Water Systems and Global Change, Wageningen University and Research, the Netherlands; Pakistan Agricultural Research Council, Islamabad, Pakistan.
Water Systems and Global Change, Wageningen University and Research, the Netherlands.
Sci Total Environ. 2021 May 10;768:144467. doi: 10.1016/j.scitotenv.2020.144467. Epub 2021 Jan 2.
Climate change is recognized as one of the greatest challenges of 21st century. This study investigated climate and hydrological regimes of the high-altitude Indus basin for the historical period and extreme scenarios of future climate during 21st century. Improved datasets of precipitation and temperature were developed and forced to a fully-distributed physically-based energy-balance Variable Infiltration Capacity (VIC) hydrological model to simulate the water balance at regional and sub-basin scale. Relative to historical baseline, the results revealed highly contrasting signals of climate and hydrological regime changes. Against an increase of 0.6 °C during the last 40 years, the median annual air temperature is projected to increase further between 0.8 and 5.7 °C by the end of 21st century. Similarly, a decline of 11.9% in annual precipitation is recorded, but future projections are highly conflicting and spatially variable. The Karakoram region is anticipated to receive more precipitation, while SW-Hindukush and parts of W-Himalayan region may experience decline in precipitation. The Model for Interdisciplinary Research On Climate version-5 (MIROC5) generally shows increases, while Max Planck Institute Earth System Model at base resolution (MPI-ESM-LR) indicates decreases in precipitation and river inflows under three Representative Concentration Pathways (RCPs) of 2.6, 4.5 and 8.5. Indus-Tarbela inflows are more likely to increase compared to Kabul, Jhelum and Chenab river inflows. Substantial increase in the magnitudes of peak flows and one-month earlier attainment is projected for all river gauges. High flows are anticipated to increase under most scenarios, while low flows may decrease for MPI-ESM-LR in Jhelum, Chenab and Kabul river basins. Hence, hydrological extremes are likely to be intensified. Critical modifications in the strategies and action plans for hydropower generation, construction and operation of storage reservoirs, irrigation withdrawals, flood control and drought management will be required to optimally manage water resources in the basin.
气候变化被公认为 21 世纪最大的挑战之一。本研究调查了 21 世纪未来气候极端情景下的高海拔印度河流域气候和水文状况。本研究开发了改进的降水和温度数据集，并将其应用于完全分布式物理基础能量平衡可变渗透能力（VIC）水文模型，以模拟区域和子流域尺度的水量平衡。相对于历史基线，研究结果显示出气候和水文状况变化的高度对比信号。在过去 40 年中，空气温度平均每年升高 0.6°C，预计到 21 世纪末，年平均气温将进一步升高 0.8°C 至 5.7°C。同样，年降水量减少了 11.9%，但未来的预测存在很大的差异和空间变化。喀喇昆仑地区预计将接收更多的降水，而西南兴都库什和部分西喜马拉雅地区的降水可能会减少。模式比较计划第五阶段气候模型（MIROC5）普遍显示增加，而马克斯·普朗克研究所地球系统模型基础分辨率（MPI-ESM-LR）则表明，在三种代表性浓度路径（RCPs）2.6、4.5 和 8.5 下，降水和河流入流减少。与喀布尔、杰赫勒姆和杰纳布河相比，印度河-塔尔贝拉的入流更有可能增加。所有河流测量站的峰值流量和一个月提前达到的幅度都预计会增加。大多数情景下，高流量预计会增加，而在杰赫勒姆、杰纳布和喀布尔河流域，MPI-ESM-LR 可能会减少低流量。因此，水文极值可能会加剧。需要对水电发电、水库建设和运行、灌溉取水、防洪和抗旱管理策略和行动计划进行重大修改，以优化流域水资源管理。
