Читать книгу Environment and Society - Paul Robbins - Страница 79

Most of the world’s crops, including almost all of the vegetables and many of the grains you probably consume, come from irrigated fields. Getting water to food plants might be the oldest problem in civilization. Indeed, the difficulties in maintaining and managing irrigation have occupied environmental managers for thousands of years. One of the greatest challenges in managing irrigation is that, typically, many water users are connected through the same complex system of ditches and walls, through which water flows from the highest point (the system “head”) to its lowest fields (its “tail”). Fields may be held privately, but the irrigation water must be managed collectively. Such systems are labyrinths of sluices, canals, and gates, requiring that each user follows a careful set of rules that allow them their share of the water for a time, but also maintenance of the supply so other users, especially downstream, get their fair share as well (Figure 4.2). The opportunities for system failure are obvious. If one person at the head of the system fails to open or close a gate after they use their supply of water, the downstream user will receive none. If all parties do not work together to flush the system as a whole, the water can become salty, leading to the loss of the crops of all farmers. These difficulties notwithstanding, the world is filled with local irrigation systems where multiple users cooperate in the actions, make decisions together, monitor the infrastructure, and achieve equitable outcomes with little waste or loss of precious water.

Figure 4.2 Irrigation systems are labyrinths of sluices, canals, and gates, which test the limits of people’s ability to cooperate in managing environmental goods. This example, from the village of Musha in the Nile Valley, shows the interrelationships of one private field to the next, tied together by the mutual need for water held communally. Source: Reproduced from Turner, B.L.,II and S.B. Brush (eds.) (1987). Comparative Farming Systems. New York: Guildford Press.