Regional differences and reasons for farmers' irrigation as households perspective: A case study of Sangong River Basin

Uneven spatial and temporal distribution of water shortage coupled with low water use efficiency is a critical constraint to socio-economic development in semi-(arid) regions. Using questionnaires, quantitative statistics and OLS estimation, this study analyzed the regional differences in irrigation as affected by farmer household characteristics in the Sangong River Basin. The study showed gradual increases in water-saving facilities and water price from the upper reaches down to the lower reaches of the basin. Water-saving irrigation ratios were 3%, 10% and 28% in the upper, middle and lower reaches, respectively. The corresponding water price in the upper, middle and lower reaches was <0.075 Yuan·m^-3, 0.069~0.075 Yuan·m^-3 and 0.13~0.35 Yuan·m^-3, respectively. There was a gradual decline in irrigation amount and water burden from the upper down to the lower reaches. Irrigation amount in the upper, middle and lower reaches was 18 510 m³·hm^-2, 12 810 m³·hm^-2 and 9 075 m³·hm^-2; water burden were 18%, 14% and 12% respectively. In the basin, planting structure had evolved from traditional to cash driven crops with increasingly rational cultivation structures. Natural factors were the most fundamental reasons for differences in irrigation among different regions. The amount of water resources, soil retention capacity, field size and fragmentation influenced not only farmers' awareness of water conservation, but also choices of water-saving facilities. This had led to differences in farmers' irrigation modes, which in turn significantly influenced local governments' decision-makings. While local governments passed irrigation burdens to farmers by increasing water price, they also enhanced water use efficiency and crop-irrigation demand curve by improving canal quality and subsidizing the costs of water-saving facilities. Empirical analysis showed that when water price rose by 0.01 Yuan·m^-3, irrigation amount dropped by 484 m³·hm^-2. By using drip irrigation, irrigation amount dropped by 1 617 m³·hm^-2. Also by improving water canal quality from earth to cement pavement, irrigation amount dropped by 736 m³·hm^-2.