Geo-informatics of upstream-downstream relations in view of climate change and degrading headwater hydrology in Himalaya

3^rd International Conference on Hydrology & Meteorology

September 15-16, 2014 Hyderabad International Convention Centre, India

Pradeep K Rawat

Accepted Abstracts: Hydrol Current Res

Abstract :

Geohydrological and ecological linkages between upstream headwaters and downstream river basins are inadequately recognized worldwide. The headwaters are key source for sustaining the structure, function, productivity, and biocomplexity of downstream ecosystems and supply with a multitude of geo-ecosystem services, including water, sediment, nutrients (e.g., nitrogen and phosphorus), food (e.g., organic matter and invertebrate prey for fishes, salamanders, insectivorous birds). Unfortunately Himalayan headwaters have been experiencing degrading geohydrological process due to high rate of climate change and other associated environmental, anthropogenic dynamics which poses a serious threat to the process of sustainable socioeconomic development in the densely populated downstream river basin in terms of silting of river beds, increased flood events, and decreased non-monsoon water discharge in rivers. The main objective of the study is to monitor geohydrological impacts of climate change in upstream Himalayan headwaters and its consequent response to densely populated downstream Ganga plain ecosystem using modern GIS technology. The Kosi River Basin in Uttarakhand Himalaya has been selected for a case illustration. This reconnaissance study developed and analyzed the meteorological database for last three decades (1983- 2013) and estimates that the average temperature and evaporation loss have been rising with the rate of 0.07oc/year and 4.03 mm/year respectively whereas the average rainfall has been decreasing with the rate of 0.60 mm/year throughout the river basin, although these rates increasing with mounting elevations. Consequently the existing micro climatic zones shifting towards higher altitudes and affecting the favorable conditions of the headwater land use pattern and decreased the ecofriendly forest and vegetation cover. The land use degradation and high rate of deforestation in the upstream headwater area leads to accelerate extreme events of land degradation, high runoff, flash floods, river-line floods, soil erosion, denudation, landslides and slope failures during monsoon season whereas extreme drought events during non-monsoon period as dryup of natural springs and decreasing trends of stream discharge etc. These hydrological problems not only affected rural livelihood and socioeconomic development but also triggering water and food insecurity problems throughout Himalaya and densely populated downstream Ganga plain. Keep in view the headwater and downstream relation a comprehensive integrated framework have been proposed to enhance community resilience to mitigate geohydrological and socioeconomic impacts of climate change in Himalaya and its downstream Ganga plain ecosystem.