Stream Discharge in Tropical Headwater Catchments as a Result of Forest Clearing and Soil Degradation

Earth Interactions

John W.Recha¹ 

关键词: Watershed;    Deforestation;    Soil degradation;    Runoff;    Erosion;   

DOI  :  10.1175/2012EI000439.1

学科分类：地球科学(综合)

来源: American Geophysical Union

【 摘 要 】

AbstractTropical Africa is affected by intense land-use change, particularly forest conversion to agricultural land. In this study, the stream discharge of four small headwater catchments located within an area of 6 km2 in western Kenya was examined for 2 years (2007 and 2008). The four catchments cover a degradation gradient ranging from intact forest to agricultural land under maize cultivation for 5, 10, and 50 years. The runoff ratio (e.g., annual catchment discharge expressed as a percentage of rainfall) increased with increasing duration of cultivation from an average of 16.0% in the forest to 32.4% in the 50-yr-old agricultural catchment. Similarly, the average runoff ratio due to the stormflow component was 0.033 in the forest and increased gradually to 0.095 with increasing duration of cultivation. The conversion from forest to agricultural land in the first 5 years caused about half of the total observed increases in runoff ratio (46.3%) and discharge in relation to rainfall (50.6%). The other h...

【 授权许可】

Unknown