Tectonic geomorphology has been evidenced as an essential tool to define and measure recent tectonic deformation. The Nandakini River originates from Nanda Ghunti glacier at 6886 m in Lesser Himalaya. It covers about ~551 km2 basin area, with a fourth-order stream. It confluences with the Alaknanda River near Nand Prayag (at elevation 852 m), Chamoli district of Uttarakhand. The drainage pattern is predominantly dendritic in the study area. The morphotectonic indices are measured to know the tectonic activity of the drainage basin. Morphometric indices reflecting hypsometric Integral is 1.07, indicating a deeper incision and a slight erosion. The basin elongation ratio is 0.17, suggesting that the area is tectonically active. The drainage basin asymmetric factor (44) suggest tilting. In addition, the drainage basin shape (3.27) indicates the basin is tectonically strong, the transverse topographic symmetry factor (0.31) indicates the asymmetric nature, the valley floor width to valley height ratio is 0.54 shows the deep, narrow valleys, and Active V-shaped incision. Stream longitudinal profile showing the area tectonically influenced. The Sinuosity Index of 1.12 suggests that low sinuous nature. The Stream length-gradient Index is 10.64, indicating high tectonic activity in valleys and basin areas. The transverse profile helps to understand the tilting of the basin. The Surface profile shows irregularity, and the linear trend of the profile shows the tilting of the basin. River carrying capacity with large boulder-size sediment indicates youth stage and tectonically active environment. The morphotectonic indices suggest that the drainage basin was affected by the regional structures and the present tectonics.

Understanding the spatiotemporal monsoonal variability during the Holocene helps in understanding the rise and fall of many civilizations. In this study, a 2.65 m high palaeo lake sedimentary profile from the Kumaun Lesser Himalaya, Uttarakhand State, India was pollen analysed to reconstruct the variability in the monsoonal precipitation during the Middle Holocene. The study revealed that between ~7522 and 7216 cal yr BP, conifers dominated mixed broad-leaved forests occurred around the landscape of the study area, indicating a less cold and dry climate with decreased monsoon precipitation. Broad-leaved taxa during this phase show increased values considerably, indicating amelioration in climatic condition, which could be, in global perspective, broadly falling within the time-interval of the Holocene Climate Optimum (HCO; 7000–4000 BP). Between ~7216 and 6526 cal yr BP, dense conifers-dominated mixed broad-leaved forests transformed the conifers-dominated broad-leaved forests around the study area under a cold and drier climate with further reduction in monsoon precipitation. Subsequently, between ~6526 and 5987 cal yr BP, conifers-dominated broad-leaved forests continued to grow, but with lesser frequencies, around the study area under a comparatively less cold and dry climate with reduced monsoon precipitation. Finally, between ~5987 and 5817 cal yr BP, the frequencies of conifers-dominated broad-leaved forests further decreased around the landscape of the study area under a comparatively lesser cold and dry climate, probably indicating decreased monsoonal precipitation. Hence, the present study mainly showed the dominance of conifers forests around the study area between ~7522 and 7216 cal yr BP, ~7216 and 6526 cal yr BP, ~6526 and 5987 cal yr BP and between ~5987 and 5817 cal yr BP; however, broad-leaved forests also demonstrated increasing tendency between ~7522 and 7216 cal yr BP in the milieu of cold and dry climates. Moreover, the study also revealed that a lake was formed around 7522 cal yr BP along the Kulur River, a tributary of Saryu River around the study area and existed until 5817 cal yr BP.