Abstract
Vegetation net primary productivity (NPP) reveals the plants capability to transform solar energy to photosynthesis. It can be used as an indicator of status of environmental processes affected by climate changes and human activities, especially in degraded areas such as Gadarif State, Sudan, where vegetation degradation has progressively taken place. In this study, three types of net primary productivity from 2000 to 2017 were used to assess the relative roles of climate variables and human activities on vegetation variability in the eastern part of Sudan (Gadarif State) by ordinary least-square regression technique. The three types of NPP are the actual NPP derived from MODIS data, potential NPP estimated using Thornthwaite memorial model and human-related NPP, the difference between the Potential NPP and actual NPP. The correlations between NPP and climate variables are calculated using Pearson’s correlation coefficient. The results revealed that 91.7% of the study area has experienced vegetation degradation caused by human activities with a variation of 97.95% in NPP. In contrast, 8.3% of the study area has a recovery by 2.05% of increase in NPP favored by climate change. The main driving forces of vegetation degradation are human activities, and the dominant factor for vegetation reversion is climate. No clear interaction between the two factors (climate change and human activities) was observed in the study area throughout the period of study. Thus, we concluded that NPP is a good indicator for assessing the relative roles of climate changes and human activities in vegetation cover dynamics that has obviously occurred in almost all districts of Gadarif, Sudan.
Similar content being viewed by others
REFERENCES
Aguilar, E., Aziz Barry, A., Brunet, M., Ekang, L., Fernandes, A., Massoukina, M., et al., Changes in temperature and precipitation extremes in western central Africa, Guinea Conakry, and Zimbabwe, 1955–2006, J. Geophys. Res.: Atmos., 2009, vol. 114, no. 2.
Amiro, B.D., Chen, J.M., and Liu, J., Net primary productivity following forest fire for Canadian ecoregions, Can. J. For. Res., 2000, vol. 30, no. 6, pp. 939–947.
Ayoub, A.T., The Need for Systematic Monitoring and Assessment of Land Degradation/Desertification in the Sudan, Vienna: UN Off. Outer Space Affairs, 2004.
Chang, J.H., The agricultural potential of the humid tropics, Geogr. Rev., 1968, vol. 58, pp. 333–361.
Choi, G., Collins, D., Ren, G., Trewin, B., Baldi, M., Fukuda, Y., et al., Changes in means and extreme events of temperature and precipitation in the Asia-Pacific Network region, 1955–2007, Int. J. Climatol., 2009, vol. 29, no. 13, pp. 1906–1925.
Elhag, M.M., Causes and impact of desertification in the Butana area of Sudan, PhD Thesis, Bloemfontein: Univ. of Free State, 2006.
Fan, J.W., Shao, Q.Q., Liu, J.Y., Wang, J.B., Harris, W., Chen, Z.Q., et al., Assessment of effects of climate change and grazing activity on grassland yield in the Three Rivers Headwaters region of Qinghai–Tibet Plateau, China, Environ. Monit. Assess., 2010, vol. 170, nos. 1–4, pp. 571–584.
Foley, J.A., Levis, S., Costa, M.H., Cramer, W., and Pollard, D., Incorporating dynamic vegetation cover within global climate models, Ecol. Appl., 2000, vol. 10, no. 6, pp. 1620–1632.
Gao, Z. and Liu, J., Simulation study of China’s net primary production, Chin. Sci. Bull., 2008, vol. 53, no. 3, pp. 434–443.
Goudriaan, J., Global carbon cycle and carbon sequestration, in Carbon Sequestration in the Biosphere: Processes and Prospects, Berlin: Springer-Verlag, 1995, pp. 3–18.
Harrison, M.N. and Jackson, J.K., Ecological classification of the vegetation of the Sudan, in Ecological Classification of the Vegetation of the Sudan, For. Bull. Ser. no. 2, Khartoum: Agric. Publ. Com., 1958.
Jahelnabi, A.E., Zhao, J., Li, C., Fadoul, S.M., Shi, Y., Bsheer, A.K., and Yagoub, Y.E., Assessment of the contribution of climate change and human activities to desertification in Northern Kordofan-Province, Sudan using net primary productivity as an indicator, Contemp. Probl. Ecol., 2016, vol. 9, no. 6, pp. 674–683.
Lieth, H., Evapotranspiration and primary productivity: CW Thornthwaite memorial model, Publ. Climatol., 1972, vol. 25, pp. 37–46.
Lieth, H., Modeling the primary productivity of the world, in Primary Productivity of the Biosphere, Berlin: Springer-Verlag, 1975, pp. 237–263.
Ma, M. and Frank, V., Interannual variability of vegetation cover in the Chinese Heihe River Basin and its relation to meteorological parameters, Int. J. Remote Sens., 2006, vol. 27, no. 16, pp. 3473–3486.
Milner, K.S., Running, S.W., and Coble, D.W., A biophysical soil—site model for estimating potential productivity of forested landscapes, Can. J. For. Res., 1996, vol. 26, no. 7, pp. 1174–1186.
Nemani, R.R., Keeling, C.D., Hashimoto, H., Jolly, W.M., Piper, S.C., Tucker, C.J., et al., Climate-driven increases in global terrestrial net primary production from 1982 to 1999, Science, 2003, vol. 300, no. 5625, pp. 1560–1563.
Patel, N.R., Bhattacharjee, B., Mohammed, A.J., Tanupriya, B., and Saha, S.K., Remote sensing of regional yield assessment of wheat in Haryana, India, Int. J. Remote Sens., 2006, vol. 27, no. 19, pp. 4071–4090.
Rehman, S., Temperature and rainfall variation over Dhahran, Saudi Arabia, (1970–2006), Int. J. Climatol., 2010, vol. 30, no. 3, pp. 445–449.
Tucker, C.J., Dregne, H.E., and Newcomb, W.W., Expansion and contraction of the Sahara Desert from 1980 to 1990, Science, 1991, vol. 253, no. 5017, pp. 299–300.
Wessels, K.J., Prince, S.D., Malherbe, J., Small, J., Frost, P.E., and van Zyl, D., Can human-induced land degradation be distinguished from the effects of rainfall variability? A case study in South Africa, J. Arid Environ., 2007, vol. 68, no. 2, pp. 271–297.
Wessels, K.J., Prince, S.D., and Reshef, I., Mapping land degradation by comparison of vegetation production to spatially derived estimates of potential production, J. Arid Environ., 2008, vol. 72, no. 10, pp. 1940–1949.
Wu, W., De Pauw, E., and Zucca, C., Using remote sensing to assess impacts of land management policies in the Ordos rangelands in China, Int. J. Digital Earth, 2013a, vol. 6, suppl. 2, pp. 81–102.
Wu, W., De Pauw, E., and Helldén, U., Assessing woody biomass in African tropical savannahs by multiscale remote sensing, Int. J. Remote Sens., 2013b, vol. 34, no. 13, pp. 4525–4549.
Xu, D.Y., Kang, X.W., Zhuang, D.F., and Pan, J.J., Multi-scale quantitative assessment of the relative roles of climate change and human activities in desertification—A case study of the Ordos Plateau, China, J. Arid Environ., 2010, vol. 74, no. 4, pp. 498–507.
Yagoub, Y.E., Musa, O.S., Siddig, A.A., Bo, Z., Li, Z., and Wang, F., Assessing the impacts of land use changes on vegetation cover in Eastern Sudan, Int. J. Res. Agric. Sci., 2017, vol. 4, no. 2, pp. 70–76.
Zhang, C., Wang, X., Li, J., and Hua, T., Roles of climate changes and human interventions in land degradation: a case study by net primary productivity analysis in China’s Shiyanghe Basin, Environ. Earth Sci., 2011, vol. 64, no. 8, pp. 2183–2193.
Zheng, Y.R., Xie, Z.X., Robert, C., Jiang, L.H., and Shimizu, H., Did climate drive ecosystem change and induce desertification in Otindag sandy land, China over the past 40 years? J. Arid Environ., 2006, vol. 64, no. 3, pp. 523–541.
Zhou, W., Li, J.L., Mu, S.J., Gang, C.C., and Sun, Z.G., Effects of ecological restoration-induced land-use change and improved management on grassland net primary productivity in the Shiyanghe River Basin, north-west China, Grass Forage Sci., 2014, vol. 69, no. 4, pp. 596–610.
Funding
This paper was partially supported by the Talented Young Scientists Program (TYSP) of the Ministry of Science and Technology of China.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interests. The authors declare that they have no conflicts of interest.
Statement on the welfare of humans or animals. This article does not contain any studies involving animals performed by any of the authors.
Rights and permissions
About this article
Cite this article
Abdelrahim E. Jahelnabi, Wu, W., Boloorani, A.D. et al. Assessment the Influence of Climate and Human Activities in Vegetation Degradation using GIS and Remote Sensing Techniques. Contemp. Probl. Ecol. 13, 685–693 (2020). https://doi.org/10.1134/S1995425520060025
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S1995425520060025