Design of Farmland Water Conservancy and Irrigation Management System Based on GIS

The farmland irrigation project is an important part of China's water conservancy project. To keep abreast of the farmland water conservancy and various related environmental parameters,we can use the external sensors to acquire real-time data,employ the computer technology,networking and communication technology,database technology,geographic information system( GIS) technology,component technology and other advanced modern information technologies combined with the automated water conservancy technology,in order to build an accurate,efficient,fast,comprehensive,standardized decision support system integrating farmland water conservancy and irrigation information collection,transmission,storage,management and analysis. In this paper,we give details about the overall framework design of farmland water conservancy and irrigation management system based on GIS,information collection and data input,and information processing and data output,to provide a reference for the digital water conservancy construction in China.

Research on Management Mode of Small-scale Irrigation Works for Farmland Based on Self-governance

The paper analyzes the practical use of management mode of small-scale farmland irrigation works in China,and studies various problems existing in the present management mode.It puts forward a mode named Water-consumer Association which is the most practical one at present.It points out some rules which must be mastered in solving problems appearing in using this mode.

The soil displacement measurement of mercury emission flux of the sewage irrigation farmlands in Northern China

Mercury fate of sewage irrigation in farmlands deserves attention with increasing scarcity of freshwater resources for agriculture in the worldwide.Soil-air total gaseous mercury(TGM)fluxes from four-sewage and one-fresh water irrigated farmlands were determined simultaneously.During maize-wheat rotation,soil-air TGM fluxes showed patterns of both emission and deposition during different growth stages.It enhanced one-order of magnitude emission with increased Hg contamination from historical sewage irrigation.A linear response relationship of TGM fluxes with soil Hg concentration was found,which showed greater TGM emission potential comparing with those from forest and urban soils.However,the ratio of soil-air TGM flux in daytime to nighttime were 3.94 in maize-season and 3.41 in wheat-season,respectively,which were little related to the change in soil Hg concentration.Furthermore,soil temperature and moisture,ambient-air TGM concentration all effected TGM evasion from sewage-irrigated soils.The data presented here suggest that evasion of TGMfromhistorical sewage irrigation farmlands with high Hg concentrations may be potential hotspots for Hg emission in atmosphere,and it was likely to underestimate Hg emissions from farmlands in existing emissions inventory.Additional regionalinvestigations and process-level researches are needed to better understand role of sewage irrigation farmlands in local-global Hg-biogeochemical-cycles.