in recent decades, neyshabour basin as a semi-arid climate has faced with dramatic increasing of groundwater withdrawal. so, water demand management is important in this basin. in this study, the effects of evapotranspiration and rainfall on groundwater fluctuations have been considered with 22 rain gage and evaporation gage station data during 1973-2006. the average amount of rainfall and evap...

Runoff forecasting in mountainous regions with processed based models is often difficult and inaccurate due to the complexity of the rainfall-runoff relationships and difficulties involved in obtaining the required data. Machine learning models offer an alternative for runoff forecasting in these regions. This paper explores and compares two machine learning methods, support vector regression (...

Phosphorus (P) losses from agricultural landscapes arise from the interaction of hydrologic, edaphic, and management factors, complicated by their spatial and temporal variability. We monitored sites along two agricultural hillslopes to assess the effects of field management and hydrology on P transfers in surface runoff at different landscape positions. Surface runoff varied by landscape posit...

Benthic invertebrate assessments can be used to gauge the impact of urban wetweather flows in receiving waters. Experiences from Cemagref in France have shown that standardized benthic indices (e.g. Oligochaete Index of Sediment Bioindication IOBS) can be used to reliably determine the ecological status of urban streams and can be incorporated into the new European Water Framework Directive. Th...

In this paper, we analyze dynamics of runoff data from actual hydrologic station on the basis of the chaos theory. Through analyzing Characteristics of power spectrum, geometric structure of attractors and calculating Lyapunov index, it confirmed that actual runoff has chaos dynamics behavior. Local prediction model based on chaotic runoff data is inferior for heavy computation load and poor ac...

The western Sierra Madre is the main water-providing area of northern Mexico. However, most of this mountain range has suffered a progressive degradation of soils and vegetation due to overgrazing and deforestation, for four or five decades. The objective of this study is to determine the impacts of these changes on water balance and hydrodynamic basin behaviour. The hydrological data of two ba...

Available energy (often expressed in terms of potential evaporation) and precipitation largely determine annual evapotranspiration and runoff rates in a region. The ratio of annual potential evaporation to precipitation, referred to as the aridity index by Budyko, has been shown to describe the evaporation ratio (the ratio of annual evapotranspiration to precipitation) of catchments from a rang...

Quantitative assessment of the frequency and magnitude drought events plays an important role in preventing disasters ensuring water security river basins. In this paper, we modified a parsimonious two-parameter monthly balance (TPMWB) model by incorporating generalized proportionality hypothesis with precipitation potential evapotranspiration as input variables. The TPMWB was then used to simu...