Variability in runoff and responses to land and oceanic parameters in the source region of the Indus River

• Published in: Ecological Indicators
• Main Authors: Azfar Hussain, Jianhua Cao, Shaukat Ali, Waheed Ullah, Sher Muhammad, Ishtiaq Hussain, Abolfazl Rezaei, Kalpana Hamal, Mobeen Akhtar, Haider Abbas, Xiuqin Wu, Jinxing Zhou
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2022
• Subjects: Hydro-climate variables; Nonparametric test; Wavelet analysis; Regional environmental factors; Global teleconnections; Source Region of the Indus River; Ecology; QH540-549.5; Arctic; Pacific; Indian; North Atlantic; North Atlantic oscillation
• Online Access: https://doi.org/10.1016/j.ecolind.2022.109014; https://doaj.org/article/92970f0fef18410abdacbbb4c13a72da

Understanding the coherent variability of runoff in the Source Region of the Indus River (SRIR) with the regional environmental parameters (precipitation, temperature, potential evapotranspiration-PET, NDVI, NDSI), and global oceanic indices (El Niño Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), North Atlantic Oscillation (NAO), Arctic Oscillation (AO), Indian Ocean Dipole (IOD) and Indian Summer Monsoon Index (ISMI) is of paramount importance. This study has attempted to show the relationship of the SRIR runoff with the regional meteorological and global oceanic indices. The monotonic Mann-Kendal, Sen Slope, and wavelet analysis were employed to assess the trends and periodicity in the hydro-meteorological variables. Monthly runoff from all sub-basins shows increasing trends from October to March and decreases from April to September, except for western tributaries. Most sub-basins in the SRIR are experiencing significant increases in winter while decreases in summer. The annual runoff trend suggests an increase after 2000 from the Kabul River Basin (KRB). However, contrasting results are evident in the Upper Indus Basin (UIB). The Jhelum River Basin (JRB) has shown a significant declining trend since the mid-1990s. Annual runoff (3.19 m3/s), precipitation (0.24 mm/year), temperature (0.011 °C/year), and NDVI (0.002) increased in the SRIR, whereas PET (−0.020 mm/year) and NDSI (−0.003) declined during 1970–2016. In general, built-up grassland, snow/ice, water bodies, and wetlands increased, while barren land, cropland, and forest/shrubland declined between 2001 and 2018. Overall, all the factors displayed a positive correlation with runoff. Generally, runoff has a stronger association with regional environmental factors than global, as evident in correlation and wavelet analysis, which implies that local factors had a more significant effect on runoff. However, NAO, AO, and ISMI shared a significant correlation other than the regional environmental factors concerning the oceanic indices. The ...