Heavy metal contents and transfer capacities of Phragmites australis and Suaeda salsa in the Yellow River Delta, China
Publication date: April 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 104Author(s): Shuai Zhang, Junhong Bai, Wei Wang, Laibing Huang, Guangliang Zhang, Dawei WangAbstractPlant samples including roots, stems and leaves of Phragmites australis and Suaeda salsa were collected in the short-term flooding and tidal flooding wetlands of the Yellow River Delta of China. Six heavy metals (e.g., As, Cd, Cr, Cu, Pb, and Zn) were measured in roots, stems and leaves of each plant species using inductively coupled plasma atomic absorption spectrometry (ICP-AAS) to investigate the levels, and transfer capabilities ...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Hydro-meteorological trends in the Gidabo catchment of the Rift Valley Lakes Basin of Ethiopia
This study examines the long term hydroclimatic changes, analyses of the hydro-climate variability and detect whether there exist significant trend or not in the Gidabo catchment, rift valley lakes basin of Ethiopia. Precipitation, temperature and stream flow time series data were used in monthly, seasonal and annual time scales. The precipitation and temperature data span is between 1982 and 2014 and that of stream flow is between 1976 and 2006. To detect trends the analysis were done by using Mann Kendal (MK), Sen's graphical method and to detect change point using the Pettit test. The comparison of trend analysis betwee...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Editorial Board
Publication date: April 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 104Author(s): (Source: Physics and Chemistry of the Earth, Parts ABC)
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Evaluation of ecosystem service based on scenario simulation of land use in Yunnan Province
Publication date: April 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 104Author(s): Hong Zhang, Xiaoli Liao, Tianlin ZhaiAbstractClimate change and rapid urbanization are important factors restricting future land use. Situational analysis, as an important foundation for the optimization of land use, needs to focus on the impact of climate factors and socio-economic factors. In this paper, the Markov model and the DLS (Simulation of Land System Dynamics) model are combined for the first time, and the land use pattern in 2020 is simulated based on the data of land use in 2000 and 2010 as well as the cli...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Projected land use changes impacts on water yields in the karst mountain areas of China
Publication date: April 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 104Author(s): Yanqing Lang, Wei Song, Xiangzheng DengAbstractHuman-induced land use changes over short time scales have significant impacts on water yield, especially in China because of the rapid social economic development. As the biggest developing country of the world, China's economy is expected to continuously grow with a high speed in the next few decades. Therefore, what kind of land use changes will occur in the future in China? How these changes will influence the water yields? To address this issue, we assessed the water ...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Association between forestry ecological engineering and dust weather in Inner Mongolia: A panel study
Publication date: April 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 104Author(s): Huang Jixia, Zhang Qibin, Tan Jing, Yue Depeng, Ge QuanshengAbstractForestry ecological engineering projects in Western China include the Three-North Shelter Forest Project (TNSFP), the Natural Forest Protection Project (NFPP), the Grain for Green Project (GGP) and the Beijing-Tianjin Sandstorm Source Project (BTSSP). Such projects play an important role in the control of dust weather in Western China. In this research, data on the frequency of sandstorms, sand-blowing and dust-floating weather, the area of four forest...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Physicochemical and microbial assessment of spring water quality for drinking supply in Piedmont of Béni-Mellal Atlas (Morocco)
Publication date: April 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 104Author(s): Ahmed Barakat, Redouane Meddah, Mustapha Afdali, Fatima TouhamiAbstractThe present study was conducted to examine the water quality of karst springs located along the Piedmont of Béni-Mellal Atlas (Morocco) for drinking purposes. Twenty-five water samples were collected from seven springs in June, July, August and September 2013, and May 2016 have been analyzed for their physicochemical and microbial characteristics.The analytical data of temperature, pH, DO, TAC, TH, oxidizability and NH4+ showed that all sampl...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Preface: Ecosystem services, ecosystem health and human communities
Publication date: April 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 104Author(s): Hans-Peter Plag (Source: Physics and Chemistry of the Earth, Parts ABC)
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Assessment of seawater intrusion in an arid coastal aquifer, south-eastern Tunisia, using multivariate statistical analysis and chloride mass balance
Publication date: Available online 8 May 2018Source: Physics and Chemistry of the Earth, Parts A/B/CAuthor(s): Faten Telahigue, Belgacem Agoubi, Faiza Souid, Adel KharroubiAbstractWater availability is a fundamental concern for coastal areas in arid and semiarid regions such as Jerba Island, southeastern Tunisia. In these areas, the water demand is steadily increasing and putting pressure on water resources. These pressures are maintained by excessive pumping to meet the needs of various agricultural, domestic, industrial and tourism sectors. The effects on the groundwater are expressed by a quantitative and qualitative de...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Implementation of Community Based Management (CBM) in Zimbabwe: The dichotomy of theory and practice and its influence on sustainability of rural water supply systems
This study was done to investigate how CBM is being implemented in Zimbabwe. The specific objectives were to analyze how practices of different stakeholders in the rural water sector differ from their roles as stipulated in the CBM framework and to analyze how discrepancies between theory and practice in CBM implementation are influencing sustainability of water supply systems. The study also sought to investigate how trainings which are stipulated in the CBM framework are being done. Data was collected using Focus Group Discussions (FGDs), Key Informant Interviews (KIIs) and a Water Point Committee questionnaire. Pearson ...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Surface water bodies mapping in Zimbabwe using landsat 8 OLI multispectral imagery: A comparison of multiple water indices
Publication date: Available online 8 May 2018Source: Physics and Chemistry of the Earth, Parts A/B/CAuthor(s): Mhosisi Masocha, Timothy Dube, Mellisa Makore, Munyaradzi D. Shekede, Jacob FunaniAbstractWater is integral for the survival of humans, animals, as well as vegetation and information on its spatial distribution is important for water resources management. Various methods have been applied to detect and map land surface water, especially due to the availability of a large range of satellite sensors. The main methods involved are either general feature classification techniques or thematic water body information ext...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Investigation of nutrients and faecal coliforms removal in wastewater using a hydroponic system
Publication date: Available online 9 May 2018Source: Physics and Chemistry of the Earth, Parts A/B/CAuthor(s): S.F. Ndulini, G.M. Sithole, M.S. MthembuAbstractFresh water resources are diminishing rapidly through increased inadequately treated or untreated wastewater disposal in water bodies. Disposal of untreated wastewater in freshwater bodies threatens the environment, aquatic and human life. The primary objective of this study was to investigate the removal of contaminants using a simple cost effective hydroponic system in the treatment of raw wastewater to allowable discharge limits. After macrophytes were planted and...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Hydrogeological conceptual model of large and complex sedimentary aquifer systems – Central Kalahari Basin (Botswana)
In this study, an efficient data integration method for developing hydrogeological conceptual model of the large and hydrogeologically-complex, Central Kalahari Basin (CKB) aquifer system, was undertaken. In that process, suitability of 3-D geological modelling with RockWorks code in iterative combination with standard GIS (ArcGIS) was tested. As a result, six hydrostratigraphic units were identified, their heads and related flow system interdependencies evaluated and hydraulic properties attached. A characteristic feature of the CKB is a thick unsaturated Kalahari Sand Unit (KSU), that restricts the erratic recharge input to
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Microwave-assisted graft synthesis and characterization of poly(methacrylic acid)-grafted polyethersulfone towards dense hydrophilic and low-fouling membranes for water treatment
Publication date: Available online 11 May 2018Source: Physics and Chemistry of the Earth, Parts A/B/CAuthor(s): Lwazi Ndlwana, Keneiloe Sikhwivhilu, Richard Moutloali, Jane Catherine NgilaAbstractHerein, we report on a fast route of microwave-assisted synthesis for powder composites towards robust and ultralow-fouling polymethacrylic acid (PMAA)-grafted polyethersulfone (PES) membranes. The grafting was confirmed by Fourier transform infra-red spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR) and X-ray diffraction spectroscopy (XRD). Microfiltration membranes were then prepared from the powder composites b...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Impacts of hydropower dam operations in the Mana Pools National Park floodplains
This study investigated the hydro-dynamics from natural and human influenced flows, particularly at the Mana Pools floodplains which are downstream of Kariba and Kafue hydropower dams. Descriptive statistics were used to analyse the differences in flow regime upstream and downstream of the hydropower reservoirs. A standard t-test was done to compare the natural and modified mean annual flows. Results show that the presence of upstream reservoirs has reduced the high peak average monthly flows by 17% and increased the average monthly low flows by 5% at Mana Pools. However, the mean annual runoff has not significantly change...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Assessment of empirical and regression methods for infilling missing streamflow data in Little Ruaha catchment Tanzania
This study therefore made a contribution by appraising empirical and regression rainfall runoff based methods in the Little Ruaha River catchment, a sub-catchment of the Great Ruaha River sub-basin both within the Rufiji River Basin. The methods employed included simple linear regression (with untransformed and log-transformed data), multiple linear regression (with untransformed and log-transformed data), rainfall-runoff relationship using double mass curve technique, flow duration matching and drainage-area ratio. In addition, rainfall runoff modeling using HBV-Light was done for further comparison. With exception to the...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Estimating spatial catchment natural hydrological response characteristics in Swaziland
This study establishes the hydrological response of 122 catchments in Swaziland's trans-boundary basins on the basis of validated WR90 hydro-meteorological time series data. The flow duration indices (FDIs: Q10, Q50, Q90) were determined and standardised by the mean monthly streamflow, and the runoff ratio was calculated as a method to determine how catchments respond to precipitation inputs. The runoff ratio and FDIs were then plotted against aridity indices, and the plot shows that the runoff ratio is consistent with the aridity index, except for a few suspected anomalies emanating from values of Q50 and Q90. The finding...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Constraints to smallholder agricultural production in the Western Cape, South Africa
Publication date: Available online 29 May 2018Source: Physics and Chemistry of the Earth, Parts A/B/CAuthor(s): Bongani NcubeAbstractImproving agricultural production remains a major challenge for smallholder farmers in South Africa. The enactment of the 1998 Water Act and subsequent water allocation reforms were meant to correct equity challenges of the past in water allocation and increase agricultural productivity in the rural sector. More than 20 years after the initiation of the processes smallholder farmers remain poor with limited agricultural productivity. With the advent of more frequent droughts and the ever incr...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

A novel photodegradation approach for the efficient removal of natural organic matter (NOM) from water
In this study, multi-walled carbon nanotubes/nitrogen, palladium co-doped titanium dioxide (MWCNT/N, Pd co-doped TiO2) (0.5–5% MWCNTs) were fabricated for the enhancement of NOM degradation under visible-light illumination. Different MWCNT/N, Pd co-doped TiO2 (also referred to as CT) nanocomposites were synthesised via a modified sol-gel method and characterised using ultraviolet visible (UV-Vis), X-ray diffraction spectroscopy (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) Spectroscopy and energy-dispersive X-ray spectroscopy (EDS) analysis. The UV-Vis ...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Understanding the impacts of human resettlement and projected land use dynamics in Chimanimani district of Zimbabwe
This study tests whether and in what way agricultural expansion drives land cover change in resettled landscapes of Zimbabwe now and in the future. Classified Landsat Thematic Mapper images of 2000, 2009, and Landsat 8 image of 2013 were analyzed, using the widely used Markov modelling framework, to determine land use and land cover changes between the year 2000 and 2013, as well as future land cover dynamics in the area of interest. Specifically, land cover data was used to simulate land cover transitions up to 2050, using Markov chain model. Historic land cover modelling and future spatial predictions revealed increases ...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Effects of land use and land cover changes on water quality in the uMngeni river catchment, South Africa
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): Jean Nepomuscene Namugize, Graham Jewitt, Mark GrahamAbstractLand use and land cover change are major drivers of water quality deterioration in watercourses and impoundments. However, understanding of the spatial and temporal variability of land use change characteristics and their link to water quality parameters in catchments is limited. As a contribution to address this limitation, the objective of this study is to assess the linkages between biophysico-chemical water quality parameters and land use and land cover (L...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Determinants of farmers' participation in collective maintenance of irrigation infrastructure in KwaZulu-Natal
This study identifies the factors influencing farmers' decision to, and extent of participation in the maintenance of irrigation infrastructure in KwaZulu-Natal province, South Africa based on cross-section data collected from 320 randomly selected smallholder irrigating farmers. A two-step Heckman regression model was applied in the analysis. It was established that households whose heads were older, block committee members, with larger irrigation plots, good soil quality and experiencing severe irrigation water shortages are more likely to participate in maintenance of irrigation infrastructure. On the other hand, farmer...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Validation and verification of lawful water use in South Africa: An overview of the process in the KwaZulu-Natal Province
The objective of the process is to determine how much water is allocated for: (1) existing lawful use in accordance with specific requirements of the NWA, and; (2) current water uses. The process identified users with or without registered use entitlements, whether claims for registered uses were correct, under-estimated, over-estimated or false; and confirmed the lawfulness of each water use in accordance with water legislation that pre-dated the NWA. The process included identifying land and non-land based water uses (industrial, mining and bulk potable water supplies, irrigation, crop types and impoundments) using remot...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Scenario planning for water resource management in semi arid zone
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): Rajiv Gupta, Gaurav KumarAbstractScenario planning for water resource management in semi arid zone is performed using systems Input-Output approach of time domain analysis. This approach derived the future weights of input variables of the hydrological system from their precedent weights. Input variables considered here are precipitation, evaporation, population and crop irrigation. Ingles & De Souza's method and Thornthwaite model have been used to estimate runoff and evaporation respectively. Difference between pr...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Editorial Board
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): (Source: Physics and Chemistry of the Earth, Parts ABC)
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Innovative solutions for intractable water problems in the face of climate change in southern and East African sub regions
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): Benjamin Mapani, Hodson Makurira, Lapologang Magole, Maideyi Meck, Theresa Mkandawire, Marloes Mul, Cosmo Ngongondo (Source: Physics and Chemistry of the Earth, Parts ABC)
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

A review of formal institutions affecting water supply and access in Botswana
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): Patricia K. Mogomotsi, Goemeone E.J. Mogomotsi, Dimpho M. MatlholaAbstractOver the years, many countries across the world have increasingly experienced the collapse of their ecosystems, leading to an elevated increase on the demand for freshwater resources. Botswana is not an exception. The problem of disrupted potable water supply is widespread across the country. However, the physical shortage of water in the country is arguably coupled by lack of effective and efficient water supply and management institutions and wa...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Relating the dynamics of climatological and hydrological droughts in semiarid Botswana
This study attempts to determine drought timescale that is suitable for monitoring the effects of drought on hydrological systems which can then be used to assess the long term persistence or reversion and forecasts of the dynamics. Based on this, climatological and hydrological drought indices characterized by Standardized precipitation evapotranspiration index (SPEI) and Standardized flow index (SFI) respectively have been determined using monthly rainfall, temperature and flow data from two major river systems. The association between climatological and hydrological droughts in Botswana has been investigated using these...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Modelling climate change impact: A case of bambara groundnut (Vigna subterranea)
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): Tafadzwanashe Mabhaudhi, Tendai Polite Chibarabada, Vimbayi Grace Petrova Chimonyo, Albert Thembinkosi ModiAbstractClimate change projections for southern Africa indicate low and erratic rainfall as well as increasing frequency and intensity of rainfall extremes such as drought. The 2015/16 drought devastated large parts of southern Africa and highlighted the need for drought tolerant crops. Bambara groundnut is an African indigenous crop, commonly cultivated in southern Africa, with a higher potential for drought toler...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Changes in streamflow contributions with increasing spatial scale in Thukela basin, South Africa
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): Macdex Mutema, Vincent ChaplotAbstractSustainable management of river basins requires precise understanding of the origin and variability of water fluxes. Water samples were collected in Thukela Basin (30,000 km2), South Africa, over the 2012 rainy season, from fifteen 1 m2 runoff microplots (for OF), a 5-m deep piezometer (SW) and 20-m deep borehole (GW), in the basin headwater and nested catchment outlets (microcatchment, 0.23 km2; subcatchment, 1.20 km2; catchment, 9.75 km2; sub-basin, 253 km2). The water...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Analysis of potential future droughts limiting maize production, in the Luvuvhu River catchment area, South Africa
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): Teboho Elisa Masupha, Mokhele Edmond MoeletsiAbstractRecurring droughts associated with global warming have raised major concern for the agricultural sector, particularly vulnerable small-scale farmers who rely on rain-fed farming such as in the Luvuvhu River catchment. The Standardized Precipitation Evapotranspiration Index (SPEI) and Water Requirement Satisfaction Index (WRSI) were calculated to assess drought on a 120-day maturing maize crop based on outputs of the CSIRO-Mk3.6.0 under RCP 4.5 emission scenario, for t...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Quantification of water resources uncertainties in the Luvuvhu sub-basin of the Limpopo river basin
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): N. Oosthuizen, D. Hughes, E. Kapangaziwiri, J. Mwenge Kahinda, V. MvandabaAbstractIn the absence of historical observed data, models are generally used to describe the different hydrological processes and generate data and information that will inform management and policy decision making. Ideally, any hydrological model should be based on a sound conceptual understanding of the processes in the basin and be backed by quantitative information for the parameterization of the model. However, these data are often inadequat...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Flood hazard vulnerability assessment in Kashmir Valley, India using geospatial approach
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): Tauseef Ahmad, Arvind Chandra Pandey, Amit Kumar (Source: Physics and Chemistry of the Earth, Parts ABC)
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

An assessment of groundwater potential and vulnerability in the Upper Manyame Sub-Catchment of Zimbabwe
This study assessed GP and vulnerability in the UMSC using Geographic Information Systems and Remote Sensing techniques. Groundwater conditioning factors: geology, slope, land-use, drainage density, topographic index, altitude, recharge and rainfall were used to develop GP zones. Validation of the GP map was done by correlating estimated GP with historical borehole yields. An assessment of groundwater vulnerability was done at micro-catchment level (Marimba) using the GOD model; a three parameter Index Overlay Model. Marimba is the most urbanised and has the second highest borehole density. It also exhibits similar landuse...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Validation of satellite-based rainfall in Kalahari
This study highlighted SREs as valuable source of daily rainfall data providing good spatio-temporal data coverage especially suitable for areas with limited rain gauges, such as the CKB, but also emphasized SREs' drawbacks, creating avenue for follow up research. (Source: Physics and Chemistry of the Earth, Parts ABC)
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Effects of climate change on evapotranspiration over the Okavango Delta water resources
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): Oliver Moses, Wame L. HambiraAbstractIn semi-arid developing countries, most poor people depend on contaminated surface or groundwater resources since they do not have access to safe and centrally supplied water. These water resources are threatened by several factors that include high evapotranspiration rates. In the Okavango Delta region in the north-western Botswana, communities facing insufficient centrally supplied water rely mainly on the surface water resources of the Delta. The Delta loses about 98% of its water...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Signature of present and projected climate change at an urban scale: The case of Addis Ababa
In this study, the 1 km2 high resolution NIMR-HadGEM2-AO simulations for future projections under Representative Concentration Pathways (RCP4.5 and RCP8.5) scenarios and gridded observations provided by Worldclim data center are used to assess changes in rainfall, minimum and maximum temperature expected under the two scenarios over Addis Ababa city. The gridded 1 km2 observational data set for the base period (1950–2000) is compared to observation from a meteorological station in the city in order to assess its quality for use as a reference (baseline) data. The comparison revealed that the data set has a very g...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

SWAT model uncertainty analysis, calibration and validation for runoff simulation in the Luvuvhu River catchment, South Africa
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): M.P. Thavhana, M.J. Savage, M.E. MoeletsiAbstractThe soil and water assessment tool (SWAT) was calibrated for the Luvuvhu River catchment, South Africa in order to simulate runoff. The model was executed through QSWAT which is an interface between SWAT and QGIS. Data from four weather stations and four weir stations evenly distributed over the catchment were used. The model was run for a 33-year period of 1983–2015. Sensitivity analysis, calibration and validation were conducted using the sequential uncertainty fi...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Key attributes of agricultural innovations in semi-arid smallholder farming systems in south-west Zimbabwe
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): Eness P. Mutsvangwa-Sammie, Emmanuel Manzungu, Shephard SizibaAbstractIn Sub-Sahara Africa, which includes Zimbabwe, about 80% of the population depends on agriculture for subsistence, employment and income. Agricultural production and productivity are, however, low. This has been attributed to a lack of appropriate innovations despite the huge investments that have been made to promote ‘innovations’ as a means to safeguarding agriculture-based livelihoods, which raises the question of how innovations are co...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Modelling nitrogen transformation and removal in mara river basin wetlands upstream of lake Victoria
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): Aloyce W. Mayo, Marwa Muraza, Joel NorbertAbstractLake Victoria, the largest lake in Africa, is a resource of social-economic potential in East Africa. This lake receives water from numerous tributaries including Mara River, which contributes about 4.8% of the total Lake water inflow. Unfortunately, Mara River basin faces environmental problems because of intensive settlement, agriculture, overgrazing in the basin and mining activities, which has lead to water pollution in the river, soil erosion and degradation, decrea...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Fertility status of cultivated floodplain soils in the Zambezi Valley, northern Zimbabwe
The objective of this study was to determine the fertility status of cultivated Zambezi Valley floodplain soils, in northern Zimbabwe. The study was conducted at three sites, along tributaries of Musengezi River. Soil samples were taken at 0.20 m depth increments to 0.60 m from hydromorphologically stratified fields, during the cropping season. Sampling points were replicated twice in each stratum at points equidistant from river edges. Relative elevations of sampling points were measured using levelling equipment. Soil was analysed using: core method for bulk density, hydrometer method for texture, loss on ignition fo...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Estimating soil organic and aboveground woody carbon stock in a protected dry Miombo ecosystem, Zimbabwe: Landsat 8 OLI data applications
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): Timothy Dube, Richard Muchena, Mhosisi Masocha, Cletah ShokoAbstractAccurate and reliable soil organic carbon stock estimation is critical in understanding forest role to regional carbon cycles. So far, the total carbon pool in dry Miombo ecosystems is often under-estimated. In that regard this study sought to model the relationship between the aboveground woody carbon pool and the soil carbon pool, using both ground-based and remote sensing methods. To achieve this objective, the Ratio Vegetation Index (RVI), Normalize...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Preparation and application of a tyre-based activated carbon solid phase extraction of heavy metals in wastewater samples
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): K. Mogolodi Dimpe, J.C. Ngila, Philiswa N. NomngongoAbstractIn this paper, the tyre-based activated carbon solid phase extraction (SPE) method was successfully developed for simultaneous preconcentration of metal ions in the model and real water samples before their determination using flame atomic absorption spectrometry (FAAS). The activation of carbon was achieved by chemical activation and the tyre-based activated carbon was used as a sorbent for solid phase extraction. The prepared activated carbon was characterize...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Synthesized af-PFCl and GG-g-P(AN)/TEOS hydrogel composite used in hybridized technique applied for AMD treatment
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): Elvis Fosso-KankeuAbstractIn the present study af-PFCl, GL-g-P(AN) hydrogel and GL-g-P(AN)/TEOS hydrogel composite were synthesized. The hydrogels were characterized using the fourier transformed infra-red (FTIR) and the scanning electron microscope (SEM) techniques. The coagulant af-PFCl and the hydrogels were applied consecutively in flocculation and adsorption processes respectively for the treatment of acid mine drainage (AMD). It was observed that the grafting process increased the amount of binding groups on the h...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Residual antibiotics, antibiotic resistant superbugs and antibiotic resistance genes in surface water catchments: Public health impact
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): Adegoke Anthony A, Faleye Adekunle C, Stenstrӧm Thor AAbstractAntibiotics are released to the surface water through different routes, like for example the wastewater treatment plants, from human and animal metabolic waste, agriculture run off, industrial antibiotic waste. The release of the antibiotics to the water catchment and/or the environments in sub-lethal concentrations for the microorganisms lead to the emergence of antibiotic resistance (AR) and selection for antibiotic resistance genes (ARGs). The bacteria ut...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Investigating waste rock, tailings, slag and coal ash clinker as adsorbents for heavy metals: Batch and column studies
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): D. Letina, W.M. LetshwenyoAbstractWastewater from the mining industry is a concern because most of the time it contains heavy metals with concentrations above permissible levels, posing a threat to terrestrial and aquatic life. The study was conducted to evaluate the effectiveness of locally available waste materials (waste rock, tailings, coal ash clinker, and slag) generated by BCL (Ltd) mine, a copper and nickel mining and smelting company in Botswana, for removal of nickel and copper from the real mining wastewater....
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Assessment of quality of water provided for wildlife in the Central Kalahari Game Reserve, Botswana
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): Moses Selebatso, Glyn Maude, Richard W.S. FynnAbstractArid and semi-arid environments have low and unpredictable rainfall patterns resulting in limited availability of surface water for wildlife. In the Central Kalahari Game Reserve (CKGR) wildlife populations have lost access to natural surface water through cordon fences, livestock and human encroachment along the access routes. Artificial waterholes have been developed in the reserve to compensate for this loss. However, there have not been any assessments of the qua...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

A geomorphological characterisation of river systems in South Africa: A case study of the Sabie River
This study reports on a case study to characterise the geomorphology of different river systems in South Africa, with the aim of better understanding their properties, controls, and implications for biophysical interactions including water quality, biodiversity (aquatic and riparian), and human activity within the catchment. The approach adopted is based on the River Styles® framework (RSF), a geomorphology-based approach developed for rivers in New Zealand and Australia, but applied here for the first time to South Africa. Based on analysis of remote sensing imagery, SRTM-2 digital topographic data and field observati...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Integrating environmental variables and geospatial technologies in landscape scale habitat modelling of edible stink bugs in Zimbabwe
In this study maximum entropy model was used to predict the probability of presence of E. delegorguei in southern Zimbabwe. The environmental factors governing its geographic distribution in Zimbabwe were also evaluated. Presence/absence data were selected along thirty-five randomly selected transects. The climatic and topographic variables used to predict the distribution of E. delegorguei were: maximum temperature of the warmest month; minimum temperature of the coldest month; the normalised difference vegetation index (NDVI); altitude; slope; and aspect. It was found that E. delegorguei is most likely to occur on steep ...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research

Influence of urbanization-driven land use/cover change on climate: The case of Addis Ababa, Ethiopia
Publication date: June 2018Source: Physics and Chemistry of the Earth, Parts A/B/C, Volume 105Author(s): Bisrat Kifle Arsiso, Gizaw Mengistu Tsidu, Gerrit Hendrik Stoffberg, Tsegaye TadesseAbstractLand use change is the second most important anthropogenic influence on climate beside the emission of greenhouse gases. Urbanization is leading to significant land use changes in Africa since the continent is undergoing rapid urbanization and population growth in recent decades. Addis Ababa is one of these fast growing cities in the continent. Therefore, detection of land use change is very important to identify its impact on cl...
Source: Physics and Chemistry of the Earth, Parts ABC - July 5, 2018 Category: Science Source Type: research