A Review of Earth Observation-Based Analyses for Major River Basins

Abstract

Regardless of political boundaries, river basins are a functional unit of the Earth’s land surface and provide an abundance of resources for the environment and humans. They supply livelihoods supported by the typical characteristics of large river basins, such as the provision of freshwater, irrigation water, and transport opportunities. At the same time, they are impacted i.e., by human-induced environmental changes, boundary conflicts, and upstream–downstream inequalities. In the framework of water resource management, monitoring of river basins is therefore of high importance, in particular for researchers, stake-holders and decision-makers. However, land surface and surface water properties of many major river basins remain largely unmonitored at basin scale. Several inventories exist, yet consistent spatial databases describing the status of major river basins at global scale are lacking. Here, Earth observation (EO) is a potential source of spatial information providing large-scale data on the status of land surface properties. This review provides a comprehensive overview of existing research articles analyzing major river basins primarily using EO. Furthermore, this review proposes to exploit EO data together with relevant open global-scale geodata to establish a database and to enable consistent spatial analyses and evaluate past and current states of major river basins.

Modeling River Discharge Using Automated River Width Measurements Derived from Sentinel-1 Time Series

“…The majority of today's global population lives in close proximity to a river, as they are a crucial resource for fresh water, agriculture, or industrial development, as well as being the source of religious and cultural values [1][2][3][4]. Although the majority of people are directly or indirectly affected by rivers, most river basins are poorly monitored or lack any hydrological information [5].…”

A Framework for Multivariate Analysis of Land Surface Dynamics and Driving Variables—A Case Study for Indo-Gangetic River Basins

“…Our framework is demonstrated using the Indus-Ganges-Brahmaputra-Meghna river basins (IGBMRB) in South Asia as a case study (Figure 1). These river basins stretch over Pakistan, India, China, Nepal, Bhutan, and Bangladesh covering an area of approximately 2.9 million km 2 [51]. The northern regions of the river basins are marked by the Himalaya mountains being dominated by cold and polar climate in high elevation.…”

Multi-faceted analyses of seasonal trends and drivers of land surface variables in Indo-Gangetic river basins

“…To enhance the understanding of land surface dynamics and the influence of climatic, hydrological, and anthropogenic factors in the Indo-Gangetic river basins, the joint analysis of multivariate time series covering multiple spheres of the Earth system is required. In this connection, satellite-based Earth observation (EO) provides essential information on several land surface variables over large areas, including characteristics on vegetation, surface water, snow cover, as well as land cover and land use (Mahecha et al, 2020;Uereyen and Kuenzer, 2019;Woodcock et al, 2020). For example, satellite imagery of the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors provide consistent data in terms of a spatio-temporal coverage since the year 2000.…”