云南元谋水化观测站改造和恢复观测分析

2022年8月,云南省元谋县政府通过招商引资,计划在热水塘村范围内建设文旅康养城。元谋水化观测站位于文旅康养城建设范围内,此建设项目会对观测数据造成很大影响,因此拟定对元谋水化观测站进行迁建,因迁建工程时间长,故先改造并恢复原井观测。改造恢复观测后,元谋水化观测站仅保留主井进行观测,观测项目为深层水温、动水位、逸出气氡和逸出气汞等4个测项。恢复观测中,水温探头投放深度由120 m变更为128 m;水位探头投放深度由2.76 m变更为1.42 m,水温值有所升高,水位值下降。重新设计制作脱气装置后,气氡值因仪器参数问题出现下降,气汞值变化不大。元谋水化观测站已恢复观测并连续观测6个月,对恢复观测前后的数据进行分析,可为以后的水化台站建设积累经验。

Temperature and Precipitation Variations at Two Meteorological Stations on Eastern Slope of Gongga Mountain,SW China in the Past Two Decades

Gongga Mountain, locates on the eastern edge of Tibetan Plateau of China, is the highest mountain in China except summits in Tibet. Only limited meteorological data on Gongga Mountain have been published so far. Here we present the meteorological records from two stations, Moxi Station （at 1,621.7 m above sea level （a.s.1.）, 1992- 2010） and Hailuogou Station （at 2,947.8 m a.s.l., 1988-2010）, on the eastern slope of Gongga Mountain. In the past two decades, the annual precipitation decreased while the annual mean temperature increased at Hailuogou Station. Both precipitation and temperature increased at Moxi Station. The precipitation variation on the eastern slope of Gongga Mountain is influenced by both East Asian Monsoon and Indian Monsoon, so that the precipitation concentrated between May and October. The temperature variation on the eastern slope of Gongga Mountain in the past two decades showed similar trends as that of the northern hemispheric and global. In the past two decades, the temperature increased o.35℃ and o.3℃/decade at Hailuogou Station and Moxi Station respectively, which was higher than the increase extents of northern hemispheric and global temperature. The most intense warming occurred at the first decade of 21St century. The winter temperature increased more at Hailuogou Station than at Moxi Station. A remarkable increase of temperature in March was observed with only a little precipitation at both high and low altitude stations.

Climate-induced Changes in Spring Maize Water Requirement in Xiliaohe River Watershed

Xiliaohe River watershed plays an important role in regional and national grain security.With the development of society and economy,water consumption that increased dramatically causes water shortages.Crop water requirement can provide quantitative basis for making regional irrigation scheme.In this study,spring maize water requirement is calculated by using PenmanMonteith formula and spring maize coefficient from May to September at 10 meteorological stations in Xiliaohe River watershed from 1951 to 2005.The variation trend of the spring maize water requirement during the whole growing stage,water requirement in every month,and meteorological influencing factors are obtained by using Mann-Kendall method,and the degree of grey incidence between the water requirement and meteorological influencing factors are shown.The results are the spring maize water requirement during the whole growing stages increases at half of the stations in Xiliaohe River watershed,and are remarkably affected by the water requirement in May.The monthly mean,maximum and minimum air temperature form May to September show an increasing trend in Xiliaohe River watershed in recent 55 years.The monthly mean and minimum air temperature increases notably.The relative humidity,precipitation,wind speed and sunshine show a decreasing trend with variety for different months.The monthly maximum air temperature,wind speed,sunshine and monthly mean air temperature have the highest correlation degree with spring maize water requirement from May to September.

Shifts in water-level variation of Namco in the central Tibetan Plateau from ICESat and Cryo Sat-2 altimetry and station observations

The dynamics of high-altitude inland lakes in the Tibetan Plateau are sensitive indicators of climate change. Due to the remoteness and hard access, satellite altimetry becomes an effective approach to obtaining largescale and temporally continuous information of lake-level changes. The CryoSat-2 altimetry is expected to solve the current problem that earlier radar altimeters are only practical for monitoring large water bodies, while ICESat laser altimetry is available only for the period 2003-2009. In this study, the comparison of CryoSat-2 altimetry for Namco with in situ water-level data suggests a high cor- relation coefficient of 0.71 （P 〈 0.01）, with the mean error of -0.12 m and root-mean-square error of 0.18 m. Further, the combination of ICESat and CryoSat-2 altimetry data and in situ lake-level observations reveals a rapid water- level rise of 0.24 4- 0.04 m/year during 2003-2008 and then a slightly decreasing trend of -0.09 4- 0.04 m/year during 2009-2013. This study suggests that the CryoSat-2 altimetry has the potential of sustaining the fine observa- tions on Tibetan lakes, following the ICESat mission. Besides, the examination of four key climatic variables （temperature, precipitation, potential evapotranspiration, and relative humidity） during 1990-2013 indicates that the wetting climate over Namco Basin stagnated or even reversed around 2006, which may be tightly related to the slowing lake growth.