Mahindawansha, A., Külls, C., Kraft, P., & Breuer, L. (2020). Investigating unproductive water losses from irrigated agricultural crops in the humid tropics through analyses of stable isotopes of water. Hydrology and Earth System Sciences, 24(7), 3627–3642.
|
Ola, I., Drebenstedt, C., Burgess, R. M., Mensah, M., Hoth, N., Okoroafor, P., et al. (2024). Assessing petroleum contamination in parts of the Niger Delta based on a sub-catchment delineated field assessment. Environmental Monitoring and Assessment, 196(6), 585.
Abstract: The Niger Delta in Nigeria is a complex and heavily contaminated area with over 150,000 interconnected contaminated sites. This intricate issue is compounded by the region’s strong hydrological processes and high-energy environment, necessitating a science-based approach for effective contamination assessment and management. This study introduces the concept of sub-catchment contamination assessment and management, providing an overarching perspective rather than addressing each site individually. A description of the sub-catchment delineation process using the digital elevation model data from an impacted area within the Delta is provided. Additionally, the contamination status from the delineated sub-catchment is reported. Sediment, surface water and groundwater samples from the sub-catchment were analyzed for total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAHs), respectively. Surface sediment TPH concentrations ranged from 129 to 20,600 mg/kg, with subsurface (2-m depth) concentrations from 15.5 to 729 mg/kg. PAHs in surface and subsurface sediment reached 9.55 mg/kg and 0.46 mg/kg, respectively. Surface water exhibited TPH concentrations from 10 to 620 mg/L, while PAHs ranged from below detection limits to 1 mg/L. Groundwater TPH concentrations spanned 3 to 473 mg/L, with total PAHs varying from below detection limits to 0.28 mg/L. These elevated TPH and PAH levels indicate extensive petroleum contamination in the investigated sediment and water environment. Along with severe impacts on large areas of mangroves and wetlands, comparison of TPH and PAH concentrations with sediment and water quality criteria found 54 to 100% of stations demonstrated exceedances, suggesting adverse biological effects on aquatic and sediment biota are likely occurring.
|
Klock, H., Külls, C., & Udluft, P. (2000). Estimation of relative recharge values for the northern Kalahari catchment, Namibia. Journal of African Earth Sciences, 30(4), 47–48.
|
Benito, G., Rohde, R., Seely, M., Külls, C., Dahan, O., Enzel, Y., et al. (2010). Management of alluvial aquifers in two southern African ephemeral rivers: implications for IWRM. Water Resources Management, 24(4), 641–667.
|
Baram, S., Ronen, Z., Kurtzman, D., Külls, C., & Dahan, O. (2013). Desiccation-crack-induced salinization in deep clay sediment. Hydrology and Earth System Sciences, 17(4), 1533.
|
Klaus, J., Külls, C., & Dahan, O. (2008). Evaluating the recharge mechanism of the Lower Kuiseb Dune area using mixing cell modeling and residence time data. Journal of Hydrology, 358(3-4), 304–316.
|
Dahan, O., Tatarsky, B., Enzel, Y., Külls, C., Seely, M., & Benito, G. (2008). Dynamics of flood water infiltration and ground water recharge in hyperarid desert. Groundwater, 46(3), 450–461.
|
Jin, Z., & Külls, C. (2020). FDM based OA-ICOS for high accuracy 13C quantification in gaseous CO2. EES, 446(3), 032061.
|
Klock, H., Külls, C., & Udluft, P. (2001). Estimating recharge values using hydrochemical and geological data: a case study from the. In Impact of Human Activity on Groundwater Dynamics: Proceedings of an International Symposium (Symposium S3) Held During the Sixth Scientific Assembly of the International Association of Hydrological Sciences (IAHS) at Maastricht, The Netherlands, from 18 t (25).
|
Külls, C. (2000). Resolving patterns of groundwater flow by inverse hydrochemical modelling in a semiarid Kalahari. In Tracers and Modelling in Hydrogeology: TraM’2000: Proceedings of TraM’2000, the International Conference on Tracers and Modelling in Hydrogeology Held at Liège, Belgium, in May 2000 (447).
|