Estimation and assessment of baseflow at an ungauged watershed according to landuse change

Abstract

Baseflow gives a significant contribution to stream function in the regions where climatic characteristics are seasonally distinct. In this regard, variable baseflow can make it difficult to maintain a stable water supply, as well as causing disruption to the stream ecosystem. Changes in land use can affect both the direct flow and baseflow of a stream, and consequently, most other components of the hydrologic cycle. Baseflow estimation depends on the observed streamflow in gauge watersheds, but accurate predictions of streamflow through modeling can be useful in determining baseflow data for ungauged watersheds. Accordingly, the objectives of this study are to 1) improve predictions of SWAT by applying the alpha factor estimated using RECESS for calibration; 2) estimate baseflow in an ungauged watershed using the WHAT system; and 3) evaluate the effects of changes in land use on baseflow characteristics. These objectives were implemented in the Gapcheon watershed, as an ungauged watershed in South Korea. The results show that the alpha factor estimated using RECESS in SWAT calibration improves the prediction for streamflow, and, in particular, recessions in the baseflow. Also, the changes in land use in the Gapcheon watershed leads to no significant difference in annual baseflow between comparable periods, regardless of precipitation, but does lead to differences in the seasonal characteristics observed for the temporal distribution of baseflow. Therefore, the Guem River, into which the stream from the Gapcheon watershed flows, requires strategic seasonal variability predictions of baseflow due to changes in land use within the region.

Analyzing Priority Management for Water Quality Improvement Strategies with Regional Characteristics

“…Climate change variability has recently increased, exacerbated by industrialization, urban population concentration, and rapid urban expansion [1][2][3][4][5]. Furthermore, distortions in the water cycle and pollution discharge rates in regions affected by heavy rainfall have sharply increased [6].…”

Study of Non-Point Pollution in the Ashe River Basin Based on SWAT Model with Different Land Use

“…An increase in surface flow will reduce groundwater recharge. In changing the cultivation of agricultural land to vegetated grassland or forest, there is some possibility of reducing the frequency of flooding, but not necessarily the duration [23].…”