Hydrological data, sediment

This chapter has summarised the main hydrological and sediment transport trends observed in the Ebro basin during the twentieth century. Most data concentrates in the lower reach of the catchment and in recent years and, therefore, this area has driven most of the attention of the work. The Ebro flow and sedimentary regimes are profoundly marked by the human action in the entire basin. Changes in land uses and especially dam construction have change the historical pattern of water and sediment yield, and the associated physical processes (i.e. riverchannel sedimentary structure and morphology). 

The first principal component values (Theta 1) for each sample were determined and these values were correlated with the total PCB concentration (Figure 14) recorded for each sample in a separate computer data base that contained other environmental data such as hydrology and sediment texture. The results indicated that certain samples deviated by factors of about two. Upon examining the sample records, the recorded dilution values... 

Under long-term action of hydrodynamic condition (runoff, tide and waves, etc.) and sand sources, seabed sediments of Leizhou Bay have complex material content and different grain size. As a newly developed port site, sedimentary environment of Leizhou Bay has not specifically studied (Han Zhi-yuan, 2012). Based on mass filed sediment and hydrologic data of Leizhou Bay, this article focus on the sediments deposition condition, sediment sources, sediment transport trends etc., and will provide strong support for the utilization and environmental protection of Leizhou Bay. 

Parameters for which measured values are not clearly defined or readily available are often determined through calibration with observed data. In watershed chemical fate modeling, calibration has traditionally been associated with hydrologic parameters (e.g., erodibility coefficients, scour and deposition rates) because the required flow and sediment data are often available. Although initial parameter values can always be estimated, calibration is usually recommended to account for local and spatial variations. 

As we have indicated in the previous sections, there is little information on sediment transport in the River Ebro, and most of it is concentrated in the lower reaches of the catchment, downstream the reservoir complex of Mequinenza-Riba-roja-Flix (Fig. 1). We present here a summary of the results obtained from direct measurements on suspended and bedload obtained by the UdL group during the period 2002-2004 upstream (i.e. SMS) and downstream (i.e. MEMS) the reservoir complex, together with the data collected downstream from the dams during the period 2005-2008 (in the later case referred only to suspended sediment). A hydrological context is provided for each of the sediment transport data sets. 

Caraco, N., and J. Cole. 1999. Regional scale export of C, N, P and sediment What river data tell us about key controlling variables. In Integrating Hydrology, Ecosystem Dynamics, and Biogeochemistry in Complex Landscapes (J. D. Tenhunen and P. Kabat, Eds.). Wiley, New York. 

The study shows the utility of clay studies to karst hydrology. These data show that suspended sediment discharged from a karst aquifer can be derived from erosion of soil tens of kilometers away from the recharge zone of the aquifer. The data also show that other clearly allochthonous material, such as wood and (probably man-made) fibers travel through the aquifer and are discharged at the springs. 

The gradient approach requires a great deal to be known about the landscape of the watershed, airshed, or other division of the area under consideration. Ideally, it is nice to have data on land use, geology, the hydrology, soil types, sediment composition, types of contaminants, the history of disturbance, and other information available when deciding a sampling plan. These data may not be available, and this uncertainty should be reported. 

Hydrological and Hydraulic Sediment Data (3rd Column Right in Figure 8.2.1)... 

Hydrological and structural features of structures for water control should be monitored for parameters such as water levels, water velodties, sedimentation rates, infiltration rates under the structures, stresses and strains and displacements. Data for many of these parameters should be available from the operators of the structure. Warning systems between the operators of the structure and the plant operators should be set up if practicable. 

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