Utilization of SPOT 5 data for mapping gold mineralized diorite–tonalite intrusion,Bulghah gold mine area,Saudi Arabia

The present study utilizes the processed SPOT 5 data to discriminate and to generate 1:10,000 geologic image map to delineate the mineralized diorite–tonalite intrusion around Bulghah gold mine area, Saudi Arabia. The rock units exposed in the area include gossan, marble, Hulayfah volcanics, diorite–tonalite, gneissose granite, and alkali granite. Gold mineralization at Bulghah mine is hosted mainly by Syn- to Late-tectonic diorite–tonalite intrusion aligned along N–S direction and is associated mainly with cataclastic zones and quartz veins. Gossans and jasparoidal gossans (Hulayfah group), recorded at the western side of Bulghah mine area as discontinuous small lenses, can be easily discriminated on 4/2 and 4/3 band ratio SPOT images by their white and black image signatures, respectively. Granitoids (gneissose granite and alkali granite) are easily discriminated in 3/2 ratio image, in which gneissose granite has gray image signature, whereas alkali granite has dark gray image signature. On the SPOT false color composite band ratios image (3/2 R, 4/2 G, and 4/3 B), gossan, marble, Hulayfah volcanics, diorite–tonalite, gneissose granite, and alkali granite have sky blue, blood red, bluish light brown, orange, brick red, and deep blue colors, respectively. Fusion of the false color composite SPOT ratios image (3/2 R, 4/2 G, and 4/3 B) with the high spatial resolution SPOT pan image is performed using IHS transformation method. The fused image is used to delineate the mineralized diorite–tonalite intrusion and to produce 1:10,000 geologic image map for Bulghah gold mine area. The present study reveals the usefulness of the processed SPOT 5 data for adding new extensions at the southern and northern boundaries of diorite–tonalite intrusion.     

Investigation of rock quality of Shirinrud dam site by engineering seismology

At this paper, we studied about the rock quality of Shirinrud dam site by engineering seismology. Shirinrud dam site is located 80 km far from Kerman and 18 km far from Hojadk village. The dam and its constructions are established in the Bidu Formation which consists of seven rock units, and the refraction profiles were surveyed on Jb_3/2, Jb₄, and Jb₅ rock units. To evaluate the rock mass quality and basement topography at this site, nine refraction seismic profiles by primary waves and two refraction seismic profiles by secondary waves were surveyed. We used some methods such as Palmer method, the reciprocal method, plus–minus method, etc. to process and interpret data. Based on investigations, primary wave velocity in unit Jb_3/2 varies between 2,100 and 2,200 m/s, in unit Jb₄ is between 2,100 and 4,200 m/s, and in unit Jb₅ is between 2,500 and 3,000 m/s. The Q values on these three units are 0.05, 1.2, and 1.9, and the rock mass rating (RMR) values are 27.1, 40.5, and 33.5, respectively. With respect to wave velocity, Q, and RMR values, the units Jb_3/2, Jb₄, and Jb₅ are evaluated as very weak, intermediate, and weak, respectively.     

Modeling the effects of controlled drainage at a watershed scale using SWATDRAIN

The recently developed SWATDRAIN model was employed to assess the impact of controlled drainage on the water table dynamics, subsurface drainage, and surface runoff in an agricultural watershed in Ontario, Canada. Controlled drainage was defined with a depth of 1.0 m to restrict flow at the drain outlet to maintain the water table at 0.5 m below the surface level during the winter (November–April) and at 0.6 m during the summer (June–August) months. The effects of the absence, or implementation, of drainage water management were predicted for the 3-year period of 1991–1993. Implementing controlled drainage resulted in a 16 % reduction in the mean annual drain flow, while increasing surface runoff by as much as 71 %. This indicates that overall watershed hydrology could be significantly impacted by the implementation of controlled drainage. This research demonstrates the SWATDRAIN model’s ability to predict the controlled drainage in small agricultural watersheds.     

Regionalization of precipitation characteristics in Iran’s Lake Urmia basin

Theoretical and Applied Climatology - Lake Urmia in northwest Iran, once one of the largest hypersaline lakes in the world, has shrunk by almost 90% in area and 80% in volume during the last four...