scholarly journals An Analysis of Regional Snow Assessments at Selected Hydrological Stations on the Danube and Tisza Rivers

2013 ◽  
Vol 21 (3) ◽  
pp. 43-56
Author(s):  
Beáta Hamar Zsideková ◽  
Balázs Gauzer ◽  
Gábor Bálint
Keyword(s):  
Surface Water ◽  
Water Balance ◽  
Land Surface ◽  
Hydrological Cycle ◽  
Time Lag ◽  
Precipitation Event ◽  
Seasonal Forecasts ◽  
The Earth ◽  
Precipitation Record ◽  
The Relationship

Abstract Precipitation falling on a land surface is one of the most important elements of the hydrological cycle, and it is the only input term of the water balance on the Earth´s surface. On those areas of the Earth where a part of the annual precipitation falls in the form of snow, the rhythm of the hydrological cycle, i.e., the water balance within a year, follows a pattern that deviates from that of the precipitation record. Precipitation falling in a solid state enters the hydrological cycle with a time lag that might be as much as several months after the precipitation event. Therefore, instead of considering the observed values of precipitation when describing the various elements of the hydrological cycle, it is more expedient to take the surface water input into account. This is a fraction of the precipitation which is present on the land surface in a liquid state. Consequently, the most important task of the various snow models within the rainfall - runoff and water budget schemes is to transform the precipitation values observed into surface water input values. Spring time runoff largely depends on the snowmelt component, and it gives the possibility of estimating the expected seasonal volume of the flow and flood peaks. Seasonal forecasts based on the relationship between snow resources and expected precipitation during the spring months have been analyzed for the Danube and Tisza rivers.

scholarly journals HydroPy (v1.0): A new global hydrology model written in Python

2021 ◽  
Author(s):  
Tobias Stacke ◽  
Stefan Hagemann
Keyword(s):  
Surface Water ◽  
Water Balance ◽  
Land Surface ◽  
Max Planck ◽  
Water Balance Components ◽  
Meteorological Model ◽  
Land Surface Water ◽  
Hydrology Model ◽  
Flexible Infrastructure ◽  
The Tropics

Abstract. Global hydrological models (GHMs) are a useful tool in the assessment of the land surface water balance. They are used to further the understanding of interactions between water balance components as well as their past evolution and potential future development under various scenarios. While GHMs are a part of the Hydrologist's toolbox since several decades, the models are continuously developed. In our study, we present the HydroPy model, a revised version of an established GHM, the Max-Planck Institute for Meteorology's Hydrology Model (MPI-HM). Being rewritten in Python, the new model requires much less effort in maintenance and due to its flexible infrastructure, new processes can be easily implemented. Besides providing a thorough documentation of the processes currently implemented in HydroPy, we demonstrate the skill of the model in simulating the land surface water balance. We find that evapotranspiration is reproduced realistically for the majority of the land surface but is underestimated in the tropics. The simulated river discharge correlates well with observations. Biases are evident for the annual accumulated discharge, however they can – at least to some part – be attributed to discrepancies between the meteorological model forcing data and the observations. Finally, we show that HydroPy performs very similar to MPI-HM and, thus, conclude the successful transition from MPI-HM to HydroPy.

scholarly journals Hydroclimatic regimes: a distributed water-balance framework for hydrologic assessment and classification

2014 ◽  
Vol 11 (3) ◽  
pp. 2933-2965 ◽  
Author(s):  
P. K. Weiskel ◽  
D. M. Wolock ◽  
P. J. Zarriello ◽  
R. M. Vogel ◽  
S. B. Levin ◽  
...  
Keyword(s):  
Surface Water ◽  
Water Balance ◽  
20Th Century ◽  
Water Availability ◽  
Land Surface ◽  
Resource Assessment ◽  
Annual Runoff ◽  
Balance Model ◽  
Equal Weight ◽  
Terrestrial Water

Abstract. Runoff-based indicators of terrestrial water availability are appropriate for humid regions, but have tended to limit our basic hydrologic understanding of drylands – the dry-sub-humid, semi-arid, and arid regions which presently cover nearly half of the global land surface. In response, we introduce an indicator framework that gives equal weight to humid and dryland regions, accounting fully for both vertical (precipitation + evapotranspiration) and horizontal (groundwater + surface-water) components of the hydrologic cycle in any given location – as well as fluxes into and out of landscape storage. We apply the framework to a diverse hydroclimatic region (the conterminous USA), using a distributed water-balance model consisting of 53 400 networked landscape hydrologic units. Our model simulations indicate that about 21% of the conterminous USA either generated no runoff or consumed runoff from upgradient sources on a mean-annual basis during the 20th century. Vertical fluxes exceeded horizontal fluxes across 76% of the conterminous area. Long-term average total water availability (TWA) during the 20th century, defined here as the total influx to a landscape hydrologic unit from precipitation, groundwater, and surface water, varied spatially by about 400 000-fold, a range of variation ~100 times larger than that for mean-annual runoff across the same area. The framework includes, but is not limited to classical, runoff-based approaches to water-resource assessment. It also incorporates and re-interprets the green-blue water perspective now gaining international acceptance. Implications of the new framework for hydrologic assessment and classification are explored.

scholarly journals A worldwide analysis of trends in water-balance evapotranspiration

2013 ◽  
Vol 10 (5) ◽  
pp. 5739-5765 ◽  
Author(s):  
A. M. Ukkola ◽  
I. C. Prentice
Keyword(s):  
Water Balance ◽  
Interannual Variability ◽  
Land Surface ◽  
Time Series Data ◽  
Hydrological Cycle ◽  
Atmospheric Co2 ◽  
Series Data ◽  
Additional Control ◽  
Terrestrial Water ◽  
Strong Control

Abstract. Climate change is expected to alter the global hydrological cycle, with inevitable consequences for freshwater availability to people and ecosystems. But the attribution of recent trends in the terrestrial water balance remains disputed. This study attempts to account statistically for both trends and interannual variability in water-balance evapotranspiration (ET), estimated from the annual observed streamflow in 109 river basins during "water years" 1961–1999 and two gridded precipitation datasets. The basins were chosen based on the availability of streamflow time-series data in the Dai et al. (2009) synthesis. They were divided into water-limited "dry" and energy-limited "wet" basins following the Budyko framework. We investigated the potential roles of precipitation, aerosol-corrected solar radiation, land-use change, wind speed, air temperature, and atmospheric CO2. Both trends and variability in ET show strong control by precipitation. There is some additional control of ET trends by vegetation processes, but little evidence for control by other factors. Interannual variability in ET was overwhelmingly dominated by precipitation, which accounted on average for 52–54% of the variation in wet basins (ranging from 0 to 99%) and 84–85% in dry basins (ranging from 13 to 100%). Precipitation accounted for 39–42% of ET trends in wet basins and 69–79% in dry basins. Cropland expansion increased ET in dry basins. Net atmospheric CO2 effects on transpiration, estimated using the Land-surface Processes and eXchanges (LPX) model, did not contribute to observed trends in ET because declining stomatal conductance was counteracted by slightly but significantly increasing foliage cover.

Detailed hydrogeological studies are often necessary to assess the water balance of a watershed. Understanding the hydrogeological structures makes it possible to establish the watershed boundaries, to verify the congruence of the watershed hydrographic boundaries and the boundaries of the groundwater basin (Chapter 2), to locate the aquifers at various depths, and to establish the relationship between these aquifers and the surface water. In reminder, the groundwater system is connected to the hydrological cycle by various processes: infiltration through the unsaturated zone, contribution to ground-water by percolation and leakage, evaporation from the unsaturated zone, and finally, groundwater outflow. Definitions: Aquifers and Types of Groundwater Hydrogeology is based on the analysis of two essential entities: the aquifer and the groundwater table: An is a permeable geological formation (soil or rock) with pores or cracks that interconnect and that are sufficiently large that water can freely circulate under the effect of gravity (examples: sands, gravels, fissured chalk, sandstone, etc). In this way, the aquifer constitutes a reservoir for the groundwater tables. The is all the water contained in the saturated zone of the

Hydrology ◽  
2010 ◽  
pp. 227-228
Keyword(s):  
Surface Water ◽  
Unsaturated Zone ◽  
Hydrological Cycle ◽  
Groundwater Table ◽  
Groundwater System ◽  
Geological Formation ◽  
Groundwater Basin ◽  
Hydrogeological Studies ◽  
The Relationship ◽  
Groundwater Outflow

Understanding the Distinct Impacts of MCS and Non-MCS Rainfall on the Surface Water Balance in the Central United States Using a Numerical Water-Tagging Technique

2020 ◽  
Vol 21 (10) ◽  
pp. 2343-2357
Author(s):  
Huancui Hu ◽  
L. Ruby Leung ◽  
Zhe Feng
Keyword(s):  
United States ◽  
Soil Moisture ◽  
Surface Water ◽  
Water Balance ◽  
Surface Runoff ◽  
Land Surface ◽  
Warm Season ◽  
Surface Model ◽  
Central United States ◽  
Infiltration Excess

ABSTRACTWarm-season rainfall associated with mesoscale convective systems (MCSs) in the central United States is characterized by higher intensity and nocturnal timing compared to rainfall from non-MCS systems, suggesting their potentially different footprints on the land surface. To differentiate the impacts of MCS and non-MCS rainfall on the surface water balance, a water tracer tool embedded in the Noah land surface model with multiparameterization options (WT-Noah-MP) is used to numerically “tag” water from MCS and non-MCS rainfall separately during April–August (1997–2018) and track their transit in the terrestrial system. From the water-tagging results, over 50% of warm-season rainfall leaves the surface–subsurface system through evapotranspiration by the end of August, but non-MCS rainfall contributes a larger fraction. However, MCS rainfall plays a more important role in generating surface runoff. These differences are mostly attributed to the rainfall intensity differences. The higher-intensity MCS rainfall tends to produce more surface runoff through infiltration excess flow and drives a deeper penetration of the rainwater into the soil. Over 70% of the top 10th percentile runoff is contributed by MCS rainfall, demonstrating its important contribution to local flooding. In contrast, lower-intensity non-MCS rainfall resides mostly in the top layer and contributes more to evapotranspiration through soil evaporation. Diurnal timing of rainfall has negligible effects on the flux partitioning for both MCS and non-MCS rainfall. Differences in soil moisture profiles for MCS and non-MCS rainfall and the resultant evapotranspiration suggest differences in their roles in soil moisture–precipitation feedbacks and ecohydrology.

GRACE a witness to the Recovery of the Tigris-Euphrates Hydrologic System

2020 ◽  
Author(s):  
Mohamed Sultan ◽  
Karem Abdelmohsen ◽  
Himanshu Save
Keyword(s):  
Surface Water ◽  
Land Surface ◽  
Global Precipitation Climatology Project ◽  
Water Levels ◽  
Dry Period ◽  
The Past ◽  
Grace Data ◽  
Precipitation Record ◽  
The World ◽  
Precipitation Events

<p>Global warming is producing climatic changes across the world that affect in major ways the livelihood of major sectors of the world’s population. Over the past decade or two, an increase in the frequency and intensity of specific climatic phenomena (e.g., hurricanes, wet or dry periods, etc.) has been reported from many parts of the globe and is believed to be climate change-related. Over the past few years, the largest and most intense precipitation events were recorded over the Tigris and Euphrates watershed (TEW), a heavily engineered watershed (> 60 main dams) that is shared by Turkey, Iran, Syria, Saudi Arabia, and Iraq. Analysis of the Global Precipitation Climatology Project (GPCP) precipitation record over the past 40 year (1979-present) across the TEW revealed a prolonged dry period (2002- to 2017; Average Annual Precipitation [AAP]: 240 km<sup>3</sup>), followed by wet years (2018 to 2020; AAP: 425 km<sup>3</sup>). The recent extensive precipitation events during the wet period are reflected in GRACE and GRACE-FO data. Throughout the dry period there was a total decline in GRACE<sub>TWS</sub> of 212 km<sup>3</sup> (13.3 km<sup>3</sup>/yr) followed by an increase of 246 km<sup>3</sup> (82 km<sup>3</sup>/yr) during the wet period.  In other words, in the past 2.5 years, the TEW more than recovered its losses during the previous 15 years. This recovery was enabled in part by the impoundment of surface water behind the many dams in the riparian countries and by infiltration of precipitation that recharged the TEW aquifers. Using radar altimetry we observe an increase in surface water levels by 8 m in Lake Ataturk, 13 m in Lake Karakaya, 1.5 m in Lake Van in Turkey, 5 m in Lake Assad in Syria, and 16 m in Lake Tharthar, and 24 m in Lake Mosul in Iraq.  These translate to a volume increase of 21.7 km<sup>3</sup> in Turkey, 3.5 km<sup>3</sup> in Syria, and 34 km<sup>3</sup> in Iraq during the wet period. Using GRACE data and outputs of land surface models, we estimate that groundwater storage GRACE<sub>TWS</sub> declined at a rate of -7 km<sup>3</sup>/yr during the dry period and increased at a rate of 60 km<sup>3</sup>/yr during the wet years.</p>

Can the Budyko framework and satellite data help improve hydrological modeling in ungauged and poorly monitored catchments? The case study of the Lurín catchment in Peru

2020 ◽  
Author(s):  
Jan Bondy ◽  
Erwin Zehe ◽  
Jan Wienhöfer
Keyword(s):  
Water Balance ◽  
Land Surface ◽  
Hydrological Modeling ◽  
Temporal Dynamics ◽  
Hydrological Cycle ◽  
Monitoring Network ◽  
Remote Sensing Data ◽  
Water Balance Components ◽  
Spatial Estimates ◽  
Predictions In Ungauged Basins

<p>Predictions in ungauged basins still present one of the major challenges in hydrology. In many cases, the absence of a stream gauge also implies a low density of the meteorological monitoring network in these catchments and surroundings as well as little available data on water management infrastructure and agricultural consumptions. This combination creates a circle of uncertainties and thus individual influences of relevant water balance components are difficult to disentangle and quantify. </p><p>The original Budyko curve presents a very general model that yields, to first order, an estimate of the steady-state water balance of a catchment at the climatological scale, assuming its landscape and functioning has evolved naturally and free of anthropogenic interferences. Even at smaller time scales, the Budyko relationship allows approximating the water partitioning in the catchment, and thus helps correct erroneous assumptions[JW1]  or missing information about for instance unknown human-induced alterations. On the other hand, an increasing variety of global remote-sensing data products is becoming available providing spatial estimates of land surface properties such as for instance vegetation indexes or soil moisture. Even if the predictive power of such products in terms of absolute values remains questionable, it is possible to derive coarse spatial patterns or temporal dynamics to narrow down zones and orders of magnitude of interferences with the natural hydrological cycle such as reservoirs or irrigated lands. This study combines these two general approaches in order to improve hydrological modelling and system understanding of the semi-arid Lurín catchment in the Western Andes of Peru.</p>

Spatial pattern evaluation of remote-sensing evapotranspiration products using surface water-balance approach: application of geostatistical functions for quantifying drivers and dependence structures of ET data

2020 ◽  
Author(s):  
Mohsen Soltani ◽  
Simon Stisen ◽  
Julian Koch
Keyword(s):  
Remote Sensing ◽  
Surface Water ◽  
Water Balance ◽  
Spatial Pattern ◽  
Land Surface ◽  
Spatial Scales ◽  
Principal Component ◽  
Balance Model ◽  
Dependence Structure ◽  
Dependence Structures

<p>Remote sensing-based RS observations can provide evapotranspiration ET estimations across temporal and spatial scales. In this study, two MODIS-based global ET, namely MODIS16 and two-source energy balance model TSEB are compared and evaluated using the surface water-balance WB ET method at monthly time-scale with 1 km spatial resolution for the entire land phase of Denmark (42,087 km<sup>2</sup>). Then, the drivers and underlying dependence structures of ET datasets against land-atmosphere parameters are appropriately quantified using a linear-based multivariate principal component analysis PCA –and nonlinear-based bivariate empirical Copula analysis. For calculation of the surface WB ET method, in addition to the standard WB ET procedure (ET = precipitation P – discharge Q), we introduce a novel modification of standard WB method, which considers a groundwater exchange term. Here, modelled net intercatchment groundwater flow (GW_net) is also included in the ET calculation (ET = P – Q + GW_net); where the simulations are done by the national water resources model of Denmark (the DK-model) executed in the physically-based distributed MIKE-SHE hydrologic modelling code. The differences between the two WB methods are presented and discussed in detail to highlight the importance of considering GW data when investigating water-budget of small catchments. Our analysis will also be extended to compare ET datasets at different spatial scales (catchment size), aiming at further exploring the performance and ET uncertainties of remote sensing-based models. Our results indicate that the novel approach of adding GW-data in WB ET calculation results in a more trustworthy WB ET spatial pattern. This is especially relevant for smaller catchments where GW-exchange can be significant. Large discrepancy is observed in TSEB/MODIS16 ET compared to WB ET spatial pattern at the national scale; however, ∆ET values are regionally small for most watersheds (~60% of all). Also, catchment-based analysis highlights that RS/WB ∆ET decreases from <100km<sup>2</sup> to >200km<sup>2</sup> watersheds, and about 56% (67%) of all catchments have ∆ET ±50 mm/year for TSEB (MODIS16). PCA-based analysis revealed that each ET dataset is largely driven by different parameters. However, land surface temperature LST and solar radiation Rs are found as most relevant driving variables. In addition, Copula-based analysis captures a nonlinear structure of the joint relationship with multiple densities amongst ET products and the parameters, showing a complex underlying dependence structure. Overall, both PCA and Copula analyses indicate that WB and MODIS16 ET products represent a closer spatial pattern compared to TSEB. This study will help improve standard WB ET estimate method and contribute to deeper understanding the inter-correlations and real complex relationships between ET datasets and the nature of land-atmosphere parameters.</p>

scholarly journals Soil Moisture–Vegetation–Carbon Flux Relationship under Agricultural Drought Condition using Optical Multispectral Sensor

2020 ◽  
Vol 12 (9) ◽  
pp. 1359
Author(s):  
Chanyang Sur ◽  
Do-Hyuk Kang ◽  
Kyoung Jae Lim ◽  
Jae E. Yang ◽  
Yongchul Shin ◽  
...  
Keyword(s):  
Soil Moisture ◽  
South Korea ◽  
Land Surface ◽  
Time Lag ◽  
Co2 Flux ◽  
Agricultural Drought ◽  
Drought Period ◽  
Flux Tower ◽  
Vegetation Activity ◽  
The Relationship

Agricultural drought is triggered by a depletion of moisture content in the soil, which hinders photosynthesis and thus increases carbon dioxide (CO2) concentrations in the atmosphere. The aim of this study is to analyze the relationship between soil moisture (SM) and vegetation activity toward quantifying CO2 concentration in the atmosphere. To this end, the MODerate resolution imaging spectroradiometer (MODIS), an optical multispectral sensor, was used to evaluate two regions in South Korea for validation. Vegetation activity was analyzed through MOD13A1 vegetation indices products, and MODIS gross primary productivity (GPP) product was used to calculate the CO2 flux based on its relationship with respiration. In the case of SM, it was calculated through the method of applying apparent thermal inertia (ATI) in combination with land surface temperature and albedo. To validate the SM and CO2 flux, flux tower data was used which are the observed measurement values for the extreme drought period of 2014 and 2015 in South Korea. These two variables were analyzed for temporal variation on flux tower data as daily time scale, and the relationship with vegetation index (VI) was synthesized and analyzed on a monthly scale. The highest correlation between SM and VI (correlation coefficient (r) = 0.82) was observed at a time lag of one month, and that between VI and CO2 (r = 0.81) at half month. This regional study suggests a potential capability of MODIS-based SM, VI, and CO2 flux, which can be applied to an assessment of the global view of the agricultural drought by using available satellite remote sensing products.

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