a perception-based analysis

People’s perceptions can reflect local issues and concerns to reveal actual impacts of climate change/variability (CCV) on their lives and livelihoods. As climate change (CC) adaptation strategies are to be implemented at the local level, involving local people right from the beginning of problem diagnosis ensures their successful implementation. This study has adopted a perception-based approach to assess CCV, its effects in terms of extreme events and prioritize adaptation strategies to enhance resilience of the communities, in the Budhi Gandaki River Basin (BGRB), Nepal. It is likely that valuing local knowledge and experiences makes people more responsive to the intervention and backing up the perception results by scientific data analysis establishes a sense of legitimacy to what people have perceived. Results showed that people have perceived CCV in various forms such as increase in temperature, decrease in pre-monsoon and monsoon rainfall, and more erratic rainfall timing in recent years. These perceived impacts are consistent with trends in observed rainfall and temperature data in the study area. The CCV has led to increase in frequency of extreme events - both floods and droughts, and associated impacts. As an adaptation strategy, people prioritized ‘technological measures’ as the most effective for both flood and drought. The analysis provided herein confirms that combining scientific facts with people’s perception helps establish more reliant knowledgebase of CC to better plan and develop climate-resilient communities.

From an open-access to a state-controlled resource: the case of groundwater in the Kathmandu Valley, Nepal

Groundwater is no longer an open-access resource in Kathmandu. Perceptions of groundwater are changing from an “infinite” to a “finite” resource and the role of the government from supply developer to caretaker of the resource. In this context, this paper aims to unfold how perceptions of groundwater in Kathmandu Valley, Nepal, are changing from an open-access resource to an overexploited, depleted, degraded, vulnerable and state-controlled resource. In the process, it produces an aggregated picture of resource availability, development dynamics, impacts and responses in the area; suggests some “soft-path” approaches for groundwater management; and discusses implications of the experience for other areas.

Groundwater as an Environmental Issue in Asian Cities

Groundwater represents by far the largest storage of unfrozen ubiquitous high-quality fresh water on Earth. It is more widely accessible and less vulnerable to quality degradation and drought than surface water. These characteristics promote its widespread development, which can be scaled and localised according to demand, obviating the need for substantial infrastructure. Globally, groundwater is the source of one third of all freshwater withdrawals, supplying an estimated 36, 42, and 27% of water used for domestic, agricultural, and industrial purposes, respectively. In many environments, natural groundwater discharge sustains baseflow to rivers, lakes, and wetlands during periods of low or no rainfall.