Hydrologic Models

Abstract: Protecting and improving water resources play an important role for meeting the future demand for drinking water and preventing flood events. Increasing population tends to cause a shift from rural to urban areas, which results in the alteration of concentration time, water quantity, and flow rate. Because of these changes, specific solutions need to be investigated to prevent flood and overflow. For this purpose, calibrated hydrodynamic models should be developed to understand the hydrodynamic behavior of the catchment. Sazlıdere Watershed,
which provides an average of 55 millionm3 of water per year, is one of the most important watersheds of Istanbul, Turkey. There is a tremendous population increase in the area, and moderate flood events are frequently observed. Therefore, in this study,
a calibrated hydrodynamic model for Sazlıdere Watershed was developed by using the Environmental Protection Agency Storm Water Management Model (EPA SWMM). The model is calibrated by using the rainfall and flow data obtained from the stations we set in the area. The most sensitive parameters of the hydrodynamic model are determined to be Manning’s roughness coefficient for both channels and subcatchments followed by the infiltration parameters, i.e., hydraulic conductivity and the initial soil-moisture condition. The flow developed on the watershed was simulated both under typical rainfall events and under extreme cases, namely, high urbanization and storm events with a high return period. It is observed that even under typical storms, floods developed on the watershed; and finally, several flood
control options are suggested.

ABSTRACT: A newly developed heuristic algorithm, Harmony Search, is applied to the parameter estimation problem of the nonlinear Muskingum model. Harmony Search found better values of parameters in the nonlinear Muskingum model than five other methods including another heuristic method, genetic algorithm, in terms of SSQ (the sum of the square of the deviations between the observed and routed outflows), SAD (the sum of the absolute value of the deviations between the observed and routed outflows), DPO (deviations of peak of routed and actual flows), and DPOT (deviations of peak time of routed and actual outflow). Harmony Search also has the advantage that it does not require the process of assuming the initial values of design parameters. The sensitivity analysis of Harmony Memory Considering Rate showed that relatively large values of Harmony Memory Considering Rate makes the Harmony Search converge to a better solution.

First of all, I would like to thank the discusser, who provided an interesting contribution to the discussion about a hybrid app roach for the parameter estimation of the nonlinear Muskingum model. However, some explanations and clarifications are necessary.

South Asia is vulnerable to extreme weather events, and the Indus River basin (IRB) is subject to flood risk. Flooding occurred in Pakistan during the monsoon seasons from 2010 to 2012, causing major economic damage and significant loss of life. The nature of slow-rise discharge on the Indus and overtopping of riverbanks in the IRB indicates the need for extended warning time (1–10 days). Daily mean streamflow at Tarbela Dam, a major control structure on the Indus River, is reproduced by using numerical weather prediction initialization data from the ECMWF to drive the Variable Infiltration Capacity macroscale hydrologic model. A one-dimensional routing model conducts base flow and surface runoff from each grid cell through a stream network. Comparisons of reconstructions with inflow data at Tarbela Dam over a 3-yr period yield an R2 correlation of 0.93 and RMSE of 692 m3 s−1. From 2010 to 2012, 276 daily ensemble hindcasts are generated. In comparing the ensemble mean of 10-day hin...

The mountain regions of the Hindu Kush, Karakoram, and Himalayas (HKH) are considered Earth’s “third pole,” and water from there plays an essential role for downstream populations. The dynamics of glaciers in Karakoram are complex, and in recent decades the area has experienced unchanged ice cover, despite rapid decline elsewhere in the world (the Karakoram anomaly). Assessment of future water resources and hydrological variability under climate change in this area is greatly needed, but the hydrology of these high-altitude catchments is still poorly studied and little understood. This study focuses on a particular watershed, the Shigar River with the control section at Shigar (about 7000 km2), nested within the upper Indus basin and fed by seasonal melt from two major glaciers (Baltoro and Biafo). Hydrological, meteorological, and glaciological data gathered during 3 years of field campaigns (2011–13) are used to set up a hydrological model, providing a depiction of instream flows,...

The mountain regions of the Hindu Kush, Karakoram, and Himalayas (HKH) are considered Earth’s “third pole,” and water from there plays an essential role for downstream populations. The dynamics of glaciers in Karakoram are complex, and in recent decades the area has experienced unchanged ice cover, despite rapid decline elsewhere in the world (the Karakoram anomaly). Assessment of future water resources and hydrological variability under climate change in this area is greatly needed, but the hydrology of these high-altitude catchments is still poorly studied and little understood. This study focuses on a particular watershed, the Shigar River with the control section at Shigar (about 7000 km2), nested within the upper Indus basin and fed by seasonal melt from two major glaciers (Baltoro and Biafo). Hydrological, meteorological, and glaciological data gathered during 3 years of field campaigns (2011–13) are used to set up a hydrological model, providing a depiction of instream flows,...