Normal Alkane Distributions in Soil Samples along a Lhasa-Bharatpur Transect

We present n-alkane distributions in the soil samples along a transect from Lhasa on the Tibetan Plateau to Bharatpur in Nepal, which covers a large geographical area and a wide range of climatic conditions. These data allow us to assess the significance of n-alkane distributions in different vegetation types and their relationships to temperature and precipitation. In the tropical rainforest and broadleaved forest zones, n-alkanes exhibit a bimodal distribution pattern with dominant homologues around n-C_（31） and n-C_（23）. The bimodal distribution of tropical rainforest n-alkanes may be a general pattern because of the presence of many lianas, epiphytic plants, algae and the strong microbial activity and degradation involved in the postdepositional process. In the warm-temperate mixed forest and needle-leaved forest zones, the long-chain alkanes have a pattern of n-C_（31） n-C_（33） n-C_（27）. In the alpine shrub and grassland zone, although the most abundant homologue is n-C_（31） , relatively high n-C_（23） concentrations have also been observed in some samples. The statistical results show a good correlation between n-alkane proxies and climatic factors. The average chain length（ACL） values are positively correlated with precipitation and temperature across the transect. The carbon preference index（CPI） values show a negative correlation with temperature and precipitation along a Lhasa–Bharatpur transect. Although there is a positive relationship between ACL and temperature, it is difficult to separate the two climatic variables（temperature and precipitation） because they are well coupled in the monsoon region.

Petrofacies Evolution of Bayana Basin Sandstones of Mesoproterozoic Delhi Supergroup, Bharatpur District, Rajasthan, Northwestern India

The paper embodies results of petrofacies, detrital mineralogy and textural aspects of Bayana Basin sandstones of the Delhi Supergroup. These sandstones consisting of various types of quartz, feldspar, mica, rock fragments and heavy minerals are medium to fine grained and moderately well sorted. These sediments are generally subangular to subrounded with low sphericity. Various factors responsible for modification of the original detrital composition of the sandstones have been critically examined. Distance of transport is one of the factors which control the composition at the time of deposition. The plots of petrofacies in QtnFnL, QmnFnLt, QpnLvnLs and QmnPnK ternary diagrams suggest mainly basement uplift source (Craton interior) in a rifted continental margin basin setting, which has also received sediment input from recycled orogen provenance.

Satellite Image-based Monitoring of Urban Land Use Change and Assessing the Driving Factors in Pokhara and Bharatpur Metropolitan Cities, Gandaki Basin, Nepal

Urban growth is a key indicator of economic development.At the same time,haphazard urban growth creates serious socioeconomic,environmental and urban land management problems.In this context,understanding the process of urban landscape change is important for guiding the sustainable growth of urban areas.This study analyzes the urban land changes during 1990–2018 in two metropolitan cities of Gandaki basin:Pokhara and Bharatpur.Landsat satellite images were analyzed using supervised classification methods.The results revealed that the built-up area has increased significantly by 300%in Pokhara and by nearly 500%in the Bharatpur during the past 28 years.Population growth,migration from surrounding areas due to urban facilities and the easy lifestyle in cities were found to be major determinants of urban growth within the study area.In addition,the changing urban definition and expansion of municipal boundaries are key factors for rapid urban growth.Both cities are likely to grow in the future as they are both located in areas that encompass the high levels of commercial activity and modern service facilities.The haphazard urban growth should be minimized through planning and policies for sustainable urban development.