ngtao Li

Estimating the Impact of Projected Climate Change on Runoff across the Tropical Savannas and Semiarid Rangelands of Northern Australia

The majority of the world’s population growth to 2050 is projected to occur in the tropics. Hence, there is a serious need for robust methods for undertaking water resource assessments to underpin the sustainable management of water in tropical regions. This paper describes the largest and most comprehensive assessment of the future impacts of runoff undertaken in a tropical region using conceptual rainfall‐runoff models (RRMs). Five conceptual RRMs were calibrated using data from 115 streamflow gauging stations, and model parameters were regionalized using a combination of spatial proximity and catchment similarity. Future rainfall and evapotranspiration projections (denoted here as GCMES) were transformed to catchment-scale variables by empirically scaling (ES) the historical climate series, informed by 15 global climate models (GCMs), to reflect a 18C increase in global average surface air temperature. Using the best-performing RRM ensemble, approximately half the GCMES used resulted in a spatially averaged increase in mean annual runoff (by up to 29%) and half resulted in a decrease (by up to 26%). However, ;70% of the GCMES resulted in a difference of within 65% of the historical rainfall (1930‐2007). The range in modeled impact on runoff, as estimated by five RRMs (for individual GCMES), was compared to the range in modeled runoff using 15 GCMES (for individual RRMs). For mid- to high runoff metrics, better predictions will come from improved GCMES projections. A new finding of this study is that in the wet‐dry tropics, for extremely large runoff events and low flows, improvements are needed in both GCMES and rainfall‐runoff modeling.

Notice of Retraction Integration of a Water Balance Model with a Decision Support Tool in the Loess Plateau of China

In order to reduce the massive soil erosion and to ensure sustainable development, the Chinese central government planned revegetation measures to reduce these environmental problems-especially in the Loess Plateau. This revegetation process will not only result in less soil erosion in the coarse sandy hilly catchments (CSHC), but also less runoff due to increased evapotranspiration (ET). A water balance model of Zhang et al. (2001) was used to estimate the subsequent impact on stream flow and its spatial distribution in this region at first, but the results showed that the model was not able to accurately simulate average annual stream flow when compared with stream flow measurements from 38 hydrologic stations in CSHC of the Loess Plateau. Zhang et al. (2008) calibrated the model, and it can accurately simulate the impacts of the region on streamflow. The recommended areas for revegetation and the suitability for each of 38 perennial species are also researched in the region. To provide a direct simulate result for policy makers and soil and water managers with the information that they need to make better decisions, a decision support tools called Revegetation Impacts on Hydrology (ReVegIH) was developed in Microsoft. NET environment using C# and the invisible modeling environment (TIME). ReVegIH provides besides basic geographical information system (GIS) functions, impacts of different revegetation result on runoff and ET, revegetation and priority areas for trees and shrubs, the suitability of 38 species for planting in the CSHC. The establishment of ReVegIH provided a very efficient way of managing revegetation species and areas, showing simulate result of the model, calibrating model coefficient. ReVegIH does not consider loading other catchments or counties dataset to simulate and also loading map is not efficient enough.