Aim of this work is the assessment of the individual and combined impacts of land use land cover change (LULCC) and inter-decadal climate variations (CV) on the water and energy cycles over India, given extensive land use land cover change over the last decades. In this study, we quantify the contributions of LULC and CV on changes in the water and energy cycles over the Indian subcontinent through a scenario-based approach, with Community Land Model version 4.5 (CLM4.5) model runs from 1981 to 2010. The approach involves four simulation scenarios: (i) the first scenario considers no LULCC or CV (LULC is fixed and the atmospheric forcings for 1981–1990 are repeated in the decades afterwards); (ii) the second scenario considers only the impact of CV; (iii) the third scenario considers only the effect of LULCC by updating the LULC every 10 years; and (iv) the fourth scenario considers the combined impact of LULCC and CV. LULCC causes an overall decrease in the evapotranspiration (ET) and soil moisture (SM) by 0.3 % and 0.1 % respectively (comparing 1991–2010 with 1981–1990), while the net radiation changes < 1 %. On the other hand, CV caused an increase in the ET, SM and net radiation by + 5.4 %, +1.5 % and + 1.0 % respectively, in spite of decrease of precipitation of 6.6 %. The combined effect of LULCC and CV leads to an increase in the overall ET by 3.8 %. Among the LULC transitions, deforestation and urbanization are found to be the major causes for hydrological changes over the decades, but their impact is much smaller, since CV has a greater impact on the hydrological cycles over India than LULC. The in-depth understanding of the distinct contributions of LULCC and CV on the water and energy cycles in tropical and subtropical regions can be used for framing future water resources planning and management policies.

这项工作的目的是评估土地利用土地覆盖变化 (LULCC) 和年代际气候变化 (CV) 对印度水和能源循环的单独和综合影响，因为过去土地利用土地覆盖发生了广泛的变化几十年。在这项研究中，我们通过基于情景的方法量化了 LULC 和 CV 对印度次大陆水和能源循环变化的贡献，社区土地模型版本 4.5 (CLM4.5) 模型从 1981 年运行到 2010 年。方法涉及四种模拟场景：（i）第一个场景不考虑 LULCC 或 CV（LULC 是固定的，并且 1981-1990 年的大气强迫在之后的几十年中重复）；(ii) 第二种情况只考虑 CV 的影响；(iii) 第三种情况仅考虑 LULCC 的影响，每 10 年更新一次 LULC；(iv) 第四种情景考虑 LULCC 和 CV 的综合影响。LULCC 导致蒸散量 (ET) 和土壤水分 (SM) 分别下降 0.3% 和 0.1%（与 1991-2010 年和 1981-1990 年相比），而净辐射变化 < 1%。另一方面，尽管降水减少了 6.6%，但 CV 导致 ET、SM 和净辐射分别增加了 +5.4%、+1.5% 和 +1.0%。LULCC 和 CV 的综合作用导致整体 ET 增加了 3.8%。在 LULC 转变中，森林砍伐和城市化被认为是几十年来水文变化的主要原因，但它们的影响要小得多，因为 CV 对印度水文循环的影响比 LULC 更大。