Reactive nitrogen budgets in human-nature coupling system in lakeside area with insufficient data - A case study of Mwanza, Tanzania.

Autor: Xiong C; Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address: chhxiong@niglas.ac.cn., Xu L; School of Geography and Environment, Jiangxi Normal University, Nanchang 330022, China., Mhagama FL; Tanzania Fisheries Research Institute, P.O. Box 475, Mwanza, Tanzania., Chen SS; Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, China; Research Centre of Urban Sustainable Development School of Geographical Sciences, Nanjing University of Information Science & Technology, Nanjing 210044, China. Electronic address: schens@niglas.ac.cn., Zhu K; Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, China; College of Mapping and Geographical Sciences, Liaoning Technical University, Fuxin 123000, China., Gao Q; Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, China., Li H; Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, China., Su W; Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2023 Jan 10; Vol. 855, pp. 158915. Date of Electronic Publication: 2022 Sep 21.
DOI: 10.1016/j.scitotenv.2022.158915
Abstrakt: Nitrogen (N) is an essential nutrient element for life, and also a major element involved in the composition of greenhouse gases, surface water pollutants, air pollutants, etc. Quantifying and evaluating the nitrogen budget of a region is very important for effectively controlling the nitrogen discharge and scientifically managing the nitrogen cycle. In this paper, the urban Rural Complex N Cycling (URCNC) model was used to analyze the nitrogen budget of Mwanza region, a typical lakeside area with insufficient data, and the nitrogen flow process of livestock subsystem, cropland subsystem, human subsystem and landfill subsystem was clearly described and the nitrogen input sources of atmospheric subsystem and surface water subsystem were clarified. And the results demonstrated: (1) the cropland subsystem was the subsystem with the largest nitrogen flux, and the input, output and accumulation of nitrogen were 33,116 t of N, 31,925 t of N and 1191 t of N, respectively. Livestock subsystem was the second largest subsystem of nitrogen flux, and the input, output and accumulation of nitrogen were 31,013 t, 30,183 t and 830 t, respectively. The nitrogen flux of the human subsystem was also large, and the nitrogen input, output and accumulation were 17,905, 17,125 and 780 t, respectively. The nitrogen input, output and accumulation of the landfill subsystem were 3700 t, 770 t and 2930 t, respectively. (2) 8093 t of N, 6864 t of N, 3959 t of N, and 758 t of N emitted into the atmospheric subsystem from the livestock subsystem, cropland subsystem, human subsystem, and landfill subsystem, respectively. (3) The total Nr input of surface water subsystem increased from 18,545 t of N in 2010 to 20,174 t of N in 2020, with an increase of 8.78 % in the past decade. It was estimated that by 2030, the total Nr input of the surface water subsystem would reach 24,946 t of N with an increase of 23.65 % compared with 2020. The livestock subsystem was the largest source, the cropland subsystem was the second largest source and human subsystem was an important source. (4) Population growth, economic development and urbanization are the main nitrogen driving factor. (5) Technology and policy together have important contributions to the reduction of nitrogen pollution in surface water.
Competing Interests: Declaration of competing interest No conflict of interest exits in the submission of this manuscript, and manuscript is approved by all authors for publication.
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Databáze: MEDLINE
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