Study On Ditch Wetlands In The Semi-arid Region

Non-point pollutants from agricultural sources has been one of main pollutes source of water environment in all over the world. Because of the using of plenty of chemical fertilizer and pesticides, and with big strengthened land cultivation, it is arouse that soil and nutrition material such as P, N run off, then these contaminants enter the water bodies such as river and lakes as surface source forms, which has promoted water body eutrophication and silt to silt up and aggravated water body pollution. As transitional reign between farmland and water bodies, ditch wetland can not only purify contaminants in drains of farmland, but also retain rainwater, adjust to rainfall runoff, and improve utilization rate of rainwater. Ditch wetland is essential to administer surface source pollutants as one of measures of technical engineering. Therefore, building ditch wetland is significant on restoring ecology and administering surface source pollutants.Basic of analysis of constructed wetland theory, the study can be carried out on semi-arid area. The major research work is listed: Water balance model of ditch wetland; reaction model of purification pollutants in ditch wetland; radio between wetland water surface area and farmland area controlled by wetland; design of ditch wetland; performance and administer of ditch wetland. On applied study, a ditch wetland design plan is given to Handan area.The models such as water balance model of ditch wetland, reaction model of purification pollutants in ditch wetland, radio between wetland water surface area and farmland area controlled by wetland which studied in this paper offer material to further study on ditch wetland. Meanwhile, the results in the paper provide theoretical basis and technological guide for how to build ditch wetland in semi-arid area.