Answer: TOPOGRAPHY
Step-by-step explanation: Surveys became a common practice under the colonial administration in india because The British believed before a country could be effectively administered, it was necessary for such countries to be extensively known therefore, by the early nineteenth century extensive surveys such as botanical surveys, zoological surveys, archaeological surveys, anthropological surveys, forest surveys were being carried out to map the entire country.
In the villages, revenue surveys were carried out to know the topography, the soil quality, the flora, the fauna, the local histories, and the cropping pattern – all the facts seen as necessary to know about to administer the region. Also, the end of the nineteenth century marked the Census operations which were held every ten years, providing extensive records of the number of people in india provinces, taking into account thier castes, religions and occupation.