2. Features 2.1. Runoff analysis mo

2. Features
2.1. Runoff analysis model
2.1.1. Public Works Research Institute Distributed Hydrological Model
So far, three versions of the PWRI Distributed Hydrological Model (ver.1 to ver.3) have been
developed with specifications as follow:
Ver1: configured as three tanks or more connected vertically (Table 2.1.1, Figure 2.1.1)
Ver2: configured as two tanks connected vertically
Ver3: considering evaporation and transpiration for low outflow calculation.


IFAS uses PWRI Distributed Hydrological Model as the runoff simulation engine with the features
listed below:
(1) The outflow from each cell is calculated by non-linear relationships based on the tank model philosophy. The non-linear relationships are not a complete Black Box or system in which only inputs and outputs are viewed but are also based on Manning and hyperbolic approximations.
(2) Parameters can roughly be estimated by using grid-based global data sets on topography, soil, geology, land use etc.
(3) Storage function runoff model enhances floods reproducibility by modifying saturation rainfall for each flood event. However, it is difficult to forecast saturation rainfall before the flood. PWRI -DHM adopts a nonlinear 2 or 3 layer tanks structure. This can solve the problem to modify the parameters for each flood event. As a result, this model doesn't


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need to estimate saturation rainfall of future flood events and this is best used as flood
forecasting model.
(4) If actual flood event is reproduced by storage function method, its reproducibility of floods is not enough in medium/small size floods in general. This is because storage function method is non-linearly 1 layer tank model and it is difficult to reproduce both heavy and medium/small size floods by same parameters since the characteristics of runoff phenomenon is different from each other. In PWRI Distributed hydrological Model enhances its reproducibility to medium/small size floods by adopting nonlinear 2 or 3 layer tanks structure.
(5) For numerical calculation, PWRI DHM does not use the convergence calculation to solve the differential equation. It uses approximation functions to solve the time integral equation. For this reason, the system can conduct numerical calculations smoothly and to realize for real-time operation.
(6) To calculate discharge in the river course tank, PWRI DHM solves Kinematic Wave equation. Moreover, PWRI-DHM Ver2 adopts 2 layer tanks vertically.
The concept is shown as follows;

Kết quả (Việt) 1:

2. Features 2.1. Runoff analysis model 2.1.1. Public Works Research Institute Distributed Hydrological Model So far, three versions of the PWRI Distributed Hydrological Model (ver.1 to ver.3) have been developed with specifications as follow: Ver1: configured as three tanks or more connected vertically (Table 2.1.1, Figure 2.1.1) Ver2: configured as two tanks connected vertically Ver3: considering evaporation and transpiration for low outflow calculation. IFAS uses PWRI Distributed Hydrological Model as the runoff simulation engine with the features listed below: (1) The outflow from each cell is calculated by non-linear relationships based on the tank model philosophy. The non-linear relationships are not a complete Black Box or system in which only inputs and outputs are viewed but are also based on Manning and hyperbolic approximations. (2) Parameters can roughly be estimated by using grid-based global data sets on topography, soil, geology, land use etc. (3) Storage function runoff model enhances floods reproducibility by modifying saturation rainfall for each flood event. However, it is difficult to forecast saturation rainfall before the flood. PWRI -DHM adopts a nonlinear 2 or 3 layer tanks structure. This can solve the problem to modify the parameters for each flood event. As a result, this model doesn't 2 need to estimate saturation rainfall of future flood events and this is best used as flood Mô hình dự báo. (4) nếu sự kiện thực tế lũ lụt sao chép bởi lí chức năng phương pháp, reproducibility lũ lụt là không đủ trong lũ lụt kích thước trung bình/nhỏ nói chung. Điều này là bởi vì lí chức năng phương pháp phòng không linearly 1 lớp xe tăng mô hình và nó là khó khăn để tái sản xuất cả lũ lụt nặng và phương tiện truyền thông/nhỏ kích thước của cùng một số thông số, kể từ khi các đặc tính của dòng chảy hiện tượng là khác nhau từ mỗi khác. Trong PWRI phân phối thuỷ văn mô hình nâng cao của nó reproducibility với kích thước trung bình/nhỏ lũ lụt bằng việc áp dụng phi tuyến 2 hoặc 3 lớp xe tăng cấu trúc. (5) đối với các tính toán số, PWRI DHM không sử dụng tính toán hội tụ để giải quyết phương trình vi phân. Nó sử dụng chức năng xấp xỉ để giải quyết các phương trình tích phân của thời gian. Vì lý do này, Hệ thống có thể thực hiện tính toán số trơn tru và để nhận ra cho thời gian thực hoạt động. (6) để tính toán xả trong khóa học sông hồ, PWRI DHM giải quyết các phương trình động sóng. Hơn nữa, PWRI-DHM Ver2 thông qua 2 lớp xe tăng theo chiều dọc. Khái niệm Hiển thị như sau;