Calculation of average stream flow rate:
1. Watershed Area \(A = 600\text{ ha} = 600 \times 10,000\text{ m}^2 = 6 \times 10^6\text{ m}^2\). 2. Rainfall depth \(P = 10\text{ cm} = 0.10\text{ m}\). 3. Runoff/Rainfall ratio \(C = 0.2\). Runoff depth \(R = C \times P = 0.2 \times 0.10\text{ m} = 0.02\text{ m}\). 4. Total runoff volume \(V = A \times R = (6 \times 10^6\text{ m}^2) \times 0.02\text{ m} = 120,000\text{ m}^3\). 5. Flow duration \(t = 10\text{ hours} = 600\text{ minutes}\). 6. Average stream flow rate: - In \(\text{m}^3/\text{h}\): \(\frac{120,000\text{ m}^3}{10\text{ h}} = 12,000\text{ m}^3/\text{h}\).

• In \(\text{m}^3/\text{minute}\): \(\frac{120,000\text{ m}^3}{600\text{ min}} = 200\text{ m}^3/\text{minute}\). - In \(\text{m}^3/\text{s}\): \(\frac{120,000\text{ m}^3}{36,000\text{ s}} = 3.33\text{ m}^3/\text{s}\).

Forms of precipitation:
Sleet: Pellets of ice formed by the freezing of raindrops or the refreezing of melted snowflakes as they fall through a subfreezing layer of air near the Earth's surface. Sleet pellets bounce when striking the ground.
Glaze (Freezing Rain): Supercooled raindrops that freeze instantly upon contact with cold surfaces on the ground, forming a smooth ice coating.
Hail: Hard, rounded balls or lumps of ice ($\gt 5\text{ mm}$) formed inside convective cumulonimbus storm clouds by alternating upward and downward drafts.
Snow: Ice crystals in the form of hexagonal flakes directly sublimated from water vapor.

Recording rain gauge mechanisms:
Weighing-bucket type raingauge: In this instrument, precipitation falling into a collector bucket is placed directly on a spring-balance or load-cell platform. The weight of the accumulated catch is continuously measured and recorded on a rotating drum clock or data logger. Because all precipitation (rain, snow, hail) remains in the bucket, it records the direct cumulative mass/depth of precipitation over time without needing siphoning.
Tipping bucket gauge: Records rainfall increments (tips) to measure rainfall rate/intensity.
Float type gauge: Siphons periodically when the chamber fills.
Symons' gauge: Non-recording type.

Assumptions of the Rational Method (\(Q_p = C I A\)):
(A) is an assumption: Rainfall occurs at uniform intensity across the entire watershed for a duration equal to or exceeding time of concentration (\(t_c\)).
(D) is an assumption: The runoff coefficient (\(C\)) is treated as a dimensionless constant dependent strictly on watershed surface characteristics (slope, soil texture, vegetative cover, land use).
(B) and (C) are NOT considered: The Rational method explicitly neglects depression storage, surface detention variation, initial abstraction dynamics, and channel attenuation/storage effects, assuming direct steady peak proportionality without hydrograph routing.