Next Article in Journal
Benthic Diatom Communities in Urban Streams and the Role of Riparian Buffers
Next Article in Special Issue
Investigating Sediment Dynamics in a Landslide-Dominated Catchment by Modeling Landslide Area and Fluvial Sediment Export
Previous Article in Journal
Quantitative Analysis of the Sub-Cloud Evaporation of Atmospheric Precipitation and Its Controlling Factors Calculated By D-Excess in an Inland River Basin of China
Previous Article in Special Issue
Modeling Sediment Yields and Stream Stability Due to Sediment-Related Disaster in Shihmen Reservoir Watershed in Taiwan
Open AccessArticle

Effects of Land Cover and Atmospheric Input on Nutrient Budget in Subtropical Mountainous Rivers, Northeastern Taiwan

1
Department of Life Science, Tunghai University, Taichung 407224, Taiwan
2
Center for Ecology and Environment, Tunghai University, Taichung 407224, Taiwan
3
Department of Geography, National Taiwan University, Taipei 10617, Taiwan
4
Department of Geography, National Taiwan Normal University, Taipei 10610, Taiwan
5
Department of Life Science, National Taiwan Normal University, Taipei 11677, Taiwan
*
Authors to whom correspondence should be addressed.
Water 2020, 12(10), 2800; https://doi.org/10.3390/w12102800
Received: 18 August 2020 / Revised: 3 October 2020 / Accepted: 7 October 2020 / Published: 9 October 2020
(This article belongs to the Special Issue Hydrological Impact of Typhoon on Rivers)
The nutrient budget, the difference between the nutrient output via stream and input via precipitation, can provide insights into how environmental processes affect forested ecosystem biogeochemistry. In this study, field measurements of the nutrient budgets—including Na+, Cl, K+, Mg2+, Ca2+, NO3, and SO42−—of 19 sites were conducted in Feitsui Reservoir Watershed (FRW) of northeastern Taiwan. A series of power-law regressions were developed to establish the relationship of the nutrient budget to the discharge, nutrient input, agricultural land cover, and slope. The result show that the weekly nutrient budget is significantly affected by agricultural land and input via precipitation (R2 of regression models ≥ 0.90), yet the relationship varies among different nutrient elements. The agricultural land cover is the major factor, while the input via precipitation plays a relatively minor role in the budget of Cl, Mg2+, Ca2+, and SO42−. These nutrients could be provisioned abundantly from the system, and thus the input via precipitation is not the predominant controlling factor. By contrast, the Na+ and K+ inputs via precipitation are indispensable for accurately estimating the riverine exports. Because weathering is a limited source of K+, the roles of agricultural activities and input via precipitation are likely decisive for transport. Besides, the NO3 budget reveals a strong interplay between the atmospheric input and agricultural land, as expected. Because the nutrient budget model of NO3 is strongly improved, the R2 changes from 0.34 to 0.99 when a larger coefficient in exponent term (10.2) for agricultural land cover (showing that NO3 export is strongly hydrologically controlled) and precipitation input are included. Our analysis is based on one year of data, so extrapolating the result to a long-term period should be done with caution, as there could be substantial inter-annual variation. The nutrient budget approach provides a preliminary assessment to evaluate the impacts of agriculture and atmospheric deposition on nutrient export, which can provide a precursory reference for watershed management for improving water quality and mitigating eutrophication. View Full-Text
Keywords: nutrient export; land cover change; subtropical mountainous rivers; Taiwan nutrient export; land cover change; subtropical mountainous rivers; Taiwan
Show Figures

Figure 1

MDPI and ACS Style

Chang, C.-T.; Shih, Y.-T.; Lee, L.-C.; Lee, J.-Y.; Lee, T.-Y.; Lin, T.-C.; Huang, J.-C. Effects of Land Cover and Atmospheric Input on Nutrient Budget in Subtropical Mountainous Rivers, Northeastern Taiwan. Water 2020, 12, 2800.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Search more from Scilit
 
Search
Back to TopTop