Instantly calculate the probability density function (PDF) for Gamma distribution using shape (α) and scale (β) parameters. Ideal for quick, precise statistical analyses across multiple disciplines. Gamma Distribution PDF Calculator Gamma Distribution PDF Calculator Calculate the PDF for a Gamma Distribution: $$ f(x;\alpha,\theta)=\frac{1}{\Gamma(\alpha)\theta^\alpha}x^{\alpha-1}e^{-x/\theta}, \quad x\ge 0. $$ * Enter \( x \) (x ≥ 0), […]
Read MoreTravel Time / Time of Concentration Calculator Travel Time / Time of Concentration Calculator Calculate the travel time (or time of concentration) for channelized or shallow concentrated flow. \( V = \frac{1.49}{n}\, R^{\frac{2}{3}} \sqrt{S} \) and \( T = \frac{L}{V} \) * Enter the flow length \(L\) (ft), channel slope \(S\) (ft/ft), Manning’s roughness \(n\), […]
Read MoreTriangle Hydrograph Method Calculator Triangle Hydrograph Method Calculator Calculate the peak discharge using a triangular hydrograph: \( V = \frac{Q_p \times T}{2} \) → \( Q_p = \frac{2V}{T} \) * Enter the runoff volume (ft³) and hydrograph duration (s). Step 1: Enter Parameters Runoff Volume, \(V\) (ft³): Example: 10,000 ft³ Hydrograph Duration, \(T\) (s): Example: […]
Read MoreDouble-End Area Method Calculator Calculate the peak discharge from a hydrograph using the double-end area method. Runoff Volume: \( V \) (ft³) Rising Limb: duration \( t_r \) (s) with shape factor \( \alpha \) Falling Limb: duration \( t_f \) (s) with shape factor \( \beta \) * For a triangular hydrograph, use \( […]
Read MoreHydrograph Method Peak Discharge Calculator Hydrograph Method Peak Discharge Calculator Estimate the peak discharge from a rainfall event using a simplified triangular hydrograph method. Runoff Volume: \( V = R \times A \times 27878.4 \) (ft³) Peak Discharge: \( Q_p = \frac{2V}{T} \) (ft³/s) * Enter the watershed area (acres), rainfall excess (inches), and runoff […]
Read MoreRequired Underdrain Lateral Spacing Calculator Required Underdrain Lateral Spacing Calculator Calculate the required spacing for underdrain laterals using: \( S = \frac{A}{L} \) * Enter the drainage area to be served \(A\) (ft²) and the lateral length \(L\) (ft). Step 1: Enter Parameters Drainage Area, \(A\) (ft²): Example: 5000 ft² Lateral Length, \(L\) (ft): Example: […]
Read MoreUnderdrain System Discharge Calculator Underdrain System Discharge Calculator Calculate the discharge of an underdrain system using the formula: \(\displaystyle Q = \frac{K_s \times A_d \times (H_{in} – H_{out})}{L_d}\) * Enter the hydraulic conductivity \(K_s\) (ft/day), effective underdrain area \(A_d\) (ft²), inlet head \(H_{in}\) (ft), outlet head \(H_{out}\) (ft), and flow length \(L_d\) (ft). Step 1: […]
Read MoreArea Served by Underdrain Laterals Calculator Calculate the drainage area served by underdrain laterals using the formula: \( A = L \times S \) * Enter the lateral length \(L\) (ft) and lateral spacing \(S\) (ft). Step 1: Enter Parameters Lateral Length, \(L\) (ft): Example: 100 ft Lateral Spacing, \(S\) (ft): Example: 50 ft Calculate […]
Read MoreVertical Unsaturated Recovery Calculator Vertical Unsaturated Recovery Calculator Estimate the vertical unsaturated recovery volume for a retention cum detention pond. Using: \(\displaystyle V_{rec} = \frac{K_s \times A_{pond} \times H_{eff} \times t}{L_{unsat}}\) * Enter the pond parameters along with recovery time. \(K_s\) is in ft/day, area in ft², head in ft, time in days, and unsaturated […]
Read MoreStage Storage Depth Calculator Stage Storage Depth Calculator Calculate the depth of stage storage in a retention/detention pond using the stage-storage relationship. Stage-Storage Relationship: \(\displaystyle V = a\, h^b\) Solved for depth: \(\displaystyle h = \left(\frac{V}{a}\right)^{\frac{1}{b}}\) * Enter the storage volume \(V\) (ft³), coefficient \(a\), and exponent \(b\). Step 1: Enter Parameters Storage Volume, \(V\) […]
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