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Soil is the important natural recourse for living things of the world and regulates its ecosystem. Soil types are depending on physiographic and climatic factors. The study discussed soil types of Nepal prepared by Land Resource Mapping Project (LRMP) based on world reference base developed by Food and Agriculture Organization of the United States  (FAO)  and Soil and Terrain (SOTER) soil type of Nepal by ISRIC-World soil Information based on universal soil classification system developed by United State Department of Agriculture (USDA)  using Geographic information system (GIS). According to LRMP the soil types of Nepal are as follow: Dystrochrepts Haplumbrepts Haplustalfs, Dystrochrepts Haplustalfs Rhodustalfs, Haplumbrepts Dystrochrepts Cryumbrepts, Udipsamments Dystrochrepts Rhodustalfs, Glaciated Mountain, Haplaquents Haplaqepts Eutrocrepts, Udorthents Ustorthents Haplaquents, Dystrochrepts Halpumbrepts Haplustalfs-calcarious Materials, Rhodustalfs Dystrochrepts Haplustalfs, Dystrochrepts Eutrochrepts Argiudolls, Dystrochrepts Hapludalfs Haplustalfs-Calcarious Materials, Haplaquents Psammaquents Ustorthents, Haplaquents Eutrocrepts Heplaquents-calcareous Materials and Haplaquepts Dystrochrepts Haplaquents covering four soil order i.e. Entisols, Inseptisols. Mollisols and Alfisols. According the SOTER map, the soil types are as follow: Gelic LEPTOSOLS, Eutric CAMBISOLS, Eutric REGOSOLS, Humic CAMBISOLS, Chromic CAMBISOLS, Dystric REGOSOLS, Eutric GLEYSOLS Calcaric, PHAEOZEMS, Gleyic CAMBISOLS, Haplic PHAEOZEMS, Calcaric FLUVISOLS and other are glacier, ice, rock croup, lake and water. These types of soils are controlled by physiography and climatic factors. The SOTER soil types are more familiar than LRMP soil map although in LRMP soil map is useful to understand the soil characteristics and soil forming processes of Nepal. The soil degradation mitigation and adaptive strategies should consider the soil diversity types and its controlling factors such as physiography and climate.

Nepal is a landlocked mountainous country in South Asia, located between China to the north and India to the south, east, and west. As such, wastewater management has become one of the most significant problems in urban area of Nepal. In Nepal, the centralized wastewater treatment systems were dysfunctional due to high cost of operation, discontinuous power supply, lack of proper maintenance and proper technical workforce to address the issues. As such, constructed wetlands (CW) were applied to treat various secondary wastewater as alternative to wastewater treatment facilities. Generally, efficiency and sustainability of CW technology depends on proper operation and maintenance and active community involvement. This study summarizes information about 26 CW in Nepal. Specifically, factors including data banking, removal efficiency, quality of discharged water, compliance to water quality standard of Nepal and operation and maintenance were investigated. Considering removal efficiency per pollutant, Ka-1 achieved the greatest reduction for most pollutant followed by B-1, L-3, Ka-5 and K-1. Nepal has practiced CW technology for more than 2 decades but currently, development of technology was interrupted by the inefficient performance of existing facilities. Public awareness about the technology, natural disaster, unavailability of specified substrate materials, lack of fund for further research and experiments has hindered the expansion of technology. In spite of these concerns, CW was still proven as an alternative solution to the present wastewater problems in urban areas of Nepal.