Seasonal discharge and chemical flux variations of rivers flowing into the Bayhead canal of Durban Harbour, South Africa

The u Mhlatuzana, u Mbilo and a Manzimnyama river catchments located on the eastern seaboard of the Kwa Zulu-Natal province, South Africa, form the core of urbanization and industrialization, contributing the only natural freshwater inflows to the Bayhead Canal portion of the Durban Harbour. In this study, seasonal discharges and physico–chemical water properties were used to quantitatively determine the material mass transport capacity of the river systems on the basis of hydrographic inputs and chemical loading from the surrounding land use sectors.The mass transport of the total dissolved solids(TDS),ammonia(NH_4), phosphorous(P), aluminum(Al), calcium(Ca), copper(Cu), chromium(Cr), mercury(Hg), potassium(K), magnesium(Mg), sodium(Na), nickel(Ni), lead(Pb), sulphur(S) and vanadium(V) was determined for each river. Results indicated that land use, seasonality and river flow were significant determinants for the material loading in the rivers and the receiving port waters. The spatio-temporal distribution patterns of chemical fluxes indicated that industrial activity associated with the a Manzimnyama canal contributed the most, with regards to TDS, NH_4, Ca, K, Mg, Na, S and V, loading in both wet and dry seasons, as well as Al, Cu, Hg and Pb during the dry season. Similarly, industrial activity associated with the u Mbilo/u Mhlatuzana Canal at the lower reaches accounted for the highest P, Al, Cu and Pb fluxes in the wet season alone. Fluxes of these parameters are used to explain theobserved elemental concentrations and patterns of the receiving port waters of the Bayhead Canal.

Erratum to： Seasonal discharge and chemical flux variations of rivers flowing into the Bayhead canal of Durban Harbour, South Africa

The u Mhlatuzana, u Mbilo and a Manzimnyama river catchments located on the eastern seaboard of the Kwa Zulu-Natal province, South Africa, form the core of urbanization and industrialization, contributing the only natural freshwater inflows to the Bayhead Canal portion of the Durban Harbour. In this study, seasonal discharges and physico–chemical water properties were used to quantitatively determine the material mass transport capacity of the river systems on the basis of hydrographic inputs and chemical loading from the surrounding land use sectors.The mass transport of the total dissolved solids（TDS）,ammonia（NH4）, phosphorous（P）, aluminum（Al）, calcium（Ca）, copper（Cu）, chromium（Cr）, mercury（Hg）, potassium（K）, magnesium（Mg）, sodium（Na）, nickel（Ni）, lead（Pb）, sulphur（S） and vanadium（V） was determined for each river. Results indicated that land use, seasonality and river flow were significant determinants for the material loading in the rivers and the receiving port waters. The spatio-temporal distribution patterns of chemical fluxes indicated that industrial activity associated with the a Manzimnyama canal contributed the most, with regards to TDS, NH4, Ca, K, Mg, Na, S and V, loading in both wet and dry seasons, as well as Al, Cu, Hg and Pb during the dry season. Similarly, industrial activity associated with the u Mbilo/u Mhlatuzana Canal at the lower reaches accounted for the highest P, Al, Cu and Pb fluxes in the wet season alone. Fluxes of these parameters are used to explain theobserved elemental concentrations and patterns of the receiving port waters of the Bayhead Canal.

Relationship between Selected Physiographic Features and Landslide Occurrence around Four Hydropower Projects in Bhagirathi Valley of Uttarakhand, Western Himalaya, India

The Himalayan mountain range is an internationally recognised landscape but one under increasing developmental threat. The lower Himalayan region possesses immense potential for hydropower generation but is also highly susceptible to tectonic deformation and mass wasting, especially landslides. Susceptibility to landslides increases markedly with human activity, especially large scale developmental projects. The impacts of massive hydropower plant construction in the Bhagirathi Valley, Uttarkhand, India on the generation of landslides are the focus of this study. Whilst many positive impacts derive from such projects, devastating negative impacts also accrue. The frequency and characteristics of land sliding within the sphere of influence of the construction sites of the various hydropower plant components were investigated. Landslide frequency was related to parameters of geology, prior land use, drainage density, slope steepness and location in terms of construction aspect. Landslide frequency was found to be greatest in gneissic terrain as well as on previously agricultural and forested lands. Statistical analysis revealed significant relationships between landslide frequency with slope and, frequency with construction aspect, especially the construction of access roads. As with other studies, road construction is the key initiator of land sliding due to slope over steepening and the indiscriminate dumping of debris. The study concludes with recommendations for reducing the frequency and magnitude of mass wasting in this environment.