摘要
[Objeetive] We aimed to calculate the flow of controlling units in a small watershed based on GIS technology. [Method] Hydrologic analysis on Qingyi River was conducted by using ArcGIS9.0, and the controlling units with response of water-land were divided according to the riv- er monitoring sections of Xuchang City; considering the wastewater entering the river and the water from its upper reach, the runoff of controlling sections in the driest month （ with guarantee rate of 90% ） was calculated by means of isoline, runoff coefficient and hydrologic analogy method, and the calculated value of Gaocun Bridge section in Linying was contrasted with the measured value in 2010. [Result] The results showed that the cal- culated value and measured value of Gaecun Bridge section in Linying in the driest month of 2010 were 6.03 and 5.93 m^3/s respectively, with relative error of 1.69%, which revealed that the result of calculated runoff was reasonable. [ Conclusion] The way to divide controlling units was reason- able, and the calculation result of runoff was accurate and can meet the precision of water environment capacity calculation.
[Objeetive] We aimed to calculate the flow of controlling units in a small watershed based on GIS technology. [Method] Hydrologic analysis on Qingyi River was conducted by using ArcGIS9.0, and the controlling units with response of water-land were divided according to the riv- er monitoring sections of Xuchang City; considering the wastewater entering the river and the water from its upper reach, the runoff of controlling sections in the driest month （ with guarantee rate of 90% ） was calculated by means of isoline, runoff coefficient and hydrologic analogy method, and the calculated value of Gaocun Bridge section in Linying was contrasted with the measured value in 2010. [Result] The results showed that the cal- culated value and measured value of Gaecun Bridge section in Linying in the driest month of 2010 were 6.03 and 5.93 m^3/s respectively, with relative error of 1.69%, which revealed that the result of calculated runoff was reasonable. [ Conclusion] The way to divide controlling units was reason- able, and the calculation result of runoff was accurate and can meet the precision of water environment capacity calculation.
