Predicting land use and land cover scenario in Indian national river basin: the Ganga

Abstract

A reliable LULC model aims at predicting the spatial distribution of specific LULC classes for a later year by utilizing the trends from previous years thereby helps in appropriate LULC planning. The Ganga River Basin (GRB) has undergone significant LULC changes during past decades. The changes in LULC pattern was investigated for 1975 and 2010 to have better understanding of the conversion process and thereby predicting the future trend for 2045 using Dyna-CLUE (Conversion of Land-Use and its Effects) model. Four types of data were fed into the model i.e., (a) spatial policies and restrictions; (b) LULC type specific conversion settings; (c) LULC requirements (demands) and (d) location characteristics. The possible and impossible conversions among LULC classes were dealt with through Restriction and No Restriction area. The land conversion allocation was determined by establishing preference between LULC classes and the driving factors using binary logistic regression. Relative Operating Characteristic curves provided an overall value of 0.86 implying acceptability of regression results. The simulated result (with ‘no restriction’ area criteria) showed 578,296 km2 agriculture area in 2010 and 579,235 km2 for 2045, wherein 575,874 km2 (99.58%) of agriculture area could remain unchanged during 2010–2045; while with the restricted area, agriculture area of 577,675 km2 in 2010 and 578,516 km2 for 2045; whereas 576,242 km2 (99.75%) of agriculture area may remain unchanged during 2010–2045. Biophysical drivers namely altitude, slope, aspect, soil types, precipitation and temperature, emerged as major controlling factors for LULC change in GRB. Logistic regression analysis showed that population density is positively related with agriculture and expansion of settlements.