Abstract Details
250 / 2024-02-28 16:46:33
REGIONAL HYDROLOGICAL METHODS FOR ESTIMATION OF MAXIMUM FLOOD DISCHARGES IN UNGAUGED DRY STREAM BEDS, GOBI REGION, MONGOLIA
rainfall flood; Gobi region, velocity, Mongolia, rainfall intensity
Abstract Accepted
ABSTRACT
More than 60% of Mongolia’s territory is arid and water-scarce areas with no surface water. Hence, groundwater is the main source for developing sectors such as mining and industry as well as other sectors in the Gobi region of the country. However, water resources from different sources need to be utilized, especially surface water that occurs during the region's short periods of heavy rainfall. Therefore, in this region's absence of climatic and hydrological observational data, it is crucial to estimate the maximum rainfall discharge for different return periods. Rainfall patterns, intensity, and geo-topographical conditions are the main factors for the estimation of heavy rainfall runoff. Mean annual rainfall in the study area varies between 94.4 mm and 130.1 mm and 92.5% of the annual rainfall falls during the summer season. Evaporation from water is higher than in other areas reaching 1000 mm. This study aims to estimate the rainfall maximum flood along the small creeks and dry beds in the Gobi region of southern Mongolia, Umnugobi province. The catchment area of the selected creeks and dry beds varies from 0.4 to 95.2 km2 with a length of 17.9 km. Filed surveys were carried out on 35 dry beds and morphological and cross-sectional data were measured. Flow velocity was estimated through Chezy-Manning, Golubetsov's method, and the rainfall intensity empirical methods. The estimated flow velocities were validated with the observed data. The Pearson correlation coefficient was 0.9 and the standard error was defined as
0.06 m/s. It is concluded that Golubetsov’s method is proper for pebbles. The maximum flood discharge with a 100-year return period is estimated by the method of “Rainfall intensity method” adopted for Mongolian conditions and applied for small rivers with a catchment area of less than 200 km2.
Keywords: rainfall flood; Gobi region, velocity, Mongolia, rainfall intensity
More than 60% of Mongolia’s territory is arid and water-scarce areas with no surface water. Hence, groundwater is the main source for developing sectors such as mining and industry as well as other sectors in the Gobi region of the country. However, water resources from different sources need to be utilized, especially surface water that occurs during the region's short periods of heavy rainfall. Therefore, in this region's absence of climatic and hydrological observational data, it is crucial to estimate the maximum rainfall discharge for different return periods. Rainfall patterns, intensity, and geo-topographical conditions are the main factors for the estimation of heavy rainfall runoff. Mean annual rainfall in the study area varies between 94.4 mm and 130.1 mm and 92.5% of the annual rainfall falls during the summer season. Evaporation from water is higher than in other areas reaching 1000 mm. This study aims to estimate the rainfall maximum flood along the small creeks and dry beds in the Gobi region of southern Mongolia, Umnugobi province. The catchment area of the selected creeks and dry beds varies from 0.4 to 95.2 km2 with a length of 17.9 km. Filed surveys were carried out on 35 dry beds and morphological and cross-sectional data were measured. Flow velocity was estimated through Chezy-Manning, Golubetsov's method, and the rainfall intensity empirical methods. The estimated flow velocities were validated with the observed data. The Pearson correlation coefficient was 0.9 and the standard error was defined as
0.06 m/s. It is concluded that Golubetsov’s method is proper for pebbles. The maximum flood discharge with a 100-year return period is estimated by the method of “Rainfall intensity method” adopted for Mongolian conditions and applied for small rivers with a catchment area of less than 200 km2. Keywords: rainfall flood; Gobi region, velocity, Mongolia, rainfall intensity
HIGHLIGHTS
- The observed rainfall intensity reaches 50.6 mm per hour in the Gobi region of Mongolia. It is valuable data to estimate rainfall probability to calculate the flood.
- The improved empirical formula of the V.V.Golubtsov was reasonable to estimate flow velocity without ungagged ephemeral rivers.
- In the Gobi region, “the maximum rainfall intensity” method is proper to use for the maximum rainfall flood.
Important Date
-
Conference Date
Oct 14
2024
toOct 17
2024
-
Sep 30 2024
Draft paper submission deadline
-
Oct 17 2024
Registration deadline
Sponsored By
International Association for Hydro Environment Engineering and Research Asia Pacific Division
Organized By
Changjiang River Scientific Research Institute
Sichuan University
Sichuan University
Contact Information
- Congress Secretariat
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