Carbon Effect Accounting and Analysis of Land Consolidation in Hubei Province
2018, 33 (11):
An analytical framework is established to analyze the carbon effects of land consolidation projects, which includes short-term effects (SE) and long-term effects (LE). The SE includes engineering construction effects (ECE) and land use conversion effects (LUCE). The LE contains farmland ecosystem effects (FEE) and agricultural activities effects (AAE). Carbon emission coefficient method and ecosystem type method were used to account carbon emission for consolidation projects. After calculating the carbon emission, the time needed to achieve carbon balance after implementation was accounted. The comparative analysis is used to analyze the carbon effects of each project which belongs to different topography regions and engineering regions. We selected fourteen consolidation projects in Hubei Province as research cases. Five of them locate in plain area, four in hilly area, and five in mountains area. Among 14 projects, eight belong to the plain engineering model area (Ⅱ2), and six belong to the river (gully) valley basin engineering model area (Ⅲ1). During the implementation, all the projects showed carbon emission effect. The average amount of carbon emissions of projects located in plain, hilly, mountain areas, Ⅱ2 region and Ⅲ1 region was 8 541.47, 14 266.45, 12 591.86, 11 415.09 and 11 901.97 t, respectively. The average carbon emission per unit area was 6.29, 12.37, 15.80, 9.06 and 14.58 t/hm2, respectively. The average carbon emission per unit investment was 2.76, 3.77, 4.92, 3.31 and 4.50 t/million yuan, respectively. As to LUCE, the projects in plain area mainly showed carbon absorption effects, with an average value of 184.13 t per project. The projects in mountainous area showed carbon emission effects with an average value of 5 398.49 t per project, depending on the conversions of land use types such as forest land or grassland with high carbon reserves converting into other types of land. After consolidation, the area, quality and biological yield of cultivated land increased in different degrees. The average added value of carbon sequestration of FEE in plain area is 1 554.43 t/a, in hilly area is 1 125.40 t/a and in mountain area is 1 241.65 t/a. After land consolidation, irrigation and drainage facilities of each project area generally increased, thus leading to a larger increase of paddy field irrigation. Therefore, the carbon emission increased. The carbon emission of AAE increased in varying degrees (from 8.11 t/a to 463.76 t/a) after consolidation. It took different time for projects to balance SE caused by remediation activities. For these projects, the average time needed to achieve carbon balance after consolidation in plain area was 5.24 a, in hilly area was 10.87 a and in mountainous area was 19.68 a. At the end of this paper, some suggestions on how to form a low-carbon consolidation model were put forward.
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