River flow reconstruction of the Lohit River Basin, North-east India based on tree-rings of Pinus merkusii (Merkus pine)

Abstract

Dendrochronological analysis of Pinus merkusii (Merkus pine) collected from Mishmi Hills, Arunachal Pradesh, North–east India shows its potential to provide continuous and long–term information about changes in river flow of Lohit River Basin (LRB). A 170 years (1830–1999 C.E.) long regional tree-ring width chronology of Merkus pine was prepared using 80 tree cores. Based on the correlation analysis between tree-ring chronology and river discharge data, the river flow was reconstructed for the month of May from 1846 to 1999 C.E. The reconstruction showed long term low and high flow periods along with extreme drought and pluvial years. Past river flow reconstruction for hydro–climatic variability in this southwest monsoon-dominated region of North–east India requires further notice. Longer tree–ring records along with wider spatio-temporal network of discharge data from Arunachal Pradesh will help to develop better records of river flow reconstructions of the region.