Fitzroy River, Queensland, Australia. II. Identification of Sources of Estuary Bottom Sediments

2006 ◽  
Vol 3 (5) ◽  
pp. 377 ◽  
Author(s):  
G. B. Douglas ◽  
P. W. Ford ◽  
M. Palmer ◽  
R. M. Noble ◽  
R. Packett

Environmental Context. The Fitzroy River Basin constitutes a major source of suspended sediment and nutrient fluxes to the southern Great Barrier Reef. Improved land management practices to ameliorate these catchment loads require an understanding of the sediment sources and dynamics. This multidisciplinary geochemical and modelling study provides for the first time a quantitative estimate of sediment sources delivered to, and their degree of retention in, the Fitzroy River Estuary. Abstract. Sources of sediment deposited in the Fitzroy River Estuary (FRE) have been identified and quantified using an integrated geochemical, modelling and reconnaissance soil sampling approach. A companion paper (this volume) identifies the major sources of sediments in impoundments on the major river systems and sediment sampled from flood events in the Fitzroy River Basin (FRB). Sediment within the FRE may display distinct longitudinal variation with little basaltic material retained. Sediments derived from the Bowen Basin, which occupies the greatest portion of the FRB, and from the Surat Basin display the greatest longitudinal variation. All FRB soils have a similar total phosphorus (P) concentration. Thus, in considering P export from the catchment it is the total sediment flux which is of major importance, rather than the relative proportions of individual catchment soils. This research provides crucial new regional scale information on the sediment sources deposited within the FRE.

2006 ◽  
Vol 3 (5) ◽  
pp. 364 ◽  
Author(s):  
G. B. Douglas ◽  
P. W. Ford ◽  
M. Palmer ◽  
R. M. Noble ◽  
R. Packett

Environmental Context. The Fitzroy River Basin is a major contributor to the loads of suspended sediment and nutrients reaching coastal areas in the southern Great Barrier Reef. Cost-effective investment in improved land, vegetation, and water management to lower these loads requires an understanding of the sources and movement of sediments within the basin. This multidisciplinary geochemical and modelling study provides for the first time a quantitative estimate of sediment sources and spatial and hydrology-related variation within the Fitzroy River Basin. Abstract. An integrated geochemical, modelling, and reconnaissance soil sampling approach has been used to identify the sources of sediment in the Fitzroy River Basin (FRB). The composition of sediment in weirs and dams within the FRB indicate that in the southern and central FRB the Dawson River contributes only a small basaltic component and the inputs are dominated by soils from the Surat and Bowen Basins. Rivers from the central FRB carry variable amounts of basaltic soils. In contrast, basaltic soils constitute the majority of sediment transported during flood events. Surat Basin soils form a minor component of flood events with little contribution from soils of the Bowen Basin despite it constituting the majority of the area of the central FRB. Soils from the Thomson Fold Belt constitute a substantial proportion of the sediment transported by, and retained in, impoundments in the central FRB and also dominate sediment delivered from the western FRB. This study will inform cost-effective investment by government to target remedial actions to reduce sediment and nutrient loads within the FRB that may be ultimately transported via the Fitzroy River Estuary to the southern Great Barrier Reef.


2008 ◽  
Vol 5 (3) ◽  
pp. 231 ◽  
Author(s):  
J. Smith ◽  
G. B. Douglas ◽  
L. C. Radke ◽  
M. Palmer ◽  
B. P. Brooke

Environmental context. The Fitzroy River Basin is a major source of suspended sediment and nutrients to the southern Great Barrier Reef lagoon. A reduction in sediment and nutrient loads is necessary to protect coastal reefs and this requires an understanding of the sediment sources. The present geochemical and modelling study provides a quantitative estimate of the spatial and temporal variations in the sources of sediment deposited in the Fitzroy River coastal zone. Abstract. Sediment sources to the Fitzroy River coastal zone have been identified and quantified using an integrated geochemical and modelling approach. The coastal sediments display little geochemical variation as a result of substantial homogenisation during hydrodynamic processes and indicate a sediment composition consistent with derivation from mixed catchment sources. A lack of substantial temporal geochemical variation in the sediment records indicates weathering regimes and hydrodynamic transport have been relatively consistent throughout the Holocene. Despite this apparent geochemical homogeneity, a modelling approach using a Bayesian statistical model revealed changes in catchment sediment sources over time. Variations in the occurrence and intensity of rainfall events in different parts of the catchment as well as land-use changes following European settlement are likely to have had a substantial effect on the relative contributions of the catchment sources delivered to and deposited in the coastal zone. Additionally, large variations in flow events and variable estuary hydrodynamics result in different catchment soil types being delivered and deposited under different conditions. The present study found that basaltic material is the dominant catchment source in the coastal surface sediments with an estimated enrichment of ~3 relative to catchment and estuary abundances. Basaltic soils present as a more recent and extensive, weathered surficial cover are more readily mobilised than other catchment soils and will be transported further within freshwater flood plumes. It is likely that in large flood events, this basaltic material may reach the coral-dominated outer shelf. Improved land management practices to reduce sediment loads can be targeted to the areas supplying the majority of sediment to the coastal zone.


2015 ◽  
Vol 28 (2) ◽  
pp. 423-450 ◽  
Author(s):  
Andre R. Erler ◽  
W. Richard Peltier ◽  
Marc D’Orgeville

Abstract Accurate identification of the impact of global warming on water resources in major river systems represents a significant challenge to the understanding of climate change on the regional scale. Here, dynamically downscaled climate projections for western Canada are presented, and impacts on hydrological variables in two major river basins, the Fraser and Athabasca, are discussed. These regions are both challenging because of the complexity of the topography and important because of the economic activity occurring within them. To obtain robust projections of future conditions, and to adequately characterize the impact of natural variability, a small initial condition ensemble of independently downscaled climate projections is employed. The Community Earth System Model, version 1 (CESM1), is used to generate the ensemble, which consists of four members. Downscaling is performed using the Weather Research and Forecasting Model, version 3.4.1 (WRF V3.4.1), in a nested configuration with two domains at 30- and 10-km resolution, respectively. The entire ensemble was integrated for a historical validation period and for a mid-twenty-first-century projection period [assuming representative concentration pathway 8.5 (RCP8.5) for the future trajectory of greenhouse gases]. The projections herein are characterized by an increase in winter precipitation for the mid-twenty-first-century period, whereas net precipitation in summer is projected to decrease, due to increased evapotranspiration. In the Fraser River basin, a shift to more liquid precipitation and earlier snowmelt will likely reduce the seasonal variability of runoff, in particular the spring freshet. In the Athabasca River basin, winter precipitation and snowmelt may increase somewhat, but increasing evapotranspiration may lead to reduced streamflow in late summer.


Think India ◽  
2019 ◽  
Vol 22 (2) ◽  
pp. 296-304
Author(s):  
Biplab Tripathy ◽  
Tanmoy Mondal

India is a subcontinent, there huge no of people lived in river basin area. In India there more or less 80% of people directly or indirectly depend on River. Ganga, Brahamputra in North and North East and Mahanadi, Govabori, Krishna, Kaveri, Narmoda, Tapti, Mahi in South are the major river basin in India. There each year due to flood and high tide lots of people are suffered in river basin region in India. These problems destroy the socio economic peace and hope of the people in river basin. There peoples are continuously suffered by lots of difficulties in sort or in long term basis. Few basin regions are always in high alert at the time of monsoon seasons. Sometime due to over migration from basin area, it becomes empty and creates an ultimate loss of resources in India and causes a dis-balance situation in this area.


Earth ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 32-50
Author(s):  
Rocky Talchabhadel ◽  
Jeeban Panthi ◽  
Sanjib Sharma ◽  
Ganesh R. Ghimire ◽  
Rupesh Baniya ◽  
...  

Streamflow and sediment flux variations in a mountain river basin directly affect the downstream biodiversity and ecological processes. Precipitation is expected to be one of the main drivers of these variations in the Himalayas. However, such relations have not been explored for the mountain river basin, Nepal. This paper explores the variation in streamflow and sediment flux from 2006 to 2019 in central Nepal’s Kali Gandaki River basin and correlates them to precipitation indices computed from 77 stations across the basin. Nine precipitation indices and four other ratio-based indices are used for comparison. Percentage contributions of maximum 1-day, consecutive 3-day, 5-day and 7-day precipitation to the annual precipitation provide information on the severity of precipitation extremeness. We found that maximum suspended sediment concentration had a significant positive correlation with the maximum consecutive 3-day precipitation. In contrast, average suspended sediment concentration had significant positive correlations with all ratio-based precipitation indices. The existing sediment erosion trend, driven by the amount, intensity, and frequency of extreme precipitation, demands urgency in sediment source management on the Nepal Himalaya’s mountain slopes. The increment in extreme sediment transports partially resulted from anthropogenic interventions, especially landslides triggered by poorly-constructed roads, and the changing nature of extreme precipitation driven by climate variability.


2021 ◽  
Vol 13 (9) ◽  
pp. 4926
Author(s):  
Nguyen Duc Luong ◽  
Nguyen Hoang Hiep ◽  
Thi Hieu Bui

The increasing serious droughts recently might have significant impacts on socioeconomic development in the Red River basin (RRB). This study applied the variable infiltration capacity (VIC) model to investigate spatio-temporal dynamics of soil moisture in the northeast, northwest, and Red River Delta (RRD) regions of the RRB part belongs to territory of Vietnam. The soil moisture dataset simulated for 10 years (2005–2014) was utilized to establish the soil moisture anomaly percentage index (SMAPI) for assessing intensity of agricultural drought. Soil moisture appeared to co-vary with precipitation, air temperature, evapotranspiration, and various features of land cover, topography, and soil type in three regions of the RRB. SMAPI analysis revealed that more areas in the northeast experienced severe droughts compared to those in other regions, especially in the dry season and transitional months. Meanwhile, the northwest mainly suffered from mild drought and a slightly wet condition during the dry season. Different from that, the RRD mainly had moderately to very wet conditions throughout the year. The areas of both agricultural and forested lands associated with severe drought in the dry season were larger than those in the wet season. Generally, VIC-based soil moisture approach offered a feasible solution for improving soil moisture and agricultural drought monitoring capabilities at the regional scale.


2021 ◽  
Vol 13 (2) ◽  
pp. 312
Author(s):  
Xiongpeng Tang ◽  
Jianyun Zhang ◽  
Guoqing Wang ◽  
Gebdang Biangbalbe Ruben ◽  
Zhenxin Bao ◽  
...  

The demand for accurate long-term precipitation data is increasing, especially in the Lancang-Mekong River Basin (LMRB), where ground-based data are mostly unavailable and inaccessible in a timely manner. Remote sensing and reanalysis quantitative precipitation products provide unprecedented observations to support water-related research, but these products are inevitably subject to errors. In this study, we propose a novel error correction framework that combines products from various institutions. The NASA Modern-Era Retrospective Analysis for Research and Applications (AgMERRA), the Asian Precipitation Highly-Resolved Observational Data Integration Towards Evaluation of Water Resources (APHRODITE), the Climate Hazards group InfraRed Precipitation with Stations (CHIRPS), the Multi-Source Weighted-Ensemble Precipitation Version 1.0 (MSWEP), and the Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Records (PERSIANN) were used. Ground-based precipitation data from 1998 to 2007 were used to select precipitation products for correction, and the remaining 1979–1997 and 2008–2014 observe data were used for validation. The resulting precipitation products MSWEP-QM derived from quantile mapping (QM) and MSWEP-LS derived from linear scaling (LS) are evaluated by statistical indicators and hydrological simulation across the LMRB. Results show that the MSWEP-QM and MSWEP-LS can better capture major annual precipitation centers, have excellent simulation results, and reduce the mean BIAS and mean absolute BIAS at most gauges across the LMRB. The two corrected products presented in this study constitute improved climatological precipitation data sources, both time and space, outperforming the five raw gridded precipitation products. Among the two corrected products, in terms of mean BIAS, MSWEP-LS was slightly better than MSWEP-QM at grid-scale, point scale, and regional scale, and it also had better simulation results at all stations except Strung Treng. During the validation period, the average absolute value BIAS of MSWEP-LS and MSWEP-QM decreased by 3.51% and 3.4%, respectively. Therefore, we recommend that MSWEP-LS be used for water-related scientific research in the LMRB.


2012 ◽  
Vol 9 (1) ◽  
pp. 57-70 ◽  
Author(s):  
L. Lassaletta ◽  
E. Romero ◽  
G. Billen ◽  
J. Garnier ◽  
H. García-Gómez ◽  
...  

Abstract. Despite the particular management practices and climate characteristics of the Mediterranean regions, the literature dealing with N budgets in large catchments subjected to Mediterranean conditions is scarce. The present study aims to deepen our knowledge on the N cycle within the Ebro River Basin (NE Spain) by means of two different approaches: (1) calculating a global N budget in the Ebro River Basin and (2) calculating a series of detailed regional budgets at higher geographical resolution. N inputs and outputs were spatialized by creating a map based on the most detailed information available. Fluvial and atmospheric N export was estimated together with N retention. The Ebro River Basin annually receives a relatively high amount of new N (5118 kg N km−2 yr−1), mostly in the form of synthetic fertilizers (50%). Although it is a highly productive catchment, the net N input as food and feed import is also high (33%). Only 8% of this N is finally exported to the delta zone. Several territorial units characterized by different predominant uses (rainfed agriculture, irrigated agriculture and pastures) have differentiated N dynamics. However, due to the high density of irrigation channels and reservoirs that characterize Mediterranean catchments, N retention is very high in all of them (median value, 91%). These results indicate that problems of eutrophication due to N delivery in the coastal area may not be too severe but that high N retention values may instead lead to problems within the catchment, such as pollution of aquifers and rivers, as well as high atmospheric emissions. The most promising management measures are those devoted to reducing agricultural surpluses through a better balanced N fertilization.


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