The Soil and Water Assessment Tool (SWAT) model was used to assess the impacts of potential future climate change on the hydrology of the Upper Mississippi River Basin (UMRB). Calibration and validation of SWAT were performed on a monthly basis for 1968-87 and 1988-97, respectively; R and Nash-Sutcliffe simulation efficiency (E) values computed for the monthly comparisons were 0.74 and 0.65 for...

Calculation and analysis of annual R-factor local values for 103 stations in Poland were the main aims of this study. Calculations were made by means of single hidden layer perceptron artificial neural network on the base of monthly precipitation totals from years: 1961-1980. For most of the analyzed stations calculated average annual R-factor values were low or moderate, at the range from 50 t...

abstract in this study, trends of threshold heavy precipitation were examined on the basis of measurements of 1437 stations (included synoptic, climatic and rain gage stations) in iran for the period of 40 years (1964-2003). for this purpose, the statistical method of nonparametric mann-kendall test is used for analyzinging the thresholds of heavy precipitation and nonparametric sen method for ...

Precipitation change has significantly influenced annual net primary productivity (ANPP) at either annual or seasonal scales in desert steppes in arid and semi-arid regions. In order to reveal the process of precipitation driving ANPP at different time scales, responses of different ANPP levels to the inter-annual and intra-annual precipitation fluctuations were analyzed. ANPP was reversed by b...

Long-term livestock over-grazing causes nitrogen outputs to exceed inputs in Inner Mongolia, suggesting that low levels of nitrogen fertilization could help restore grasslands degraded by overgrazing. However, the effectiveness of such an approach depends on the response of production and species composition to the interactive drivers of nitrogen and water availability. We conducted a five-year...

tree-ring cellulose was examined in ponderosa pine (Pinus ponderosa Dougl.) trees in the western USA to study seasonal patterns of precipitation inputs. Two sites (California and Oregon) had minimal summer rainfall inputs, whereas a third site (Arizona) received as much as 70% of its annual precipitation during the summer months (North American monsoon). For the Arizona site, both the δO and δC...

Long-term water quality records for assessing natural variability, impact of management, and that guide regulatory processes to safeguard water resources are rare for California oak woodland rangelands. This study presents a 20-yr record (1981-2000) of nitrate-nitrogen (NO(3)-N) and suspended sediment export from a typical, grazed oak woodland watershed (103 ha) in the northern Sierra Nevada fo...

Dust samples collected annually for 5 years from 55 sites in southern Nevada and California provide the first regional source of information on modem rates of dust deposition, grain size, and mineralogical and chemical composition relative to climate and to type and lithology of dust source. The average silt and clay flux (rate of deposition) in southern Nevada and southeastern California range...

A validation study has been performed using the Soil and Water Assessment Tool (SWAT) model with data collected for the Upper Maquoketa River Watershed (UMRW), which drains over 16,000 ha in northeast Iowa. This validation assessment builds on a previous study with nested modeling for the UMRW that required both the Agricultural Policy EXtender (APEX) model and SWAT. In the nested modeling appr...

Annual natural discharge (Q) of the River Murray and its most extensive tributary, the Darling River system, is often inversely related to sea surface temperature (SST) anomalies in the eastern tropical Pacific Ocean. These SST variations are components of a planetary-scale phenomenon referred to as E1 Nino-Southern Oscillation (ENSO). Darling and Murray river historical values of Q indicate th...