Water, Rice, People
Individual work, 2022Lingmuteychu is a watershed located in central Western Bhutan. Terraced rice planting is the main source of livelihood for all villages. A seasonal river relies on rainwater in the basin, which is also the only irrigation water source for villages. Farmers in Limbukha recognize their advantage of being at the top of the basin and grabbing water once the rice transplanting season begins. As a result, during the water shortage period, only a small amount of water may enter Dompola’s farmland, resulting in the conflict of water resources between the two villages. Nevertheless, the site has a large amount of rainfall in July and August, but the irrigation channels between villages can not carry sudden rainwater, resulting in a large amount of rainwater loss.
Considering the particularity of rice planting to residents’ livelihood, the design envisages easing the conflict of water shortage based on redistribution of field functions. The first is to improve the water transportation efficiency, so the minimum production water demand and the rainwater utilization potential are calculated based on crop species and land types of the two villages. The second is to design several forms to keep the terraces at a low water level, to make up for the water shortage faced by farmers downstream, so the best rice-planting scope, the rainwater-collecting points, and the route scope of rainwater transmission are evaluated and planned in two villages.
To facilitate the operation of the villagers, the existing terrace forms of the two villages are classified into different functions and slightly changed in terrain, so that the newly designed forms can carry more functions and effectively control the water flow. Another strategy is to implement different crop-planting combination types to the new terrace prototypes according to the previous evaluation.
Based on the planning layout obtained from the previous evaluation, The designed prototypes are combined in the 50m×50m grid. Under the guidance of the newly designed terrace terrain, sufficient water is intercepted for rice irrigation in Limbukha village, and the small ditches will connect some irrigation channels. In the lowest part of the terrace, a large number of rice planting and transformation areas are set up to make effective use of rainwater. The excess water is filtered and discharged into the channel instead of becoming stagnant. Fruit trees are planted in fish scale pits around the residential area, while the remaining intercepted rainwater will continue to be transported to Dompola village downstream along the canal to directly irrigate crops. Rainwater flowing from higher elevation terraces will be filtered and stored in scattered reservoirs, some of which will be used for rice irrigation. The other part will be used to supplement domestic water.
The planning provides a cooperative way of field transformation that enables the rainwater transmission and storage capacity to become higher, to make more rainwater from the upstream will flow to the downstream, and reduce the contradiction between the two villages.
Watershed/Culture