scholarly journals Comments on ‘Role of subsurface flow in generating surface runoff: 1, Base flow contributions to channel flow’ by R. Allan Freeze

1973 ◽  
Vol 9 (2) ◽  
pp. 489-490 ◽  
Author(s):  
W. M. Snyder
Author(s):  
Saed Khayat

Possible factors that play a role in restoring a flow regime that supports a healthy environment were identified for Wadi Zomar, Palestine. The hydrograph shows that threshold discharges for bed drying are less than 0.14 m3/s, bar formation is less than 0.4 ms/s and floodplain inundation events are over 3 m3/s. The HEC-RAS model suggests a continuous discharge throughout the year that maintains the base flow in the range of 0.5 m3/s. The model suggests that the restoration process is controlled by two main factors: role of sufficient flow and flood inundation frequency


2021 ◽  
Vol 25 (3) ◽  
pp. 65-72
Author(s):  
A.S. Solomentseva ◽  

The critical abrasion situation manifests itself on the coastal part of the Kalachevsky district due to the increasing anthropogenic load. The most important element of the complex of measures to combat silting of reservoirs and coastal abrasion, as well as an effective measure to strengthen the banks is forest vegetation. The objectives of the research were to study the soil, forest and climatic conditions of the object under study, to develop an assortment of shrubs and features of the formation of protective forest stands, as well as criteria for selecting an adapted assortment of tree and shrub vegetation and methods of caring for the soil and plantings. During the research, the most promising types of shrubs for creating upper protective forest stands were identified: Ligustrum vilgare L., Berberis vulgaris L., Cotoneaster lucidus Schltdl., Amelanchier Medik., Ribes aureum Pursh., Rosa canina L. It was found that the useful role of forest stands is manifested in their ability to convert surface runoff into subsurface runoff, to clean surface stock water from fine-grained soil, to weaken the speed of movement and to extinguish the energy of waves, binding the soil with roots. Recommendations are given for the creation and placement of anti-abrasion plantings, depending on the steepness and height of the slope. It is stated that one of the main measures for the care of the aboveground part of the plantings is the pruning of the crown, carried out taking into account the biological characteristics of their growth and development, including the removal of dry and damaged branches, thinning of the crown, preservation of the previously given crown size, rejuvenation of the crown. It is recommended to place shrubs depending on the landscape, soil and climatic conditions and features of abrasive processes in areas of constant, periodic, episodic flooding and strong moderate and weak flooding of the coastline.


2016 ◽  
Vol 8 (1) ◽  
pp. 17
Author(s):  
Tadashi Tanaka

Variation of water chemistry does not merely occur due to in situ chemical process, but also transport process. The study was carried out to address the role of subsurface flow dynamic on spatial and temporal variation of water chemistry in a headwater catchment. Hydrometric and hydrochemistry measurements were done in transect with nested piezometers, tensiometers, and suction samplers at different depths across hillslope and riparian zone in a 5.2 ha first-order drainage of the Kawakami experimental basin, Nagano, Central Japan from August 2000 to August 2001. Spatial variation of solute concentration was defined by the standard deviation and coefficient of variation of the seasonal observed concentrations. Autocorrelation analysis was performed to define temporal variation of solute concentration. The results showed that spatial variation of water chemistry was mainly influenced by the variation of subsurface flow through the hillslope and riparian zone. Solute concentration in the deep riparian groundwater was almost three times higher than that in the hillslope segment. A prominent downward flow in deep riparian groundwater zone provided transport of solutes to the deeper layer. Time series analysis showed that in the deep riparian groundwater, Ca2+, Mg2+, SO42- and HCO3- concentrations underwent a random process, Na+ concentration of a random process superimposed by a trend process, and SiO2 of a random process superimposed by a periodic process. Near the riparian surface, SO42- concentration was composed of a random process superimposed by a periodic process, whereas other solutes were mainly in a random process. In the hillslope soil water, there was no trend observed for the Na+ concentration, but there were for Ca2+ and Mg2+. The magnitude and direction of subsurface flow across hillslope and riparian zone created transport and deposition processes that changed solute concentration spatially and temporally.


Sign in / Sign up

Export Citation Format

Share Document