A simple topography-driven and calibration-free runoff generation module

Abstract. Reading landscapes and developing calibration-free runoff generation models that adequately reflect land surface heterogeneities remains the focus of much hydrological research. In this study, we report a novel and simple topography-driven runoff generation parameterization – the HAND-based Storage Capacity curve (HSC), that uses a topographic index (HAND, Height Above the Nearest Drainage) to identify hydrological similarity and the extent of saturated areas in catchments. The HSC can be used as a module in any conceptual rainfall-runoff model. Further, coupling the HSC parameterization with the Mass Curve Technique (MCT) to estimate root zone storage capacity (SuMax), we developed a calibration-free runoff generation module HSC-MCT. The runoff generation modules of HBV and TOPMODEL were used for comparison purposes. The performance of these two modules (HSC and HSC-MCT) was first checked against the data-rich Bruntland Burn (BB) catchment in Scotland, which has a long time series of field-mapped saturation area extent. We found that the HSC performed better in reproducing the spatio-temporal pattern of the observed saturated areas in the BB compared to TOPMODEL. The HSC and HSC-MCT modules were subsequently tested for 323 MOPEX catchments in the US, with diverse climate, soil, vegetation and geological characteristics. Comparing with HBV and TOPMODEL, the HSC performs better in both calibration and validation. Despite having no calibrated parameters, the HSC-MCT module performed comparably well with calibrated modules, highlighting the robustness of the HSC parameterization to describe the spatial distribution of the root zone storage capacity and the efficiency of the MCT method to estimate SuMax. Moreover, the HSC-MCT module facilitated effective visualization of the saturated area, which has the potential to be used for broader hydrological, ecological, climatological, geomorphological, and biogeochemical studies.

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A simple topography-driven and calibration-free runoff generation module

Hydrology and Earth System Sciences ◽

10.5194/hess-23-787-2019 ◽

2019 ◽

Vol 23 (2) ◽

pp. 787-809 ◽

Cited By ~ 10

Author(s):

Hongkai Gao ◽

Christian Birkel ◽

Markus Hrachowitz ◽

Doerthe Tetzlaff ◽

Chris Soulsby ◽

...

Keyword(s):

Land Surface ◽

Forest Cover ◽

Storage Capacity ◽

Root Zone ◽

Global Scale ◽

Runoff Generation ◽

The Us ◽

Long Time ◽

Calibration Free ◽

Rainfall Runoff Model

Abstract. Reading landscapes and developing calibration-free runoff generation models that adequately reflect land surface heterogeneities remains the focus of much hydrological research. In this study, we report a novel and simple topography-driven runoff generation parameterization – the HAND-based Storage Capacity curve (HSC), which uses a topographic index (HAND, Height Above the Nearest Drainage) to identify hydrological similarity and the extent of saturated areas in catchments. The HSC can be used as a module in any conceptual rainfall–runoff model. Further, coupling the HSC parameterization with the mass curve technique (MCT) to estimate root zone storage capacity (SuMax), we developed a calibration-free runoff generation module, HSC-MCT. The runoff generation modules of HBV and TOPMODEL were used for comparison purposes. The performance of these two modules (HSC and HSC-MCT) was first checked against the data-rich Bruntland Burn (BB) catchment in Scotland, which has a long time series of field-mapped saturation area extent. We found that HSC, HBV and TOPMODEL all perform well to reproduce the hydrograph, but the HSC module performs better in reproducing saturated area variation, in terms of correlation coefficient and spatial pattern. The HSC and HSC-MCT modules were subsequently tested for 323 MOPEX catchments in the US, with diverse climate, soil, vegetation and geological characteristics. In comparison with HBV and TOPMODEL, the HSC performs better in both calibration and validation, particularly in the catchments with gentle topography, less forest cover, and arid climate. Despite having no calibrated parameters, the HSC-MCT module performed comparably well with calibrated modules, highlighting the robustness of the HSC parameterization to describe the spatial distribution of the root zone storage capacity and the efficiency of the MCT method to estimate SuMax. This novel and calibration-free runoff generation module helps to improve the prediction in ungauged basins and has great potential to be generalized at the global scale.

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Cosmic Ray Neutron Sensing: Integration with land surface modelling using data assimilation for improved field-scale soil moisture estimates

10.5194/egusphere-egu2020-10419 ◽

2020 ◽

Author(s):

Amol Patil ◽

Benjamin Fersch ◽

Harrie-Jan Hendricks-Franssen ◽

Harald Kunstmann

Keyword(s):

Soil Moisture ◽

Data Assimilation ◽

Spatial Resolution ◽

Land Surface ◽

Root Zone ◽

Cosmic Ray ◽

Soil Parameters ◽

Surface Model ◽

Field Scale ◽

Spatio Temporal

<p>Soil moisture is a key variable in atmospheric modelling to resolve the partitioning of net radiation into sensible and latent heat fluxes. Therefore, high resolution spatio-temporal soil moisture estimation is getting growing attention in this decade. The recent developments to observe soil moisture at field scale (170 to 250 m spatial resolution) using Cosmic Ray Neutron Sensing (CRNS) technique has created new opportunities to better resolve land surface atmospheric interactions; however, many challenges remain such as spatial resolution mismatch and estimation uncertainties. Our study couples the Noah-MP land surface model to the Data Assimilation Research Testbed (DART) for assimilating CRN intensities to update model soil moisture. For evaluation, the spatially distributed Noah-MP was set up to simulate the land surface variables at 1 km horizontal resolution for the Rott and Ammer catchments in southern Germany. The study site comprises the TERENO-preAlpine observatory with five CRNS stations and additional CRNS measurements for summer 2019 operated by our Cosmic Sense research group. We adjusted the soil parametrization in Noah-MP to allow the usage of EU soil data along with Mualem-van Genuchten soil hydraulic parameters. We use independent observations from extensive soil moisture sensor network (SoilNet) within the vicinity of CRNS sensors for validation. Our detailed synthetic and real data experiments are evaluated for the analysis of the spatio-temporal changes in updated root zone soil moisture and for implications on the energy balance component of Noah-MP. Furthermore, we present possibilities to estimate root zone soil parameters within the data assimilation framework to enhance standalone model performance.</p>

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Derivation of the Spatial Distribution of Free Water Storage Capacity Based on Topographic Index

Water ◽

10.3390/w10101407 ◽

2018 ◽

Vol 10 (10) ◽

pp. 1407

Author(s):

Bingxing Tong ◽

Zhijia Li ◽

Cheng Yao ◽

Jingfeng Wang ◽

Yingchun Huang

Keyword(s):

Spatial Distribution ◽

Spatial Variability ◽

Land Surface ◽

Storage Capacity ◽

Water Storage ◽

Free Water ◽

Flood Events ◽

Runoff Generation ◽

Topographic Index ◽

Water Storage Capacity

Free water storage capacity, an important characteristic of land surface related to runoff process, has a significant influence on runoff generation and separation. It is thus necessary to derive reasonable spatial distribution of free water storage capacity for rainfall-runoff simulation, especially in distributed modeling. In this paper, a topographic index based approach is proposed for the derivation of free water storage capacity spatial distribution. The topographic index, which can be obtained from digital elevation model (DEM), are used to establish a functional relationship with free water storage capacity in the proposed approach. In this case, the spatial variability of free water storage capacity can be directly estimated from the characteristics of watershed topography. This approach was tested at two medium sized watersheds, including Changhua and Chenhe, with the drainage areas of 905 km2 and 1395 km2, respectively. The results show that locations with larger values of free water storage capacity generally correspond to locations with higher topographic index values, such as riparian region. The estimated spatial distribution of free water storage capacity is also used in a distributed, grid-based Xinanjiang model to simulate 10 flood events for Chenhe Watershed and 17 flood events for Changhua Watershed. Our analysis indicates that the proposed approach based on topographic index can produce reasonable spatial variability of free water storage capacity and is more suitable for flood simulation.

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Global root zone storage capacity from satellite-based evaporation

Hydrology and Earth System Sciences ◽

10.5194/hess-20-1459-2016 ◽

2016 ◽

Vol 20 (4) ◽

pp. 1459-1481 ◽

Cited By ~ 43

Author(s):

Lan Wang-Erlandsson ◽

Wim G. M. Bastiaanssen ◽

Hongkai Gao ◽

Jonas Jägermeyr ◽

Gabriel B. Senay ◽

...

Keyword(s):

Return Period ◽

Land Surface ◽

Storage Capacity ◽

Root Zone ◽

Global Scale ◽

Rooting Depth ◽

Surface Modelling ◽

Direct Measurements ◽

Land Surface Modelling ◽

Model Independent

Abstract. This study presents an "Earth observation-based" method for estimating root zone storage capacity – a critical, yet uncertain parameter in hydrological and land surface modelling. By assuming that vegetation optimises its root zone storage capacity to bridge critical dry periods, we were able to use state-of-the-art satellite-based evaporation data computed with independent energy balance equations to derive gridded root zone storage capacity at global scale. This approach does not require soil or vegetation information, is model independent, and is in principle scale independent. In contrast to a traditional look-up table approach, our method captures the variability in root zone storage capacity within land cover types, including in rainforests where direct measurements of root depths otherwise are scarce. Implementing the estimated root zone storage capacity in the global hydrological model STEAM (Simple Terrestrial Evaporation to Atmosphere Model) improved evaporation simulation overall, and in particular during the least evaporating months in sub-humid to humid regions with moderate to high seasonality. Our results suggest that several forest types are able to create a large storage to buffer for severe droughts (with a very long return period), in contrast to, for example, savannahs and woody savannahs (medium length return period), as well as grasslands, shrublands, and croplands (very short return period). The presented method to estimate root zone storage capacity eliminates the need for poor resolution soil and rooting depth data that form a limitation for achieving progress in the global land surface modelling community.

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Effects of drainage treatment and stand growth on changes in runoff components from a forested watershed

Journal of Forest Science ◽

10.17221/103/2009-jfs ◽

2010 ◽

Vol 56 (No. 7) ◽

pp. 307-313

Author(s):

V. Černohous ◽

F. Šach ◽

D. Kacálek

Keyword(s):

Land Surface ◽

Overland Flow ◽

Source Area ◽

Base Flow ◽

Forested Watershed ◽

Runoff Generation ◽

Forest Environment ◽

Variable Source ◽

Positive Ratio ◽

Long Time

Runoff generation under various natural conditions has often been studied in forested watersheds for a long time. In 1967, Hewlett designed a variable source area model. The model is based on the expansion and shrinkage of variable source areas and consequent changes in a drainage network during a discharge event. The runoff investigation was carried out in a forested watershed situated in the summit area of the Orlické hory Mts. The watershed has a drainage area of 32.6 ha with the land-surface elevation ranging from 880 to 940 m a.s.l. Runoff components, their amounts and ratios were calculated using a simple graphical-mathematical method of the hydrograph recession limb analysis according to a reservoir model representing the particular components (base flow, subsurface flow and overland flow, in other words slow, accelerated and rapid flows). Comparing the amount of slow and rapid runoff constituents (89.5–99.4% and 0.6–10.5%, respectively), the greater amount of slowly moving water confirmed that overland flow was absent under conditions of forest environment. Not even the drainage treatment altered this positive ratio of the runoff constituents. During the third period, under stabilized hydrology and stand conditions, the accelerated and rapid runoff increased again, however maximally by 10% and 4%, respectively, not reaching the initial size of the calibration period.

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Global root zone storage capacity from satellite-based evaporation

10.5194/hess-2015-533 ◽

2016 ◽

Cited By ~ 3

Author(s):

L. Wang-Erlandsson ◽

W. G. M. Bastiaanssen ◽

H. Gao ◽

J. Jägermeyr ◽

G. B. Senay ◽

...

Keyword(s):

Return Period ◽

Land Surface ◽

Storage Capacity ◽

Root Zone ◽

Global Scale ◽

Rooting Depth ◽

Surface Modelling ◽

Evergreen Forests ◽

Direct Measurements ◽

Land Surface Modelling

Abstract. This study presents an "earth observation-based" method for estimating root zone storage capacity – a critical, yet uncertain parameter in hydrological and land surface modelling. By assuming that vegetation optimises its root zone storage capacity to bridge critical dry periods, we were able to use state-of-the-art satellite-based evaporation data computed with independent energy balance equations to derive gridded root zone storage capacity at global scale. This approach does not require soil or vegetation information, is model-independent, and is in principle scale-independent. In contrast to traditional look-up table approaches, our method captures the variability in root zone storage capacity within land cover types, including in rainforests where direct measurements of root depths otherwise are scarce. Implementing the estimated root zone storage capacity in the global hydrological model STEAM improved evaporation simulation overall, and in particular during the least evaporating months in sub-humid to humid regions with moderate to high seasonality. We find that evergreen forests are able to create a large storage to buffer for severe droughts (with a return period of 10–20 years), in contrast to short vegetation and crops (which seem to adapt to a drought return period of about 2 years). The presented method to estimate root zone storage capacity reduces the dependency on soil and rooting depth data of poor resolution that form a limitation for achieving progress in the global land surface modelling community.

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Challenges of the parliamentary system in Iraq after 2003

Tikrit Journal For Political Science ◽

10.25130/poltic.v3i10.27 ◽

2019 ◽

Vol 3 (10) ◽

pp. 101

Author(s):

Emad Wakaa Ajil

Keyword(s):

Political System ◽

Separation Of Powers ◽

Political Process ◽

The United States ◽

Arab Countries ◽

The Political ◽

Parliamentary System ◽

Political Transformations ◽

The Us ◽

Long Time

Iraq is one of the most Arab countries where the system of government has undergone major political transformations and violent events since the emergence of the modern Iraqi state in 1921 and up to the present. It began with the monarchy and the transformation of the regime into the republican system in 1958. In the republican system, Continued until 2003, and after the US occupation of Iraq in 2003, the regime changed from presidential to parliamentary system, and the parliamentary experience is a modern experience for Iraq, as he lived for a long time without parliamentary experience, what existed before 2003, can not be a parliamentary experience , The experience righteousness The study of the parliamentary system in particular and the political process in general has not been easy, because it is a complex and complex process that concerns the political system and its internal and external environment, both of which are influential in the political system and thus on the political process as a whole, After the US occupation of Iraq, the United States intervened to establish a permanent constitution for the country. Despite all the circumstances accompanying the drafting of the constitution, it is the first constitution to be drafted by an elected Constituent Assembly. The Iraqi Constitution adopted the parliamentary system of government and approved the principle of flexible separation of powers in order to achieve cooperation and balance between the authorities.

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Comparison of spatio-temporal transmission characteristics of COVID-19 and its mitigation strategies in China and the US

Journal of Geographical Sciences ◽

10.1007/s11442-020-1822-8 ◽

2020 ◽

Vol 30 (12) ◽

pp. 1963-1984

Author(s):

Zhiming Feng ◽

Chiwei Xiao ◽

Peng Li ◽

Zhen You ◽

Xu Yin ◽

...

Keyword(s):

Mitigation Strategies ◽

Transmission Characteristics ◽

The Us ◽

Spatio Temporal

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Spatio-Temporal Hydrological Model Structure and Parametrization Analysis

Journal of Marine Science and Engineering ◽

10.3390/jmse9050467 ◽

2021 ◽

Vol 9 (5) ◽

pp. 467

Author(s):

Mostafa Farrag ◽

Gerald Corzo Perez ◽

Dimitri Solomatine

Keyword(s):

Hydrological Modeling ◽

Model Building ◽

Model Performance ◽

Model Description ◽

Generation Model ◽

Model Structure ◽

Runoff Generation ◽

Spatial Sensitivity ◽

Spatio Temporal ◽

Set Up

Many grid-based spatial hydrological models suffer from the complexity of setting up a coherent spatial structure to calibrate such a complex, highly parameterized system. There are essential aspects of model-building to be taken into account: spatial resolution, the routing equation limitations, and calibration of spatial parameters, and their influence on modeling results, all are decisions that are often made without adequate analysis. In this research, an experimental analysis of grid discretization level, an analysis of processes integration, and the routing concepts are analyzed. The HBV-96 model is set up for each cell, and later on, cells are integrated into an interlinked modeling system (Hapi). The Jiboa River Basin in El Salvador is used as a case study. The first concept tested is the model structure temporal responses, which are highly linked to the runoff dynamics. By changing the runoff generation model description, we explore the responses to events. Two routing models are considered: Muskingum, which routes the runoff from each cell following the river network, and Maxbas, which routes the runoff directly to the outlet. The second concept is the spatial representation, where the model is built and tested for different spatial resolutions (500 m, 1 km, 2 km, and 4 km). The results show that the spatial sensitivity of the resolution is highly linked to the routing method, and it was found that routing sensitivity influenced the model performance more than the spatial discretization, and allowing for coarser discretization makes the model simpler and computationally faster. Slight performance improvement is gained by using different parameters’ values for each cell. It was found that the 2 km cell size corresponds to the least model error values. The proposed hydrological modeling codes have been published as open-source.

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Enhanced Estimation of Root Zone Soil Moisture at 1 km Resolution Using SMAR Model and MODIS-Based Downscaled AMSR2 Soil Moisture Data

Sensors ◽

10.3390/s21155211 ◽

2021 ◽

Vol 21 (15) ◽

pp. 5211

Author(s):

Maedeh Farokhi ◽

Farid Faridani ◽

Rosa Lasaponara ◽

Hossein Ansari ◽

Alireza Faridhosseini

Keyword(s):

Soil Moisture ◽

Prediction Models ◽

Surface Soil ◽

Root Zone ◽

Analytical Relationship ◽

Moisture Profile ◽

Essential Variable ◽

Potential Benefits ◽

Spatio Temporal ◽

Hydrological Prediction

Root zone soil moisture (RZSM) is an essential variable for weather and hydrological prediction models. Satellite-based microwave observations have been frequently utilized for the estimation of surface soil moisture (SSM) at various spatio-temporal resolutions. Moreover, previous studies have shown that satellite-based SSM products, coupled with the soil moisture analytical relationship (SMAR) can estimate RZSM variations. However, satellite-based SSM products are of low-resolution, rendering the application of the above-mentioned approach for local and pointwise applications problematic. This study initially attempted to estimate SSM at a finer resolution (1 km) using a downscaling technique based on a linear equation between AMSR2 SM data (25 km) with three MODIS parameters (NDVI, LST, and Albedo); then used the downscaled SSM in the SMAR model to monitor the RZSM for Rafsanjan Plain (RP), Iran. The performance of the proposed method was evaluated by measuring the soil moisture profile at ten stations in RP. The results of this study revealed that the downscaled AMSR2 SM data had a higher accuracy in relation to the ground-based SSM data in terms of MAE (↓0.021), RMSE (↓0.02), and R (↑0.199) metrics. Moreover, the SMAR model was run using three different SSM input data with different spatial resolution: (a) ground-based SSM, (b) conventional AMSR2, and (c) downscaled AMSR2 products. The results showed that while the SMAR model itself was capable of estimating RZSM from the variation of ground-based SSM data, its performance increased when using downscaled SSM data suggesting the potential benefits of proposed method in different hydrological applications.

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