Assessment of hydrological changes in a river basin as affected by climate change and water management practices, by using the cat model

• Published in: Irrigation and drainage 2016-12, Vol.65 (S2), p.26-35
• Main Authors: Jang, Cheol Hee, Kim, Hyeon Jun, Ahn, So Ra, Kim, Seong Joon
• Format: Article
• Language: English
• Subjects: Adaptation; Annual; Annual runoff; Assessments; CAT; Catchment area; Catchments; changement climatique; Circulation; Climate; Climate change; Climatology; cycle de l'eau; Evapotranspiration; Freshwater; Ground-water flow; Groundwater; Groundwater flow; Groundwater runoff; HadCM3; Hydrologic cycle; Hydrologic models; Hydrological cycle; Hydrology; installations d'amélioration; Mathematical models; MIROC3.2; MIROC3.2 hires; River basins; Rivers; Runoff; Surface runoff; Water; Water circulation; water cycle improvement facilities; Water flow; Water management; Weather
• ISSN: 1531-0353; 1531-0361
• DOI: 10.1002/ird.2044

This study describes the applicability of the Catchment hydrologic cycle Assessment Tool (CAT) for improving the water cycle in a river basin, and suggests appropriate water cycle improvement methods for adapting the impact of future climate change on river basin hydrology. For future assessment, the Gyeongan‐Cheon River Basin located in the north‐eastern part of South Korea was selected. To evaluate future water cycle improvement, the data from two general circulation models (GCMs), MIROC3.2 hires and HadCM3 with A1B and B1 scenarios, were adopted and downscaled by using the Long Ashton Research Station–Weather Generator (LARS‐WG) after bias correction with 30 year (baseline; 1970 ~ 2000) ground measurements. The future annual surface runoff, groundwater flow and evapotranspiration changed up to +49, −45 and +44% in the late twenty‐first‐century of MIROC3.2hires A1B scenario and up to +56, −44 and +47% in the late twenty‐first‐century of HadCM3 A1B scenario. Under the condition of water cycle improvement are included by facilities, the hydrological cycle was enhanced by increasing groundwater flow and evapotranspiration, and decreasing surface runoff. The future annual surface runoff, groundwater flow and evapotranspiration were improved by −38, +13 and +24% in the late twenty‐first century MIROC3.2hires A1B scenario, and by −38, +13 and +25% for the HadCM3 A1B scenario. Copyright © 2016 John Wiley & Sons, Ltd. Résumé Cette étude décrit l'applicabilité de l'outil d'évaluation hydrologique d'un bassin (CAT) pour améliorer le cycle de l'eau dans un bassin versant, et suggère des adaptations du bassin pour limiter l'impact des changements climatiques futurs sur l'hydrologie de la rivière. Pour l'évaluation future, nous avons choisi le bassin de la Gyeongan‐Cheon située dans la partie nord‐est. de la Corée du Sud. Pour évaluer les améliorations possibles, nous avons adopté et dégradé les données provenant de deux modèles de circulation générale (MCG) MIROC3.2 et HadCM3 pour les scénarios d'émissions (SRES) A1B et B1. Les données ont été dégradées en utilisant le générateur stochastique de Research Station–Weather Generator (LARS‐WG) après correction des biais sur 30 années (1970 à 2000) de mesures au sol de trois stations. Les données quotidiennes du futur, de 2021 à 2100, ont été générées pour chaque station météorologique. Le ruissellement de surface annuel, l'écoulement vers les eaux souterraines et l'évapotranspiration varieraient jusqu'à +49, −45 et +44%