Climate change amplifies plant invasion hotspots in Nepal

Aim Climate change has increased the risk of biological invasions, particularly by increasing the climatically suitable regions for invasive alien species. The distribution of many native and invasive species has been predicted to change under future climate. We performed species distribution modelling of invasive alien plants (IAPs) to identify hotspots under current and future climate scenarios in Nepal, a country ranked among the most vulnerable countries to biological invasions and climate change in the world. Location Nepal. Methods We predicted climatically suitable niches of 24 out of the total 26 reported IAPs in Nepal under current and future climate (2050 for RCP 6.0) using an ensemble of species distribution models. We also conducted hotspot analysis to highlight the geographic hotspots for IAPs in different climatic zones, land cover, ecoregions, physiography and federal states. Results Under future climate, climatically suitable regions for 75% of IAPs will expand in contrast to a contraction of the climatically suitable regions for the remaining 25% of the IAPs. A high proportion of the modelled suitable niches of IAPs occurred on agricultural lands followed by forests. In aggregation, both extent and intensity (invasion hotspots) of the climatically suitable regions for IAPs will increase in Nepal under future climate scenarios. The invasion hotspots will expand towards the high‐elevation mountainous regions. In these regions, land use is rapidly transforming due to the development of infrastructure and expansion of tourism and trade. Main conclusions Negative impacts on livelihood, biodiversity and ecosystem services, as well as economic loss caused by IAPs in the future, may be amplified if preventive and control measures are not immediately initiated. Therefore, the management of IAPs in Nepal should account for the vulnerability of climate change‐induced biological invasions into new areas, primarily in the mountains

Does the Informal Sector Thrive Under Democracy or Autocracy?: The Case of Nepal

Our paper investigates the size and development of the informal sector in Nepal using aggregate data over the period 1991 to 2009. Our estimation using the Multiple Indicator Multiple Cause (MIMIC) model shows that the average size of the informal sector has been about 44%. Nepal has been classified as having a hybrid political regime, so we show the effect that autocracy and democracy has had on the growth of the informal sector. Our results shows that a high degree of autocracy reduced the size of the informal sector by about 2% while greater direct democracy reduced the informal sector by about 10%

Study of thermal conductivity design for thermal loaded geomaterials.

Soil thermal conductivity plays preponderant role in many geoengineering projects involving thermal effects, such as high voltage underground power cables, oil and gas pipelines, nuclear waste disposal facilities, ground heat energy storage and heat exchanger piles. A thorough understanding of thermal conductivity is necessary in heat transfer modelling. Depending upon the application and desired purpose of such projects, materials with either high or low thermal conductivity are used. Materials with high thermal conductivity are desirable in cases such as high voltage underground power cables to dissipate the generated heat rapidly to the surrounding soil. On the other hand, ground heat energy storage needs materials with low thermal conductivity and high heat capacity to hinder the heat energy loss. In this study, high conductive backfill materials for underground power cables were analysed based on existing knowledge of heat transfer mechanism in granular media and models of soil thermal conductivity in both dry and wet conditions (Yun and Santamarina, 2007, Cortes and Santamarina, 2009). Several researchers have developed theoretical, empirical and semi-empirical models to estimate the thermal conductivity of natural soils and crushed rock materials based on various factors such as particle shape and size, particle distribution, mineral composition, dry density, and wate

Parametric Study On Behavior Of Reinforced Soil Walls With Combined Horizontal And Vertical Geosynthetics

The reinforced soil system employing geogrids, as a cost effective reinforcement technique, has come to play an important role in a variety of civil and geotechnical engineering applications. In regular reinforced soil wal1s, the reinforcements are usually laid horizontally in the soil. In this study, the behaviour of reinforced soil retaining walls with combined horizontal and vertical reinforcements are investigated experimentally as well as numerically. The results, indicating the effects of vertical reinforcement inclusion, are compared to conventional reinforcing types under static and dynamic loads. The performance of retaining walls employing vertical reinforcement in conjunction with horizontal reinforcement is convincing from the results of the shake table tests conducted by the authors. In this paper, PLAXIS, well-known geotechnical software, is used for conducting a series of pararoetric studies on behaviour of reinforced soil walls under construction and subject to earthquake loading, incorporating the vertical reinforcement. The vertical reinforcement layout and its strength are among the major variables of the investigation. The geometry of the model, soil properties and reinforcement characteristics have been kept identical in all different cases selected for parametric studies. The performance of the wall is presented for the facing deformation and crest surface settlement, lateral earth pressure, tensile force in the reinforcement layers and acceleration amplification. The vertical ctefOlIDation, horizontal deflection, reinforcement force and earth pressure develop drastically under earthquake loading compared to the end of construction. The results show that these variables are considerably reduced when incorporating the vertical reinforcement in the system. In addition, the findings suggest better performance and higher structural safety for reinforced soil walls, when employing this proposed orthogonally horizontal-vertical geosynthetics

Is Investment in Maize Research Balanced and Justified? an Empirical Study

The objective of this study was to investigate whether the investment in maize research was adequate and balanced in Nepalese context. Resource use in maize research was empirically studied with standard congruency analysis by using Full Time Equivalent (FTE) of researchers as a proxy measure of investment. The number of researchers involved in maize was 61 but it was only 21.25 on FTE basis, indicating that full time researchers were very few as compared to the cultivated area of maize in the country. Statistical analysis revealed that the investment in maize research was higher in Tarai and lower in the Hills. Congruency index on actual production basis was found low across the eco-zones and even lower across the geographical regions indicating that the investment in maize research was a mismatch and not justified. While adjusted with the equity factor and the research progress factor in the analysis substantial difference was not found in congruency index. This study recommends that substantial increase in investment in maize research is needed with balanced and justified manner across the eco-zones and the geographical regions. Hills need special attention to increase the investment as maize output value is higher in this eco-zone. Eastern and western regions also need increased investment in maize according to their contribution in the output value