Estimation of Reference Crop Evapotranspiration in Northwest China
Biao Wang,
Xinmin Zeng,
Gang Huang
Issue:
Volume 9, Issue 3, June 2020
Pages:
89-99
Received:
29 February 2020
Accepted:
17 March 2020
Published:
14 May 2020
Abstract: Based on the daily meteorological data from 1956 to 2011 in Northwest (NW) China and the Penman-Monteith (PM) equation, the regional reference crop evapotranspiration (ET0) is estimated. The ET0 variations in time series and spatial distributions are analyzed. The trend analysis, Mann-Kendall (M-K) test, wavelet analysis, stepwise regression and EOF analysis methods are used to investigate the spatiotemporal variability of ET0 and its contributing climatic factors, the mutation of ET0, the period of ET0, and the main influencing meteorological factors, respectively. Major conclusions are obtained as follows: (1) In the past 56 years, the trend of average annual ET0 time series in the NW China is significantly reduced, the differences exists in different seasons, i.e., the trends of ET0 in spring (-0.26mm/a), summer (-0.72mm/a) and autumn (-0.31mm/a) are decreased, respectively, the ET0 in winter is slowly increased (0.02mm/a). (2) The region which ET0 decreased most is located at the field from Kumul to Hotan (from northeast to southwest). ET0 has a sharply decrease around the 1980s, with a multiple-time scale nesting complex structure in the period. The first, second and third EOF models account 36.84%, 13.87% and 9.04% for the explained variance, respectively. The summer EOF model is the main contributor to the annual first model. (3) The upward trend of mean surface air temperature (T) and the decreased trend of sunshine duration (SD), relative humidity (RH) and wind speed at 2 m high (U2) induce ET0 to decline. The variability of annual ET0 rate is most influenced by the variations of U2, followed by SD, RH and T, which is influenced by various climatic variables. The investigation of spatiotemporal variability of ET0 and its contributor meteorological factors may help us better understand how ET0 responds to regional climate change.
Abstract: Based on the daily meteorological data from 1956 to 2011 in Northwest (NW) China and the Penman-Monteith (PM) equation, the regional reference crop evapotranspiration (ET0) is estimated. The ET0 variations in time series and spatial distributions are analyzed. The trend analysis, Mann-Kendall (M-K) test, wavelet analysis, stepwise regression and EO...
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Reference GNSS Stations for Warning on Possibility of Upcoming Earthquake in Zagreb
Nikola Solaric,
Miljenko Solaric,
Marijan Marjanovic,
Zlatko Bogdanovski,
Sasho Dimeski
Issue:
Volume 9, Issue 3, June 2020
Pages:
100-107
Received:
9 March 2020
Accepted:
9 April 2020
Published:
18 May 2020
Abstract: Distances between permanent GNSSS stations in positional systems are usually short between 30 km and 80 km. So calculated distances between the GNSS stations from their position coordinates calculated by processing collected GNSS data with Bernese software will be very well determined. The first time we determined that two days before earthquake in Kraljevo 2010 were shortening of sides between the GNSS referent stations, that this was a compression of the Earth’s crust two days before the earthquake. This effect was also confirmed on the Earthquakes Dreznica 2013, Skopje 2016 and Zagreb 2018 and that after compression two or several days after the earthquake occurs. However, they can also enable geophysicists to determine warn of possible earthquakes. On the end it was suggested that in the Control Center of CROPOS is required to establish a department for determination of compression in Earth crust based on GNSS measurement of the reference GNSS stations. This compression is possible to determine by "The method of daily changing the distance between GNSS permanent referent stations". After determination compression in Earth crust and using other geophysical methods will be probably possible to warn to upcoming earthquakes.
Abstract: Distances between permanent GNSSS stations in positional systems are usually short between 30 km and 80 km. So calculated distances between the GNSS stations from their position coordinates calculated by processing collected GNSS data with Bernese software will be very well determined. The first time we determined that two days before earthquake in...
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Water Seepage Source at the Extension of Tourah Clay Quarry, Southeastern Cairo Based on Geological and Geoelectrical Resistivity Measurements
Issue:
Volume 9, Issue 3, June 2020
Pages:
108-116
Received:
19 April 2020
Accepted:
7 May 2020
Published:
27 May 2020
Abstract: The cement industry depends essentially on the clay as one of the main raw materials for the industry. The Tourah clay quarry is one of the oldest and largest quarries of clays in Egypt, which is located to the southeastern of Cairo. The biggest problems that affect the clay quarries and may cause them to be closed forever is that, the water reaches them and leads to the difficulty of extracting raw materials from the quarries and ultimately leads to their closure. During the mining operations and extraction of raw materials from the extension of Tourah clay quarry, a water leak was observed that reached the bottom of the quarry, and the water began to increase and led to the difficulty of entering and exiting the equipments from the quarry. A detailed geological field study and geoelectrical resistivity survey were conducted in and around the extension of Tourah clay quarry to find out the source and cause of the water leak, which was increasing rapidly on the bottom of quarry. A geoelectrical resistivity survey was performed in the form of thirteen vertical electrical soundings and two horizontal profiling were made using the Wenner configuration in order to understand and solve the formentioned problem. The interpretation of the geoelectrical data shows three main units; surface layer from dry sand, gravel and rock fragments followed by a second layer of loose sand and is partially saturated with water and finally a clay layer which is extracted as a raw material in cement industry. Accordingly, based on the field geological observations in addition to the geoelectrical resistivity interpretations, we can conclude that, the possible water source in the bottom of clay quarry is due to the second loose partially saturated sand unit and the direction of water invasion in this particular area comes from the northeastern direction. To save the extension of Tourah clay quarry from closure it is recommended to extract the water from the sand unit before it reached the quarry bottom either by water head compensation or dewatering of the well field area.
Abstract: The cement industry depends essentially on the clay as one of the main raw materials for the industry. The Tourah clay quarry is one of the oldest and largest quarries of clays in Egypt, which is located to the southeastern of Cairo. The biggest problems that affect the clay quarries and may cause them to be closed forever is that, the water reache...
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