SULFOARSENIC ORE FORMATION WITH GOLD INTO THE SHEAR ZONE OF EAST TRANSBAIKALIA BRANCH OF THE MONGOL-OKHOTSK SUTURE (POGROMNOE DEPOSIT, EAST TRANSBAIKALIA, RUSSIA)

Pogromnoe deposit of gold-sulfide-quartz formation of stringer-disseminated ore type is formed into shear zone between overthrusts within the block of volcanic-sediment basin along the part of the Mongol-Okhotsk suture. Paragenesises of zonal quartz-albite-mica metasomatic formation correspond to profile of the moderate acid leaching. Near ore metasomatic replacements are dated as 139.5± 1.2 Ma. The absolute age of gold-bearing stockworks formation is 131±1.2 Ma. Ore minerals are arsenopyrite, pyrite, additional sphalerite, chalcopyrite, pyrrohotite, sulfosalts, gersdorffite, rare molybdenite and magnetite. Diffusion coefficient of As was calculated into zonal metacrystals of arsenopyrite and pyrite in ores. The established temperature interval of ore gold sedimentation is based on the physico-chemical modeling with SEJEKTOR software as equal 350–150°C. The ore gold formation was generated by sulfoarsenide hydrothermal solution containing gold as AuAsS2 and H2AuAsS3 complexes for concentration of dissolved S ≥ 0.01 ÷ 0.001 m and As ≥ 0.005 ÷ 0.0005 m respectively.

Multi Criteria Decision Making to Optimize the Best Runoff Control Measure Contributing to Haditha Dam Reservoir

In Iraq, the two dominating surface water sources are Tigris and Euphrates Rivers in which some dams constructed on both of them forming reservoirs. Haditha Dam reservoir is one of the most essential sources of drinking, irrigation, flood control and hydropower generation in Anbar State, Western Part of Iraq. Besides, the reservoir is a unique habitat with a wide spectrum of biodiversity. The objective of this study is to investigate and monitor the water quality in Haditha Dam reservoir and introduce the Multi Criteria Analysis (MCA) to highlight the best runoff control measure depending on selected criteria and criteria weights. Experts were interviewed for the selection of criteria and for the assignment of the weight factor and scores. Four criteria from three categories such as technical, economic and environmental aspects were selected. Results from this study indicated that a distinguished difference in TSS and Turbidity between the dry and wet seasons and necessitates the installation of runoff control measures. It was found that the soil binders, sediment basin and diversion channel are the best alternatives for controlling erosion, sediment and drainage respectively. The sensitivity analysis showed very strong decision made by the experts for the technical, economic and environmental criteria.

Measuring High Levels of Total Suspended Solids and Turbidity Using Small Unoccupied Aerial Systems (sUAS) Multispectral Imagery

Due to land development, high concentrations of suspended sediment are produced from erosion after rain events. Sediment basins are commonly used for the settlement of suspended sediments before discharge. Stormwater regulations may require frequent sampling and monitoring of these basins, both of which are time and labor intensive. Potential remedies are small, unoccupied aerial systems (sUAS). The goal of this study was to demonstrate whether sUAS multispectral imagery could measure high levels of total suspended solids (TSS) and turbidity in a sediment basin. The sediment basin at the Auburn University Erosion and Sediment Control Testing Facility was used to simulate a local 2-year, 24-h storm event with a 30-min flow rate. Water samples were collected at three depths in two locations every 15 min for six hours with corresponding sUAS multispectral imagery. Multispectral pixel values were related to TSS and turbidity in separate models using multiple linear regressions. TSS and turbidity regression models had coefficients of determination (r2) values of 0.926 and 0.851, respectively. When water column measurements were averaged, the r2 values increased to 0.965 and 0.929, respectively. The results indicated that sUAS multispectral imagery is a viable option for monitoring and assessing sediment basins during high-concentration events.

Sediments as Factor in the Fate of the Threatened Endemic Fish Species Romanichthys Valsanicola Dumitrescu, Bănărescu and Stoica, 1957 (Vâlsan River Basin, Danube Basin)

The main emphasis of this paper is on the negative effects of sedimentation on the most highly endangered fish of Europe Romanichthys valsanicola and the habitats of its main trophic resource Rhithrogena semicolorata. Some inexpensive and easy-to-implement solutions are identified and proposed (dam reservoir related recommendations for basin sediments management, forestry related recommendations for sediment basin management, basin sediments general management recommendations, riverbed ecological reconstruction approach proposal, etc.) in the paper with the same conservative purpose for Romanichthys valsanicola species in the actual situation of habitat loss and drastic regress of this globaly-unique fish population.

Large-Scale Performance Testing of Temporary Sediment Basin Treatments and High-Rate Lamella Settlers

Sediment basins are temporary practices commonly used to detain stormwater runoff and capture suspended sediment on construction sites. A 79.0 m3 (2790 ft3) sediment basin testing apparatus at the Auburn University—Erosion and Sediment Control Testing Facility was used to provide a series of controlled and repeatable, large-scale tests to understand the performance of sediment basins and provide improvements. This research evaluated five sediment basin configurations over the course of 27 individual tests, including: (1) a standard configuration, (2) the addition of an excavated sump upstream of a ditch check, (3) the modification of the first baffle, (4) a high-rate lamella settler in upward flow, and (5) a high-rate lamella settler in parallel flow. The primary metric for evaluating performance and the treatment effectiveness of a configuration’s ability in capturing sediment was assessed from turbidity measured across the basin surface. Multiple linear regression analysis indicated that an excavated sump provided insignificant improvement in sediment capture effectiveness. Furthermore, the modification to the first baffle was deemed ineffective in improving treatment efficiency. Lamella settler results indicated a 18.2% and 29.0% reduction in turbidity across the basin for upward and parallel flow configurations, respectively.