Increasing Urbanization Pose Challenges In Soil And Human Health

• Dr. Shova Shrestha, Sujan Maharjan and Dr Shree Prasad Bista

Once again, 5th December has come to our door steps to communicate about the importance of soil health in sustaining life on earth. It aims to create awareness among the people about the roles of soils in ecosystem functioning, sustainable agriculture and food security. The day alerts humans to act consciously and wisely on soil resources. Since 2014, this day has been celebrated every year globally with a soul aim to enhance understanding towards maintaining soil health. However, the achievements are not satisfying and the speeded rate of soil degradation only discourages the efforts and interests of all soil conservationists.

According to UN report, soil supports about 59% of the total biodiversity and it is the medium for the production of around 95% of food for human consumption. However, soil fertility is gradually declining globally. At present, a total of 33% of soils are moderately to highly degradedue to different factors like soil erosion, soil nutrient depletion, soil contamination, organic matter loss, soil acidification, alkalinization, and soil salinization and the trend is accelerating. A prime implication of soil degradation is declining crop production which ultimately contributes to food insecurity and human health. In Nepal, soil degradation greatly impacts human health as soils are low in vital nutrients, leading to malnutrition and low cognitive growth.

The expansion of the cities is increasing day by day threatening the services the soils are providing such as food production, water purification, carbon sequestration, biodiversity conservation and regulating temperatures. City development not only sealing the soils with concrete structures, but also increasing soil pollution, disturbing water drainage, escalating urban heat islands ultimately increasing risks to human life.

Among key drivers, soil degradation has been worsened due to the expansion of urban settlements. In the world, cities cover approximately 2% to 2.7% of the world's total land area which is estimated to be around 3.5 million square kilometers excluding Antarctica. Around 75% of the world's material resources are consumed in city areas. The expansion of the cities is increasing day by day threatening the services the soils are providing such as food production, water purification, carbon sequestration, biodiversity conservation and regulating temperatures. City development not only sealing the soils with concrete structures, but also increasing soil pollution, disturbing water drainage, escalating urban heat islands ultimately increasing risks to human life. Unfortunately, due to soil degradation and nutrient depletion, people are being compelled for the consumption of nutrient poor diets. In the present world, around 2 billion people are suffering from micronutrient deficiency, also known as hidden hunger.

Nepal is one of the fastest urbanizing countries in the world, with the rapid expansion of its cities and urban population in recent decades. The migration from rural areas to cities has heightened dramatically in recent times. Around 19.29 million population i.e. 66 % of the total population of Nepal lives in municipalities. The authorities of municipalities are facing challenges to address such a big mass of people by managing space and other basic facilities. As a mountainous country, compared to sloppy terrains, Nepal contains very less flat lands around 25-30 % of its total land area including Terai and other plains. Urban area in Terai has been increasing by an annual average rate of 12% for the last 30 years since 1989. More surprising fact is that the increase in built-up area in Kathmandu valley was estimated from 3% in 1967 to 25% in 2011 and it is swelling. The trend is not much different in other cities as well.

On the other hand, plain lands are the main crop producing lands of Nepal. Terai is even called the “food basket” of Nepal as it produces food sufficient for 15.5 million people i.e. around 50% of the country's population. However, the big cities like Kathmandu, Pokhara, Biratnagar, are located mostly at productive flat lands and other recently developing cities such as Itahari, Bharatpur, Butwal, Bhairahwa, and Nepaligunj are also being established over productive plains. Soil sealing or paving, soil compaction, loss of organic matter and soil biodiversity, soil contamination and pollution due to improper industrial and even hospital waste disposal and extensive use of plastics in agricultural lands, altering biological processes, physical removal and mixing of soil as the major impacts and consequences of urban development and sprawling. In addition, expansion of cities is not only converting productive lands into unproductive and impermeable layers but also increasing the country's dependency on importing foods and other agricultural goods which once the country used to be self-sufficient.

Immediate actions the government can take could be the preparation of land use plan or land zonation with clear demarcation for human settlement, industrial development, agricultural production, greenery development and others as laws allow and forming a mechanism to monitor it to make all actions stick with the plan.

There are several laws in Nepal related to soil conservation and sustainable management such as Land Administrative Act, 1967, Soil and Watershed Conservation Act, 1982, Plant Protection Act, 2007, Land Use Policy, 2015, Land Use Act, 2019, Forest Act, 2019, Environment Protection Act, 2019, National Land Policy, 2019, National Climate Change Policy, 2019, National Basin Management Strategy, 2023, Agricultural Development strategy, 2015-2035, etc.. These all legal instruments have certain provisions that support proper land management such as land use zoning i.e. classifying land for specific uses. For saying, land zonation is in progress but at a very slow pace. Besides, there are many governmental organizations established in Federal and provincial levels with the mandate to conserve and manage soil sustainably. Such institutions include the Ministry of Forests and Environment, Ministry of Agriculture and Livestock Development, Department of Forests and Soil Conservation, Nepal Agricultural Research Council and others working under these institutions. Though the legal instruments and institutions exists but are working in their own capacities. However, the results are not very satisfying and there are still gaps to be filled up.

Immediate actions the government can take could be the preparation of land use plan or land zonation with clear demarcation for human settlement, industrial development, agricultural production, greenery development and others as laws allow and forming a mechanism to monitor it to make all actions stick with the plan. It is not an easy task though if political will is there, implementers are ready with public support. Moreover, as remedies, governments can proceed with actions like de-sealing, promotion for green roofs, urban vegetation and agriculture, maximizing soil organic matter through composting and waste recycling, , strengthening extension and knowledge systems to advance awareness on soil health amongst many. There is an urgent need for agri-food system value chain development to encourage families and city dwellers to adopt sustainable lifestyles, healthier eating habits and livable spaces.

Although given the least priority despite being the most important foundation of urban life, the soil ought to be managed sustainably. To raise this awareness to the global population including city dwellers, the 2025 World Soil Day is celebrated with the theme: “Healthy Soils for Healthy Cities” highlighting the unbreakable relation between healthy soil and well-being of urban populations. It is anticipated that the theme conveys a message to reach the targeted audiences including political leaders, bureaucrats, development workers and other concerned institutions and it is envisaged for collaborative action to reimagine more greener urban spaces for healthier people and nature.

The authors are Dr. Shova Shrestha, Soil Scientist, National Soil Science Research Center (NSSRC), NARC
SujanMaharjan, Under Secretary,Building a Resilient Churia Region in Nepal(BRCRN), Ministry of Forests and Environment Kathmandu, and
Dr. Shree Prasad Bista, Senior Scientist and Chief, NSSRC, NARC