Solute concentrations in headwater streams vary with discharge due to changing flow paths through the catchment during precipitation events. A comparison of stream chemistry across three headwater catchments reveals that solute heterogeneity across each landscape controls how different solutes respond to increasing discharge. Solute heterogeneity is at least partially controlled by landscape distributions of vegetation and soil organic matter.

This paper describes a methodology in analysing the interdependencies between components of the hydrological cycle and vegetation characteristics at different elevation zones of two endorheic river basins in an arid-mountainous region of NW China. The analysis shows that oasis vegetation has an important function in sustaining the water cycle in the river basins and oasis vegetation is dependent on surface and shallow subsurface water flow from mountain sources.

We introduce a new online global database of riverine water stable isotopes (Global Network of Isotopes in Rivers) and evaluate its longer-term data holdings. A regionalized, cluster-based precipitation isotope model was used to compare measured to predicted isotope compositions of riverine catchments. The study demonstrated that the seasonal isotopic composition and variation of river water can be predicted, which will improve the application of water stable isotopes in rivers.

Predicting hydrological effects of land use change, e.g. enhanced cultivation of short rotation coppices, requires an adequate parameterisation. Measurements and modelling results show that leaf area index, stomatal resistance and in particular start and length of growing season are most sensitive to soil hydrological quantities, like ground water recharge (GWR). Only simulations over 30 years, reflecting long-term climate variability, show even zero GWR, especially in succeeding dry years.

This paper introduces a new variant of the triple collocation technique with multiplicative error model. The method is applied, for the first time, to precipitation products across the central part of continental USA. Results show distinctive patterns of error variance in each product that are estimated without a priori assumption of any of the error distributions. The correlation coefficients between each product and the truth are also estimated, which provides another performance perspective.

A field method for assessing soil moisture in semi-arid conditions is proposed and tested in terms of inter-rater reliability with 40 Tanzanian farmers, students and experts. The seven wetness classes are based on qualitative indicators that one can see, feel or hear. It could be shown that the qualitative wetness classes reflect differences in volumetric water content and neither experience nor a certain level of education was a prerequisite to gain high agreement among raters.

Historical hydrology combines documentary data with hydrological methods to lengthen flow records to the past centuries. We describe the methodological evolution of historical hydrology under the influence of developments in hydraulics and statistics. Analysis of 45 case studies in Europe show that present flood magnitudes are not unusual in the context of the past, whereas flood frequency has decreased, although some rivers show a reactivation of rare floods over the last two decades.

This study quantifies the impacts of beaver on hydrologic and temperature regimes, as well as highlights the importance of understanding the spatial and temporal scales of those impacts. Reach-scale discharge showed shift from losing to gaining. Temperature increased by 0.38°C (3.8%) and mean residence time by 230%. At the sub-reach scale, discharge gains and losses increased in variability. At the beaver dam scale, we observed increase in thermal heterogeneity with warmer and cooler niches.

This study investigates the effectiveness of a sensitivity-informed method for multi-objective operation of reservoir systems, which uses a global sensitivity analysis method to screen out insensitive decision variables and thus forms simplified problems with a significantly reduced number of decision variables. We find that it is important to consider variable interactions when formulating simplified problems, and problem decomposition dramatically improves search efficiency and effectiveness.

Commercial cellular networks are built for telecommunication purposes. These kinds of networks have lately been used to obtain rainfall maps at country-wide scales. From previous studies, we now quantify the uncertainties associated with such maps. To do so, we divided the sources or error into two categories: from microwave link measurements and from mapping. It was found that the former is the source that contributes the most to the overall error in rainfall maps from microwave link network.

The objective of this study was to analyze the changes and uncertainties related to water availability in the future, in the Ijuí River basin (south of Brazil), using a stochastic approach. In general the results showed a trend to increased flows. It can be concluded that there is a tendency to increase the hydrological variability during the period between 2011 and 2040, which indicates the possibility of occurrence of time series with more marked periods of droughts and floods.

We combine in situ soil moisture observations with radar-derived precipitation to evaluate soil moisture feedback on convective rainfall in the US Southern Great Plains. We find strong connections between morning soil moisture and atmospheric conditions including boundary layer height, surface temperature, and relative humidity at the boundary layer top. The results of this study demonstrate both positive and negative soil moisture feedbacks are important in this region of the USA.

A simple hydrologic modeling-based approach to segregate the impacts of land use (LU) and climate change on streamflow is presented. Upper part of Ganga River basin in India is selected as study area for investigation. Results suggest that climate is the dominant contributor to the changes observed in the simulated streamflow. LU did not contribute significantly to the simulated streamflow which could be attributed to smaller spatial extent of sensitive LU categories in the study region.

We present a forecasting system comprising additively set-up conceptual and simple error model. Parameters of the conceptual model were left unaltered, as are in most operational set-ups, and the data-driven model was arranged to forecast the corrective measures the conceptual model needs. We demonstrate that the present procedure could effectively improve forecast accuracy over extended lead times with a reliability degree varying inter-annually and inter-seasonally.