In all these four countries, urban centres are broadly defined in terms of a population threshold and the nature of economic activities carried out by a majority of the population. Many of these countries have revised their definition of what constitutes urban centres over the last few decades, making it difficult to compare long-term trends of urbanisation in the mountains. In this section, a critical look is taken at what constitutes urban, and if urban so defined meets the special needs of the mountains as a region. In Bangladesh, according to the censuses of 1981 and 2001, an urban area included city corporations, municipalities, upazila (sub-district) headquarters, growth centres, a cantonment, and urban agglomerations adjacent to large cities, i.e., city corporations termed as statistical metropolitan areas (SMA). In 2011, the concept of SMA, growth centre, and some other urban areas was abandoned, thereby, urban areas are limited to only city corporations, paurashavas (municipality areas), upazila headquarters and cantonment areas (BBS, 2014b) with amenities such as metalled roads, improved communication, electricity, gas, water supply, sewerage, sanitation, and a high population density and people mostly engaged in non-agricultural occupations (Islam & Khan, 2013). One direct consequence of changing the definition was that the percentage of urban population of the country declined to 23.3% in 2011, which otherwise would have been around 28% according to the previous definition. In India, a place is considered an urban centre, if it has a minimum population of 5,000 and at least 75% of the main workers1 are engaged in non-agricultural pursuits and the density of population is at least 400 per km2. Urban centres that meet the above criteria are designated as ‘census towns’. Other places, such as municipality, corporation, cantonment board, notified town area committee, etc., are ‘statutory towns’ and mostly belong to size class VI (Census of India, 2011a). However, this definition poses difficulty for urban geography studies, since some settlements, especially in the Himalayan region, which truly are urban centres from a physical and economic standpoint, fail to meet the criteria laid down by the Census of India. In Nepal, the term ‘urban centre’ has been defined differently across the census years from 1952, 1962, and 1992 (CBS, 2003). A final consensus only emerged as late as 1999. From merely counting people living in prominent settlements (with over 5,000 population), Nepal provided a specific definition of a sahar or urban centre for the first time in 1961. The 1962 Nagar Panchayat Act provided municipal status to urban centres with a minimum population of 10,000, which was again reduced to 9,000 in 1976, since several urban centres were excluded when the Village Development Committee (VDC) became the main unit of enumeration in the 1971 census. After the Local SelfGovernance Act of 1999 came into force, these municipalities were categorised into three types, i.e., metropolitan city, sub-metropolitan, and municipality with different criteria for municipalities of the hills and the Terai. In Pakistan, the census definition of an urban area was almost similar in the 1951, 1961 and 1972 censuses, where a place qualified as an urban centre if it had a minimum of 5,000 inhabitants. In 1981, the definition was changed by replacing the size-specific definition with an administrative criterion, whereby an urban area included a metropolitan corporation, municipal corporation, municipal committee or cantonment (Arif & Ibrahim, 1998). According to this criterion, 361 places identified as rural areas in the previous census but now showing more urban characteristics were added as urban centres in 1998 (Arif, 2003; Ali, 2013). While several efforts are in place to improve the water security of people living in the mountains, Tortajada (2014) identifies that there is a need for constant accountability from users, donors, government and non-governmental organisations for their decisions and actions. With good information networks (Rouse, 2014), planning can be more precise and can yield better results.