scholarly journals Anthropogenic influences on Zambian water quality: hydropower and land-use change

2021 ◽  
Author(s):  
R. Scott Winton ◽  
Cristian R. Teodoru ◽  
Elisa Calamita ◽  
Fritz Kleinschroth ◽  
Kawawa Banda ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Field Data ◽  
Agricultural Land ◽  
Land Use Changes ◽  
Surface Water Quality ◽  
Anthropogenic Influences ◽  
Hydropower Dams ◽  
Local Impacts ◽  
Zambezi River

Hydropower dams along with urban and agricultural land-use changes are altering surface water quality in the Zambezi River Basin, Zambia. Field data reveal local impacts and point to monitoring needs for safeguarding water resources under pressure.

scholarly journals Modelling Impacts of a Municipal Spatial Plan of Land-Use Changes on Surface Water Quality—Example from Goriška Brda in Slovenia

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 189 ◽  
Author(s):  
Matjaž Glavan ◽  
Sara Bele ◽  
Miha Curk ◽  
Marina Pintar
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Surface Water ◽  
Land Use Change ◽  
Agricultural Land ◽  
Surface Water Quality ◽  
Erosion Processes ◽  
Phosphorus Loads ◽  
The Impact ◽  
Spatial Plan

Intensive agriculture causes nutrient leaching and accelerates erosion processes, which threatens the good quality status of surface waters, as proposed by the European Union (EU) Water Framework Directive. The purpose of this study was to define the impact of two alternative agricultural land-use change scenarios defined in a Municipal Spatial Plan on surface water quality by using the Agricultural Policy/Environmental eXtender (APEX) model. As experimental area, we chose a small Kožbanjšček stream catchment (1464 ha) situated in the Goriška Brda region in Slovenia. The area, due to favorable conditions for vineyards, is facing increasing deforestation. The change of 66.3 ha of forests to vineyards would increase the sediment, nitrate, and phosphorus loads in the stream by 24.8%, 17.1%, and 10.7%, respectively. With the implementation of vegetative buffer strips as a mitigation measure of the current situation, we could reduce the sediment, nitrate, and phosphorus loads by 17.9%, 11.1%, and 3.1%, respectively, while a combination of the two land-use change scenarios would result in a slight increase of the above-mentioned loads, corresponding to 0.61%, 2.1%, and 6.6%, respectively, compared to the baseline situation. The results confirm that, as we can increase pollution levels with deforestation, we can also reduce water pollution by choosing proper types of land management measures.

Effect of land use and moisture on phosphorus forms in upland stream beds in South Otago, New Zealand

2009 ◽  
Vol 60 (7) ◽  
pp. 619 ◽  
Author(s):  
Richard W. McDowell
Keyword(s):  
Water Quality ◽  
Land Use ◽  
New Zealand ◽  
Land Use Changes ◽  
Surface Water Quality ◽  
Moisture Regime ◽  
Organic P ◽  
Stream Beds ◽  
Total P ◽  
P Bioavailability

Land use can influence stream sediment composition and water quality, whereas moisture status affects sediment phosphorus (P) bioavailability to algae. Declining upland surface-water quality in South Otago, New Zealand, may reflect land-use changes from sheep- to dairy-farming. I sampled sediment (0–20 cm) from streams draining 12 dairy- and 12 sheep-farmed catchments in spring (wet) and autumn (dry). 31P nuclear magnetic resonance (NMR) spectroscopy and the EDTA-fractionation scheme were used to determine different P forms and infer P bioavailability. Significantly more P was present in the sediment of streams draining dairy- than sheep-farmed catchments. Total P did not differ with the moisture regime; however, changes occurred in the following P fractions: acid-soluble organic P, NaOH-P, CaCO3≈P, Fe(OOH)≈P and residual organic P. Extraction for 31P NMR analysis removed 78–85% of sediment total P and isolated five P classes. More bioavailable P such as orthophosphate (23–40% of P extracted) and diesters (2–6% of P extracted) was present in dry than in wet sediments, and in sediments draining dairy streams than in those from sheep-farmed catchments. This indicates substantial reserves of bioavailable P in sediment from these catchments, especially from dairy-farmed catchments, sustaining in-stream P concentrations for many years even without additional P input from land.

scholarly journals Land Use and Stream Nitrogen Concentrations in Agricultural Watersheds Along the Central Coast of California

2001 ◽  
Vol 1 ◽  
pp. 615-622 ◽  
Author(s):  
Marc Los Huertos ◽  
Lowell E. Gentry ◽  
Carol Shennan
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Agricultural Land ◽  
Shallow Groundwater ◽  
Surface Water Quality ◽  
Spatial And Temporal Patterns ◽  
Total N ◽  
Nitrogen Concentrations ◽  
High Concentrations ◽  
N Loading

In coastal California nitrogen (N) in runoff from urban and agricultural land is suspected to impair surface water quality of creeks and rivers that discharge into the Monterey Bay Sanctuary. However, quantitative data on the impacts of land use activities on water quality are largely limited to unpublished reports and do not estimate N loading. We report on spatial and temporal patterns of N concentrations for several coastal creeks and rivers in central California. During the 2001 water year, we estimated that the Pajaro River at Chittenden exported 302.4 Mg of total N. Nitrate-N concentrations were typically <1 mg N l–1in grazing lands, oak woodlands, and forests, but increased to a range of 1 to 20 mg N l–1as surface waters passed through agricultural lands. Very high concentrations of nitrate (in excess of 80 mg N l–1) were found in selected agricultural ditches that received drainage from tiles (buried perforated pipes). Nitrate concentrations in these ditches remained high throughout the winter and spring, indicating nitrate was not being flushed out of the soil profile. We believe unused N fertilizer has accumulated in the shallow groundwater through many cropping cycles. Results are being used to organize landowners, resource managers, and growers to develop voluntary monitoring and water quality protection plans.

Assessing the impact of agricultural land use changes on water quality

1999 ◽  
Vol 40 (2) ◽  
pp. 1-10 ◽  
Author(s):  
R. Meissner ◽  
J. Seeger ◽  
H. Rupp ◽  
H. Balla
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Agricultural Land ◽  
Land Use Changes ◽  
Agricultural Land Use ◽  
N Loss ◽  
Ground Water Recharge ◽  
Catchment Areas ◽  
One Year ◽  
The Impact

To study and predict environmental impacts of land use changes on water quality we conducted different types of lysimeter experiments. All of them are linked to representative experimental catchment areas in the field. This allows the verification and extrapolation of lysimeter results. The objective of this paper is to discuss a strategy for using and scaling-up of lysimeter results to a field and catchment scale. It will be shown that the N-loss determined with lysimeters falls within the variation of N-balance based model calculations, and also within ground water recharge rates calculated with models commonly used in hydrology. Extrapolation of lysimeter data to a catchment with similar soils provides a reliable basis for estimating the N-leaching caused by a change in agricultural land use. On the basis of the N-loss from the soil and the N-load of the stream, the calculations show that an increase in the proportion of one year rotation fallow from 10 to 25% results in nearly a 10% increase in the N-load of the stream. However, from the point of view of protecting drinking water quality, rotation fallow for one year is not recommended because of the resulting intensified leaching of nitrates.

Sign in / Sign up

Export Citation Format

Share Document