How to improve the performance of runoff predictions in ungauged basins (PUB) is challenging. Recently, the long short-term memory (LSTM) based models have excellent performance and receive many attentions. In this paper, to improve the performance for 1-day-ahead runoff PUB and provide good performance for multi-day-ahead runoff PUB, we propose four sequence-to-sequence (S2S) models to deal with PUB

Better understanding for the likelihood of drought occur in the main grain production zones of China is key to minimize the risk for food security, especially in a changing climate. In an attempt to encompass the climate variability in the assessment of drought, a nonstationary standardized precipitation index (NSPI) was established for three major grain production zones (Songnen Plain (SN), North

Soil erosion is one of the major threats to the environment and agriculture in the world and rainfall erosivity is the most active factor to lead changes in soil erosion. Here, we use statistically downscaled, bias-corrected Community Earth Syatem Model (CESM) low-warming simulations to investigate the future changes in rainfall erosivity in mainland China under the Paris Agreement global warming targets

Increases in extreme rainfall intensities as a result of climate change pose a great risk due to the possibility of increases in pluvial flooding, particularly in urban and developed areas. But evidence is emerging that the observed increases in extreme rainfall are not resulting in universal increases in flooding. Indeed, on a global scale, studies consistently find more gauge stations with decreasing

Tracing decomposition of organic carbon sources can balance carbon budget and reduce soil erosion targetedly. However, tracers may provide inaccurate source information, possibly due to the instability of organic matter under different land use types. Little is known about which stable tracer to choose based on different erosion scenarios. We, therefore, evaluated the availability of three commonly-used

Hydrologic extremes often lead to droughts and floods that adversely affect the socio-economic development. Change in the characteristics and causes of hydrologic extremes due to climate variability and climate change poses a challenge for its reliable prediction. We propose a time-varying approach to capture such temporal changes, often gradual, in hydrologic extremes through temporal networks (a

Data assimilation of snow observations significantly improves the accuracy of snow cover simulations. However, remotely-sensed snowpack observations made in areas of complex topography are typically subject to large error and biases, creating a challenge for data assimilation. To improve the reliability of ensemble snowpack simulations, this study investigated the appropriate conditions for assimilating

Spontaneous imbibition profiles are widely used for wettability evaluation of porous media such as rocks. However, mostly the equilibrium imbibed volume is the basis for wettability evaluation. Here, we model the relationship between the shape of imbibition profile and wettability of a medium. We develop a wettability evaluation criterion based on the change in Helmholtz free energy of the system during

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged from a zoonotic spill-over event and has led to a global pandemic. The public health response has been predominantly informed by surveillance of symptomatic individuals and contact tracing, with quarantine, and other preventive measures have then been applied to mitigate further spread. Non-traditional methods of surveillance such

Fulvic acids (FAs) are known to regulate the fate of mercury (Hg) in sediments, but the key effects of their properties are still unclear. In this study, field investigations and simulation experiments were conducted in a heavy metal-polluted wetland to identify FA characteristics and their association with the production and bioaccumulation of methylmercury (MeHg). Compared to permanently inundated

Bathymetric mapping for an accurate estimation of stored water volume in drying lakes is a key information for an effective monitoring of their recession or restoration status. Extraction of bathymetry in shallow saline lakes using remote sensing techniques has always been challenging due to the complex influences imposed by the physical properties of substrate and the spatial variability of salinity

Artificial thermal effluent (ATE) is used as an effective measure for solving the problem of ice damage in cold regions; the ATE outlets introduce thermal water (approximately 10 °C) into the diversion channel to increase the temperature of the channel water. This study discusses two approaches for determining the change in the water temperature during the winter operation period at the Hongshanzui

In the paper, we tested and compared the potential of some standardized meteorological indices to identify agricultural drought impacts in central Italy. The indices considered are the Standardized Precipitation Index (SPI), the Standardized Precipitation Evapotranspiration Index (SPEI), the Reconnaissance Drought Index (RDI), and the Standardized Deficit Distance Index (SDDI), a new index that is

After operating the middle route of South-to-North Water Diversion Project (SNWDP), the total water transfer to Beijing has exceeded 5.0 km3, bringing significant changes to the water use structure of Beijing. This article compiles historic data from 2007 to 2020 to analyze changes in water circulation, groundwater level, climate factors and subsidence patterns in Beijing following implementation of

This paper reviews the current status of flow duration curve (FDC) studies that attempt to relate climate and catchment attributes to reproduce or explain the process controls on its shape – toward improving global-scale applicability and transferability of FDC studies. A collection of FDC literature from the past two decades is presented (2000–2020). They are grouped as exemplifying either: (1) studies

Depth-damage relationships of residential typologies have an important bearing on the reliability of flood risk assessments. Yet, the information for creating adequate functions is frequently missing in places where they are needed the most: developing countries where floods inflict severe losses. To overcome the lack of site-specific functions, modelers usually adopt functions from foreign typologies

Groundwater quality is affected by numerous uncertain factors, and the evaluation process is liable to randomness and fuzziness. To evaluate the quality of groundwater effectively, this study proposed a multi-index evaluation system termed the Modified Cloud Model-Level Eigenvalue Method (MCM-LEM) model, which is based on cloud model theory. In this evaluation system, the water quality was classified

Rain-on-Grid (RoG) modelling is an increasingly popular approach within the storm risk management, in which the hydrological and hydrodynamic flood processes are modelled entirely within the 2D hydrodynamic model. Contrarily to what was done in the context of flood propagation in rivers, at the present time no systematic benchmarking study of the software packages implementing this approach is available

We derive a general, tilt-dependent, nighttime, radiative deficit model with an eye towards improved dew collection. The model incorporates atmospheric/environmental incoming radiation, a linear precipitable water vapor transmittance function dependent on local meteo data and the influence of near-horizon obstacles. A brief discussion of cloud cover is given. The model is then used more specifically

A multi-dimensional mass conservative numerical method, particularly suitable for limited computational resources, is developed for solving transient variably saturated groundwater flow problems. The Richards equation is discretized spatially with a finite element method and temporally with an implicit Euler scheme, in which mass-conservative and mass-lumping techniques are used to keep the numerical

Streamflow from forested mountain watersheds is critical to aquatic ecosystems and social development in watersheds. However, understanding the intra-annual variability of streamflow is limited by the lack of observation of terrestrial water storage (TWS) in large-scale watersheds. This study developed a monthly Budyko framework incorporating TWS from the Gravity Recovery and Climate Experiment (GRACE)

The widely used Feddes reduction function (FRF) was reviewed in the context of its merits and shortcomings for modeling root water uptake (RWU), crop transpiration, and soil water balance components. The empirical nature of the FRF was contrasted to few calibrations reported in the literature, and the conditions where the correct operation of the FRF was of limited importance were discussed. Some alerts

Weirs are commonly used for controlling, measuring, and regulating water flow in conveyance structures such as canals or dams. In this study, hydraulic properties of flow over broad-crested weirs including the effects of different sloping crests and upstream and downstream ramps were characterized by using the finite volume method. Numerical simulations were validated by experimental results; the numerical

As the fifth-largest super tropical cyclone landed on Mainland China in history, typhoon Lekima occurred in August 2019 caused at least 71 deaths, 14 million disaster victims, and cost RMB 65.37 billion in damages. Here we use six latest GPM-based near-real-time satellite precipitation estimates (IMERG-Early, IMERG-Late, GSMaP-NOW, GSMaP-NRT, GSMaP-MVK, and CMORPH-RT) to quantify the spatiotemporal

Fracture surface topography exhibits long-range spatial correlations resulting in a heterogeneous aperture field. This leads to the formation, within fracture planes, of preferential flow channels controlling flow and transport processes. By means of a 3-D heat transport model coupled with a 2-D fracture flow model based on the lubrification approximation (i.e., local cubic law), we investigate how

When a smoothed particle hydrodynamics (SPH) method, a Lagrangian and meshfree numerical scheme, is used to solve the advection-dispersion equation (ADE), SPH solutions may not be accurate when particles are irregularly distributed, i.e., the distance between two neighbor particles varies irregularly in a simulation domain. Particle irregularity may be caused by nonuniform groundwater flow in a heterogeneous

Free Nitrous Acid (FNA) pre-treatment is a promising technology demonstrated effective in improving waste activated sludge degradability and anaerobic digestion (AD) performance. Pre-treatment conditions including FNA concentration and treatment duration determine operational and capital cost of full-scale implementation, which have not been studied in long-term experiments. The knowledge of FNA pre-treatment

Interest in anaerobic co-digestion (AcoD) has increased significantly in recent decades owing to enhanced biogas productivity due to the utilization of different organic wastes, such as food waste and sewage sludge. In this study, a robust AcoD model for biogas prediction is developed using deep learning (DL). We propose a hybrid DL architecture, i.e., DA–LSTM–VSN, wherein a dual-stage-attention (DA)-based

Land surface model (LSM) simulations forced by observed meteorological data provide spatially continuous and temporally complete soil moisture estimates, but the influences of models and meteorological forcings are yet to be validated over a large area due to the lack of in situ measurements. In this study, the Conjunctive Surface-Subsurface Process version 2 (CSSPv2) model was driven by three meteorological

A deficit in rainy days can affect crop production and escalate groundwater abstraction leading to groundwater depletion, thus may threaten food and water security in the Indian subcontinent. The available researches on rainfall occurrence in India represent inconsistency in several fundamental considerations (spatial scale of analysis, the definition of rainfall classes, methods, dataset, study period

Water-repellent soils usually experience water flow impedance during the early stage of a wetting process followed by progressive increase of infiltration rate. Current infiltration models are not formulated to describe this peculiar process. Similarly, simplified methods of soil hydraulic characterization (e.g., BEST) are not equipped to handle water-repellent soils. Here, we present an adaptation

Estimating extreme precipitation return levels at ungauged locations is key for hydrological applications and risk management, and demands improved techniques to decrease the large uncertainty of traditional methods. Here, we leverage the perks of the simplified metastatistical extreme value (SMEV) approach with a twofold aim: we show how it can be effectively used in situations in which the ordinary

As the largest tributary of the Yellow River, the Wei River drains a basin mainly comprising two different geological settings, i.e., the Chinese Loess Plateau (CLP) in the north covered by Quaternary loess and the Qinling Mountains area in the south. Exploring the influence of natural weathering processes and human activities on river chemistry has high significance in understanding chemical transport

Modeling the washoff of pollutants from urban catchments is a difficult task. Although the exponential washoff model has been in use for decades, there is a general lack of data on model parameters and much less is known about how the model parameters are influenced by storm and climate characteristics. This study was done to understand how model parameters vary between different catchments having

The deterioration of water quality in shallow groundwater systems over the past decades has attracted increased amounts of attention from hydrogeologists. Groundwater vulnerability and its changes are the factors that cause groundwater deterioration. Combining of the mean residence times (MRTs) with chemical characteristics of groundwater can be applied to understand groundwater vulnerability and its

High-resolution characterization of dense non-aqueous phase liquid (DNAPL) source zone architecture (SZA) is crucial for developing remediation strategies. Inverse modeling approaches are widely used to characterize DNAPL SZA. However, unknown parameters (permeability and DNAPL saturation) are usually assumed as Gaussian distribution in traditional geostatistical inverse methods (e.g., ensemble smoother