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This paper examines the effect of rainfall decline on water resources in each sub-basin (Bozoum: 8100 km2 and Bossangoa: 22,800 km2) and at the outlet of Batangafo (43,650 km2) over the 1951–1995 period, due to a lack of measurements since 1996. Annual, monthly, and daily series of rainfall and discharges were subjected to statistical tests (rainfall and flow indices, SPI, search for ruptures/breaks, depletion coefficient, and potential groundwater discharge) to present and discuss the rainfall variability impact on the water resources of the whole basin. The average rainfall per sub-basin decreases from the west to the east according to the Ouham river direction: 1423 mm at Bozoum, 1439 mm at Bossangoa, and 1393 mm at Batangafo, the main outlet. The SPI approach provides evidence of a moderate to normal drought in the whole basin in the 1980s, mainly compared to the 1970s. Thus, deficient breaks in the rainfall series of the Ouham Basin at Batangafo were noticed in 1967 (Bossangoa and Batangafo) and 1969 (Bozoum). A declining rainfall of −5% on average tended to have the highest impact on the runoff deficit, from about −30 to −43%. The deficit seems more important from west to east, and is also high over the groundwater in each outlet (−33% at Bozoum, −29% at Bossangoa, and −31% at Batangafo) in the 1986–1995 period, despite rainfall recovery in 1991 having generated a flow increase in 1995 at Bossangoa as well as at Batangafo. At the same time, Chari/Logone at Ndjamena recorded critical discharges in both 1987 (313 m3/s) and 1990 (390 m3/s) before they increased, such as on the Ouham. These results demonstrate the decline in water resources in the Ouham River, and their direct impact on the water level of the Chari River and Lake Chad in the targeted period. [ABSTRACT FROM AUTHOR]

Public gardens in urban areas play an important role in the development of physical and mental health of the people. These spaces are also social spaces, where people meet to interact, exchange, and organize collective activities. They create a unique identity for each residential area in the city, which is a premise for green urban development. In Hanoi, public flower gardens (PFGs) were formed and developed from the French colonial period, mainly those in the historic city centre. Facing the forceful urbanization process and the changing of urban structure, in order to evaluate the role of all public flower gardens in the historic city centre area, we carried out a systematic survey from 2019 to 2022. We surveyed all 30 PFGs in five central districts of Hanoi, and interviewed 229 users at these gardens. We also conducted research on relevant documents regarding the management and planning of green space and water infrastructure in the city. Moreover, we implemented an experimental workshop, combining an urban living lab (ULL) approach and an in situ landscape approach, to develop urban landscape design ideas with community participation. Based on the data from this research, this paper analyzes the potential for the establishment of urban blue-green infrastructure (BGI) from these PFGs and aims to evaluate the role of community participation in landscape design for the city. Data from multiple collection methods provide a multi-faceted understanding of the original characteristics of the PFGs in Hanoi and their importance in urban life. The project results supply experimental lessons from urban landscape design activities through community participation, which opens up the potential for developing sustainable urban spaces based on existing natural structures in the city. The main result proves that active community participation until the end of the research project raises public awareness and ensures the social acceptance of the final design. These lessons allow the improvement of urban landscape design practices and the establishment of BGIs from PFGs in an efficient and sustainable manner for green cities in the future. [ABSTRACT FROM AUTHOR]

Sustainable water management in semi‐arid agriculture practices requires quantitative knowledge of water fluxes within the soil‐vegetation‐atmosphere system. Therefore, we used stable‐isotope approaches to evaluate evaporation (Ea), transpiration (Ta), and groundwater recharge (R) at sites in Senegal's Groundnut basin and Ferlo Valley pasture region during the pre‐monsoon, monsoon, and post‐monsoon seasons of 2021. The approaches were based upon (i) the isothermal evaporation model (for quantifying Ea); (ii) water and isotope mass balances (to partition Ea and Ta for groundnut and pasture); and (iii) the piston displacement method (for estimating R). Ea losses derived from the isothermal evaporation model corresponded primarily to Stage II evaporation, and ranged from 0.02 to 0.09 mm d−1 in the Groundnut basin, versus 0.02–0.11 mm d−1 in Ferlo. At the groundnut site, Ea rates ranged from 0.01 to 0.69 mm d−1; Ta was in the range 0.55–2.29 mm d−1; and the Ta/ETa ratio was 74%–90%. At the pasture site, the ranges were 0.02–0.39 mm d−1 for Ea; 0.9–1.69 mm d−1 for Ta; and 62–90% for Ta/ETa. The ETa value derived for the groundnut site via the isotope approach was similar to those from eddy covariance measurements, and also to the results from the previous validated HYDRUS‐1D model. However, the HYDRUS‐1D model gave a lower Ta/ETa ratio (23.2%). The computed groundwater recharge for the groundnut site amounted to less than 2% of the local annual precipitation. Recommendations are made regarding protocols for preventing changes to isotopic compositions of water in samples that are collected in remote arid regions, but must be analysed days later. The article ends with suggestions for studies to follow up on evidence that local aquifers are being recharged via preferential pathways. [ABSTRACT FROM AUTHOR]

Soil hydraulic parameters (SHPs) required as inputs for numerical models are scarce in Sahelian regions. Instead, they are estimated using pedotransfer functions (PTFs), but their ability to simulate soil water dynamics has not been evaluated. This study aims to parameterize SHPs with seven different PTFs and inverse modelling to examine their ability to simulate water fluxes in Senegal's Groundnut basin. We used four years of field measurements of soil water content (SWC) and actual evapotranspiration (ETa) under pearl millet and groundnut crop rotation for model evaluation. Inverse modelling for SWC (root mean square error [RMSE] ≤ 0.015 cm3 cm−3) and ETa (RMSE ≤ 0.62 mm d−1) yielded the best model performance compared to PTFs (0.024–0.175 cm3 cm−3 and 0.68–0.96 mm d−1, respectively). Where field measurements are lacking for inverse estimation, three of the seven tested PTFs yielded good modelling results and could be used as a parsimonious approach for cultivated Sahelian soils. [ABSTRACT FROM AUTHOR]

Theoretical and functional ecology is a source of useful knowledge for ecological engineering. The better understanding of the natural service of water quality regulation is now inspiring for optimization of water resource management, restoration and bioremediation practices. This transfer with a biomimicry approach applies particularly well in the urban, rural and agricultural areas, but is yet underexplored for water quality purposes. This natural service intensely involves the benthic boundary layer as a biogeochemical hot spot with living communities. A selection of processes related to the bioturbation phenomena is explored because of their influence on properties of the aquatic environment. The applications are valuable in a range of fields, from water treatment technology to management of ecosystems such as constructed and natural wetlands, streams, rivers, lagoons and coastal ecosystems. This paper gathers the more obvious cases of potential applications of bioturbation research findings on the biomimicry of natural services to water practices. These include pollution pumping by bioturbated sediment, water column oxygen saving during early diagenesis of deposits under conveyors transport and conservation of macroporous as well as fine sediment. Some applications for constructed devices are also emerging, including infiltration optimization and sewage reduction based on cross-biological community involvement. [ABSTRACT FROM AUTHOR]

Inside sand filters, as inside other microporous substrates, several invertebrates create temporary burrows that impact on water movement through the filter. Lumbricids Eisenia fetida and Eisenia andrei live under a wide range of environmental conditions and have a high reproduction rate so they are good candidates for ecological engineering tests. We assessed the impact of these species at different densities (0, 100, 500, 1000 g m−2) on the hydraulic conductivity of small-sized experimental filters made of columns filled with filter sand classically used for sanitation mixed with 5% organic matter. The hydraulic conductivity was recorded every 7 days over 37 days in non-saturated conditions. On day 23, 40 g of peat bedding was added at the column surfaces to simulate a surface clogging organic matter pulse input. Columns with an earthworm density equal or superior to 500 g m−2 revealed the highest hydraulic conductivities during the first 21 days. At these densities, the hydraulic conductivity was also restored in less than 7 days after the addition of the surface organic matter, showing the influence of the earthworm species on the resilience capacity of the hydraulic conductivity. It was also highlighted that the hydraulic flow was dependent on the lumbricid densities with an optimal density/effect around 500 g m−2 in this specific substrate composition. This study showed that the feeding habits and burrowing activity of both Eisenia species significantly enhanced the hydraulic flow in a sandy substrate, providing a sustainable solution to limit the clogging of the substrate similar to the one used in filters to treat wastewater. [ABSTRACT FROM AUTHOR]

The humid tropics are exposed to an unprecedented modernisation of agriculture involving rapid and mixed land-use changes with contrasted environmental impacts. Afforestation is often mentioned as an unambiguous solution for restoring ecosystem services and enhancing biodiversity. One consequence of afforestation is the alteration of streamflow variability which controls habitats, water resources, and flood risks. We demonstrate that afforestation by tree planting or by natural forest regeneration can induce opposite hydrological changes. An observatory including long-term field measurements of fine-scale land-use mosaics and of hydrometeorological variables has been operating in several headwater catchments in tropical southeast Asia since 2000. The GR2M water balance model, repeatedly calibrated over successive 1-year periods and used in simulation mode with the same year of rainfall input, allowed the hydrological effect of land-use change to be isolated from that of rainfall variability in two of these catchments in Laos and Vietnam. Visual inspection of hydrographs, correlation analyses, and trend detection tests allowed causality between land-use changes and changes in seasonal streamflow to be ascertained. In Laos, the combination of shifting cultivation system (alternation of rice and fallow) and the gradual increase of teak tree plantations replacing fallow led to intricate streamflow patterns: pluri-annual streamflow cycles induced by the shifting system, on top of a gradual streamflow increase over years caused by the spread of the plantations. In Vietnam, the abandonment of continuously cropped areas combined with patches of mix-trees plantations led to the natural re-growth of forest communities followed by a gradual drop in streamflow. Soil infiltrability controlled by surface crusting is the predominant process explaining why two modes of afforestation (natural regeneration vs. planting) led to opposite changes in streamflow regime. Given that commercial tree plantations will continue to expand in the humid tropics, careful consideration is needed before attributing to them positive effects on water and soil conservation. [ABSTRACT FROM AUTHOR]

Organic fertilizer application is often touted as an economical and effective method to increase soil fertility. However, this amendment may increase dissolved organic carbon (DOC) runoff into downstream aquatic ecosystems and may consequently alter aquatic microbial community. We focused on understanding the effects of DOC runoff from soils amended with compost, vermicompost, or biochar on the aquatic microbial community of a tropical reservoir. Runoff collected from a series of rainfall simulations on soils amended with different organic fertilizers was incubated for 16 days in a series of 200 L mesocosms filled with water from a downstream reservoir. We applied 454 high throughput pyrosequencing for bacterial 16S rRNA genes to analyze microbial communities. After 16 days of incubation, the richness and evenness of the microbial communities present decreased in the mesocosms amended with any organic fertilizers, except for the evenness in the mesocosms amended with compost runoff. In contrast, they increased in the reservoir water control and soil-only amended mesocosms. Community structure was mainly affected by pH and DOC concentration. Compared to the autochthonous organic carbon produced during primary production, the addition of allochthonous DOC from these organic amendments seemed to exert a stronger effect on the communities over the period of incubation. While the Proteobacteria and Actinobacteria classes were positively associated with higher DOC concentration, the number of sequences representing key bacterial groups differed between mesocosms particularly between the biochar runoff addition and the compost or vermi-compost runoff additions. The genera of Propionibacterium spp. and Methylobacterium spp. were highly abundant in the compost runoff additions suggesting that they may represent sentinel species of complex organic carbon inputs. Overall, this work further underlines the importance of studying the off-site impacts of organic fertilizers as their impact on downstream aquatic systems is not negligible. [ABSTRACT FROM AUTHOR]

The Congo (Zaire) River, the world's second largest river in terms both of water discharges and of drainage area after the Amazon River, has remained to date in a near-pristine state. For a period between 2 and 6 years, the mainstream near the river mouth (Brazzaville/Kinshasa station) and some of the major and minor tributaries (the Oubangui, Mpoko, and Ngoko-Sangha) were monitored every month for total suspended sediment (TSS), particulate organic carbon (POC), and dissolved organic carbon (DOC). In this large but relatively flat equatorial basin, TSS levels are very low and organic carbon is essentially exported as DOC: from 74% of TOC for the tributaries flowing in savannah regions and 86% for those flowing in the rain forest. The seasonal patterns of TSS, POC, and DOC show clockwise hysteresis in relation to river discharges, with maximum levels recorded 2 to 4 months before peak flows. At the Kinshasa/Brazzaville station, the DOC distribution is largely influenced by the input from the tributaries draining the large marshy forest area located in the center of the basin. There is a marked difference between specific fluxes, threefold higher in the forest basins than in the savannah basins. The computation of inputs to the Atlantic Ocean demonstrates that the Congo is responsible for 14.4 × 106 t/yr of TOC of which 12.4 × 6 t/r is DOC and 2 × 106 t/yr is POC. The three biggest tropical rivers (the Amazon, the Congo, and the Orinoco), with only 10% of the exoreic world area drained to world oceans, contribute ∼4% of its TSS inputs but 15-18% of its organic carbon inputs. These proportions may double when considering only world rivers discharging into the open ocean. [ABSTRACT FROM AUTHOR]

The ecological effects of intermittent water supplement in Lake Baiyangdian were analyzed with an NDVI time series based on the data from 1 April 1998 to 31 July 2008. Four NDVI categories were extracted, and twelve stages were grouped based on the specific replenishment time of water allocation. STR (a seasonal-trend decomposition procedure based on regression) and its corresponding linear regression and abrupt change detection were used to highlight the temporal variations in vegetation under the effects of water allocation. ANOVA was used to identify the response quality of the vegetation in each stage. The results showed that the significant increasing trend of each NDVI category was detected by linear regression (p < 0.001). The 95% abrupt change intervals showed uncertainty and complexity in the immediate vegetation response to water division times. The most abrupt changes were detected in the growing seasons. The extremely significant differences in NDVI variation before and after water allocations were detected by ANOVA (p < 0.001, t-test). The longer the duration of water allocation was maintained, the higher the detection of vegetation coverage was relatively. The increased vegetation coverage benefited from the constant water supply. Our results provide evidence of vegetation responses to intermittent water divisions. The positive effects of water allocation on regional ecological restoration were confirmed. This study strengthened the water division effects of regional vegetation restoration and provided a practical strategy for an effective implementation of water allocation. [ABSTRACT FROM AUTHOR]

The industrial symbiosis (IS) landscape is evolving rapidly. While previous studies have argued for the importance of municipalities participating in the governing of IS, research on the implications of different forms of municipal organization is still lacking. This paper aims to investigate how municipal administration and municipally-owned corporations, as two forms of organization, impact the governing of IS in the water and sewage sector. This is explored in relation to the Swedish municipality Simrishamn, which recently underwent changes in the form of organization. Results show that municipal administration contributes to a more inclusive process where many actors can influence and bring ideas and perspectives on how to develop an IS. The risk, however, is that other issues within the municipality are seen as more pressing and, therefore, get prioritized before IS. In corporate form, the development of IS becomes more business-like as the focus is kept on core business. Technology development is strengthened as skills and competencies are promoted through the expertise of the employees. Drawbacks include processes becoming less transparent and political goals, such as citizen welfare not receiving the same level of priority as within municipal administration. There is also a risk that fewer perspectives are included in the process of developing IS, which may inhibit innovation, even if the results also indicate that an increased business focus of the corporate form strengthens the innovation capacity. [ABSTRACT FROM AUTHOR]

For three decades, the solid and dissolved fluxes of the Congo River have been regularly monitored on a monthly basis, despite 12 years of deficiencies (1994–2005). Two programs successively carried out these follow-ups: PEGI/GBF (1987–1993) and SO HYBAM (2006–2017), upstream and downstream, respectively, of the Malebo Pool near Brazzaville, the main hydrometric station of the Congo River. The objective of this study is to examine the temporal dynamic of TSS, TDS and DOC, to explore how these descriptors change over time. Comparison with the two time programs will shed more light on how these descriptors are related to discharge. Afterward, we then find a relationship between total TSS in the water column and that measured in surface for eventual estimation of TSS by remote sensing. In the last decade, compared to the PEGI/GBF period, the discharge of the Congo River was mainly marked by a 4% increase, leading to a significant change on TDS and DOC behaviors. The TSS was quite stable (from 8.2 and 9.3 t km−2 yr−1) due to the low physical erosion well known in this region. The TDS concentrations decreased slightly, by a simple dilution effect. However, the mineral dissolved fluxes (from 11.6 and 10.1 t km-2 yr-1) due to the chemical weathering and atmospheric inputs still predominate over the solid fluxes. Therefore, there was no radical change in the monthly geochemical regime of Congo River Basin (CRB) during these last 30 years. Contrariwise, the DOC concentration marking the biogeochemical processes significantly increased, from 9.0+/−3.0 mg L−1 to 12.7+/−5.0 mg L−1, due to more flooding events in the central part of the CRB. The change for the DOC fluxes is more relevant, with an increase of 45% between the two studied periods, from 11.1 × 106 to 16.2 × 106 t yr−1. This highlights the continuous and actual importance of the "Cuvette Centrale" in the heart of the CRB for dissolved organic matter transport by the Congo River. [ABSTRACT FROM AUTHOR]

Although the Congo Basin is still one of the least studied river basins in the world, this paper attempts to provide a multidisciplinary but non-exhaustive synthesis on the general hydrology of the Congo River by highlighting some points of interest and some particular results obtained over a century of surveys and scientific studies. The Congo River is especially marked by its hydrological regularity only interrupted by the wet decade of 1960, which is its major anomaly over nearly 120 years of daily observations. Its interannual flow is 40,500 m3 s−1. This great flow regularity should not hide important spatial variations. As an example, we can cite the Ubangi basin, which is the most northern and the most affected by a reduction in flow, which has been a cause for concern since 1970 and constitutes a serious hindrance for river navigation. With regard to material fluxes, nearly 88 × 106 tonnes of material are exported annually from the Congo Basin to the Atlantic Ocean, composed of 33.6 × 106 tonnes of TSS, 38.1 × 106 tonnes of TDS and 16.2 × 106 tonnes of DOC. In this ancient flat basin, the absence of mountains chains and the extent of its coverage by dense rainforest explains that chemical weathering (10.6 t km−2 year−1 of TDS) slightly predominates physical erosion (9.3 t km−2 year−1 of TSS), followed by organic production (4.5 t km−2 year−1 of DOC). As the interannual mean discharges are similar, it can be assumed that these interannual averages of material fluxes, calculated over the longest period (2006–2017) of monthly monitoring of its sedimentology and bio-physical-chemistry, are therefore representative of the flow record available since 1902 (with the exception of the wet decade of 1960). Spatial heterogeneity within the Congo Basin has made it possible to establish an original hydrological classification of right bank tributaries, which takes into account vegetation cover and lithology to explain their hydrological regimes. Those of the Batéké plateau present a hydroclimatic paradox with hydrological regimes that are among the most stable on the planet, but also with some of the most pristine waters as a result of the intense drainage of an immense sandy-sandstone aquifer. This aquifer contributes to the regularity of the Congo River flows, as does the buffer role of the mysterious "Cuvette Centrale". As the study of this last one sector can only be done indirectly, this paper presents its first hydrological regime calculated by inter-gauging station water balance. Without neglecting the indispensable in situ work, the contributions of remote sensing and numerical modelling should be increasingly used to try to circumvent the dramatic lack of field data that persists in this basin. [ABSTRACT FROM AUTHOR]

The Paris Climate Agreements and Sustainable Development Goals, signed by 197 countries, present agendas and address key issues for implementing multi-scale responses for sustainable development under climate change—an effort that must involve local, regional, national, and supra-national stakeholders. In that regard, Continental Carbon Sequestration (CoCS) and conservation of carbon sinks are recognized increasingly as having potentially important roles in mitigating climate change and adapting to it. Making that potential a reality will require indicators of success for various stakeholders from multidisciplinary backgrounds, plus promotion of long-term implementation of strategic action towards civil society (e.g., law and policy makers, economists, and farmers). To help meet those challenges, this discussion paper summarizes the state of the art and uncertainties regarding CoCS, taking an interdisciplinary, holistic approach toward understanding these complex issues. The first part of the paper discusses the carbon cycle's bio-geophysical processes, while the second introduces the plurality of geographical scales to be addressed when dealing with landscape management for CoCS. The third part addresses systemic viability, vulnerability, and resilience in CoCS practices, before concluding with the need to develop inter-disciplinarity in sustainable science, participative research, and the societal implications of sustainable CoCS actions. [ABSTRACT FROM AUTHOR]

The Red River basin is a typical Asian river system affected by climate and anthropogenic changes. The purpose of this study is to build a tool to separate the effect of climate variability and anthropogenic influences on hydrology and suspended sediments. A modeling method combining in situ and climatic satellite data was used to analyze the discharge (Q) and suspended sediment concentration (SSC) at a daily time scale from 2000 to 2014. Scenarios of natural and actual conditions were implemented to quantify the impacts of climate variability and dams. The modeling gained satisfactory simulation results of water regime and SSC compared to the observations. Under natural conditions, the Q and SSC show decreasing tendencies, and climate variability is the main influence factor reducing the Q. Under actual conditions, SSC is mainly reduced by dams. At the outlet, annual mean Q got reduced by 13% (9% by climate and 4% by dams), and annual mean SSC got reduced to 89% (13% due to climate and 76% due to dams) of that under natural conditions. The climate tendencies are mainly explained by a decrease of 9% on precipitation and 5% on evapotranspiration, which results in a 13% decrease of available water for the whole basin. [ABSTRACT FROM AUTHOR]

This work focuses on a new approach to quantify the effects of above-ground earthworm''s activity on soil erosion in steep slope ecosystems such as in Northern Vietnam. In these areas and in many others in the world, soil erosion becomes a major issue while the factors that determine it are still misunderstood. Earthworm''s activity is believed to influence soil erosion rate, but we are still unable to precisely quantify their contribution to soil erosion. In this study, we used Near Infrared Reflectance Spectroscopy (NIRS) to quantify the proportion of soil aggregate in eroded soil coming from earthworm activity. This was done by generating NIRS signatures corresponding to different soil surface aggregates (above-ground soil casts produced by earthworms vs. surrounding topsoil). In order to test the proposed approach, we compared the NIRS-signature of eroded soil sediments to those of earthworms'' casts and of the surrounding soils. Our results strongly supported that NIRS spectra might be used as “fingerprints” to identify the origin of soil aggregates. Although earthworms are generally assumed to play a favorable role in promoting soil fertility and ecosystem services, this method shows that cast aggregates constitute about 36 and 77% of sediments in two tropical plantations, Paspalum atratum and Panicum maximum plantations, respectively. In light with these results, we estimated that earthworms led to an annual loss of 3.3 and 15.8kg of carbon ha−1 yr−1, respectively in P. atratum and P. maximum agroecosystems. [Copyright &y& Elsevier]

Abstract: This manuscript focuses on the effects of above-ground earthworm casts on water runoff and soil erosion in steep-slope ecosystems in Northern Vietnam. We investigated the effects of Amynthas khami, an anecic species producing above-ground casts of prominent size, on water infiltration and soil detachment along a land-use intensification gradient: a cultivation of cassava (Mahinot esculenta; CAS), a plantation of Bracharia (Bracharia ruzziziensis; BRA), a fallow (FAL), a fallow after a forest of Eucalyptus sp. (EUC) and a plantation of trees (Acacia mangium and Venicia Montana; FOR). Two scales of studies were considered: (i) at the structure scale (cm2), a water runoff simulation was used to differentiate the effects of casts, free biogenic aggregates that previously belong to casts, and free physicogenic aggregates; (ii) at the station levels, 1-m2 plots were used to determine runoff and soil detachment rates during the rainy season in 2005. A. khami was sensitive to land-use management. Earthworm density was low in all the fields (0–1 ind m−2). The highest densities were found in EUC and FOR and no individual was found in CAS. As a consequence, soil surface in EUC and FOR was covered with casts and free biogenic aggregates (approximately 22 and 8 kg m−2, respectively). In FAL and BRA, casts covered the soil only sparsely with <3 kg m−2. In CAS, soil surface was characterized by free physicogenic aggregates that might be produced by human activity or endogeic earthworms through tillage (approximately 1 kg m−2). Water runoff simulation clearly showed an enhancement of water infiltration with earthworm casting activity. Water runoff was more decreased with casts (R 2 =0.26) than free biogenic aggregates (R 2 =0.49). Conversely, physicogenic aggregates were not associated with higher water infiltration. Analyses of runoff and soil detachment rates during the rainy season underlined that the more land-use type have aggregates on soil surface and the less important is surface runoff (R 2 =0.922). Conversely, no relation occurred between aggregates and soil detachment rate. While above-ground casting activity decreased surface runoff, they were not involved in soil detachment, and therefore soil erosion. [Copyright &y& Elsevier]

• Suspended sediment flux (SF) was estimated at basin scale considering new damming. • The annual mean SF at the outlet of the basin got reduced by 90%. • Dams showed larger impacts on SF than climate variability. • High soil erosion happened in the middle parts of the basin. • Simple rating curves between discharge and SF were proposed. The Red River is an Asian river system strongly affected by global changes. This paper aims to characterize and quantify the suspended sediment flux (SF) over the basin under the influences of short-term climate variability and dam constructions. SF was evaluated at the outlets of main tributaries and along the main course of the Red River from 2000 to 2013 based on daily simulations from a modelling study. A reference scenario (without dams) was carried out to disentangle the impacts of short-term climate variability and damming by comparing to actual conditions. Without dams (reference scenario), the basin would generate 106.9 Mt yr−1 of SF to the downstream delta from 2000 to 2013, with a specific sediment yield (SSY) of 778.8 t km−2 yr−1. However, under the impacts of short-term climate variability and dams, the mean annual SSY decreased to 84.5 t km−2 yr−1. At the outlet of the basin, the annual mean SF of 2008–2013 (after new dam constructions) got reduced by 90% (10% related to short-term climate or atmospheric variability and 80% to dam constructions) compared to the reference scenario (without dams) during 2000–2007. The Thao tributary is the most sensitive to short-term climate variability while the Da tributary is mostly affected by the huge-capacity dams. Mean annual retentions of sediment by dams ranged from 7.1 to 111.0 Mt yr−1. Simple rating curves between monthly mean discharge (Q) and SF were established for estimating SF at the outlet of the tributaries and the Red River. High soil erosion (above 2000 t km−2 yr−1) occurred in the middle Thao and the lower Da tributaries. Precipitation, slope and agriculture practices are the key influence factors for soil erosion in the basin. [ABSTRACT FROM AUTHOR]