Hydrological response to agricultural land degradation in the Lesser Himalayas

India, as many areas of the world, is experiencing widespread rural to urban migration, coupled with rapid population growth. Taken together, these two factors are resulting in significant land use and land cover changes, causing land degradation in particular in the mountainous Lesser Himalayan regions of Northern India (Tiwari and Joshi, 2012; Khanal and Watanabe, 2006).

The interactions between agriculture and the water cycle present a number of key scientific questions, the answers to which are central to future sustainable food production (Pretty et al. 2010). In India, rain-fed agriculture account of an estimated 44% of food production (Sharma, 2011). For centuries, agricultural land management practices have utilised localised irrigation methods of terracing and small-scale onfarm water harvesting to maximise crop yields. Now, with the increasing trend in migration towards urban centres (particularly by younger generations) many of these previously highly managed upland catchments are being partially or completely abandoned (e.g. Khanal and Watanabe, 2006). The impacts of the resulting land degradation on river basin hydrological processes (and hence on downstream water resources, flood risk and sediment transport) are largely unknown.

Changes to the hydrological regime may play an important role in driving such abandonment, with changing hydroclimatology and runoff generation mechanism meaning traditional small scale farms may not be sustainable in areas of rapid agricultural intensification and rising demand for food from a growing population.

Understanding the changing hydrology of agricultural catchments is critically important to issues of water security in the Himalayas. This project will build knowledge through innovative field experiments in the Aglar catchment in northern India (Figure 1).
The cost and practical challenges in maintaining remote high spatial and temporal resolution field monitoring in upland environments often limit research studies. This project will pioneer the use of low-cost environmental sensors to address such challenges.
Therefore, the project aims to:

1. Assess the impacts of agricultural land degradation on hydrological functioning in the Aglar river basin, Uttarakhand, India
2. Quantify the implications of changing hydroclimatology and runoff generation on sustainable agricultural water management in this Himalayan river basin
3. Test capabilities of low cost sensors to monitor hydrological variables in remote mountain river basin
4. Reconceptualise interactions and feedbacks in the water-food nexus and their implications for water security and migration in rural India