Geological and Hydrological Study

SCOPE OF WORK:

Since the study area located parallel to the shorline, the hydrological invistigation
should cover the effects from the following items:
1. surface runoff from or flash flood (water flow) from the inland.
2. the effects from marine environment.
3. the waterlands (small lagoon) in the coast area.
The main goal of the present study is delineated the drainage network (wadis and
tributaries) which come from the mountain and high land area to predict surface
waterrunoff, and consequently the flash flood hazards zones in the study area. Also,
hazarad of maine (such as erosion) on the study area.
To providing solutions and recommendations to protect the prohect area from any
hazards, caused by flash flood or surface runoff, it should first outline the highandlow risk zones. Consequently, from the hydrological study, it can suggest the suitable
location for future urban extension and development

PROCEDURES OF WORK:

To achieve the objective of the hydrological study, the methodology of work will be as follows:

2.1

SURFACE HYDROLOGY STUDY:

The surface hydrology study includes the following item: • collection and analysis of all avialable data necessary for the study (surveying data, climate, meterology, hydrology, geology, etc.)

2.1.1

Meteorological Study

• Meteorological study of rainfall data and climate ( from the nearest meteorological weather stations to period note less than 30 year) in the region and anaysis of these data by the specialized statical softwear programs such as HYFRAN PLUS OR SMADA.
• Identification the design return period of thte project constructs.
• determination of the rainfall intensity corresponding to return period such
• as 2,5,10,25,50 and 100 year.
• identification the intensity - duration - frequency (IDF) curve of the project site.
• Geological study. SRH Company Profile Page 61 of 74
• conduct giological investigation of the soils to identify the hydrological group and curvve number (CN)

2.1.2

Identifying the drainage basin characteristics

Conduct topographic and geomorphology investigation from topographic maps (1:50000), Digital elevation modeling (DEM) map and satellite maps (Landsat ETM).
• Delinate wadies cross and affect study area.
• Identifying the drainage basin and its characteristic drom topographic maps and digital elevation modeling (DEM) map by watershed modeling system WMS softwear programs.
• Identifying the engineering properties (properties morphometric) morphometric parameters of drainage basin (such as area, shape, length, slope, maon channel length and slope etc..).

2.1.3

Estimating Peak Discharge:

• Estimate the colume and depth of surface runoff.
• Estimate peak discharge (Qp).
• Determination the location which collecting rainfall water.
• Determiination risk flood areas in the project.
• Propose the suitable solutions and methods (alternative methods) for protection of flash flood risk and rainfall (such as conversion valleys, refine valleys, open channel, box culvert, dams, storm water attenuation ponds, leaks, etc.

2.2

Marine and Wetland (lagoon) study:

•The marine study includes investigation of the following effects:
• Investigate current.
• Wave direction.
• Tidal water-level flutuations. • Erosin in the shoreline

SOFTWEAR PROGRAMS WILL BE USED IN THE STUDY:

• WATERSHED MODELING SYSTEM (WMS 9.1).
• HYFRAN PLUS AND SMADA SOFTWEAR PROGRAMS.
• STORM CAD.
• GLOBAL MAPPER (Vr. 16). • GIS Arc Mao 9.3.

CODES ANAD REFERENCE MAY BE / WILL USED IN THE STUDY:

• RIYADH Municipality, Engineering Standards for flood mitigation hazards, flood control structure manual (1432 H).
• RIYADH Municipality, Engineering Standards for flood mitigation hazards, storm drainage network manual (1432 H).
• MOTStandards, particulary the highway design manual:
• Highway Design Manual Vol. 01, Highway Development 1425 H (2004), Ministry of Communication, (at present, Ministry of transport), K.S.A
• Guideline for preparation of hydrology reports: 1407 H (1987), Ministry of Communication, (at present, Ministry of transport) K.S.A
• Richard M. McCuen (2018). Fluid Mechanics for Civil and Environmental Engineers, CRC Press.
• Ayyub, Bilal M.; McCuen, Richard H.(2012). Probability, Statistics, and Reliability for Engineers and Scientists, CRC Press.
• McCuen, R H., 2005 Hydrologic Analysis andDesign, Third Edition, Prentice Hall, Pearson Education Inc. upper saddle river, NJ 07458.
• Ponce, V. M. (1989). Engineering Hydrology Principles and Practice. new jersey, Prentice Hall.
• Bondelid, T., McCuen, R. H. and Jackson, T. (1982). Sensitivity of SCS models to curve number variation - Water Resources Bulletin 12:337 - 349 P.
• Soil Conservation Service SCS(1986). National Engineering Handbook - US Department of Agriculture, Washington DC.
• US . Army Corps of Engineers 2000. Hydrological Modeling System HEC: Technical Refrence Manual, Hydrological Engineering Center.
• USDA National Resources Conservation Services. National Engineering Handbook, Part 630, Hydrology.
• Brown, L.N 1965. Small Earth Dams. University of California, USA.
• AASHTO 1991. Model Drainage Manual. AASHTO Washingtopn DS.