Temporal variations of reference evapotranspiration in Heihe River basin of China

2012 ◽  
Vol 44 (5) ◽  
pp. 904-916 ◽  
Author(s):  
Zhanling Li ◽  
Zhanjie Li ◽  
Zongxue Xu ◽  
Xun Zhou
Keyword(s):  
River Basin ◽  
Influence Factor ◽  
Reference Evapotranspiration ◽  
Temporal Variations ◽  
Heihe River Basin ◽  
Maximum Temperature ◽  
Heihe River ◽  
Agricultural Crop ◽  
Different Seasons ◽  
Increasing Trends

Temporal variations in reference evapotranspiration (ETo) have profound implications for hydrological processes as well as for agricultural crop performance. The main aim of this study was to analyze the annual, seasonal trends in ETo in the Heihe River basin. The likely causative meteorological variables for such temporal changes in ETo were also identified. Results showed that, on a seasonal and annual scale, ETo for the upper reach showed increasing trends from 1960 to 2010; both increasing and decreasing trends were observed for the middle and lower reaches. In spring, wind speed (WS) and relative humidity (RH) were the most likely causative variables for changes of ETo for the whole basin; in summer and autumn, maximum temperature (Tmax) and RH contributed more to the trends in ETo for the upper reach, and WS contributed more for the middle and lower reaches; in winter, Tmax, WS and RH contributed more in different locations and in different seasons. From the spatial perspective, WS, RH and Tmax contributed more to the changes of ETo in the upper reach; WS was the main likely influence factor in the middle reach, and WS and RH were the probable main factors in the lower reach.

scholarly journals Accuracy Assessment on MODIS (V006), GLASS and MuSyQ Land-Surface Albedo Products: A Case Study in the Heihe River Basin, China

2018 ◽  
Vol 10 (12) ◽  
pp. 2045 ◽  
Author(s):  
Xiaodan Wu ◽  
Jianguang Wen ◽  
Qing Xiao ◽  
Dongqin You ◽  
Baocheng Dou ◽  
...  
Keyword(s):  
River Basin ◽  
Land Surface ◽  
Accuracy Assessment ◽  
Temporal Variations ◽  
Geographic Region ◽  
Heihe River Basin ◽  
Heihe River ◽  
Quantitative Remote Sensing ◽  
Mean Square Errors ◽  
The Heihe River Basin

This study assessed accuracies of MCD43A3, Global Land-Surface Satellite (GLASS) and forthcoming Multi-source Data Synergized Quantitative Remote Sensing Production system (MuSyQ) albedos using ground observations and Huan Jing (HJ) data over the Heihe River Basin. MCD43A3 and MuSyQ albedos show similar high accuracies with identical root mean square errors (RMSE). Nevertheless, MuSyQ albedo is better correlated with ground measurements when sufficient valid observations are available or snow-free. The opposite happens when less than seven valid observations are available. GLASS albedo presents a larger RMSE than MCD43A3 and MuSyQ albedos in comparison with ground measurements. Over surfaces with smaller seasonal variations, MCD43A3 and MuSyQ albedos show smaller RMSEs than GLASS albedo in comparison with HJ albedo. However, for surfaces with larger temporal variations, both RMSEs and R2 of GLASS albedo are comparable with MCD43A3 and MuSyQ. Generally, MCD43A3 and MuSyQ albedos featured the same RMSEs of 0.034 and similar R2 (0.920 and 0.903, respectively), which are better than GLASS albedo (RMSE = 0.043, R2 = 0.787). However, when it comes to comparison with aggregated HJ albedo, MuSyQ and GLASS albedos are with lower RMSEs of 0.027 and 0.032 and higher R2 of 0.900 and 0.898 respectively than MCD43A3 (RMSE = 0.038, R2 = 0.836). Despite the limited geographic region of the study area, they still provide an important insight into the accuracies of three albedo products.

Spatiotemporal Variability of Potential Evaporation in Heihe River Basin Influenced by Irrigation

2020 ◽  
Author(s):  
Congying Han
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Spatial Pattern ◽  
River Basin ◽  
Meteorological Factors ◽  
Heihe River Basin ◽  
Spatiotemporal Variability ◽  
Maximum Temperature ◽  
Heihe River ◽  
Potential Evaporation

<p><strong>Spatiotemporal Variability of Potential Evaporation in Heihe River Basin Influenced by Irrigation </strong></p><p>Congying Han<sup>1,2</sup>, Baozhong Zhang<sup>1,2</sup>, Songjun Han<sup>1,2</sup></p><p><sup>1</sup> State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China.</p><p><sup>2</sup> National Center of Efficient Irrigation Engineering and Technology Research-Beijing, Beijing 100048, China.</p><p>Corresponding author: Baozhong Zhang ([email protected])</p><p><strong>Abstract: </strong>Potential evaporation is a key factor in crop water requirement estimation and agricultural water resource planning. The spatial pattern and temporal changes of potential evaporation calculated by Penman equation (E<sub>Pen</sub>) (1970-2017) in Heihe River Basin (HRB), Northwest China were evaluated by using data from 10 meteorological stations, with a serious consideration of the influences of irrigation development. Results indicated that the spatial pattern of annual E<sub>Pen</sub> in HRB was significantly different, among which the E<sub>Pen</sub> of agricultural sites (average between 1154 mm and 1333 mm) was significantly higher than that of natural sites (average between 794 mm and 899 mm). Besides, the coefficient of spatial variation of the aerodynamic term (E<sub>aero</sub>) was 0.4, while that of the radiation term (E<sub>rad</sub>) was 0.09. The agricultural irrigation water withdrawal increased annually before 2000, but decreased significantly after 2000 which was influenced by the agricultural development and the water policy. Coincidentally, the annual variation of E<sub>pen</sub> in agricultural sites decreased at -40 mm/decade in 1970-2000 but increased at 60 mm/decade in 2001-2017, while that in natural sites with little influence of irrigation, only decreased at -0.5mm/decade in 1970-2000 but increased at 11 mm/decade in 2001-2017. So it was obvious that irrigation influenced E<sub>pen </sub>significantly and the change of E<sub>pen</sub> was mainly caused by the aerodynamic term. The analysis of the main meteorological factors that affect E<sub>pen</sub> showed that wind speed had the greatest impact on E<sub>pen</sub> of agricultural sites, followed by relative humidity and average temperature, while the meteorological factors that had the greatest impact on E<sub>pen</sub> of natural sites were maximum temperature, followed by wind speed and relative humidity.</p>

scholarly journals Reference Evapotranspiration Changes: Sensitivities to and Contributions of Meteorological Factors in the Heihe River Basin of Northwestern China (1961–2014)

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Chaoyang Du ◽  
Jingjie Yu ◽  
Ping Wang ◽  
Yichi Zhang
Keyword(s):  
Sensitivity Analysis ◽  
River Basin ◽  
Reference Evapotranspiration ◽  
Meteorological Factors ◽  
Heihe River Basin ◽  
Heihe River ◽  
Negative Contribution ◽  
Sensitive Factor ◽  
Increasing Trend ◽  
The Heihe River Basin

This paper investigates reference evapotranspiration(ET0)changes, sensitivities to and contributions of meteorological factors in the Heihe River Basin (arid and inland region). Results show that annualET0over the whole basin has increasing trend (2.01 mm·10 yr−2) and there are significant increasing spatial variations from the upper (753 mm yr−1) to the lower (1553 mm yr−1) regions. Sensitivity analysis indicates that relative humidity is the most sensitive factor for seasonal and annualET0change, and the influence is negative. The sensitivity of minimum temperature is the weakest and negative. Contribution analysis shows that the main contributors toET0changes are aerodynamic factors rather than radiative factors. This study could be helpful to understand the response of ecoenvironment to the meteorological factors changes in the Heihe River Basin.

scholarly journals Spatial variations of river–groundwater interactions from upstream mountain to midstream oasis and downstream desert in Heihe River basin, China

2015 ◽  
Vol 47 (2) ◽  
pp. 501-520 ◽  
Author(s):  
Yi Cai ◽  
Wenrui Huang ◽  
Fei Teng ◽  
Beibei Wang ◽  
Ke Ni ◽  
...  
Keyword(s):  
River Basin ◽  
Human Activities ◽  
Heihe River Basin ◽  
Heihe River ◽  
Mountain Area ◽  
Desert Region ◽  
Irrigation Period ◽  
Sustainable Water Resources Management ◽  
Different Seasons ◽  
Agriculture Irrigation

The Heihe River basin consists of three different characteristic regions: upstream mountain area, midstream oasis region, and downstream desert region. Understanding the river–groundwater interactions in different river reaches is important for sustainable water resources management. In this study, river–groundwater interactions in three different river regions are investigated by the analysis of geophysical characteristics, meteor-hydrological characteristics, agricultural irrigations, and channel water balance equation in the river reaches in different seasons. Results indicate that the river–groundwater interactions vary geographically in the three different regions, and change seasonally with the strongest interactions during the summer. Groundwater discharges into the river in the upstream mountainous reach (annual 2.57 × 108m3) while the river water seeps into aquifers in the downstream desert reach (annual 10.39 × 108m3). In the midstream oasis region, pumping water for agriculture irrigation significantly affects the river–groundwater interaction. The river loses water to the ground during the major- and medium-irrigation periods, and gains water from groundwater during the minor-irrigation period in the midstream reach. The characteristics of the river–groundwater interactions are primarily dominated by physiographic features and precipitation in the upstream mountainous region, by human activities and precipitation in the midstream oasis region, and by evaporation and human activities in the downstream desert region.

Sign in / Sign up

Export Citation Format

Share Document