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

Ibrahim Mohammed,John Bolten,Venkat Lakshmi,Raghavan Srinivasan

doi:10.3390/rs10060885

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.

Highlights

The complexity of managing water resource, e.g., the Mekong River, stems from the fact that there are many competing interests, such as societal, cultural, economic, and environmental interests, that all need to be synchronized to achieve the goal of prosperity and sustainability [1,2,3,4,5,6]
It is worth mentioning here that our calibration and validation work (Cal/Val) was done for years before the onset of GPM data, the simulated discharge results driven by the GPM precipitation data using the precipitation adjustment parameters obtained by the Cal/Val work were promising and matched the observed discharge values along the Lower Mekong River
The ability of our developed hydrological model to represent the variability of the observed discharge at multiple sites along the Lower Mekong River when driven by satellite-based earth observation data corroborates the role of quality climate forcing as one of the main determinants in hydrologic modeling

Summary

Introduction

The complexity of managing water resource, e.g., the Mekong River, stems from the fact that there are many competing interests, such as societal, cultural, economic, and environmental interests, that all need to be synchronized to achieve the goal of prosperity and sustainability [1,2,3,4,5,6]. This work integrates multiple satellite-based earth observation systems, in-situ station data and spatial data with the Soil & Water Assessment Tool (SWAT) hydrologic model employed in the Mekong River Basin region to improve the Lower Mekong River Basin region’s hydrological decision support system, based on both hydrological flow and total water demand/use. The scarcity and the incompleteness of the data observations from many stations make it imperative to use satellite-based remote sensing data when modeling the hydrological fluxes in the Lower Mekong River Basin (LMRB). This work explores streamflow simulation for the Lower Mekong River by examining the usability of satellite-based remote sensing data products, comparing them to the traditional in-situ station data. Our work aims to assess the value-added information from the simulation of hydrological processes in the LMRB by using SWAT with climatological forcing data from satellite-based earth observations as an alternative to scarce in-situ station data

Objectives

Methods

Results

Conclusion