Rainfall intensity-frequency-duration (IFD) relationships are required for the design and planning of water supply and management systems around the world. Currently IFD information is based on the "stationary climate assumption". However, this paper provides evidence of regime shifts in annual maxima rainfall time series using 96 daily rainfall stations and 66 sub-daily rainfall stations across Australia. Importantly, current IFD relationships may under- or overestimate the design rainfall.

This work aims at deriving high spatially resolved maps of atmospheric water vapor by the fusion data from Interferometric Synthetic Aperture Radar (InSAR), Global Navigation Satellite Systems (GNSS), and the Weather Research and Forecasting (WRF) model. The data fusion approach exploits the redundant and complementary spatial properties of all data sets to provide more accurate and high-resolution maps of water vapor. The comparison with maps from MERIS shows rms values of less than 1 mm.

This paper gives a comprehensive evaluation of a simple newly developed downscaling scheme using in situ measurements from REMEDHUS network, a first cross-comparison of the performance of the downscaled soil moisture from MODIS and MSG SEVIRI, an evaluation of the performance of the downscaled soil moisture at different spatial resolutions, and an exploration of the influence of LST, vegetation index, terrain, clouds, and land cover heterogeneity on the performance of VTCI.

South Asia is a highly variable region where there is concern over water and food security. The simulations presented suggest an increasing trend in water resources, in some cases almost doubling by the end of the century although this is masked by the large annual variability of river flows for this region. Future peak river flows still occur during the monsoon period, with a tendency for reduced frequency of lowest flows and increased magnitude of highest flows across the selected locations.

The ensemble Kalman filter (EnKF) and simplified extended Kalman filter (SEKF) root-zone soil moisture analyses are compared when assimilating in situ surface observations. In the synthetic experiments, the EnKF performs best because it can stochastically capture the errors in the precipitation. The two methods perform similarly in the real experiments. During the summer period, both methods perform poorly as a result of nonlinearities in the land surface model.

A soil moisture assimilation experiment is evaluated separately at sub-seasonal, seasonal, and inter-annual timescales. In addition to previously reported improvements in sub-seasonal scale soil moisture, it is show that such an assimilation can also improve the model soil moisture at seasonal and inter-annual timescales, demonstrating the potential for near-surface soil moisture assimilation to improve model representation of important long-term events, such as droughts.

In forests of the western United States, annual evapotranspiration (ET) varies with precipitation and temperature; geologically mediated drainage and storage properties may influence the relationship between climate and ET. A process-based model is used to evaluate how water storage capacity influences model estimates of ET-climate relationships for three snow-dominated basins. Results show that uncertainty in subsurface properties can strongly influence model estimates of watershed-scale ET.

Nitrate contamination in agricultural groundwater systems is a concern in many regions worldwide. In this study, a model is applied to a regional-scale irrigated stream--aquifer system to identify the system inputs and processes that govern nitrate fate and transport at multiple scales: for the entire study region, for spatial areas irrigated by individual canals, and for individual cultivated fields. Results can be used to guide the localized application of best-management practices.

This paper provides the first detailed and comprehensive study regarding the potential for reducing the consumptive WF of a crop by changing management practice such as irrigation technique, irrigation strategy and mulching practice. If we consider all the cases of drip or subsurface drip irrigation with synthetic mulching, including all crops and environments, we find an average consumptive WF reduction of 28-29%. The corresponding blue WF reduction is 44% and the green WF reduction 14%.