Has the Kullu district experienced an increase in natural hazard activity over the past 27 years?- a case study in risk and land use/cover change The Kullu District has been settled for several millennia with relatively long periods of social and political stability (Gardner et al., 1997). However parts of the area have undergone noticeable land use change over the past century, particularly since about 1970. Land use change is usually brought about by a change in the socioeconomic situation of an area. Agriculture has been the dominant economic and land use activity in the region for centuries, at times employing ~90% of the population (Singh, 1992). The construction of National Highway 21 in the 1950's linked this remote region with centers to the south. This increase in transportation capacity led to a shift from subsistence crop agriculture to commercial horticultural orchards. Cultivated and abandoned fields were converted to stands of various types of fruit trees, and orchardry became an important economic as well as land use activity. Conversion of land to orchards continued until a second major land use change occurred during the 1980's when the district experienced a large influx of tourists avoiding the unstable political situation in the Kashmir region. This led to the construction of hotels, restaurants, roads, and development of other tourist-related facilities. By the early 1990's, agricultural land was being developed or abandoned in favor of tourism-related opportunities. The region has recently (past decade) become popular with foreign tourists as well, further promoting development of urban infrastructure. The increasing population, rapidly expanding infrastructure, and continued intensification of land use are superimposed onto a physically unstable landscape characterized by frequent mass wasting and erosion, activity and floods. Risk to life and property is a consequence of natural hazards, which result from this juxtaposition of the human and physical environments. Disasters are the realization of risk and often occur at specific sites (i.e. hazard sites). Methods used to locate and identify hazard sites are discussed below. 
Hazard site identification and mapping Current and potential hazard sites were located and identified through fieldwork because in most cases maps, satellite imagery, and air photos are not accurate enough to yield sufficiently detailed information on the activity of various processes, their location, and proximity to settlements or other infrastructure. Hazard maps do not exist or are unreliable for many mountainous areas. Although maps, air photos, and historical information should always be evaluated and used when available the main source of information should come from work carried out on the ground. A hazard site is defined as the area of release/failure that can potentially comes into contact with settlements and/or infrastructure. In many cases the initial point of contact will be a road, trail, railroad, or other linear feature which cuts across the path of an erosion process. Examples of geomorphic processes examined in the field include landslides, composite and progressive failures, and rockfall. All accessible roads and settlements in the study area were surveyed in order to collect information on all current and potential hazard sites. Thus the dataset represents the entire population of hazard sites in the Valley. The severity of potential damages in terms of human and economic losses at each hazard site was not addressed due to a lack of reliable socioeconomic data and only the possibility of occurrence was noted. Geomorphic evidence was used to identify the type of active process operating at each site. Geomorphic characteristics examined in the field included, slope, aspect, type of surficial materials, slope surface morphology, and microrelief (Table 1). Aspect and slope were measured using a compass and inclinometer respectively. Unconsolidated, poorly sorted materials such as colluvium usually indicate unstable slopes especially in sparsely vegetated areas. Highly jointed, steep, and exposed rock faces indicate areas of rockfall activity, particularly in locations where fresh deposits are frequently found near a cliff base. In many instances fresh deposits at the base of a slope or cliff following a heavy rainfall or other destabilizing event (e.g. earthquake) provided clear evidence of the type and magnitude of process operating at that location. Other areas with similar morphological and vegetative characteristics were investigated in order to assess their potential for failure. Mitigative structures such as retaining walls, gabion baskets, deflection bars, and channel baffles are another source of evidence that a certain type of erosion process has recurred there with some frequency in the past. |