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Groundnut cultivation in Bhutan is predominantly restricted to few farmers for its kernels whereby oil is usually not extracted. The rich agro-ecological diversity hosts a multitude of groundnut accessions that have not been studied so far. Based on geographical location, seed colour, seed shape or pattern, five local accessions, namely Chalipa badam, Bartshampa white badam, Yangbrangpa red badam, Yangbrangpa white and purple badam, and Nanongpa badam were identified in eastern Bhutan. A multi-location trial using RCB design was conducted across four agro-ecologically diverse locations namely; ARDC-Wengkhar, ARDSC-Lingmethang, ARDC-Samtenling, and ARDSC-Tsirang in April 2019. Days to 50 % flowering, plant height, number of pods per plant, thousand-seed weight, shelling %, yield, and oil recovery % were assessed. The yield performance of all five accessions was poor in the low/hot environment as compared to that in the mid/cool environment where all accessions, except Nanongpa badam which was marginally low yielding, gave satisfactory and similar yields. Correlation between the number of pods per plant and yield showed a high positive relationship (r = 0.75) whereas that between plant height and yield was negative (r=-0.57).

Seismic performance of reinforced concrete (RC) frame buildings is mostly assessed based on the distinct interstorey drift limits defined by many existing guidelines. In reality, damage of a structure is a continuous process under the action of the load and also depends on a number of factors. Therefore damage can be more logically defined with a fuzzy performance level than a distinct interstorey drift limit. In this paper, probability and fuzzy set theory are used to estimate the realistic failure probabilities of the RC buildings in Bhutan by considering randomness in material and geometrical parameters and fuzziness in the damage criteria. Three typical RC frame buildings in Thimphu, Bhutan and the ground motions predicted at the generic soil sites in Thimphu are used for the structural response prediction. Rosenbluth Point Estimate Method is used for modelling the statistical variation of the input parameters and the computer program Perform 3D is used for carrying out the dynamic nonlinear analysis of the buildings. Monte Carlo Simulation is employed to validate the accuracy of the Rosenbluth Point Estimate Method and determine the statistical distribution of the response quantities. Soil structure interaction (SSI) is considered at the soft soil site using the uncoupled spring model. Based on the mean and standard deviation of the intersotrey drifts obtained from the analyses, the fuzzy failure probabilities of the buildings are estimated. It is found that under the 475 year return period ground motions, typical buildings experience a high probability of irreparable and severe damages, while the high probability of severe damage and complete collapse are predicted under the 2475 year return period ground motions. SSI is found to be detrimental to the 3 storey building, while no significant effect is observed to the 6 storey building.

Bhutan locates in a high seismicity region but has no seismic design code of its own. Recent devastating earthquake in Nepal, which is located in the same region as Bhutan and with similar construction types, raises the concern on the seismic safety of building structures in Bhutan. This study is aimed at assessing the performance of masonry-infilled and soft storey reinforced concrete frame buildings in Bhutan under the 475- and 2475-year return period ground motions predicted from the Probabilistic Seismic Hazard Analysis. A nonlinear strut model is used to model the infill wall, and the influence of openings and soil–structure interaction are considered in the analyses. The result suggests that the masonry-infilled reinforced concrete frame buildings in Bhutan could suffer repairable and irreparable damages under the 475-year return period ground motions and severe damages and even collapse under the 2475-year return period ground motion. The buildings with the soft storey are found to be more vulnerable than the normal masonry-infilled reinforced concrete buildings. The design recommendation of Indian Seismic Code improves the performance of soft storey buildings but cannot fully negate the soft storey effect. This study is the first such effort in assessing the performance of general building stocks in the high seismicity Bhutan. The results can guide the seismic strengthening options and can be used for further loss predictions for seismic preparedness of the country.

International audience; Although the first-order pattern of present-day deformation is relatively well resolved across the Himalayas, irregular data coverage limits detailed analyses of spatial variations of interseismic coupling. We provide the first GPS velocity field for the Bhutan Himalaya. Combined with published data, these observations show strong east-west variations in coupling between central and eastern Bhutan. In contrast with previous estimations of first-order uniform interseismic coupling along the Himalayan arc, we identify significant lateral variations: In western and central Bhutan, the fully coupled segment is 135–155 km wide with an abrupt downdip transition, whereas in eastern Bhutan the fully coupled segment is 100–120 km wide and is limited updip and downdip by partially creeping segments. This is the first observation of decoupling on the upper ramp along the Himalayan arc, with important implications for large earthquake surface rupture and seismic hazard.

Inspite of its location in one of the most active seismic zones in the world, Bhutan has no seismic design code of its own and no detailed study on the performance of buildings under expected earthquake ground excitation has been carried out. In this study, probabilistic seismic hazard analysis is first carried out to predict the design ground motions in Thimphu, Bhutan for the return periods (RPs) of 475 and 2475 years. These ground motions are then used to assess the performance of three typical RC buildings in the capital city, Thimphu. Soil–structure interaction (SSI) is incorporated at different soil sites and the effects of SSI are discussed. Adequacy of using Indian Seismic Code in Bhutan is also studied and discussed. The study suggests that the typical buildings in Bhutan could undergo moderate to severe damages under the 475 year RP and could even collapse under the 2475 year RP ground motions. This study is the first such effort in predicting the design ground motions and then assessing the performance of the general building stocks in Bhutan. The result can guide the seismic preparedness of the country through proper design and mitigation measures.