Determinants of Spatio Temporal Variability of Water Quality in The

Home , Barotse Floodplain, Kafue Flats, Kalabo, Limulunga, Mongu, Senanga

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Suggestion for citations: Volume: Revermann, R., Krewenka, K.M., Schmiedel, U., Olwoch, J.M., Helmschrot, J. & Jürgens, N. (eds.) (2018) Climate change and adaptive land management in southern Africa – assessments, changes, challenges, and solutions. Biodiversity & Ecology, 6, Klaus Hess Publishers, Göttingen & Windhoek.

Articles (example): Archer, E., Engelbrecht, F., Hänsler, A., Landman, W., Tadross, M. & Helmschrot, J. (2018) Seasonal prediction and regional climate projections for southern Africa. In: Climate change and adaptive land management in southern Africa – assessments, changes, challenges, and solutions (ed. by Revermann, R., Krewenka, K.M., Schmiedel, U., Olwoch, J.M., Helmschrot, J. & Jürgens, N.), pp. 14–21, Biodiversity & Ecology, 6, Klaus Hess Publishers, Göttingen & Windhoek.

Corrections brought to our attention will be published at the following location: http://www.biodiversity-plants.de/biodivers_ecol/biodivers_ecol .php Biodiversity & Ecology

Journal of the Division Biodiversity, Evolution and Ecology of Plants, Institute for Plant Science and Microbiology, University of Hamburg

Volume 6:

Climate change and adaptive land management in southern Africa

Assessments, changes, challenges, and solutions

Edited by

Rasmus Revermann1, Kristin M. Krewenka1, Ute Schmiedel1, Jane M. Olwoch2, Jörg Helmschrot2,3, Norbert Jürgens1

1 Institute for Plant Science and Microbiology, University of Hamburg 2 Southern African Science Service Centre for Climate Change and Adaptive Land Management 3 Department of Soil Science, Faculty of AgriSciences, Stellenbosch University

Hamburg 2018

RPlease cite the article as follows:

Nyambe, I., Chabala, A., Banda, K., Zimba, H. & Phiri, W. (2018) Determinants of spatio-temporal variability of water quality in the Barotse Floodplain, western Zambia. In: Climate change and adaptive land management in southern Africa – assessments, changes, challenges, and solutions (ed. by Revermann, R., Krewenka, K.M., Schmiedel, U., Olwoch, J.M., Helmschrot, J. & Jürgens, N.), pp. 96-105, Biodiversity & Ecology, 6, Klaus Hess Publishers, Göttingen & Windhoek. doi:10.7809/b-e.00310 Water resources * Corresponding author: [email protected] 1 Integrated Water Resources Management Centre, University of Imasiku Nyambe western Zambia of water quality in the Barotse Floodplain, Determinants of spatio-temporal variability 6 96 Zambezi, demodoagarantir Resumo: Écadavezmaiscrucialodesenvolvimentodeumabased plays as a natural sink. fl the in concentrations element and levels conclusively not was phenomenon this however, period, sampling confl the Tool (SWAT) and measured turbidity suggested the likely existen total coliforms (> 200 coliforms/100 ml). An assessment of the quality.a registered communities to close points sampling All fl lower to led that rainfall land use and climate change. To realise this goal, it is import potent of face the in management and monitoring resources water Abstract: pelos efeitos antropogénicos resultantes do uso das terras e da year 2014, which experienced higher fl also noted to be active and attributed to land use change and fl to bepredominantandappearedinfl this important water resource. It was the potentially geogenica This suggestedthatcurrentlar fell withinthe World HealthOrganization (WHO)andZambiaBure (i.e., copper, lead, cadmium, mercury, arsenic, zinc, and chrom Zambia western Floodplain, Barotse the in 2015 and 2014 between stream and quality water study,analysed this we ity.in Thus, ticularmente o cálcio, foram observados como predominantes, par Aluvial de Barotse não têm nenhum efeito neste importante recur ac mineiras actividades as que sugere Isto potável. água a para mg/l), sendo abrangidas pelas normas da Organização Mundial da chumbo, cádmio, mercúrio, arsénio, zinco e crómio) encontravam- 2015 na Planície Aluvial de Barotse, na Zâmbia Ocidental. Verifi mod de corrente, da sedimentos dos parâmetros os e água da dade q da variação a controlam que factores estabelecer importante é taram aqualidadedaágua. T em inundações menos acentuadas. A análise dos resultados bacter Este valor caiu para < 0,5 mg/l em 2015, possivelmente devido à e aos padrões de inundação. Os nitratos aumentaram até > 24 mg/ cial o pH. O recrutamento sazonal de nutrientes foi também obse uence of the Zambezi and the Luanginga Rivers than within and within than Rivers Luanginga the and Zambezi the of uence Developing a water quality database for the Upper Zambezi Basin 1 *, Anthony Chabala oods. Analysis of bacteriological results indicated that anthr that indicated results bacteriological of Analysis oods. odos ospontosdeamostragem perto a monitorizaçãoegestãoreforçada ge-scale miningactivitiestakin 1 oods. This value dropped to < 0.5 mg/l in 2015, possibly as a , Kawawa Banda uenced byphysicalparameters,especiallypH.Seasonalnutrien oodplain may be a strong indicator of a critical role that the that role critical a of indicator strong a be may oodplain C A 1 , Henry Zimba ant to establish factors that control the variation of water qu ood inundation patterns. Nitrates spiked up to > 24 mg/l in th s alterações climáticas. De modo a materializar este objectivo, lly derived elements, particularly calcium, that were observed g placeupstreamofthe sediment parameters to infer their spatio-temporal variation spatio-temporal their infer to parameters sediment too-numerous-to-count (TNTC) concentration of faecal and faecal of concentration (TNTC) too-numerous-to-count ium) were mostly below detection limits (< 0.002 mg/l) and sediment yields predicted by the Soil and Water Assessment tuais de grande escala a decorrerem a montante da Planície da montante a decorrerem a escala grande de tuais ualidade da água. Assim, neste estudo, analisámos a quali- água. a da analisámos ualidade estudo, neste Assim, cou-se que as concentrações de metais pesados (i.e. cobre, ocorrência de precipitação abaixo do normal, que resultou rvado como activo e atribuído às alterações do uso da terra ce of a stronger relationship in the upstream areas and near dos recursoshídricosface so hídrico. Os elementos potencialmente geogénicos, par- l no ano de 2014, o qual sofreu inundações mais elevadas. iológicos indicou que as actividades antropogénicas afec- ecendo ser infl se essencialmente abaixo dos limites de detecção (< 0.002 ial threats posed by anthropogenically induced eff induced anthropogenically by posed threats ial de comunidadesregistaramconcentrações decoliformes Saúde (OMS) e da Zambia Bureau of Standards (ZABS) o a inferir a sua variação espacio-temporal entre 2014 e 2014 entre espacio-temporal variação sua a inferir a o e dadossobreaqualidadedaáguabaciasuperiordo au ofStandards(ZABS)guidelinesfordrinkingwater. . It was found that the concentrations of heavy metals heavy of concentrations the that found was It . assessed. Nevertheless, the observed lower turbidity lower observed the Nevertheless, assessed. Zambia, Lusaka 10101, Zambia 1 after the main fl main the after , Wilson Phiri is becoming crucial for ensuring strengthened uenciados por parâmetros físicos, em espe- Barotse Floodplainhavenoeff opogenic activities aff activities opogenic 1 oodplain. Because of the limited the of Because oodplain. a potenciaisameaças,causadas result of below-normal Barotse Floodplain Barotse t recruitmentwas ected water ected ects of ects ect on al- e

B E 6 spatial extent of all tropical wetlands re- wetlands tropical all of extent spatial 2002; Naiman et al., 2005). A study of the Stanford, & Tockner 1997; Décamps, & Naiman 1991; al., et (Gregory Earth on ecosystems diverse and productive cally fl makes nature dynamic This processes. exchange water ground-surface complex and levels, water rising during periods hydro- prolonged or inundation ments, sedi- of deposition and erosion repeated by shaped are that systems dynamic as described are Floodplains 2005). al., et (Naiman development urban for points quently,fl Conse- production. crop support which soils, alluvial the particularly resources, fl the exploited have people history, Throughout 2014). tions arose in fertile fl nomic importance,asmostearlycivilisa- Floodplains areofgreatculturalandeco- Introduction Figure 1: Location of the Barotse Floodplain in the western par odlis mn te ot biologi- most the among oodplains podem possivelmente ser um forte indicador do papel crítico da tivamente avaliado. Não obstante, os baixos níveis de turbidez da e após a principal planície aluvial. No entanto, devido ao p existência de uma relação mais forte nas áreas a montante e jun Solo de Avaliaçãodos do Ferramenta pela previstos sedimentos fecais e totais incontáveis (Too-Numerous-To-Count ou TNTC) (> oodplains have served as focal as served have oodplains odlis o ter rich their for oodplains oodplains (Polunin,

2018 & Stanford, 2002; Zuijdgeest et al., 2015). wetlands, with areas of > 10 veals that 2.5 to 3.5% of Earth’s surface is America and 10 and America crucially pointoutthatfl et al., 2007). Zuijdgeest et al. (2015) also as well as substrate where they react contaminants (Lovett these for mechanism transport a provide which sediments, to bind chemically nutrients and metals, heavy agrochemicals, many Moreover, 2007). Hupp, & (Noe transformers trient of organic nutrients — in other words, nu- sources and nutrients inorganic of sinks fl because is This loads. nutrient sustain and process to system the of ability the infl most the ably et al. (2010) describes sediments as prob- by Ahiablame Research 2007). Hupp, & fl in sediment and nutrients of transformation and uptake the for locations important as regarded oodplains are frequently thought of as of thought frequently are oodplains elns r fl or Wetlands t of Zambia. 5 km odlis r widely are oodplains uential determinant of determinant uential uvial landscapes (Noe landscapes uvial eríodo limitado de amostragem, este fenómeno não foi defi 2 to à confl observados e a concentração de elementos na planície aluvial in Africa (TocknerAfrica in Planície Aluvial de Barotse como um sumidoro natural. ows arerestrict- e da Água (SWAT) e turbidez medida sugere a provável a (SWAT)sugere Água medida da turbidez e e 200 coliforms/100 ml). Uma avaliação dos rendimentos 6 km uência dos rios Zambezi e Luanginga que no interior 2 in South area is estimated at 1.2 million hectares. wetland total the (1999), al. et Turpie to 240 km long and 34 km wide. According fl The 1). (Fig. Zambia western of part covers which 27°E, and 18°E longitudes and sin lies between latitudes 11°S and 19°S, the Upper Zambezi Basin (UZB). The ba- within found is Floodplain Barotse The Study location Zambia. north-western of Basin the River Kabombo in upstream activities mining and resource, water this around farming as such activities anthropogenic increasing eters of the Barotse Floodplain in light of param- quality water in variations poral present study area. the in relevant are activities mining and nants resulting from agricultural land use phates from road de-icers. Only contami- sul- and sodium as well as metals heavy and oil, fragments, rubber with enriched inclusive) (mines areas urban veloped de- highly nutrients, with enriched lands nants, which may come from agricultural enriched with diff diff from ity’, Tong & Chen (2002) state that runoff between land use and surface water qual- relationship the ‘modeling on Writing spect to where they are being discharged. contaminants can be categorised with re- Nutrient Brazier,2008). & (Bilotta body cal, and biological properties of the water lead to alterations of the physical, chemi- can which perturbations, anthropogenic by caused be may contaminants nutrient hence, particles have time to settle. ed in most lakes and fl In this study, we assessed spatio-tem- assessed we study, this In and metal, heavy agrochemical, The odli maue approximately measures oodplain erent types of land use may be may use land of types erent erent kinds of contami- oodplains systems; ni- 97

Water resources Water resources scoop. They were immediately closed in closed immediately were They scoop. samples were collected using a perforated These metres. few a within chosen was water quality locations, an alternative site same the at them collect to practical not lected at the same locations. Where it was These two sample types were mostly col- samples. quality water alongside lected plot the sampling points using ArcGIS. to used also were latter The coordinates. geographical and photographs taking by created was site sampled each of record hours. 48 within Zambia of AUniversity the to transported were analyses ratory and pH. preserved forlabo- The samples (EC), conductivity electrical perature, parameters: dissolved oxygen (DO), tem- physical following the measured Multi- metres multi-metres. using conducted simultaneously were measurements situ tion protocols at each site. In addition, in ing ice packs upon completing the collec- contain- boxes cooler into put mediately im- were samples The rinsing. for used was water same the and surface, water collected was approximately were 50 cm from the samples the which at depth The lids. respective their with together times three rinsed were bottles the ples, membrane fi the was analysis bacteriological for used method principal The stored bottles. plastic in were samples physiochemical whereas bottles glass in taken were ples sam- Bacteriological walls. container to losses sorption and activity, microbial precipitation, reduced and metals trace fi samples meant for cation analysis. Acidi- water to added was acid nitric of ml 250 of (2%) Twopercent analysis. riological bacte- for third the and analysis, cation one sample for anion analysis, another for diff for served pre- and point each at triplicate in lected col- were samples These characteristics. chemical and bacteriological, physical, fl the across high fl and low during characterised were plain Flood- Barotse the of sediments stream and quality water surface study, this In Methods 8 98 cation of water samples preserved most tem eiet ape wr col- were samples sediment Stream sam- water of collection the Before ows. Water samples were collected oodplain and tested for their for tested and oodplain ltration (MF) method. erent laboratory analyses: laboratory erent 1984 and 2015. tion of Landsat satellite imagery between was estimated from supervised classifi fi pro- current Doppler acoustic the using measured was which discharge, stream with calibrated was It yields. sediment fl hydrological estimate to used was model The model. (SWAT) Tool Assessment and Water Soil the into put classifi cover land for Collected remotesensingdatawereused water. the in was what with compare to measured were sediments riverbed the in constituents Elemental respectively. scoop, the and bottles sampling using collected were which samples, sediment stream and water were data measured Field- data. sensing remote (2) and data fi (1) used: were datasets the of methods used is given in Figure 2. summary A 2015. and 2014 of seasons October) to (September dry and June) to (April wet the during campaign: paper were collected over a two-year fi this in presented data The (XRF). cence fl X-ray or (AS) spectophotometry absorption atomic atom using elements ments were tested only for their chemical sedi- Stream samples. soil for boxes er sampling bottles and placed into the cool- Acoustic Doppler Current Profi ler (ADCP), X-ray fl uorescence (X Figure 2: A fl ow chart illustrating the methods used in this st ler (ADCP) (Fig. 2). Land cover change s hw i Fgr 2 to ye of types two 2, Figure in shown As C A cto ad s in- as and cation eld-measured ows and ows uores- ca- eld Results tion of these points is shown in Figure 3. nel from Mongu to Senanga. The distribu- chan- River Zambezi main the of middle to Kalabo. Samples were also taken in the Plain Matebele the through Sioma from fl central the of side western the on Sioma-Kalabo the (4) and Senanga, to River) Zambezi fl central of side eastern the on Mongu-Senanga (3) Lukulu, to River Zambezi main the of part northern the on Mongu-Lukulu (2) Town, in Kalabo Harbour River Luanginga the to gu Mon- in Harbour Mulambwa the from Mongu-Kalabo (1) transects: of spective per- the from parameters quality water ement of the approach was to characterise Barotse Floodplain(Fig.3). The basicel- Sampling points were selected around the distribution of sampling points Representativeness and spatial are described and interpreted. metals and anions, and (5) sediment yields nutrients, (3) heavy metals, (4) non-heavy agricultural of variability (2) parameters, physical and bacteriological (1) which from points sampling of distribution tial spa- representative using presented are fi our of results the paper, this In oodplain (main Zambezi River) Zambezi (main oodplain udy, which included use of the -RF), and remote sensing. odli (main oodplain ndings

tical feasibility presented at each location. prac- the on depending location same the nearly or same the at taken were samples were also collected. Water samples and stream sediment sediment stream 124 of set Another analysis. bacteriological and chemical, physical, for collected were B E 6 in the Barotse Floodplain, western Zambia. Senanga transect, and (c) Sioma-Kalabo transects for the 2014 w Figure 4: Faecal and total coliform distribution along (a) Mong Figure 3: Spatial distribution of sampling points in the Barots ttl f 2 srae ae samples water surface 124 of total A

2018 coliforms in a 100 ml sample exceeded sample ml 100 a in coliforms of number the if coliforms TNTC considered were faecal and total both study, this In 4). (Fig. points sampling many at forms were too numerous to count (TNTC) Results indicate that faecal and total coli- parameters Bacteriological and physical e Floodplain, western Zambia. u-Kalabo transect, (b) Mongu- et-season fi eld campaign uSnna transect gu-Senanga Mon- the along instance, For activities. anthropogenic increased with associated were areas these of most as surprising, not were indicators bacteriological these 200. The observed high concentrations of 05 e sao. tes uh s as total such Others season. wet 2015 which experienced higher fl 6), (Fig. season wet 2014 the in ticularly par- higher, relatively be to found was nitrate nutrients, agricultural the Among nutrients Variability of agricultural after this point (Fig. 5). fl then and 17) (IB Limulunga in (Jauteni) Charleton as known locally stream a to 1) (IB Station Hydrometric Matongo from constant nearly was ture tempera- The DO. deplete that materials anthropogenic of absence the of because mg/l) at Sesheke-Senanga Bridge (IB 25) On the other hand, DO was highest (7.62 is used as fertiliser in the gardens nearby. This is attributed to animal manure, which 31). (IB School Basic Sinungu at mg/l) (1.24 lowest was DO the that found was Barotse Floodplain were also analysed. It the in points sampling the all at DO and Mongu Habour (IB 15). location on this last transect was found at spot hot The 32). (IB School Basic kana Si- and 31), (IB School 28), Basic Sinungu (IB School Basic Nakatwalenge at found were These requirements. ing adjacent areaswhenmeetingtheirdrink- or points same these accessed also tle) cat- (mainly animals cases some in that their domesticuses.Itwasalsoobserved for water obtained beings human where places included transect former the on fected by human activities. The hot spots af- are which transects, Mongu-Kalabo and Sioma-Kalabo the on points pling sam- at Similarly,TNTC were coliforms line. sewer School Secondary Senanga a sewerage disposal site (IB 23) from the (IB 20), Mapungu fl Bridge Litoya 19), (IB Scheme rigation Ir- Rice Sefula 18), (IB stream Sianda at spots along this transect were found to be hot The contamination. water of sources identifi were streams the into disposal sewerage and defecation, open sawmilling, rearing, livestock as such hscl aaees f temperature of parameters Physical ood area (IB 22), and , ua activities human oods than the ed as being as ed uctuated 99

Water resources Water resources in the Barotse Floodplain, western Zambia. Figure 7: Variation of some non-heavy metals and the anion of c 100 ŚĞŵŝĐĂůĞůĞŵĞŶƚ;ŵŐͬůͿ plain, western Zambia. Kalabo transect in the wet and dry seasons of 2014 and 2015, Ba Figure 6: Seasonal values of nitrate concentration in water alo Figure 5: Dissolved oxygen (DO) and temperature variation at di pling points in the Barotse Floodplain, Western Zambia ϭϬ ϮϬ ϯϬ ϰϬ ϱϬ ϲϬ ϳϬ Ϭ

/ϭ DĂŶŐĂŶĞƐĞ /ϯ

/ϱ /ϳ /ϵ /ϭϭ DĂŐŶĞƐŝƵŵ /ϭϯ /ϭϱ /ϭϳ ^ĂŵƉůŝŶŐůŽĐĂƚŝŽŶ /ϭϵ /Ϯϭ ^ŽĚŝƵŵ

C A /Ϯϯ /Ϯϱ /Ϯϳ /Ϯϵ hloride at sampling points /ϯϭ ĂůĐŝƵŵ

/ϯϯ ng the Mongu- ff erent sam- /ϯϱ rotse Flood- /ϯϳ /ϯϵ /ϰϭ ŚůŽƌŝĚĞƐ /ϰϯ areas around the fl in 2015 the source was restricted to small during the higher fl sources anthropogenic from element this of recruitment and mobilisation creased in- to attributed therefore was 6 Figure higher concentration of nitrates shown in fl higher experienced 2014 year the that plain duringthewetseason.Itwasnoted to the highlands and margins of the fl moved are animals system. The riculture son and also practice a complex fl fl the within cattle of lot a keep Lozi) (mainly people fl the to be agriculture-related activities around replenished during higher fl signifi are nutrients nitrate that suggests also 6 Figure plain. Flood- Barotse the in grown vegetables and maize as such crops agricultural of growth the supporting nutrient main est high- the be to considered were nitrates results, these From concentration. in ble negligi- be to found were mg/l) 0.001 (< nitrites and mg/l) 0.01 (< phosphates etain o tee lmns Fg 7) were (Fig. attributed to a number of factors and elements these of centrations (Fig. 7). to be relatively high in the water samples found were that sodium and magnesium, calcium, of cations and chlorides, of ons ani- of concentrations the instead was It Non-heavy metals and anions state in relation to mining contaminants. fl the within samples. This indicates that water quality sediment stream and water the both in water potable for standards (ZABS) ards Stand- of Bureau Zambia and (WHO) Organization Health World the within and mg/l) 0.002 (< negligible were um) chromi- and zinc, arsenic, mercury, um, of heavy metals (i.e., copper, lead, cadmi- concentrations that found was it — plain Flood- Barotse the from upstream River ern Zambia — a tributary of the Zambezi the Kabombo River Basin of north-west- up- of stream large-scale mining, particularly in impact environmental the On Heavy metals od ees hn 05 Te observed The 2015. than levels ood The source of the nitrate was suspected h rltvl eeae lvl o con- of levels elevated relatively The odli. o isac, h local the instance, For oodplain. oodplain is still in its natural its in still is oodplain oodplain during the dry sea- dry the during oodplain oodplain. oods of 2014, whereas cantly mobilised and mobilised cantly ood seasons. ood ag- ood-

cium concentration were attributed to to attributed were concentration cium sonal changes within the years (Tab. 1). sea- for concentration calcium in crease season. However, there was a general de- from the 2014 dry season to the 2015 dry wet season. Similar trends were observed tion from the 2014 wet season to the 2015 concentra- calcium in increase siderable = 14.4 mg/l and Q and mg/l 14.4 = B E 6 Q were medians the that indicated transect Mongu-Senanga the stream sediments. most abundantelementinbothwaterand the frequently was which calcium, using per, however, we present such an analysis pa- variability.this their In understand to analysis of these elements was carried out was taken from which a borehole. Seasonal 36)], trend (IB School Basic [Lukona samples the of one in found was nesium mag- of concentration high a instance, For magnesium. of concentrations high that geogenic factors could be inﬂ however,suspected, also was It 30)]. (IB Libuba Stream at Nambwae Basic School [e.g., locations sampling some at waste animal and materials organic of presence the with associated were magnesium of concentrations High 31)]. (IB School sic Ba- Sinungu [e.g., place taking were ing garden- as such activities anthropogenic found to be high in places where intensive also were elements These 7). (Fig. ride chlo- and sodium of amounts highest the taken of some contained and location this from was 37)] (IB Pond Salt [Sisima samples quality water the of One Plain. Matebele the on located pan, salt Sisima the is feature a such of example An son. sea- dry the during evaporation of rates These form salt pans as a result of the high ponds. isolated in high be to found were water, salty to lead which chloride, and sodium of levels instance, For processes. kwes o bt saos ta is, Q that — seasons both for skewness positive a indicted transect respec- This tively. 2015, of seasons dry and wet tiles — that is, upper (Q upper is, that — tiles quar- for stands Q where 8), (Fig. mean and lower quartiles (Q seasons of 2014, respectively, and Q and respectively, 2014, of seasons and Q and 3 The observed seasonal changes in cal- in changes seasonal observed The con- a was there that observed was It The trends in calcium concentration on – Q – 2dry 2 > Q = 2.6 mg/l for the wet and dry and wet the for mg/l 2.6 = 2 – Q 1 , or mode < median < median < mode or , 2dry = 13.3 mg/l for the for mg/l 13.3 = 1 ). 3 ), median (Q2), median ), 2wet 52 mg/l 5.2 =

uencing 2018 2wet

fl the into brought is calcium instance, For calcium. of uptake plant and seasons, dry fl the in variations as such factors complex (main Zambezi River) for the wet and dry seasons of 2014 and 20 Figure 8: Box plot distribution of calcium concentration on the tration of calcium was high (~15mg/l). coincided withaperiodwhenthe concen- low fl the during 9) (Fig. transect gu-Senanga was mostly lower than 6.9 along the Mon- pH the that noted was It calcium. of tion dissolu- the favours pH Lower pH. larly water,particu- the of parameters physical cium wasalsoattributedtochangesinthe Furthermore, the seasonal variation of cal- shoots. and roots as such tissues new of formation the in plants by up used is and seasonal changes (∆). as well as within-the-year 2015 yearly changes (∆) transect based on 2014 and on the Mongu-Senanga es in calcium concentration Table 1: Percentage chang- oodplain system through overland fl overland through system oodplain the and wet the between regimes ow ows (i.e., dry season) of 2015, which Seasonal %∆ 2014 04WtSao 05WtSao Yearly %∆ 2015Wet Season 2014 Wet Season 2014 Dry Season 2015 Dry Season 2015Dry Season 2014 Dry Q Q Q Q Q Q 1 2 3 1 2 3 ows ows 5.%0.0% –9.7% –52.5% –50.5% –45.5% Mongu-Senanga Transect . Q Q Q 1.8 2.6 3.7 Q Q Q 3.8 5.2 6.7 areas where sedimentation is high within Tool (SWAT). and WaterSoil the by erated Assessment gen- as 10) (Fig. sedimentation of rates fl main the within sub-basins the that found was It water quality parameters Sediment yields and physical low and high fl error (MSE) was 0.22 and 0.20 during the technique indicatedthatthemeansquare sessment of the predictive accuracy of the As- ArcGIS. in technique geostatistical a kriging, using generated were 9 Figure h sail oain o te o spot hot the of locations spatial The The spatially distributed pH values in values pH distributed spatially The Seasonal %∆ 2015 odli eprecd high experienced oodplain 1 2 3 1 2 3 Mongu-Senanga transect ow periods, respectively. 15. –21.9% 44+176.6% +185.0% 14.4 19.2 2+561.5% +404.5% 12 +308.2% 13 15 +214.5% 12 101

Water resources Water resources Floodplain. the sub-basins falling within the Barotse cumulation for the years 2001 to 2005 for Figure 10: SWAT-estimated sediment ac- Figure 9: Spatially modelled pH distribution in the dry and wet 102 and 2015,forestcoverdeclined byabout 1984 between that found work, present the as Zambia) western for database tity quan- and quality water a Developing 191: Task SASCCAL (i.e., framework broader same the within conducted was which (2018), al. et land. Zimba by agricultural study A in turned was land forested as changes cover land to uted fl the in mentation ging of irrigation channels in these fi clog- frequent to led has accumulation sediment of rate high The Scheme. tion fi rice the hosts 158 basins 140, 153, 157, and 158. Sub- basin sub- are brown) (coloured areas These fl the The potential cause of increased sedi- increased of cause potential The odli ae hw i Fgr 11. Figure in shown are oodplain

odli ws attrib- was oodplain elds at Sefula Irriga- Sefula at elds elds. ﬂ the enrich that nutrients of source other an- be to suspected was uses other and land agricultural to forest of conversion all changeinwaterquality. Furthermore, over- an and sedimentation of rates high minor changes in forest cover can lead to the soil type in the area is sandy in nature, Since 12). (Fig. 0.3% about of rate tion 10%, which translates to an annual reduc- coloured areas), as simulated by the SWAT model. Figure 11: Spatial visualisation of the sub-basins highly impac oodplain in the wet season. C A seasons, Barotse Floodplain, western Zambia. during the wet season (April 2014) than 2014) (April season wet the during transported being TS more has transect Mongu-Kalabo the that show 13) (Fig. ﬂ the within sediment of conveyance the infer to done was tion calcula- This (TDS). solids dissolved tal to- and (TSS) solids suspended total of sum a is which (TS), solids total the on was analysis This samples. quality ter Further analysis was done on the wa- the on done was analysis Further ted by sedimentation (brown- oodwaters. Results oodwaters.

Mongu-Senanga transect. compared to main Zambezi River along the Zambezi River (Mongu-Lukulu transect) River (Mongu–Kalabo transect) and main Figure 14: Turbidity in the Luanginga Mongu-Kalabo transect. the wet and dry seasons of 2014 along the Figure 13: Variation of TS concentration in B E 6 (Mon- River Zambezi main and transect) (Mongu-Kalabo River Luanginga the in to Senanga. Mongu and Mongu to Lukulu from larly particu- transects, other the along served ob- were trends Similar River. Zambezi the to River Luanginga the from nating in the dry season (September 2014) ema- Zambia (Zimba et al., 2018). Figure 12: Land cover change between 1984 and 2015 in the Barot It wasobservedthatturbidity high

2018 to any particular processes. Nevertheless, Nevertheless, processes. particular any to elements these of variability the attribute not did studies aforementioned the that however,noted, be should It detection. of phosphorus were largely close to the limit as such nutrients agricultural other that observed also They Floodplain. Barotse fl the in nitrate of tions jdgeest et al. (2015) found high concentra- Zui- Similarly, concentration. calcium in variability seasonal high a observed land, Wet- Kafue dam-impacted the and plain the biogeochemistry of the Barotse Flood- studied who (2012), Zurbrügg instance, For area. same the in conducted studies fi fl higher during occurring recruitment to attributed concentrations calcium and nitrate high included trend fl to linked fl the in elements chemical the in variations The Discussion the Mongu-Senanga transect (Fig. 14). fl the after and within ity be responsible for fi to assumed was process This sediments. the riverbanks and sieving out some of the on deposited be to sediments the forcing ever, vegetation acts like a porous barrier, fl main the Within rivers. confl streams tributary various from water as recruited is that sediment of amount huge the to attributed was This transect). gu-Lukulu ndings are in agreement with previous previous with agreement in are ndings oodplain were noted to be closely closely be to noted were oodplain ood inundation patterns. This This patterns. inundation ood uence upstream from these from upstream uence se sub-basin, western nally reducing turbid- ood season in the the in season ood oodplain, how- oodplain, oodplain along oodplain oods. These These oods. Floodplain diff Floodplain noted that the Kafue Flats and the Barotse part ofthebasin.Zuijdgeestetal.(2015) northern the in contamination of sources mining the from threat under yet not is fl the of quality water the that suggested concentration element related able calcium supports tissue development. etation during the wet season, as the avail- ed that fl water bodies. Schot & Wassen (1993) not- these of functions ecological unique the of natural processes that serve to maintain variability of elements in a wetland is part the that 2002) al., et Sinkala (e.g., shown been has it instance, For functions. land numerous wet- of processes fundamental on studies by supported reasonably is ments isassociatedwithfl ele- of variability the that hypothesis our biophysical water quality, evidence also evidence quality, water biophysical eff adverse have to noted were because of the destruction of crops. hunger and diseases exacerbate will bility dictable fl unpre- that and growth population with increase likely will Floodplain Barotse the in sedimentation that noted also has (2013) steadily.Mutonga increasing been fl the in settling people of number The land. agricultural to est for- of conversion increased to attributed signifi be to found was Scheme) Rice Sefula (e.g., locations the of some in sedimentation instance, fl and fauna, soils, fertile include overexploited for its rich resources, which signifi a that means population in increase An tion will increase with population growth. is expected that such anthropogenic pollu- source of livelihood for the local people, it major a is Floodplain Barotse the Since contamination. bacteriological of peaks high registered areas settled near points ter parameters.Itwasnotedthatsampling wa- biophysical of predicators major the fl the within estation) (e.g., farming, wetland grazing, and defor- brügg (2012) and Nyoni (2014). Zur-as such researchers other by upheld also was view This parts. large in tine pris- be to latter the considered and ence h osre lw ees f mining- of levels low observed The lhuh nhooei activities anthropogenic Although activities economic Anthropogenic cn pr o te fl the of part cant oodplains tend to have dense veg- oods arising from climate varia- er in anthropogenic infl anthropogenic in er cantly high and was was and high cantly oodplain seem to be be to seem oodplain oodplain has since since has oodplain oodplain will be be will oodplain ooding patterns ooding patterns oodplain ora. For For ora. et on ects 103 u-

Water resources Water resources anand n ta te ytm o be- not system the that and maintained be balance this that important therefore is It decades. for Floodplain Barotse in the people local the among agriculture fl sustaining been have that soils, the in nutrients replenishing including tions, func- many serves process This season. wet the in occurred nitrate) and calcium (e.g., elements some of recruitment high fl the of balance biogeochemical processes and ecological ‘renewal’of the in critical are processes fl high and low as was also related to natural processes such parameters quality water in change the hand, other the On scenario. this erbate fl the around tivities. Future economic pressures in and ac- these of result the as increase the on be to observed also was Sedimentation courses. water settled in especially ter, and bacteriological contamination of wa- related tohighnutrientloading,lowDO, were resource water critical this around production agricultural and forestation de- as such activities Increased cesses. pro- natural and anthropogenic both to attributed are changes these seasons). of Drivers dry and wet (i.e., time over signifi varied parameters these of All rameters. pa- physiochemical and bacteriological included These Floodplain. Barotse the in parameters quality water selected in variations spatio-temporal of terminants This study was aimed at assessing the de- Conclusion fl were found to be predominant during low that malaria as such diseases certain ly, high-fl during itself ‘cleanses’ system the that implies This (2014). Nyoni by noted also were trends during the low fl areas non-settled in observed were tion contamina- bacteriological high and gen oxy- dissolved low instance, For trends. seasonal of part was this that suggests 104 levels regress. biological organisms to replicate as fl micro- for environment conducive a ates stagnant water during the dry season cre- riods (Banda et al., 2015). This is because ows were very low during high fl cnl ars te td ae and area study the across cantly oodplain are likely to exac- to likely are oodplain ows or dry season. These

odli. o instance, For oodplain. ooding patterns. These ooding ow periods. Similar- periods. ow ow pe- ood ood anthropogenic activities. increased resulting and area, the in tion popula- increased mining, copper scale large- upstream of because encouraged is monitoring continuous state, pristine a in still is Floodplain Barotse the that indicating data baseline current Despite come overloadedbyeconomicactivities. Ah iablame, L., Chaubey, I. & Smith, D. (2010) D. Smith, Ah & I. Chaubey, L., iablame, References Resources Management (IWRM) Centre. Water Integrated (UNZA) Zambia’s of University the by provided was support Operational 01LG1201M. number tion tion and Research (BMBF) under promo- Educa- of Ministry Federal German the work of SASSCAL and was sponsored by The research was carried out in the frame- Acknowledgements con- should sampling quality water • tutions and stakeholders that: The studyrecommends Recommendations te aba niomna Manage- Environmental Zambia the • defor- halt to plan a of development • Publications, mospheric, andPlanetarySciences Faculty Purdue University ditches. drainage agricultural tile-fed of face inter- sediment-water the at content Nutrient of the ﬂ upstream and around activities nomic eco- increased of light in (WARMA) Authority Management Resources ter tinue tobedoneseasonallybythe Wa- Zambia’s Northwestern Province. in upstream mining copper large-scale coming heavy metal pollution from the on water pollution plans to halt any in- focus should WARMA, with gether to- working (ZEMA), Agency ment quality; and water poor overall and sedimentation reduce to Livestock and Agriculture of Ministry the with together working Resources Natural and Lands of istry by the Forestry Department in the Min- ﬂ the estation inthecatchmentssurrounding C A oodplain should be done urgentlydone be should oodplain oodplain;

2 , 411–428.

Department ofEarth, At- to relevantinsti- Bilotta, G.S. & Brazier, R.E. (2008) Understand- W.W. Chakanika, & C.M. Namafe S., Banda, rgr, .. Sasn FJ, ce, .. & W.A. McKee, F.J., Swanson, S.V.,Gregory, Lovett, S., Price, P.Price, S., Lovett, Edgar,& (2007) B. Nyoni, F.C. (2014) Naiman, R.J. & Décamps, H. (1997) The ecology Mutonga, M. (2013) oui, .. (2014) V.C.N Polunin, ikl,T, ws, .. Maa M (2002) M. Mwala, & E.T. Mwase, T., Sinkala, P.P.Schot, & Wassen,con- Calcium (1993) M.J. Noe, G.B. & Hupp, C.R. (2007) Seasonal vari- Seasonal (2007) C.R. Hupp, & G.B. Noe, M. McClain, & H. Décamps, R.J., Naiman, wetlands. J. Barnes, & L. Emerton, B., Smith, J., Turpie, ib, . Bna K, hbl,A, hr, W., Phiri, A., Chabala, K., Banda, H., Zimba, the Modeling (2002) W. Chen, S.T.Y.Tong,& Riverine (2002) J.A. Stanford, & K. Tockner, quality and aquatic biota. ing the infl cial Sciences,andEducation bia. Zam- western of Plains Barotse the in change knowl- climate mitigating in adults Lozi among environmental edge Traditional (2015) Hydrology: RegionalStudies Basin: Aapproach. sensing remote River Zambezi upper Floodplain, Barotse the in extent inundation in trends of Assessment Selma, P., Meinhardt, M. & Nyambe, I. (2018) pcie f iain zones. riparian of spective per- ecosystem An (1991) K.W. Cummins, 2849–2861. 540–551. search and Applications of EcologyandSystematics, of interfaces — riparian zones. bia, Lusaka, Zambia. ronment Barotse Floodplainsanditsimpactonenvi- man adaptationtoannual gram. from theNationalRiverContaminantsPro- trient, sedimentandinteractions.Findings sis, University of Zambia, Lusaka, Zambia. Zambezi andtheKafueRivers. systems inZambia:acomparativestudyofthe Zambia. agement approach in the lower Kafue River of man- weed a utilization: weed and reduction pollutant through weeds aquatic of Control 197–217. area. recharge the in conditions soil and sources water to tion rela- in groundwater wetland in centrations versity Press, Cambridge, UK. trends andglobalprospects. f sothdoeid fl short-hydroperiod a of inundation during retention nutrient in ation sevier, San Diego, CA, USA. management ofstreamside communities. (2005) (1999) ment CD) Uiest o Cp Tw, Cape Town, Cape Town, South Africa. of University (CIDA), Agency Development International Canadian Offi Regional IUCN Project, Utilization Resource and tion ter quality. relationship between land use and surface wa- Environmental Conservation, fl 27 od lis peet tt ad uue trends. future and state present plains: ood , 983–991. International JournalofHumanities,So- , Land & Water Australia, Canberra. 66 Economic valueoftheZambezibasin Riparia: ecology, conservationand abz Bsn elns Conserva- Wetlands Basin Zambezi . Master’s thesis, University of Zam- of University thesis, Master’s . , 377–393. Physics andChemistryoftheEarth, uence of suspended solids on water Journal ofEnvironmental Manage- e o Suhr Arc, The Africa, Southern for ce Carbondynamicsintworiver An ethicalassessmentofhu- Journal ofHydrology , Aquatic ecosystems: oodplain. 23 Water Research, fl , 1088–1101. oods inMongu’s 28 , , Bio-Science Cambridge Uni- Cambridge

2 29 15 Annual Review , 621–658. , 89–108. Master’s the- Master’s , 308–330. , 149–170. Journalof River Re- Salt, nu- , , 141

42 41 El- , , ,

B E 6 Zurbrügg, R., 2012. R., Zurbrügg, Zuijdgeest, A.L., Zurbrugg, R., Blank, N., Ful- N., Blank, R., Zurbrugg, A.L., Zuijdgeest, 20309), ETH Zürich, Switzerland. impacts bia): river- tropical 7535–7547. the Zambezi River basin. River Zambezi the fl tropical contrasting two from nutrients and carbon of dynamics sonal Sea- (2015) Wehrli,B. & D.B. Senn, R., cri, PD israin DS. T No. ETH (DISS. dissertation PhD . fl oodplain system(Kafue Flats,Zam- fl oodplain exchangeanddam Biogeochemistry ofalarge oodplain systems in systems oodplain Biogeosciences

2018 , 12 , 105

Water resources References [CrossRef] Tockner, K. & Stanford, J.A. (2002) Riverine flood plains: present state and future trends. Ahiablame, L., Chaubey, I. & Smith, D. (2010) Environmental Conservation, 29, 308–330. Nutrient content at the sediment-water CrossRef interface of tile-fed agricultural drainage Tong, S.T.Y. & Chen, W. (2002) Modeling the ditches. Purdue University Department of relationship between land use and surface Earth, Atmospheric, and Planetary Sciences water quality. Journal of Environmental Faculty Publications, 2, 411–428. CrossRef Management, 66, 377–393. CrossRef Banda, S., Namafe C.M. & Chakanika, W.W. Turpie, J., Smith, B., Emerton, L. & Barnes, J. (2015) Traditional environmental knowledge (1999) Economic value of the Zambezi basin among Lozi adults in mitigating climate wetlands. Zambezi Basin Wetlands change in the Barotse Plains of western Conservation and Resource Utilization Zambia. International Journal of Project, IUCN Regional Office for Southern Humanities, Social Sciences, and Education, Africa, The Canadian International 2, 89–108. Development Agency (CIDA), University of Bilotta, G.S. & Brazier, R.E. (2008) Cape Town, Cape Town, South Africa. Understanding the influence of suspended Zimba, H., Banda, K., Chabala, A., Phiri, W., solids on water quality and aquatic biota. Selma, P., Meinhardt, M. & Nyambe, I. Water Research, 42, 2849–2861. CrossRef (2018) Earth observation assessment of Gregory, S.V., Swanson, F.J., McKee, W.A. & wetland inundation extent variations in the Cummins, K.W. (1991) An ecosystem Barotse wetland, Upper Zambezi basin using perspective of riparian zones. Bio-Science, Desert Flood Index. Journal of Hydrology: 41, 540–551. CrossRef Regional Studies, 15, 149–170. Lovett, S., Price, P. & Edgar, B. (2007) Salt, Zuijdgeest, A.L., Zurbrugg, R., Blank, N., nutrient, sediment and interactions. Findings Fulcri, R., Senn, D.B. & Wehrli, B. (2015) from the National River Contaminants Seasonal dynamics of carbon and nutrients Program. Land & Water Australia, from two contrasting tropical floodplain Canberra. systems in the Zambezi River basin. Mutonga, M. (2013) An ethical assessment of Biogeosciences, 12, 7535–7547. CrossRef human adaptation to annual floods in Zurbrügg, R., 2012. Biogeochemistry of a large Mongu’s Barotse Floodplains and its impact tropical floodplain system (Kafue Flats, on environment. Master’s thesis, University Zambia): river-floodplain exchange and of Zambia, Lusaka, Zambia. dam impacts. PhD dissertation (DISS. ETH Naiman, R.J. & Décamps, H. (1997) The No. 20309), ETH Zürich, Switzerland. ecology of interfaces — riparian zones. Annual Review of Ecology and Systematics, 28, 621–658. CrossRef Naiman, R.J., Décamps, H. & McClain, M. (2005) Riparia: ecology, conservation and management of streamside communities. Elsevier, San Diego, CA, USA. Noe, G.B. & Hupp, C.R. (2007) Seasonal variation in nutrient retention during inundation of a short-hydroperiod floodplain. River Research and Applications, 23, 1088–1101. CrossRef Nyoni, F.C. (2014) Carbon dynamics in two river systems in Zambia: a comparative study of the Zambezi and the Kafue Rivers. Master’s thesis, University of Zambia, Lusaka, Zambia. Polunin, V.C.N (2014) Aquatic ecosystems: trends and global prospects. Cambridge University Press, Cambridge, UK. Schot, P.P. & Wassen, M.J. (1993) Calcium concentrations in wetland groundwater in relation to water sources and soil conditions in the recharge area. Journal of Hydrology, 141, 197–217. CrossRef Sinkala, T., Mwase, E.T. & Mwala, M. (2002) Control of aquatic weeds through pollutant reduction and weed utilization: a weed management approach in the lower Kafue River of Zambia. Physics and Chemistry of the Earth, 27, 983–991. CrossRef