CAJ | 학술논문

黑龙江省江川灌区实施旱田改水田后，粮食产量持续上升，同时也暴露了以总氮和总磷为主的非点源污染问题。该文在GIS平台的支持下，运用SWAT模型，建立了模型所需的空间数据库和属性数据库，并运用实测资料对模型参数进行了率定。最后，设置了不同的情景，在耕地面积不变的情况下，改变水田比例为现状的70%、50%，从而研究农业非点源污染输出变化。研究表明：水田面积为70%和50%的情况下，月平均径流深比现状减少20.95、41.37 mm，总氮负荷减少27.84、48.16 t/a，总磷负荷减少1.66、2.89 t/a，说明旱田改水田将会对水环境产生不利影响。通过情景模拟发现，减少施肥量和节水灌溉均可以在一定程度上控制污染物输出，施肥量减少50%后，总氮输出减少25.23%，总磷减少16.32%。在实际生产生活中，为保证粮食产量，可以通过改变施肥方式或设置人工湿地等方法减少农业面源污染。
흑룡강성강천관구실시한전개수전후，양식산량지속상승，동시야폭로료이총담화총린위주적비점원오염문제。해문재GIS평태적지지하，운용SWAT모형，건립료모형소수적공간수거고화속성수거고，병운용실측자료대모형삼수진행료솔정。최후，설치료불동적정경，재경지면적불변적정황하，개변수전비례위현상적70%、50%，종이연구농업비점원오염수출변화。연구표명：수전면적위70%화50%적정황하，월평균경류심비현상감소20.95、41.37 mm，총담부하감소27.84、48.16 t/a，총린부하감소1.66、2.89 t/a，설명한전개수전장회대수배경산생불리영향。통과정경모의발현，감소시비량화절수관개균가이재일정정도상공제오염물수출，시비량감소50%후，총담수출감소25.23%，총린감소16.32%。재실제생산생활중，위보증양식산량，가이통과개변시비방식혹설치인공습지등방법감소농업면원오염。
After changing from upland farming to paddy field in Jiangchuan irrigation area, the grain production continues to increase, but problem of the non-point source pollution occurs predominantly with total nitrogen and total phosphorus. Both paddy fields and upland fields can experience surface runoff of chemical fertilizers and pesticides, but which land use can cause more surface runoff remains largely unknown. There are many point source pollution researches in water systems in China, and the technology and methods are relatively mature. But for agricultural non-point source pollution, most research is done in the south, and less in the northeast of China. Therefore, it is needed for research on surface nutrient or pesticide runoff when changing from upland farming to paddy fields. With the use of GIS and SWAT model, the spatial database and attribute database of the model for the research area were established. The spatial database included digital elevation map (DEM), land use map and soil map. The attribute database basically included the meteorological, soil property, and agricultural management data. Based on the feature of natural rivers distribution on the edge of the irrigation area, we used“burn-in”algorithm to make the artificial canal system network as the water system, and set up the threshold watershed area to delimit sub basin in the river basin. Next, we used LH-OAT method of SWAT model to analyze parameter sensitivity, and selected the important factors for the model output. We then used the measured data of runoff, total nitrogen and total phosphorus from the years of 2008 to 2009 as the calibration period, and years of 2010 to 2013 as validation period to explore the model applicability in the research area. Finally, the nitrogen and phosphorus pollution load in the study area under different scenarios were simulated. These scenarios were: no change of the existing farmland area, 70%, or 50% of land converted to paddy field. The results showed that: compared with the present situation, under 70% and 50% conversion, runoff water was reduced 20.95 and 41.37 mm, respectively. The total nitrogen load was respectively reduced to 27.84 and 48.16 t per year, and the total phosphorus load was respectively reduced to 1.66 and 2.89 t per year. The results showed that upland farmland after converted to paddy field can cause nutrient pollution from runoff to the surface water. The increasing rate of fertilization and irrigation was another variable that led to the increasing fertilizer loss, and the pollutants in the return water and surface runoff were discharged into Songhua River causing enrichment of nutrients in water. Last, both reducing fertilizer application and use of water saving irrigation can control the total N and total P output to some extent by the scenario simulation. After fertilizer uses were decreased by 50%, the total N and the total P load decreased by 25.23%and 16.32%, respectively. In practice, to ensure the grain production and to control the agricultural non-point source pollution to the water system, change of fertilization methods and use of constructed wetland are needed.