The assessment of climate and land-use transformations upon the hydrologic response is crucial for decision-makers to accomplish various adaptation strategies. The Regional Climate Models (RCMs) have been extensively employed to study the impact of climate change on various hydrologic components. However, these climate models are subjected to a large number of uncertainties, which demands a careful selection of an appropriate climate model. To rationalize such uncertainties and select suitable models, a multi-criteria ranking technique has been employed. Ranking of RCMs has been done on its capability to simulate hydrologic components, i.e., simulations of the surface runoff by employing Soil Water Assessment Tool (SWAT), exercising Entropy, and PROMETHEE-2 approach. The spatial extent of changes in the hydrologic components is examined over the Ganga river basin, using the top three ranked RCMs, for a period from January 2021-December 2100. For the monsoon months (June-September), the future annual mean surface runoff will decrease substantially (−50% to −10%), while the flows for post-monsoon months (October-December) are projected to increase (10–20%). Extremes are noted to increase during the non-monsoon months, while a substantial decrease in medium events is also highlighted. Snow-melt is projected to increase during the months of November-March (50% to 400%). Major loss of recharge is expected to occur in the central part of the basin. The investigation presents not only a reliable impact assessment but also the valuation of future alterations in individual hydrological components and will furnish the administrators with substantive information, a prerequisite to formulating ameliorative policies.

根据水文响应评估气候和土地利用的转变对于决策者完成各种适应战略至关重要。区域气候模型（RCM）已被广泛用于研究气候变化对各种水文要素的影响。但是，这些气候模型存在大量不确定性，因此需要仔细选择合适的气候模型。为了合理化此类不确定性并选择合适的模型，已采用了多标准排名技术。RCM的排名已依据其模拟水文要素的能力进行，即通过使用土壤水评估工具（SWAT），行使熵和PROMETHEE-2方法模拟地表径流。使用排名前三位的RCM，对甘加河流域水文要素的空间变化程度进行了研究（从2100年1月1日到2100年12月）。对于季风月份（6月至9月），未来的年平均地表径流量流量将大幅下降（−50％至-10％），而季风后月份（10月至12月）的流量预计将增加（10–20％）。在非季风月份，极端事件有所增加，而中等活动的事件也明显减少。预计在11月至3月的几个月中融雪会增加（50％至400％）。预计补给的主要损失将发生在盆地中部。