Influence of climate variability on land degradation (desertification) in the watershed of the upper Paraíba River

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• 作者：Telma Lucia Bezerra Alves ; Pedro Vieira de Azevedo…
• 刊名：Theoretical and Applied Climatology
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：127
• 期：3-4
• 页码：741-751
• 全文大小：
• 刊物类别：Earth and Environmental Science
• 刊物主题：Atmospheric Sciences; Climatology; Atmospheric Protection/Air Quality Control/Air Pollution; Waste Water Technology / Water Pollution Control / Water Management / Aquatic Pollution;
• 出版者：Springer Vienna
• ISSN：1434-4483
• 卷排序：127

文摘

The study aimed to evaluate the influence of the rainfall and aridity index variability on the process of land degradation (desertification) in order to establish the current degree of increase or decrease in dryness in the watershed of the upper Paraíba River. It included all or part of 18 municipalities, distributed in the western and eastern Cariri regions of Paraíba state. The monthly average values of reference evapotranspiration according to Penman-Monteith method were applied in the annual hydrological balance for obtaining the annual time series of the aridity index for the period from 1950 to 2013. The Mann-Kendall test (MK) was used for trend identification in the annual time series of rainfall and aridity index, at a significance level of α = 0.05. The slope of the trends was obtained by Sen’s method, and the values of rainfall, aridity index, and statistics MK were spatially kriging, to generate thematic maps. The results indicate an increase in rainfall and reduced dryness in the watershed of the upper Paraíba River, conditions that do not contribute to trigger the process of land degradation (desertification), indicating that the cause of this environmental problem is not climatic. Thus, it can be suggested that the observed manifestations of land degradation (desertification) derive much of human than climatic actions. However, there is a trend of increasing dryness and reducing rainfall in the central portion of the watershed, with stronger core in the location of Camalaú. The spatial distribution of rainfall and aridity index shows that minimum values of rainfall coincide with maximum values of the aridity index. Higher values of rainfall were observed in the northwestern portion of the watershed, while the northeast and southeast portions had the lower rainfall values, with the strongest core in the locality of Cabaceiras. The eastern sector of the watershed has high dryness, unlike the western sector, rainier, with minimum values of dryness. In the western portion of the watershed, the aridity index was in the range considered semiarid, with moderate susceptibility to land degradation process. Similarly, in the eastern portion, the dryness stood in the range considered arid, with high susceptibility. The cores with more pronounced dryness correspond to the municipalities of Cabaceiras, Caraúbas, and São João do Cariri.