Identifying Watershed Regions Sensitive to Soil Erosion and Contributing to Lake Eutrophication—A Case Study in the Taihu Lake Basin (China)

Abstract

Taihu Lake in China is suffering from severe eutrophication partly due to non-point pollution from the watershed. There is an increasing need to identify the regions within the watershed that most contribute to lake water degradation. The selection of appropriate temporal scales and lake indicators is important to identify sensitive watershed regions. This study selected three eutrophic lake areas, including Meiliang Bay (ML), Zhushan Bay (ZS), and the Western Coastal region (WC), as well as multiple buffer zones next to the lake boundary as the study sites. Soil erosion intensity was designated as a watershed indicator, and the lake algae area was designated as a lake quality indicator. The sensitive watershed region was identified based on the relationship between these two indicators among different lake divisions for a temporal sequence from 2000 to 2012. The results show that the relationship between soil erosion modulus and lake quality varied among different lake areas. Soil erosion from the two bay areas was more closely correlated with water quality than soil erosion from the WC region. This was most apparent at distances of 5 km to 10 km from the lake, where the r2 was as high as 0.764. Results indicate that soil erosion could be used as an indicator for identifying key watershed protection areas. Different lake areas need to be considered separately due to differences in geographical features, land use, and the corresponding effects on lake water quality.

The Effect of Erosion Control Practices on the Vulnerability of Soil Degradation in Oued EL Malleh Catchment using the USLE Model Integrated into GIS, Morocco

“…This was because of the inter-annual irregularity at the meteorological stations. The resulting values are most relevant than thus obtained by including the factor of anti-erosion practices P estimated according to [57] (Figure 9) in the overlay of the maps, with minimum values of 0 t.ha 1 .year 1 and maximum values of 65 t.ha 1 .year 1 , with an average of 0.4 (Figure 11). The soil losses finding displays the importance of support practices on decreasing soil losses, as well as the inefficiency of the existing conservation practices to restricting the soil degradation in the Oued El Malleh catchment.…”

“…It should be noted that in this study, the value of the P-factor for the biological and the mechanical treatment was determined according to [55,56]. Since more than 22.32 % of the study area represents slope classes ranging from 7 to 21 % medium-high (Figure 2), it is proposed to map the erosion control practices (Figure 9) according to the slope [57].…”

Basin Water Sensitivity and Its Impact on Spatial Expansion: A Case Study of the Taihu Basin, China

“…Few researchers have described and explored the basic principles and contents of WSUD [26] or applied it to inspirational urban design [27], landscape architecture and/or extension design [28]. The practice of WSUD theory in China is even more limited, as the consideration of water sensitivity in basin development is still in its initial stages.…”

Study of ecodrainage system for hydrometeorological disaster mitigation

“…According to [5], rainwater is one of the water sources that can be used as groundwater supplementation and/or used directly to overcome water shortages in the dry season and floods in the rainy season. Human activities and land cover/use changes have resulted in increased soil erosion and sources of pollution in a watershed area [6]. Watershed management which includes the management of land, water resources, soil, organic matter, and other natural resources in the watershed area, requires continuous efforts and the latest technology for ecological, social, and economic purposes [7].…”