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Challenges in coping with water problems
Published in Amithirigala Widhanelage Jayawardena, Fluid Mechanics, Hydraulics, Hydrology and Water Resources for Civil Engineers, 2021
Amithirigala Widhanelage Jayawardena
Catchment is a topographically demarcated region which is influenced by the atmosphere from above, the geosphere from below and the biosphere and the hydrosphere from within. The main challenges of catchment hydrology arise as a result of the interactions of influences from these various components, influences brought about by human activities and the need to ensure that the catchment processes are sustainable. In the past, such influences may have existed but to a lesser degree with no conspicuous adverse effects. In recent times, human influences have accelerated, and the cry for a sustainable future has become louder. A better understanding of the dynamics of the catchment is the key to face such challenges.
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Published in Seleshi Getahun Yalew, Integrated Modeling of Land and Water Resources in two African Catchments, 2018
Changes in LULC involve complex socio-economic and biophysical processes: drivers and rates of changes in LULC are different from location to location, and from society to society. The use of static LULC map in hydrologic models as an input to simulating hydrologic responses ignores the fact that LULC is essentially dynamic. Catchment hydrology is, therefore, affected by direct or indirect changes in LULC and associated anthropogenic effects. Direct and indirect effects of natural and human-induced changes in LULC that can affect hydrology include river morphology (roughness), leaf area index, surface resistance, runoff curve number (CN), and rooting depth; all of which are important parameters in hydrologic modelling (Tang, 2016). Recent developments in interdisciplinary socioenvironmental study related to land and water, known as ‘socio-hydrology’ (Elshafei et al., 2015; Gober and Wheater, 2015; Sivapalan et al., 2014), has highlighted the importance of anthropogenic effects on hydrology via proxies such as land-use. Socio-hydrology brings an interest in human values, markets, social organizations and public policy to the traditional emphasis of water science on climate and hydrology. As much as we believe this is an interesting development, the process-response representation of LULC changes in many hydrologic models employed for such analysis is still simplistic. LULC is taken either as a static input or as one that may be, depending on the design of the particular hydrologic model used for the analysis, set to change statistically. Thus, hydrologic responses to dynamic LULC are not well investigated in general, and in the Abbay (Upper Blue Nile) basin in particular.
Water and sustainable cities
Published in Sarah Bell, Urban Water Sustainability, 2017
The movement for water sensitive cities and communities extends earlier efforts in water sensitive urban design, low-impact development and sustainable drainage systems that focussed on sustainable approaches to stormwater management. Since the 1970s engineers and urban designers have developed principles and techniques that mimic natural catchment hydrology in how rainwater that falls on cities is stored, flows, infiltrates the ground and is passively treated before reaching local rivers and other receiving waters (see Chapter 7).
Human-nature relationships and its implications on the management of eastern arc water catchments of Tanzania
Published in Water Science, 2023
M. W. Lema, A. G. Kapinga, G. T. Madamombe, D. Kwawuvi
The relationships existing between humans and water catchments have co-evolved over time and are complicated in nature (Klaver, 2011; Sivapalan, Savenije, & Blöschl, 2012; Troy, Pavao‐zuckerman, & Evans, 2015; Van Meter, Basu, McLaughlin, & Steiff, 2015). This natural complexity is influenced by catchment hydrology, socio-economic and cultural systems, as well as climate patterns (Klaver, 2011; Van Meter, Basu, McLaughlin, & Steiff, 2015). It is well understood that catchment ecosystems provide biotic and abiotic resources that support human life, all over the world (Krause & Strang, 2016; Troy, Pavao‐zuckerman, & Evans, 2015). Despite the importance of catchment resources to human life, it is universally acknowledged that humans have been modifying the catchment ecosystem in various ways, altering the catchment system’s ability to provide relevant goods and services to humans (Klaver, 2011; Krause & Strang, 2016; Sivapalan, Savenije, & Blöschl, 2012). Overexploitation of the catchment resources by humans is one of the major processes that negatively affects the catchment resources’ ability to provide goods and services (Troy, Pavao‐zuckerman, & Evans, 2015).
Quantifying the effects of sediment transport on river channel geometry and flood level – a case study of the December 2014 flood
Published in International Journal of River Basin Management, 2022
Chun Kiat Chang, Aminuddin Ab. Ghani
The effect of rapid urbanization has an accelerated impact on catchment hydrology and geomorphology. Land use and land cover change as a result of development or human activities such as logging in the river catchment areas will cause a dramatic increase in surface runoff. It is noted that during the flood stage, the river stability threatens the entire corridor, due to high sediment yields from the river catchment and consequent generation of sediment load into the river when water floods the riverbanks (Ab. Ghani et al., 2011; Guan et al., 2016). These will cause deposition in the river channels and estuary, which leads to an increased tendency to flooding due to the decrease of the flow capacity of the channels and interruption of boat navigation (He et al., 2020; Slater et al., 2015).
Effect on sediment delivery ratio by changes in land use land cover and construction of hydraulic structures at sub basin scale
Published in Journal of Applied Water Engineering and Research, 2022
The data needed for catchment hydrology modeling are hydro-meteorological, geomorphologic, agricultural, geologic, and hydrologic. The SWAT model needs various input types, like soil classification, LULC, topography, climate, etc. Input data were collected from various sources such as soil data were collected from the National Bureau of Soil Survey and land Use Planning (NBSSULP), LULC images were downloaded from L8OLI/TIRS, climate data like precipitation, temperature data was collected from Central Water Commission (CWC), Indian Meteorological Data (IMD), and Narmada Control Authority (NCA).