干旱区生态环境知识资源中心

Using net primary productivity (NPP) as an indicator to desertification driving factor and expansions is one of the importance tools in the assessment of the contribution of climate change and human activity in desertification. In this study we used three types of net primary productivity; the actual NPP, Potential NPP and HNPP (human appropriation of NPP) to discriminate the relative role of climate change and human activities in desertification from 2000 to 2008 in Northern Kordofan province-Sudan. The results showed, 63.75% of the study area experienced desertification expansion. Within which, 67.32% was induced by Human activities compared with 32.03% caused by climate change and 0.65% caused by a combination of the two factors. By contrast, climate change is the dominant factor of desertification reversion, 2.3% of desertification reversion caused by human activities compared with 97.7% induced by climate change and there isn’t interaction between climate change and human activities in reversion area. The largest area of expansion and reversion occurred in northeast and western parts of the study area respectively. We developed two propositions in the study area. First, the desertification expansion was induced by human activities, whereas desertification reversion was induced by climate change as typified in north south part, central part and western part. Second, both desertification expansion and reversion was induced by climate change as typified in northeast part of study area.