China
Africa
Explore chapters and articles related to this topic
4
Published in Jeremiah Kipkulei Kiptala, Managing Basin Interdependencies in a Heterogeneous, Highly Utilized and Data Scarce River Basin in Semi-Arid Africa, 2020
Natural environments such as forests and wetlands provide a wealth of ecosystems goods and services in terms of delayed peak runoff due to retention of excess rainfall, sufficient catchment water yield that ensures base flow in the dry season, sustaining rainfall by means of atmospheric moisture recycling, reduced erosion and improved water quality, from which downstream societies benefit. Natural ecosystems good and services also provide a buffer to local communities during periods of droughts in semi-arid African landscapes (Enfors and Gordon, 2008). Degradation of such environments reduces such benefits significantly. Similarly, increased withdrawals in upper catchments directly affect downstream ecosystems, such as wetlands, riparian vegetation and delta and estuarine ecosystems. Because of undesirable upstream developments, most perennial tributaries in our study area, i. e. the Pangani River Basin in Tanzania, have actually become seasonal in the last few decades (IUCN, 2009).
Isotopic characterization of waters across chile
Published in Diego A. Rivera, Alex Godoy-Faundez, Mario Lillo-Saavedra, Andean Hydrology, 2018
R. Sánchez-Murillo, E. Aguirre-Dueñas, M. Gallardo-Amestica, P. Moya-Vega, C. Birkel, G. Esquivel-Hernández, J. Boll
From a larger scale perspective, Bershaw et al. (2016) conducted an extensive study in modern surface water samples (including the northern Andean Plateau and surrounding regions) to elucidate patterns and causes of isotope fractionation in this continental environment. The authors reported a progressive increase in δ18Ο of stream water west of the eastern Cordillera (~ 1%o/70 km), which they attributed to a larger fraction of moisture recycling and a potential evaporative enrichment downwind, concluding that elevation is a primary control on the isotopic composition of surface water across the entire Andean Plateau and its surrounding areas. Consistent with the early findings by Aravena et al. (1999), Bershaw et al. (2016) and Fiorella et al. (2015a, b) suggested that precipitation patterns in the central Andes Cordillera are mainly governed by the easterly winds, which provide a large supply of moisture. The southeastern Pacific-derived moisture only contributes a minor amount at low elevations near the coast of, for example, La Serena. Similarly, Hoke et al. (2013) conducted a study on the eastern flank of the Andes in the Mendoza Province of Argentina, including a sampling transect in the western flank of the border with Chile (Las Cuevas, 3,200 m a.s.l.). Their results indicated that precipitation on the eastern slopes of the Andes at ~ 33° S, at elevations above 2 km, is largely derived from a westerly Pacific-source component and a mixture of easterly and westerly sources below 2 km.
Seasonal contributions of water and pollutants to Lake St. Charles, a drinking water reservoir
Published in Canadian Water Resources Journal / Revue canadienne des ressources hydriques, 2020
Biljana Narancic, Isabelle Laurion, Brent B. Wolfe, Sonja Behmel, Alain N. Rousseau
A six-season snapshot of LSC and its water source isotope composition provides insights into the hydrological regime of this lake. LSC and its water sources span a narrow range of isotope compositions and do not display any evaporative enrichment, supporting the known fluvial nature of this lake with a relatively short residence time. Some water source isotope compositions plotted above the GMWL/LMWL, reflecting the importance of precipitation from local moisture recycling (Clark and Fritz 1997; Froehlich et al. 2008; Wenling et al. 2017).
Water resilience and human life support - global outlook for the next half century
Published in International Journal of Water Resources Development, 2020
Agricultural and land use decisions involve direct impacts on vertical water flows, i.e. the amounts of water that enter and leave the atmosphere. Keys (2016) showed that the removal of vegetation in Mato Grosso, Brazil, altered the amount of rainfall over the land downwind, and even the seasonality of the rainfall. Such moisture-recycling-related findings imply that vegetation changes in one location may cause large changes far away in rainfall, soil moisture, crop production and even blue water flows (Figure 5).