Evaluation of gridded precipitation products in the selected sub-basins of Lower Mekong River Basin

Abstract

Hydrological and meteorological studies demand accurate, continuous long-term reliable and uniformly distributed precipitation datasets. A plethora of gridded precipitation products (GPPs) has made their place as an alternate to rain gauge records. However, GPPs house inherent depending on the type of data, data density, gridding algorithm, etc. Hence it is crucial to evaluate them prior to their application. This study evaluated eight GPPs: Asian Precipitation Highly Resolved Observational Data Integration towards Evaluation data (APHRODITE), Climate Prediction Center (CPC), Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS), Southeast Asian Observed dataset (SA-OBS), Climate Prediction Center Morphing Technique (CMORPH), The Tropical Rainfall Measuring Mission (TRMM) -daily products and Climate Research Unit (CRU) and Global Precipitation Climatology Center (GPCC)-monthly products for 17 years (1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)). An entropy-based weight calculation for each statistical indices and compromise programming was employed to rank GPPs in the selected sub-basins basins (Nam Ngum River Basin (NRB) and Vietnam Mekong Delta (VMD)) of Lower Mekong Region (LMR) for mean and six extreme precipitation indices. The correlation coefficient (r), Root Mean Square Error (RMSE), and skilled score (SS) were the statistical indices used in this study. In terms of capturing mean monthly precipitation, GPCC outweighed all other products for both the studied basin. However, APHRODITE ranked first on a daily based product based on compromise programming for NRB. APHRODITE consistently recorded r between 0.85 to 0.95, RMSE in between 50 and 100 mm/month and SS between 0.72 to 0.90 for the 5 observed stations. Similarly, in case of VMD, TRMM ranked first for the daily precipitation products with r in between 0.8 to 0.95, RMSE between 50 to 70 mm/month and SS between 0.56 to 0.9 when evaluated with 11 observed stations. The APHRODITE for NRB and TRMM for VMD could be reliable GPPs for hydrological and meteorological studies.

Harnessing multisatellite remote sensing data and machine learning for flood risk assessment in Nam Ngum River Basin, Lao PDR

“…Nam Ngum River, a major river in Lao PDR, flows from the Xiengkhouang plateau to the Nam Ngum 1 reservoir, through the Vientiane Plain, and joins the Mekong near the capital. The Nam Ngum River Basin, spanning 16,800 km 2 , comprises hilly and mountainous terrain, with elevations ranging from 2,569 meters to 114 meters above sea level 21,22 (Figure 1). It encompasses 19 development districts across six provinces and contributes 4% of the mean annual flow of the Mekong basin.…”

Evaluation of five gridded precipitation products for estimating precipitation and drought over Yobe, Nigeria

“…Ground observations are often regarded as the most reliable and precise source of precipitation data. However, the lack of resources, uneven distribution of ground observations, political instability, and various other causes particularly make it frequently challenging to get accurate precipitation observations, especially in arid and mountainous regions (Tan et al 2021;Dhungana et al 2023). Scientific research from West Africa demonstrates that the limited ground observation networks in the region fail to accurately capture the temporal and geographical climatic features (Ogbu et al 2020).…”