Modeling Solid Waste Minimization Performance at Source in Dar es Salaam City, Tanzania

Municipal solid waste generation is strongly linked to rising human population and expanding urban areas, with significant implications on urban metabolism as well as space and place values redefinition. Effective management performance of municipal solid waste management underscores the interdisciplinarity strategies. Such knowledge and skills are paramount to uncover the sources of waste generation as well as means of waste storage, collection, recycling, transportation, handling/treatment, disposal, and monitoring. This study was conducted in Dar es Salaam city. Driven by the curiosity model of the solid waste minimization performance at source, study data was collected using focus group discussion techniques to ward-level local government officers, which was triangulated with literature and documentary review. The main themes of the FGD were situational factors (SFA) and local government by-laws (LGBY). In the FGD session, sub-themes of SFA tricked to understand how MSW minimization is related to the presence and effect of services such as land use planning, availability of landfills, solid waste transfer stations, material recovery facilities, incinerators, solid waste collection bins, solid waste trucks, solid waste management budget and solid waste collection agents. Similarly, FGD on LGBY was extended by sub-themes such as contents of the by-law, community awareness of the by-law, and by-law enforcement mechanisms. While data preparation applied an analytical hierarchy process, data analysis applied an ordinary least square (OLS) regression model for sub-criteria that explain SFA and LGBY;and OLS standard residues as variables into geographically weighted regression with a resolution of 241 × 241 meter in ArcMap v10.5. Results showed that situational factors and local government by-laws have a strong relationship with the rate of minimizing solid waste dumping in water bodies (local R square = 0.94).

Prediction and Protection of Cultivated Land in China

[Objectives]To protect cultivated land and ensure national food security and to forecast the cultivated land area of China and the provinces(cities)in 2030,2035 and 2050.[Methods]Based on the cultivated land area data of the whole country and provinces(autonomous regions and municipalities)from 2009 to 2017,the OLS model is used to forecast the cultivated land area of China and the provinces(cities)in 2030,2035 and 2050.[Results]The results show that the predicted area of cultivated land in 2030,2035 and 2050 is 134.0886,133.7856 and 132.8764 million ha,respectively,showing an obvious decreasing trend.The national cultivated land scale predicted in this paper can meet the requirements of the 2030 national cultivated land retention target set in the National Land Planning Outline(2016-2030).However,in the total area of existing cultivated land,there is still a certain area of sloping cultivated land(accounting for about 4%of the total cultivated land area,it is appropriate to gradually return farmland to forest).At the same time,nearly 20%of the cultivated land has been polluted,and the low-quality cultivated land accounts for about 22%of the total cultivated land.[Conclusions]The situation of cultivated land protection in the whole country is not rosy.For this reason,some measures and suggestions are put forward:strengthening land consolidation,striving to improve the quality of cultivated land,and appropriately increasing new cultivated land;strengthening the protection of cultivated land resources and strictly controlling the reduction of cultivated land.