Due to climate change, the agricultural and socio-economic development over the eastern Himalayan region of India is greatly affected. The present study has been carried out to investigate the implications of climate change on regional crop water requirements (CWR) and crop irrigation requirement (CIR) of major crops (maize, wheat and, rice) over a Himalayan state, i.e., Sikkim. Daily climatic datasets such as rainfall, minimum temperature, maximum temperature, wind speed, sunshine hours, and relative humidity are used for this analysis along with crop and soil data. For future period (2021–2099), climatic datasets are collected from the four climate models (ACCESS1-0, CCSM4, CNRM-CM5 and MPI-ESM-LR) of CORDEX under two different scenarios, i.e., Representative Concentration Pathway (RCP) 4.5 and 8.5. CWR & CIR of maize, wheat and rice crops are projected for three-time windows, i.e. start term (2021–2046), mid-term (2047–2073), and end term (2074–2099) by taking 1998–2015 as baseline period. In addition, uncertainty and sensitivity analysis is carried out. The outcomes from the study suggest an increase in the CWR towards the end of the twenty-first century for rice and wheat over West (8% and 39%) and South (11% and 37%) Sikkim with respect to baseline period. In case of Maize, a decreasing trend is noticed over West (− 4%) and East (− 15%) Sikkim. For all the crops in East Sikkim, a declining trend is likely to occur. In most of the cases, the CIR has increased towards the end of the twenty-first century. The uncertainty analysis reveals RCP 4.5 as the possible scenario over the study area. The outcomes from the study facilitate the agricultural and water managers for adopting effective measures to ensure sustainability.

由于气候变化，印度喜马拉雅东部地区的农业和社会经济发展受到很大影响。本研究旨在调查气候变化对喜马拉雅州（锡金）主要作物（玉米，小麦和水稻）的区域作物需水量（CWR）和作物灌溉需求（CIR）的影响。每日气候数据集（例如降雨量，最低温度，最高温度，风速，日照时间和相对湿度）与作物和土壤数据一起用于此分析。对于未来时期（2021年至2099年），在两种不同的情况下，即代表浓度路径（RCP）下，从CORDEX的四个气候模型（ACCESS1-0，CCSM4，CNRM-CM5和MPI-ESM-LR）收集了气候数据集。 4.5和8.5。玉米的CWR和CIR，预计以1998-2015年为基准期，小麦和水稻作物的三个时段，即开始期（2021-2046），中期（2047-2073）和结束期（2074-2099）。另外，进行不确定性和敏感性分析。该研究的结果表明，相对于基线期，到二十世纪末，锡金的稻米和小麦的CWR高于西部（分别为8％和39％）和南部（分别为11％和37％）。在玉米方面，锡金西部（− 4％）和东部（− 15％）呈下降趋势。对于东部锡金的所有农作物来说，下降趋势都有可能发生。在大多数情况下，到21世纪末，CIR有所增加。不确定性分析表明，RCP 4.5是研究区域内的可能方案。