Improved Hydrological Decision Support System for the Lower Mekong River Basin Using Satellite-Based Earth Observations

Abstract

Multiple satellite-based earth observations and traditional station data along with the Soil & Water Assessment Tool (SWAT) hydrologic model were employed to enhance the Lower Mekong River Basin region’s hydrological decision support system. A nearest neighbor approximation methodology was introduced to fill the Integrated Multi-satellite Retrieval for the Global Precipitation Measurement mission (IMERG) grid points from 2001 to 2014, together with the Tropical Rainfall Measurement Mission (TRMM) data points for continuous precipitation forcing for our hydrological decision support system. A software tool to access and format satellite-based earth observation systems of precipitation and minimum and maximum air temperatures was developed and is presented. Our results suggest that the model-simulated streamflow utilizing TRMM and IMERG forcing data was able to capture the variability of the observed streamflow patterns in the Lower Mekong better than model-simulated streamflow with in-situ precipitation station data. We also present satellite-based and in-situ precipitation adjustment maps that can serve to correct precipitation data for the Lower Mekong region for use in other applications. The inconsistency, scarcity, poor spatial representation, difficult access and incompleteness of the available in-situ precipitation data for the Mekong region make it imperative to adopt satellite-based earth observations to pursue hydrologic modeling.

A Review of SWAT Studies in Southeast Asia: Applications, Challenges and Future Directions

“…The Mekong River Commission selected SWAT as one of main hydrological models for their decision framework related to water related issues [43,182]. Besides that, they also coupled SWAT with other hydrodynamic models to extend the usefulness and effectiveness of the modelling framework.…”

“…Some of the earliest applications of SWAT in the SEA were for hydrologic analyses of the Mekong River basin [14,39,40]. Analyses of parts or all of the Mekong system with SWAT have continued to the present [41][42][43][44][45] along with increasing numbers of studies that have been performed for specific watersheds located in various SEA countries [46][47][48][49][50][51][52][53]. These SWAT studies have been performed for a wide range of water resource issues, watershed size, and climatic conditions, but there have been no analyses to date of the overall implications of these studies for the SEA region.…”

Preliminary Evaluation of GPM‐IMERG Rainfall Estimates Over Three Distinct Climate Zones With APHRODITE

“…Various real‐time/research applications of MPEs in meteorology and hydrology research stand them as an important segment of meteorological data sets. Various applications of MPEs in water resource management provide important information for freshwater resources management and their mitigation challenges (Mohammed et al, ; Siddique‐E‐Akbor et al, ). MPEs have also been considered as a subset to traditional ground‐based measurements for disaster management applications such as landslides and floods (Kirschbaum et al, ; Wu et al, , ).…”

Evaluation of Satellite-Based Rainfall Estimates in the Lower Mekong River Basin (Southeast Asia)

“…Allowing for continuous and repetitive rainfall measurements, remotely sensed satellite precipitation estimates are, thus, very useful in the LMRB due to its large geographic extent [14]. Utilizing remote sensing products and models is essential for addressing hydrological issues in the Mekong region [15,16]. To effectively utilize satellite-observed precipitation products, their accuracies should be examined over various spatial extents and time periods [14].…”