Heo J.,Texas A&M University |
Yu J.,Chungnam National University |
Giardino J.R.,Texas A&M University |
Cho H.,Water Resources Engineer Dewberry
Water and Environment Journal | Year: 2015
This study investigates the response of water resources regarding the climate and land-cover changes in a humid subtropical watershed during the period 1970-2009. A 0.7°C increase in temperature and a 16.3% increase in precipitation were observed. Temperature had a lower increase trend, and precipitation showed definite increasing trend compared to previous studies. The main trend of land-cover change was conversion of vegetation and barren lands to developed and crop lands affected by human intervention, and forest and grass to bush/shrub which considered to be caused by natural climate system. Hydrologic responses to climate and land-cover changes resulted in increases of surface run-off (15.0%), soil water content (2.7%), evapotranspiration (20.1%) and a decrease in groundwater discharge (9.2%). We found that surface run-off is relatively stable with precipitation, whereas groundwater discharge and soil water content are sensitive to changes in land cover, especially land cover brought about by human intervention. © 2014 CIWEM.
Cho H.,Water Resources Engineer Dewberry |
Bones E.,Water Resources Engineer Dewberry
Journal of Hydrology | Year: 2016
The Federal Emergency Management Agency has introduced the concept of the "1-percent plus" flow to incorporate various uncertainties in estimation of the 100-year or 1-percent flow. However, to the best of the authors' knowledge, no clear directions for calculating the 1-percent plus flow have been defined in the literature. Although information about standard errors of estimation and prediction is provided along with the regression equations that are often used to estimate the 1-percent flow at ungaged sites, uncertainty estimation becomes more complicated when there is a nearby gaged station because regression flows and the peak flow estimate from a gage analysis should be weighted to compute the weighted estimate of the 1-percent flow. In this study, an equation for calculating the 1-percent plus flow at an ungaged site near a gaged station is analytically derived. Also, a detailed process is introduced for calculating the 1-percent plus flow for an ungaged site near a gaged station in Georgia as an example and a case study is performed. This study provides engineers and practitioners with a method that helps them better assess flood risks and develop mitigation plans accordingly. © 2016 Elsevier B.V.