Landuse change impact on sub-watersheds prioritization by analytical hierarchy process (AHP)

Landuse change analysis is considered as elementary in planning and land management of a basin. The present study provides information of change in landuse in 1990, 2000, 2011, and future prediction of the year 2020, 2030, 2040 and 2050 of different sub-watersheds within a basin, which is a part of the Narmada river basin in central India. The major objectives involve landuse prediction by Markov Chain model and sub-watershed prioritization using analytical hierarchy process (AHP) to identify and manage environmentally unstable areas in future. Different landuse categories are used as factors in prioritization analysis. Landuse of 2011 indicates a transition of about 312 km² of forest area to agricultural land and 10.64 km² to settlement in 2020, which increases to 678 km² and 21.29 km² in 2050 respectively. There is also a transition of forest to scattered forest and grasslands and increase in the areas of the rocky surface. AHP is applied to identify sub-watersheds of highest priority, which indicates the sub-watersheds 5 and 6 are of very high priority in 2011 along with 1, 2, 3, 4 and 7 that are in most places plain areas used for agriculture and settlements. Sub-watersheds 8 and 9, which are forest areas, are observed to be of medium to low priority in future. However, 2050 projects high priority for all the sub-watersheds that calls for efficient landuse management and decision. Most of the northern sub-watersheds of 1 to 7 and 12 of south need high priority.