RUNOFF RESPONSE IN A SEMI-ARID HEADWATER DRIVEN BY CATCHMENT-SCALE WATER MOVEMENT

2017 ◽  
Author(s):  
Suzanne P. Anderson ◽  
◽  
Adam Wlostowski ◽  
Sheila Murphy ◽  
Nathan D. Rock ◽  
...  
Keyword(s):  
Water Movement ◽  
Catchment Scale ◽  
Semi Arid

Water movement and fate of nitrogen during drip dispersal of wastewater effluent into a semi-arid landscape

2014 ◽  
Vol 52 ◽  
pp. 178-187 ◽  
Author(s):  
Robert L. Siegrist ◽  
Rebecca Parzen ◽  
Jill Tomaras ◽  
Kathryn S. Lowe
Keyword(s):  
Water Movement ◽  
Wastewater Effluent ◽  
Fate Of Nitrogen ◽  
Semi Arid

scholarly journals Towards a simple representation of chalk hydrology in land surface modelling

2017 ◽  
Vol 21 (1) ◽  
pp. 459-471 ◽  
Author(s):  
Mostaquimur Rahman ◽  
Rafael Rosolem
Keyword(s):  
Land Surface ◽  
Unsaturated Zone ◽  
Large Scale ◽  
Management Practices ◽  
Preferential Flow ◽  
Water Movement ◽  
Model Parameters ◽  
Catchment Scale ◽  
Surface Modelling ◽  
Land Surface Modelling

Abstract. Modelling and monitoring of hydrological processes in the unsaturated zone of chalk, a porous medium with fractures, is important to optimize water resource assessment and management practices in the United Kingdom (UK). However, incorporating the processes governing water movement through a chalk unsaturated zone in a numerical model is complicated mainly due to the fractured nature of chalk that creates high-velocity preferential flow paths in the subsurface. In general, flow through a chalk unsaturated zone is simulated using the dual-porosity concept, which often involves calibration of a relatively large number of model parameters, potentially undermining applications to large regions. In this study, a simplified parameterization, namely the Bulk Conductivity (BC) model, is proposed for simulating hydrology in a chalk unsaturated zone. This new parameterization introduces only two additional parameters (namely the macroporosity factor and the soil wetness threshold parameter for fracture flow activation) and uses the saturated hydraulic conductivity from the chalk matrix. The BC model is implemented in the Joint UK Land Environment Simulator (JULES) and applied to a study area encompassing the Kennet catchment in the southern UK. This parameterization is further calibrated at the point scale using soil moisture profile observations. The performance of the calibrated BC model in JULES is assessed and compared against the performance of both the default JULES parameterization and the uncalibrated version of the BC model implemented in JULES. Finally, the model performance at the catchment scale is evaluated against independent data sets (e.g. runoff and latent heat flux). The results demonstrate that the inclusion of the BC model in JULES improves simulated land surface mass and energy fluxes over the chalk-dominated Kennet catchment. Therefore, the simple approach described in this study may be used to incorporate the flow processes through a chalk unsaturated zone in large-scale land surface modelling applications.

scholarly journals Aquatic systems in semi-arid Brazil: limnology and management

2012 ◽  
Vol 24 (1) ◽  
pp. 103-118 ◽  
Author(s):  
José Etham de Lucena Barbosa ◽  
Elvio Sérgio Figueredo Medeiros ◽  
Jandeson Brasil ◽  
Raquel da Silva Cordeiro ◽  
Maria Cristina Basilio Crispim ◽  
...  
Keyword(s):  
Arid Region ◽  
Aquatic Systems ◽  
Future Research ◽  
Catchment Scale ◽  
Water Shortages ◽  
Holistic Model ◽  
Biological Communities ◽  
Lakes And Reservoirs ◽  
Semi Arid Region ◽  
Semi Arid

Aquatic systems in semi-arid Brazil include natural shallow lakes, artificial reservoirs and intermittent streams and rivers. These systems are distinctive features in the semi-arid landscape and comprise a range of associated systems functioning as an ever-changing mosaic of dry/wet patches. Lakes and reservoirs in semi-arid Brazil are subject to important periods of water shortages, whereas rivers and streams are characterized as highly variable and driven by the extremes of water flow and its absence. Within this view a catchment-scale approach must be used to create a holistic model to conceptualize and comprehend these aquatic systems, since the aquatic environment types in the semi-arid region of Brazil incorporate broader aspects within the catchment scale such as geomorphology, vegetation, climate and land use. This paper summarizes some of the information on the aquatic systems of the Brazilian semi-arid region and shows the importance of limnological studies in this region. It also attempts to establish perspectives for future research considering the catchment as a scale for surveying biological processes and limnological characteristics of the various aquatic systems. It is presented information on their overall structure and functioning, as well as characteristics of some biological communities, such as phytoplankton, periphyton, aquatic macrophytes, benthic invertebrates and fish. The importance of the understanding of eutrophication in reservoirs and the role of the dry phase in streams is emphasized, and information on possible actions of planning and management to improve water quality of reservoirs are presented.

scholarly journals Modelling Small-Scale Storage Interventions in Semi-Arid India at the Basin Scale

2021 ◽  
Vol 13 (11) ◽  
pp. 6129
Author(s):  
Robyn Horan ◽  
Pawan S. Wable ◽  
Veena Srinivasan ◽  
Helen E. Baron ◽  
Virginie J. D. Keller ◽  
...  
Keyword(s):  
Water Resource Management ◽  
Large Scale ◽  
Data Availability ◽  
Small Scale ◽  
Catchment Scale ◽  
Check Dams ◽  
Basin Scale ◽  
The Impact ◽  
Availability Assessment ◽  
Semi Arid

There has been renewed interest in the performance, functionality, and sustainability of traditional small-scale storage interventions (check dams, farm bunds and tanks) used within semi-arid regions for the improvement of local water security and landscape preservation. The Central Groundwater Board of India is encouraging the construction of such interventions for the alleviation of water scarcity and to improve groundwater recharge. It is important for water resource management to understand the hydrological effect of these interventions at the basin scale. The quantification of small-scale interventions in hydrological modelling is often neglected, especially in large-scale modelling activities, as data availability is low and their hydrological functioning is uncertain. A version of the Global Water Availability Assessment (GWAVA) water resources model was developed to assess the impact of interventions on the water balance of the Cauvery Basin and two smaller sub-catchments. Model results demonstrate that farm bunds appear to have a negligible effect on the average annual simulated streamflow at the outlets of the two sub-catchments and the basin, whereas tanks and check dams have a more significant and time varying effect. The open water surface of the interventions contributed to an increase in evaporation losses across the catchment. The change in simulated groundwater storage with the inclusion of interventions was not as significant as catchment-scale literature and field studies suggest. The model adaption used in this study provides a step-change in the conceptualisation and quantification of the consequences of small-scale storage interventions in large- or basin-scale hydrological models.

scholarly journals Water Storage in Dry Riverbeds of Arid and Semi-Arid Regions: Overview, Challenges, and Prospects of Sand Dam Technology

2021 ◽  
Vol 13 (11) ◽  
pp. 5905
Author(s):  
Bisrat Ayalew Yifru ◽  
Min-Gyu Kim ◽  
Jeong-Woo Lee ◽  
Il-Hwan Kim ◽  
Sun-Woo Chang ◽  
...  
Keyword(s):  
Arid Regions ◽  
Maintenance Cost ◽  
Water Harvesting ◽  
Catchment Scale ◽  
Open Defecation ◽  
Sediment Properties ◽  
Hydrogeological Characteristics ◽  
And Storage ◽  
Semi Arid ◽  
The Ideal

Augmenting water availability using water-harvesting structures is of importance in arid and semi-arid regions (ASARs). This paper provides an overview and examines challenges and prospects of the sand dam application in dry riverbeds of ASARs. The technology filters and protects water from contamination and evaporation with low to no maintenance cost. Sand dams improve the socio-economy of the community and help to cope with drought and climate change. However, success depends on the site selection, design, and construction. The ideal site for a sand dam is at a transition between mountains and plains, with no bend, intermediate slope, and impermeable riverbed in a catchment with a slope greater than 2°. The spillway dimensioning considers the flow velocity, sediment properties, and storage target, and the construction is in multi-stages. Recently, the failure of several sand dams because of incorrect siting, evaporation loss, and one-stage construction were reported. Revision of practitioners’ manuals by considering catchment scale hydrological and hydrogeological characteristics, spillway height, and sediment transport are recommended. Research shows that protected wells have better water quality than open wells and scoop holes. Therefore, the community should avoid open defecation, pit latrines, tethering of animals, and applying pesticides near the sand dam.

scholarly journals Soil Freeze-Thaw and Water Transport Characteristics Under Different Vegetation Types in Seasonal Freeze-Thaw Areas of the Loess Plateau

2021 ◽  
Vol 9 ◽  
Author(s):  
Lanfeng Bo ◽  
Zhanbin Li ◽  
Peng Li ◽  
Guoche Xu ◽  
Lie Xiao ◽  
...  
Keyword(s):  
Soil Water ◽  
Loess Plateau ◽  
Water Movement ◽  
Vegetation Types ◽  
The Loess Plateau ◽  
Freezing And Thawing ◽  
Freezing Period ◽  
Thawing Processes ◽  
Semi Arid ◽  
Soil Water Movement

In the arid and semi-arid regions of the Loess Plateau, seasonal freezing and thawing influence soil water movement, and water movement directly influences vegetation growth. However, currently, research with regard to freezing and thawing processes under various vegetation types and the mechanism of soil water movement is lacking. Therefore, the present study explored soil water migration characteristics of two typical vegetation types [arbor land (AL) and shrub land (SL)] on the Loess Plateau during seasonal freezing and thawing processes using bare land (BL) as a control. We used field measured data for hourly soil temperature (ST) and soil water content (SWC) at a depth of 100 cm below the soil surface from November 2017 to March 2018. Freezing and thawing process was divided into three stages based on ST change (initial freezing period, stable freezing period, and thawing period). Compared with previous studies in this area, ST is lower than expected, and SWC migration characteristics are also different. The results revealed that: 1) the maximum freezing depth of AL and SL was 60 cm, which was 30 cm less than that of BL. The freezing date of each soil layer in BL was the earliest and average ST value was the lowest. BL had the highest degree of freezing. The freezing of all soil layers in AL occurred at a later date than that of SL. ST and the minimum soil freezing temperatures were higher than those of SL, and the capacity of AL to resist freezing was higher; 2) the SWCs in AL and BL at depths of 0–10 cm and 10–30 cm decreased, whereas SWCs of AL and BL at a depth of 60 cm increased by 152 and 146%, respectively. The SWCs of SL at soil depths of 0–10 cm, 10–30 cm, and 30–60 cm increased by 46.3, 78.4 and 205%, respectively. The amount and distribution of soil moisture in SL were optimum when compared to those of AL and BL. The results of the present study could provide a scientific basis for vegetation restoration in arid and semi-arid areas of the Loess Plateau.

Sign in / Sign up

Export Citation Format

Share Document