Since the early 1970s, the agricultural frontier of southeastern Amazon has undergone extensive land use changes. These alterations, combined with regional climate changes, have the potential to influence the hydrologic cycle at small to large scales. We evaluated a 40-year time series (1976 to 2015) of rainfall and water yield and related them to land use changes in the Upper Xingu River Basin (UX). We acquired data from six rainfall stations and four river gauges and mapped land use changes. Mann-Kendall trend analysis and Pettitt’s change point detection were employed to describe annual and seasonal changes in the time series. Monthly water yield from the Xingu River was used to derive annual, seasonal, and monthly water yield, as well as the runoff coefficient. The largest changes in land use occurred during the last two decades and approximately 60,900 km 2 in the Upper Xingu Basin were deforested between 1985 and 2015. Rainfall in the Xingu Basin decreased by about 245 mm over the period but there was no trend in water yield. The number of rainy days and intensity of events also decreased, but the length of the rainy season and seasonal and annual water yield did not change. Although watershed deforestation has increased water yield in other Amazon rivers, the reduction in rainfall in the Upper Xingu Basin was high enough to mask this effect.

中文翻译：

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1976-2015年亚马逊东南部土地利用变化及新谷河降雨和产水量变化趋势

自 1970 年代初以来，亚马逊东南部的农业前沿经历了广泛的土地利用变化。这些变化与区域气候变化相结合，有可能影响小到大尺度的水文循环。我们评估了 40 年时间序列（1976 年至 2015 年）的降雨量和产水量，并将它们与新古河流域上游 (UX) 的土地利用变化相关联。我们从六个降雨站和四个河流测量仪获取数据并绘制了土地利用变化图。Mann-Kendall 趋势分析和 Pettitt 的变化点检测被用来描述时间序列中的年度和季节性变化。新谷河的月产水量用于推算年、季节和月产水量以及径流系数。土地利用的最大变化发生在过去 20 年，1985 年至 2015 年期间，新谷盆地上游约有 60,900 km 2 被砍伐。在此期间，新谷盆地的降雨量减少了约 245 mm，但水产量没有趋势. 雨天数和事件强度也有所减少，但雨季长度和季节和年产水量没有变化。尽管流域森林砍伐增加了其他亚马逊河流的水产量，但新谷盆地上游降雨量的减少足以掩盖这种影响。但雨季的长度和季节和年产水量没有变化。尽管流域森林砍伐增加了亚马逊河其他河流的产水量，但新谷盆地上游降雨量的减少足以掩盖这种影响。但雨季的长度和季节和年产水量没有变化。尽管流域森林砍伐增加了其他亚马逊河流的水产量，但新谷盆地上游降雨量的减少足以掩盖这种影响。