A study of variability of annual river flow of the southern African region

Fanta, Berhanu; Zaake, B. T.; Kachroo, R.K.

doi:10.1080/02626660109492847

Cited by 42 publications

(38 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Wilk and Hughes (2002) studied the impacts of land-use and climate change on water resource availability for a large south Indian catchment. Fanta et al (2001) studied the availability of annual river flow in the southern African region. Xu (2000) modeled the effects of climate change on water resources in central Sweden.…”

Section: Global Warming and Its Hydrological Impactsmentioning

confidence: 99%

Hydro-Climatic Trends of the Yellow River Basin for the Last 50 Years

et al. 2004

View full text Add to dashboard Cite

Abstract. Kendall's test was used to analyze the hydro-climatic trends of the Yellow River over the last half century. The results show that: (1) the runoff of the basin has decreased even after allowing for human uses, (2) the watershed has become warmer with a more significant increase in minimum temperature than in mean and maximum temperatures, and (3) no significant change in precipitation trend was observed. The major reasons for these results include human activities, global warming, land use/land cover change, and others, such as accuracy of natural runoff estimation, precipitation characteristics, groundwater exploitation, water transfer, and snowmelt. Homogeneity analysis indicated that precipitation, temperature, maximum temperature, and minimum temperature were all heterogeneous and the trends varied from region to region and from month to month. If the Intergovernmental Panel on Climate Change (IPCC) projections of continued warming in the region during the 21st century are correct, the present results then suggest that the trend towards reduced runoff is likely to lead to exacerbated problems for agriculture, industry, urban communities, and the overall regional environment.

show abstract

Section: Global Warming and Its Hydrological Impactsmentioning

confidence: 99%

Hydro-Climatic Trends of the Yellow River Basin for the Last 50 Years

et al. 2004

View full text Add to dashboard Cite

show abstract

“…However, not many studies are available concerning the magnitude of such changes and what the main drivers are (Hughes et al, 2014). Projections on the impact of climate change on the water resources of South Africa were investigated by Schulze (2012) and streamflow trends of some southern Africa rivers have been analysed (Fanta et al, 2001;Love et al, 2010), but no such studies are available for the Incomati basin.…”

Section: Introductionmentioning

confidence: 99%

Drivers of spatial and temporal variability of streamflow in the Incomati River basin

Okello

Masih

Uhlenbrook

et al. 2015

Hydrol. Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract. The Incomati is a semi-arid trans-boundary river basin in southern Africa, with a high variability of streamflow and competing water demands from irrigated agriculture, energy, forestry and industries. These sectors compete with environmental flows and basic human water needs, resulting in a "stressed" water resource system. The impacts of these demands, relative to the natural flow regime, appear significant. However, despite being a relatively well-gauged basin in South Africa, the natural flow regime and its spatial and temporal variability are poorly understood and remain poorly described, resulting in a limited knowledge base for water resource planning and management decisions. Thus, there is an opportunity to improve water management, if it can be underpinned by a better scientific understanding of the drivers of streamflow availability and variability in the catchment.In this study, long-term rainfall and streamflow records were analysed. Statistical analysis, using annual anomalies, was conducted on 20 rainfall stations, for the period 1950-2011. The Spearman test was used to identify trends in the records on annual and monthly timescales. The variability of rainfall across the basin was confirmed to be high, both intraand inter-annually. The statistical analysis of rainfall data revealed no significant trend of increase or decrease. Observed flow data from 33 gauges were screened and analysed, using the Indicators of Hydrologic Alteration (IHA) approach. Temporal variability was high, with the coefficient of variation of annual flows in the range of 1 to 3.6. Significant declining trends in October flows, and low flow indicators, were also identified at most gauging stations of the Komati and Crocodile sub-catchments; however, no trends were evident in the other parameters, including high flows. The trends were mapped using GIS and were compared with historical and current land use. These results suggest that land use and flow regulation are larger drivers of temporal changes in streamflow than climatic forces. Indeed, over the past 40 years, the areas under commercial forestry and irrigated agriculture have increased over 4 times.

show abstract

“…Initially observed and studied in the Sahelian regions, this drought also appeared in wetter regions, near the Gulf of Guinea (Sircoulon, 1976;Nicholson, 1985;Hubert & Carbonnel, 1987;Nicholson et al, 1988;Hubert et al, 1989;Demarée, 1990;Mahé & Citeau, 1993;Paturel et al, 1997Paturel et al, , 1998Servat et al, 1997a,b;Mahé et al, 2001b;L'Hôte et al, 2002). The rainfall deficit, observed over several consecutive years, has reduced flows of the region (Sircoulon, 1987;Sutcliffe & Knot, 1987;Olivry et al, 1993;Mahé & Olivry, 1991, 1999Aka et al, 1996;Servat et al, 1997c;Fanta et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

The concept of rainfall and streamflow normals in West and Central Africa in a context of climatic variability

Paturel¹,

Ouedraogo²,

Servat

et al. 2003

Hydrological Sciences Journal

View full text Add to dashboard Cite

This contribution to the debate on the revision of rainfall and streamflow normals concerns three countries of West Africa: Burkina Faso, Ivory Coast and Mali. The rainfall deficit (15-20% on average in the study area) and the river flow deficit (about 30-50% and sometimes more) observed over the past 30 years in West and Central Africa raise the problem of the reference period that must be considered in estimates of hydrological characteristics. The hypothesis of the concept of "normal" supporting these estimates is a stability of the climate. However, the effect of taking or not taking into account the data of recent years on the estimates of these characteristics can lead to very different results. This would have serious consequences for the development and management of water resources systems, as seen in two examples of dams.Key words rainfall normal; streamflow normal; climatic variability; drought; West and Central Africa Le concept de normales pluviométriques et hydrométriques en Afrique de l'Ouest et Centrale dans un contexte de variabilité climatiqueRésumé Cette étude concerne trois pays d'Afrique de l'Ouest: le Burkina Faso, la Côte d'Ivoire et le Mali. Il s'agit d'une contribution au débat sur la révision des normes hydrologiques tant en matière de précipitations que de débits. Les déficits pluviométriques (de l'ordre de 15 à 20% en moyenne dans la région étudiée) et sur les débits (de 30 à 50% et parfois plus) observés durant ces 30 dernières années en Afrique de l'Ouest et Centrale soulèvent la question de la période de référence qu'il convient de retenir pour la définition des caractéristiques hydrologiques. Par définition, le concept de normes hydrologiques fait référence à une stabilité du climat. A l'opposé, le fait de prendre en compte, ou non, les données des années récentes pour estimer les caractéristiques hydrologiques peut conduire à des résultats très différents et à de sérieuses conséquences sur la conception et le fonctionnement des ouvrages équipant les bassins versants. Le cas de deux barrages est évoqué ici.Mots clefs normales pluviométriques; normales hydrométriques; variabilité climatique; sécheresse; Afrique de l'Ouest et Centrale Jean

show abstract

A study of variability of annual river flow of the southern African region

Cited by 42 publications

References 8 publications

Hydro-Climatic Trends of the Yellow River Basin for the Last 50 Years

Hydro-Climatic Trends of the Yellow River Basin for the Last 50 Years

Drivers of spatial and temporal variability of streamflow in the Incomati River basin

The concept of rainfall and streamflow normals in West and Central Africa in a context of climatic variability

Contact Info

Product

Resources

About