The impact of climate change on the Niger River Basin hydroclimatology, West Africa

被引：0
作者：
Philip G. Oguntunde
Babatunde J. Abiodun
机构：
[1] Leibniz Center for Agricultural Landscape Research (ZALF),Institute of Landscape Hydrology
[2] University of Cape Town,Department of Environmental and Geographical Science
[3] The Federal University of Technology,Soil, Water and Environment Section, Department of Agricultural Engineering
来源：
Climate Dynamics | 2013年 / 40卷
关键词：
Climate change; Niger River Basin; Hydroclimatology; Water balance; Moisture recycling ratios;
D O I：
暂无
中图分类号：
学科分类号：
摘要：
Climate change has the potential to reduce water availability in West Africa. This study aims to quantify the expected impact of increased greenhouse gases (GHGs) on hydroclimatology of Niger River Basin (NRB). Boundary data from a general circulation model are used to force a regional climate model, to produce dynamically downscaled hydroclimatic variables of NRB under present-day (PRS) and future climate scenarios. The data were further analyzed to detect changes in atmospheric and surface water balance components and moisture recycling ratio (β). The results show that elevated GHGs (under A1B scenario) would produce a drier climate during the rainy season and a wetter climate during the dry season. A warmer climate over NRB in all months was projected. Highest temperature increase of 3 °C occurs about 14°N in May and June, and the smallest increase of 0.5 °C occurs below 8°N in wet-dry transition period. Evaporation reduces during wet season and increases during the dry periods. Humidity increases by 2 % in the dry season, but decreases by 2–4 % in the wet season. Maximum change in moisture influx of 20.7 % and outflux of 20.6 % occur in June and July, respectively. β is projected to decrease in 75 % of the months with biggest relative change of −18.4 % in June. The projected decrease in precipitation efficiency (ρ) during the wet season reaches −20.3 % in June. For PRS run, about 66 % of the available atmospheric moisture in NRB precipitates between June and September, of which around 21 % originates from local evaporation. The result suggests that under enhanced GHGs, local evaporation will contribute less to atmospheric moisture and precipitation over the basin. Projected changes in rainfall and streamflow for Upper Niger and Benue sub-basin are significantly different during the wet season.
引用
收藏
页码：81 / 94
页数：13
相关论文
共 133 条
  • [21] Brubaker KL(2011)Application of Water Evaluation and Planning (WEAP): a model to assess future water demands in the Niger River (In Niger Republic) Mod Appl Sci 5 38-29594
  • [22] Entekhabi D(2006)Hydroclimatology of the Volta River Basin in West Africa: trends and variability from 1901 to 2002 Phys Chem Earth 31 1180-1409
  • [23] Eagleson PS(2011)Trends and variability in pan evaporation and other climatic variables at Ibadan, Nigeria, 1973–2008 Meteorol Appl 14 209-212
  • [24] Conway D(2007)A numerical study of moisture build-up and rainfall over West Africa Meteorol Appl 105 29579-741
  • [25] Mahe G(2000)Simulation of regional-scale water and energy budgets: representation of sub-grid cloud and precipitation processes within RegCM J Geophys Res 88 1395-1048
  • [26] Cook KH(2007)The ICTP RegCM3 and RegCNET: regional climate modeling for the developing world Bull Am Meteorol Soc 35 193-414
  • [27] Eltahir EAB(2009)Northern African climate at the end of the twenty-first century: an integrated application of regional and global climate models Clim Dyn 12 722-314
  • [28] Bras RL(2010)Sub-Saharan Northern African climate at the end of the twenty-first century: forcing factors and climate change processes Clim Dyn 247 1043-197
  • [29] Friederichs P(1999)The soil precipitation feedback: a process study with a regional climate model J Clim 104 403-1381
  • [30] Paeth H(1990)Biological feedbacks in global desertification Science 98 293-2644
12345678910