Differences in Irrigation Systems Between Hilly and Plain Areas: Key Design Considerations for Local Conditions

Differences in Irrigation Systems Between Hilly and Plain Areas: Key Design Considerations for Local Conditions

Hillary and plain areas differ significantly in topography, water resources, and farming conditions. The design of their irrigation systems, especially in pipeline layout and pump station configuration, must follow drastically different principles, with "adapting to local conditions" at its core.

Plain areas are flat and open, with concentrated, contiguous farmland. The core characteristic of their irrigation systems is gravity-fed irrigation over large areas. Water sources (such as reservoirs and rivers) are typically located at higher elevations. The main engineering work involves constructing a network of open channels, including main canals, branch canals, and field canals, to deliver water to the fields. Pipeline systems are often used for more precise sprinkler or drip irrigation, with a grid-like, uniform layout, minimal pipe diameter variations, and simple hydraulic conditions. Pump stations are relatively concentrated, primarily used to lift water from lower-level sources (such as groundwater) to the main canals or for localized pressurization for efficient, water-saving irrigation. Overall, plain systems aim for large-scale, high-efficiency, and low-cost water delivery.

Hillary areas, on the other hand, have undulating terrain, scattered plots, and significant elevation differences. The core of its irrigation system design is tiered water lifting and pressure zone management. Pipeline layout must adapt to the terrain, with main pipelines running along ridges or contour lines to minimize unnecessary ascents and pressure fluctuations; branch pipelines extend downwards to terraces or plateaus at different elevations. Pumping station configuration is multi-tiered and distributed, requiring the construction of pumping stations in sections according to elevation differences. Water is progressively lifted to reservoirs or pressure tanks at different heights, and then irrigated to the fields via gravity or low-pressure irrigation. The system's requirements for pipeline pressure resistance, valve regulation, and pressure control are far higher than in plains, necessitating special attention to prevent excessively high pipeline pressure at lower elevations or insufficient water supply at higher elevations.

In summary, plain irrigation is like "laying a carpet," focusing on building a wide-coverage, smoothly flowing network; hilly irrigation is like "climbing stairs," focusing on solving vertical transportation and tiered distribution problems. Only by fully respecting the terrain conditions and adopting matching pipeline and pumping station designs can an efficient, stable, and economical irrigation system be constructed.