2 Beighley, E., Tshimanga, R., & Moukandi N’kaya, G. (2019). Establishing science campaigns in sub‐Saharan Africa. Eos, 100. https://doi.org/10.1029/2019EO117249
Photo: Attendees of the AGU Chapman Conference on the “Hydrologic Research in the Congo Basin” held in Washington, D.C., September 2018 [Beighley et al., 2019].
Credit: Beth Bagley/AGU.
1 Congo Basin Research: Building a Foundation for the Future
Raphael M. Tshimanga1, Guy D. Moukandi N’kaya2, Alain Laraque3, Sharon E. Nicholson4, Jean‐Marie Kileshye Onema5, Raymond Lumbuenamo6, and Douglas Alsdorf7
1 Congo Basin Water Resources Research Center (CRREBaC), Department of Natural Resources Management, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
2 Mechanical, Energy, and Engineering Laboratory, National School of Polytechnic Studies, Marien Ngouabi University, Brazzaville, Republic of the Congo
3 Joint Research Unit “Geosciences Environment Toulouse” (UMR GET), CNRS, IRD, UT3, CNAP, CNES, Midi-Pyrénées Observatory, Toulouse, France
4 Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, Florida, USA
5 WaterNet, Harare, Zimbabwe; and Faculty of Engineering, University of Lubumbashi, Lubumbashi, Democratic Republic of the Congo
6 Environment and Natural Resources, The World Bank, Kinshasa, Democratic Republic of the Congo
7 Byrd Polar and Climate Research Center; and School of Earth Sciences, Ohio State University, Columbus, Ohio, USA
ABSTRACT
The Congo is the second‐largest river basin in the world. Its water, climate, and river passages are crucial for the millions of people living in this central region of sub‐Saharan Africa. Despite its importance, the Congo Basin has not been well represented in hydrologic research over recent decades, particularly in comparison to the Amazon Basin. Thus, the Congo and the surrounding basins represent an excellent opportunity for scientific discovery. This chapter is an introduction to a bilingual monograph with an international assemblage of authors that helps to overcome limitations by presenting insights into the hydrology, climate, and biogeochemistry of the region. First‐order scientific questions remain to be fully answered and such answers are well needed to guide resource management.
1.1. INTRODUCTION
Bienvenue au Congo! The mighty Congo River and the vast Congo Basin that feeds it have attracted the attention of travelers, writers, and scientists for centuries. Henry Morton Stanley (1885) likely published the first water‐related findings in the Congo Basin. He and his team found the plunge pools on the mainstem Congo below Kinshasa with “a strong under‐current of water flowing up stream” and estimated its discharge at 40,700 m3/s.
During the first half of the twentieth century, hundreds of monitoring stations were established and maintained on the river, providing streamflow and rainfall measurements (Figure 1.1). There were also research institutes that coalesced these measurements into collections, notably the four‐volume Atlas Climatique du Bassin Congolais by Franz Bultot (e.g., Bultot, 1971). From this research effort, we now have a time capsule stretching back a century upon which to build today’s understanding of changing climate. These historic archives are unique among the world’s tropical watersheds. Likewise, the Congo itself stands alone, belying easy characterizations. For example, the vast majority of the basin is above 300 m elevation, which is much higher than the world’s other major rivers such as the Amazon or Mississippi. How does this simple difference in elevation factor into the Congo’s atmospheric and fluvial processes? What governs the meteorology and hydrology of the Congo? Our monograph brings these basic questions and many others to the fore. Despite the opportunity to address such key science questions, over the past half century scientific knowledge about the Congo has been overshadowed by its cousin, the Amazon. In 1973, Marlier noted that “we know less about the physical characteristics of the Amazon” than the Congo Basin, but this was soon reversed. Amazon research has grown considerably since then, both within its basin and internationally, while the Congo Basin has experienced relatively little interest from outside scientists.
Figure 1.1 Map of the Congo Basin. See Alsdorf et al. (2016) for details. Created by Brian Alsdorf for the AGU Chapman Conference on “Hydrologic Research in the Congo Basin” (Beighley et al., 2019).
Alsdorf et al. (2016) compared the number of published papers related to hydrology in the Congo with those of the Amazon and found about ten times fewer Congo papers. This comparison is appropriate because both basins lie under tropical rain belts, constitute the two largest river water flows in the world, and have an abundance of tropical forests and wetlands. Note that the comparison by Alsdorf et al. was not intended to be a comprehensive review of all hydrological literature (indeed, their focus is on English‐language journals available internationally) but rather illustrated the relative comparison between the two basins in the peer‐reviewed English language scientific literature of an international audience.
Although our contemporary understanding of the Congo Basin and its hydrology is an order of magnitude smaller than that of the Amazon, important advances have been made regarding Congo research, but these have been limited by language and economic barriers. This monograph aims to address some of these issues by presenting new science on the Congo Basin, with chapters written by experts from and in the region, and presented in both English and French to enable greater access and discoverability.
This monograph is a foundation for new scientific discoveries. A key for making a new discovery is to study a location that has not been well explored and hence not well documented (e.g., Oliver, 1991). The 27 chapters in this monograph document new in‐situ and remotely sensed measurements, describe recent model results, and provide insights toward exploring the Congo and surrounding sub‐Saharan basins (Photo 1.1). Another key for making a new discovery is to rework historic data using new methods and to combine it with contemporary measurements (e.g., Oliver, 1991). Historically, there were more than 400 stream gauges and rainfall stations operating throughout the Congo Basin at various times during the first half of the 1900s. Some of the data from these gauges are available via the Global Runoff Data Center (GRDC, 2021) but much of it is available thanks to collaborations with those who contributed to this book. Adding to these in‐situ measurements, satellites from the past two decades have provided measurements of rainfall, changes in total storage, water surface elevation, flooded areas throughout the entire basin, and land‐use land‐cover change. And in the past year, new streamflow and sediment flux measurements have been recorded by chapter authors (Photo 1.2). Therefore, a foundation of hydrologic research and measurements upon which to build opportunities for scientific discovery exist in the Congo Basin.