US-CHINA WORKSHOP ON ADVANCED COMPUTATIONAL MODELLING IN HYDROSCIENCE & ENGINEERING September 19-21, Oxford, Mississippi, USA MODELING HYDRODYNAMICS, CHANNEL MORPHOLOGY, AND WATER QUALITY USING CCHE1D
CCHE1D is a one-dimensional model for the simulation of unsteady flows, sediment transport, and water quality in stream networks. The model can be applied to a variety of engineering problems, but it is particularly useful in the determination of channel–watershed system responses to natural and man-made changes in both channels and upland areas. The model can be used in combination with the watershed model AGNPS in the analysis of watershed hydrology and nonpoint source pollution problems caused by erosion or pollutants such as nutrients and pesticides. CCHE1D’s flow module – CCHE1D-FL – computes one-dimensional unsteady flows in dendritic channel networks of arbitrary cross-sectional shapes. The sediment transport module – CCHE1D-ST – simulates the transport of sediment mixtures using a nonequilibrium approach, predicting sediment yields and channel morphological changes. The recently developed water quality module – CCHE1D-WQ – simulates transport and fate of pollutants in streams for continuous, unsteady flow conditions. The model computes advective-dispersive transport of a number of pollutants, simulating the biogeochemical processes of the main nutrient cycles, phytoplankton growth, and the process of eutrophication. GIS-based graphical software complements the modeling system, providing automated methods for watershed delineation, channel network generation, data transfers and conversions, and visualization.
Effects of Stream Tube Numbers on Flow and Sediments using GSTARS-3-A Case Study of the Karkheh Reservoir Dam in Western Dezful
Simulation of the flow and sedimentation process in the reservoir dams can be made by two methods of physical and mathematical modeling. The study area was within a region which ranged from the Jelogir hydrometric station to the Karkheh reservoir dam aimed at investigating the effects of stream tubes on the GSTARS-3 model behavior. The methodologies was to run the model based on 5 stream tubes in order to observe the influence of each scenario on longitudinal profiles, cross-section, flow velocity and bed load sediment size. Results further suggest that the use of two stream tubes or more which result in the semi-two-dimensional model will yield relatively closer results to the observational data than a singular stream tube modeling. Moreover, the results of modeling with three stream tubes shown to yield a relatively close results with the observational data. The overall conclusion of the paper is with applying various stream tubes; it would be possible to yield a significant influence on the modeling behavior Vis-a Vis the bed load sediment size. Keywords—Karkheh, stream tubes, GSTARS-3 Model, Jelogir hydrometric station.
Natural Radioactivity of Intrusive-Metamorphic and Sedimentary Rocks of the Balkan Mountain Range (Serbia, Stara Planina)
Stara Planina (also known as the Balkan mountain range) is known for numerous occurrences and deposits of uranium and associated radionuclides. It is also famous for its geodiversity. The geologic framework is highly complex. The mountain is situated between the latitudes of 43° and 44° N and the longitudes from 22°16′ to 23°00′ E. Uranium exploration and radioactivity testing on Stara Planina began back in 1948. Uranium has also been mined in the zone of Kalna, within the Janja granite intrusive. The naturally radioactive geologic units of Stara Planina are presented in detail in this paper. The main sources of radioactivity on Stara Planina can be classified as: 1. Granitic endogenous—syngenetic–epigenetic deposits and occurrences; 2. Metamorphogenic—syngenetic; and 3. Sedimentary, including occurrences of uranium deposition and fluctuation caused by water in different types of sedimentary rocks formed in a continental setting, which could be classified under epigenetic types. The area of Stara Planina with increased radioactivity (higher than 200 cps), measured by airborne gamma spectrometry, is about 380 square kilometers. The highest values of measured radioactivity and uranium grade were obtained from a sample taken from the Mezdreja uranium mine tailing dump, where 226Ra measures 2600 ± 100 Bq/kg and the uranium grade is from 76.54 to 77.65 ppm U. The highest uranium (and lead) concentration, among all samples, is measured in graphitic schist with high concentrations of organic (graphitic) material from the Inovska Series—99.47 ppm U and 107.69 ppm Pb. Thorium related radioactivity is the highest in granite samples from the Janja granite in the vicinity of the Mezdreja granite mine and the Gabrovnica granite mine tailing dump, and it is the same—250 ± 10 Bq/kg for 232Th, while the thorium grade varies from 30.82 to 60.27 ppm Th. In gray siltstones with a small amount of organic material, the highest radioactivity is related to potassium—2080 ± 90 Bq/kg for 40K.