Sustainable Agriculture for Hanoi City: An Application of Thünen’s Agricultural Rings based on the Gravity Model Nguyen An Thinh (1)* (1) VNU University of Economics and Business, Vietnam National University, Hanoi, Vietnam * Correspondence: anthinhhus@gmail.com Abstract: Since Hanoi city expanded its administrative boundary in 2008, the peri-urban agriculture significantly changed when it comes to production, product development and consumption This explicitly challenged to sustainable agriculture in this area This paper deals with the Thünen’s agricultural ring model, which expresses the standardized potential values of objects, phenomena and supports opportunities in a multi-central network It allows analyzing cost-demand of the agricultural production Using this model, maize products were shown to be only consumed at the factories, whereas rice and vegetables were two different types of agricultural products During 20002015, they did not showed changes in the consumption pattern of the city and the area of origin In contrast, changing trends were found for livestock products as beef Consumption between the regions of origin and the city changed between 2000 and 2015 Pig products were consumed in a different way in the production areas or compared to the city Conversion was likely affected by the gravitational forces of the consumption market in downtown Hanoi city Study results are a basis to propose a future sustainable development for agricultural planning in Hanoi Keywords: Thünen’s agricultural rings; gravity model; consumption type; Hanoi city; Vietnam Introduction Vietnam has a long tradition as an agricultural country and economy However, despite the great potential, the yields and the effectiveness of agriculture production are still limited Forty percent of the land in the country is used for agriculture and approximately thirty percent of the labor force works in this sector, but it contributes only 13.8 percent to the national GDP (VIAS, 2009) This raises the issue of maximizing the yields and income from agriculture and of using the land in an effective way The letter also applies to land use in cities as Hanoi where the economic transformation and land use changes are robust and fast In August 2008, the Ha Tay province and parts of the Vinh Phuc and the Hoa Binh province were merged to Hanoi, which increased its surface three times The greater part of merged lands is used for agriculture; consequently Hanoi’s agricultural production and consumption changed While before most of Hanoi’s meat and vegetables were produced in the neighboring villages, the products are now produced within the metropolis This context necessitates re-definding the market of agricultural production and its trends in Hanoi This contributes to a scientific base to plan or sustainable agriculture development in Hanoi This paper deals with an application of the Thünen’s agricultural ring and gravity model, which expresses the standardized potential values of objects, phenomena and supports opportunities in a multi-central network (Jones, 1984; Tsekeris and Stathopoulos, 2006) The combination of these models allow analyzing cost-demand of the agricultural production (Peet, 1970) Also the applications of these models were experienced in EU (Mattas and Tzouvelekas, 2002; Melitz, 2007), Japan (Negishi, 1990; Miyasaka, 1995) Methodology 2.1 Thünen structure of agriculture In the 18th century, Johann Heinrich von Thünen (1783-1850) launched a model of agriculture patterns that became popular and was applied in many countries worldwide The model based on two hypotheses: “just one market in a region where the land has similar physical location conditions” and “only one major transport” Accordingly, the benefit formula was measured as: = ×( − )− × × (1) Where: P is profit ($/km2); Y is yield (tons/km2); p is market price during a season ($/tons); c is the production prices ($/tons); D is the distance from market (km); and F is the transport cost ($/tons/km) Based this formula (1), Thünen established a model with concentric rings around a city in, each of which, an agriculture product is produced This specialized agricultural ring, model allowed concluding that farming activities were only profitable if they happened at a suitable distance from the city Production areas too far from the city center, resulted in high transport fee and offer less competitive prices than products grown near the city center, even when fees are higher Therefore, according to Thünen, agriculture production shows on adaptive distance, which at the limit moves to maximizing the benefits The main limitation of the Thünen model is that it is limited to studying the spatial relationship of two locations at same time In reality, many centers co-exist and their relationships affect the appearance of the agricultural rings The gravity model consequently upgrated the Thünen model using the formula (1) = (2) Where: Pi is the yield of a production in a region (i = 1, 2, n); Di is distance from the manufacture area O to another manufacture area (km) 2.2 Gravity model The gravity model is based on the Newtonian view on the driving forces of a center in the multi-center network Potential driving forces is a concept regularly applied in social sciences Potential gravity is used in a content of universal gravity; it refers to the potential energy of an object Potential gravity depends on the weight, distance and intensity of gravity forces Yield from agriculture can also make potential driving forces like gravity defined by Newton The higher the yield of the farms the more this likely drives worker, transport services, agriculture services and the processing industry In this study that influenced forces were directly proportional to the agricultural yield and inversely proportional to distance to the market Gravity values V in point O are calculated by the formula (3): = ×∑ (3) Where: V0 is potential values in point O (tons/km); Pi is yield of a production in a defined region (i = 1, 2, n); Di is distance from the production area O to another manufacture area (km); G is a constant; n is number of production; and a is a weighting factor The weighting factor expresses influenced levels of distance When “a” equals zero, the distance does not affect the production, the consumption of agricultural products When “a” equals one, each production region had a similar weighting factor When “a” equals {1, 2}, the distance affects other rates And when “a” ≥ 2, the distance is the most important impact In a case study of Tokyo city (Japan), Miyasaka (1995) classified agriculture with bellowing values a = and G = with formula (4): = (4) The distance (D) is the mean distance from center to outside the town or haft the distance from center to the nearest province This formula is selected for this research 2.3 Standardized potential of agricultural products The concept of standardized potential values of products clarifies the above analysis This value combines all forces that agricultural products attract in between these production areas and the market, or it is the total of the forces affecting profits in a defined sphere The gravitational potential values of the farming products, which was calculated by formula (4) to prove a series of distribution maps attractive potential value of them Each point of the iso product potential line equals the total of the gravitational forces in a defined sphere around it This study hypothesizes that the profit of agricultural products is as high at thieving their point of production near to the center Four types of consumption is assumed for the Distribution Type of the Iso Product Line They differ in their gravitational potential value This is related to the highest value of the potential set in a city, or at the point of production, or both, and further depends on whether each of the areas of consumption These hypotheses allowed that there was a city (A) and production areas (B) in a certain sphere, and would list and explain each type of distribution lines offer attractive potential value products 2.4 Data collection Data used in this study includes (i) spatial data: maps of Hanoi before and after 2008, the land use map of Hanoi in 2015 at a scale of 1:10.000; and (ii) Non-spatial data: statistic data on farming areas and agricultural yields in districts of Hanoi From equation (4), the collected data contain: (i) the agricultural product data is collected include rice, maize, vegetables, beef, pork and poultry in Hanoi in 2000 and 2015 (GSO Hanoi, 2000, 2015); (ii) the distances are measured using MapInfo software Equation (4), allows calculating the iso potential value of products If a district is referenced by one point, Hanoi points and each point shows potential product value This allows calculating iso product potential value all over Hanoi Vertical Mapper 3.5 software is used to establish a value line showing the iso potential values of the products Natural Neighbor interpolation is used to perform interpolation along line The technique allows to interpolate the sparse points and limits the effects of the maximum and minimum values; MapInfo Professional 15.0 (MapInfo Professional, version 15.0, Pitney Bowes MapInfo, USA) was used to establish maps of the potential values of the gravitational changes in expansion time of Hanoi after 2008 Results Maps of the agricultural product distribution show the gravitational potential value contours They are used to interpolation in 20 points districts and urban districts of Hanoi with the gravitational potential value of agricultural products The maps are calculated assuming that the profitability of agricultural products is as high in the place of origin or on the market This affects the space definition: potential values increase closer to the center and decrease further from the central point The iso product potential line is sparse in some areas and thick in other ones The peaks allow classifying the agricultural products in four types of agricultural products each with their specific characteristics The result shows that, the potential value of beef products significantly rapid increase from 8,000 (ton/km) in 2000 to 12,000 (ton/km) in 2015 Another change in 2000 was at the maximum potential value in 2000 in the Dan Phuong and Hoai Duc districts, and it decreased around the two areas Beef products in 2000 were consumed downtown and production areas In 2015, the maximum potential value area declined and fit in central districts It changed the consumption pattern in the city The lower price of beef this product to a growing inability to sell well in suburban areas where the economic conditions are higher than across districts, consequently, the consumer is moving stronger into the city Agricultural sources thus had a trend of the moving from suburbs into the city for consumption, and the number of beef shops in the city has increased in recent years (see Figure 1) The changes of other types of agricultural products are shown in figures 2-6 These changes allow classifying the iso product potential in Hanoi in 2000 and 2015 as shown in table Vegetables are less subject to variation than livestock The changing livestock pattern follow the trend of consumable suction and the potential values of most agricultural products increased Maize is one of the six agricultural products that are only consumed at the origin because they are the main food for livestock Rice and vegetables are two agricultural products of which the consumption did not have any change during the study period They are consumed both in the city and at their place of origin as well in 2000 as in 2015 The major changes are detected during 15 years The trend of change was significant for beef Both production and consumption in the city increased (in 2015) The production and consumption of pork different Likely, the conversion was affected by the gravitational forces of the consumption market in central Hanoi Crops were strongly affected by the center of Hanoi and other the suburbs Table Classified configuration of the iso product potential distribution in Hanoi city in 2000 and 2015 Year 2000 Agricultural products Rice Maize Vegetables Beef Pork Poultry Consumption type The maximum point of potential value In the city and in Tu Liem, Dan the production Phuong, Chuong area My, Ung Hoa In the production area Hoai Duc, Ba Vi Year 2015 Consumption type The maximum point of potential value In the city and in Hoai Duc, Gia the production area Lam, Thanh Oai In the production area Ba Vi In the city and Dan Phuong, Phuc In the city and in Tu Liem, Dan production area Tho, My Duc the production area Phuong, Hoai Duc In the city and in Dan Phuong, Tu the production Liem, Hoai Duc and In the city Central districts area central districts In the production area In the city Ba Vi, Dan Phuong Central districts In the city and production area In the city and production area Tu Liem, Ba Vi Tu Liem, Chuong My, central districts Beef production (Year 2000) Beef production (Year 2015) Rice consumption (Year 2000) Rice consumption (Year 2015) Maize consumption (Year 2015) Maize consumption (Year 2000) Vegetable consumption (Year 2000) Vegetable consumption (Year 2015) Pork consumption (Year 2000) Pork consumption (Year 2015) Poultry product (Year 2000) Poultry product (Year 2015) Figure Distribution of agricultural products in Hanoi during 2000-2015 (ton/km) Conclusions and discussion The transition of the agricultural production and the change in the processing industry in Hanoi is fundamental While field products tend to be stable, the livestock changed in a significant way The crops and livestock are grown in the places that have favorable conditions for it Due to limited data, this study examined only the six major agricultural products of Hanoi city Because of the importance of planning and land for agriculture and rural development with trend of commodity production, the province had implemented several policies to promote land consolidation, reducing fragmentation of land, transformation of crops, and etc The policy was responded and provided some initial performance to develop concentrated production Regarding to the conversion of iso potential value, the cause was that the agricultural production in the past was strongly depended on biophysical condition during the past few years, the agricultural products were produced on the demand of the market, as the market economy develops stronger in Vietnam Prior to the expansion, agricultural commodities produced in the former Ha Tay province were not as frequently transported to Hanoi as today Following the expansion of the city, the yields of vegetables and cereal declined, while livestock production increased The consumption also changed and the attraction of the market in the center of Hanoi is stronger than ever before The Hanoi model on the structure of agriculture (using linear equations) and the land use can be extended_ to other areas in Vietnam Moreover, the gravity model provider information on the potential for labor, resources use out, the accessibility The urban models or constructs allow defining threshold is out capacities of a locality, a region or establish standards to structure the territory The method should integrate economic issues including the movement of goods, and income per person At that moment, it can be applied to addressing economic and social problems References Dascal, D., Mattas, K., Tzouvelekas, V (2002) An analysis of EU wine trade: A gravity model approach Dana Dascal International Advances in Economic Research 8(2), 135–147 Jones, D.W (1984) Nonland factor markets in the Thünen model Papers of the Regional Science Association 54(1), 43-57 Melitz, J (2007) North, South and distance in the gravity model European Economic Review 51(4), 971-991 Miyasaka, M (1995) The Thünen structure of agriculture in Japan, basing on gravity model Tokyo Moriyama Shoten, Japan 192 pages Negishi, T (1990) 2(3), 199-209 Studies of von Thünen in Japan Japan and the World Economy Peet, R (1970) Von Thünen theory and the dynamics of agricultural expansion Explorations in Economic History 8(2), 181-201 Tsekeris, T., Stathopoulos, A (2006) Gravity models for dynamic transport planning: Development and implementation in urban networks Transport Geography 14(2), 152-160 ... attraction of the market in the center of Hanoi is stronger than ever before The Hanoi model on the structure of agriculture (using linear equations) and the land use can be extended_ to other areas... 2015) The production and consumption of pork different Likely, the conversion was affected by the gravitational forces of the consumption market in central Hanoi Crops were strongly affected by the. .. (ton/km) Conclusions and discussion The transition of the agricultural production and the change in the processing industry in Hanoi is fundamental While field products tend to be stable, the