LAND-USE COVER CHANGES, EXTREME EVENTS AND ECOHYDROLOGICAL RESPONSES IN THE HIMALAYAN REGION

Land use describes human activities on the earth, and forms a major el ement of the terrestrial ecosystem modified by humans in the Himalayan region, where developmental activities are increasing rapidly to supp ort the tourism infrastructure. The unprecedented growth in population is putting extremely high pressure on the limited land available for cultivation. Land use and agricultural practices have undergone drasti c changes since the mid-1960s through the introduction of development programmes and the application of various newly developed techniques i n agrosciences. An analysis of the land use as it has occurred over th e last 70 years suggests that it and property rights in the Upper Beas Basin are complex and dynamic. For example, people are giving importa nce to orchards because of their high profitability. Thus, some agricu ltural land has been encroached on by orchards. In addition, wasteland s are now being used by people for orchards, agriculture and residenti al and commercial building. Since the Upper Beas River Basin is mounta inous, it is fragile and prone to processes like soil erosion, slope i nstability, landslides and floods. Risks from natural hazards are incr easing. However, the state of ecohydrological responses highlight that human-induced ecological changes can be largely proved at the microwa tershed level. The findings are not extended to the Himalayan scale. T here is also an uncertain correlation between anthropogenic activities (deforestation) in the mountains and hazards in the plains such as fl oods. Owing to a lack of basic research, there is little effective inf ormation which cannot be used for long-term effective monitoring of ec ological and hydrological responses to global change. Such an uncertai n situation calls for integrated watershed management and development using geographical information systems (GISs). (C) 1998 John Wiley & S ons, Ltd.