Assessment of Soil Degradation in a Palustrine Wetland and the Implication on Its Water Purification Potential

Abstract

This study determines the extent of degradation of soils in Khubelu wetland in Lesotho and the impact this may have on its water purification potential. 72 soil samples are collected at different sites and depths around the wetland and characterized for different properties. The values of these properties are then used to determine the chemical degradation index (CDI) of the wetland soils. The soils are non‐saline (electrical conductivity < 0.25 mS cm−1), mostly acidic (4.5 < pH < 5.22) with moderate organic matter content (2.06–3.9%). Soil properties vary with depth and from upstream to downstream of the wetland. Values for soil CDI are 3.42, 3.25, and 3.06 for soils from upstream, midstream, and downstream of the wetland respectively, indicating a decrease in soil degradation from upstream to downstream. The dominance of emergent vegetation in the wetland indicates a potential to get rid of sediments in wetland influents but the soil characteristics may present a challenge in the removal of nutrients and organic and inorganic pollutants from these influents. The characteristics of the soils and the extent of soil degradation present some challenges in the wetland’s ability to filter out nutrients and organic and inorganic pollutants.

The Application of Geographic Information System in Urban Forest Ecological Compensation and Sustainable Development Evaluation

“…The meaning of water quality purification capacity is the removal amount of COD, the purification of total nitrogen, and the purification of total phosphorus [29]. The ability to fix carbon In Figure 7, ecological benefits are mainly reflected in water source conservation, soil conservation, air purification, water quality purification, carbon sequestration and oxygen release, climate regulation, wind and sand fixation, and other aspects [28]. The connotation of water conservation capacity is mainly reflected in two aspects: regulating water quantity and purifying water quality.…”