灌漑・排水システム工学

Modernizing Surface Irrigation and Land Levelling in Hetao with Application of the Decision Support Systems SADREG

Abstract

Miao Q, Shi H and Li R

Water resources allocated to the agricultural sector in the Yellow River basin are being reduced due to severe water scarcity and an increasing demand by the non-agricultural sectors, which imply surface irrigation modernization and the adopting water-saving technologies. The Hetao irrigation district has 0,570 Mha of irrigated land; traditional basin irrigation is the most common irrigation method. Its general conditions are adequate for surface irrigation due to the high charge of sediments on irrigation water and, among other factors, due to its appropriateness to leach salts. The new technologies of surface irrigation, including the modernized furrowed and flat basin irrigation systems, require the adoption of effective precise land leveling to reach the best performance standards. In this context, the development of high quality land leveling operation is a main condition for irrigation modernization. The laser land leveling technology provides for high land leveling quality, with significant benefits on water saving, salinity control and crop productivity. The irrigation modernization also requires adopting adequate irrigation scheduling, control of inflow discharges and of related application times. The DSS methodology may contribute to improved design and management. The DSS SADREG aims to support design and selection of farm surface irrigation alternatives; it ranks those alternatives relative to irrigation performance and environmental and economic impacts using Multicriteria analysis. The DSS application bases on three years field work to evaluate the traditional practices and for the parameterization of design models from field irrigation systems evaluation. This paper presents the following SADREG application results: (i) evaluation of land leveling operation based on field observations and the comparison between laser and common practices; (ii) land parcels description, namely its size, slopes and water supply conditions; (iii) SADREG base models parameterization, including crop irrigation scheduling, infiltration, SIRMOD hydraulic simulation and economics; and (iv) presentation and comparison of alternatives of field irrigation modernization.