Catchment

a rainwater harvesting technique consisting in digging semilunar holes in the ground with the opening perpendicular to the flow of water. 

These holes are oriented against the slope of the ground, generating a small dike in the curved area with the soil from the hole itself, so they capture the rainwater running downhills.[3]

These structures allow water to seep into the soil, retaining in the subsoil a greater amount of moisture. But also, it prevents the loss of fertile soil.[4]

Semi-circular bunds are used to reforest arid zones with irregular rain patterns, allowing the growth of plants and trees, such as in the Sahel.[5]

https://www.greener.land/index.php/product/demi-lunes-semi-circular-bunds/

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Zaï or Tassa is a farming technique to dig pits (20-30 cm long and deep and 90 cm apart) in the soil during the preseason to catch water and concentrate compost.[1] The technique is traditionally used in western Sahel (Burkina Faso, Niger, Mali) to restore degraded drylands and increase soil fertility.

Zaï holes were reintroduced since the 1980s by Yacouba Sawadogo, a farmer from Burkina Faso, who introduced the innovation of filling them with manure and compost to provide plant nutrients. The manure attracts termites, whose tunnels help further break up the soil. He also slightly increased the size of the holes over the traditional models. Zaï holes help by improving the yields of trees, sorghum, and millet by up to 500 percent.[2]

As an alternative to the zaï-technique some agricultural engineers suggest a diking technique, especially in the case of very light soils.[3]

How This Woman Turned Arizona's Desert into a Farmland Oasis

https://youtu.be/jM9j12VfqcQ?si=89A-dMshus1ZybWf