Trend Analysis and Periodicity Analysis of Annual Precipitation in Dongxi River Basin of Xiamen

The Awash river basin has been the most extensively developed and used river basin in Ethiopia since modern agriculture was introduced. This paper investigated the annual precipitation, temperature, and river discharge variability using the innovative trend analysis method (ITAM), Mann–Kendall (MK) test, and Sen’s slope estimator test. The results showed that the trend of annual precipitation was significantly increasing in Fitche (Z = 0.82) and Gewane (Z = 0.80), whereas the trend in Bui (Z = 69) was slightly decreasing and the trend in Sekoru (Z = 0.45) was sharply decreasing. As far as temperature trends were concerned, a statistically significant increasing trend was observed in Fitche (Z = 3.77), Bui (Z = 4.84), and Gewane (Z = 5.59). However, the trend in Sekoru (Z = 1.37) was decreasing with statistical significance. The discharge in the study basin showed a decreasing trend during the study period. Generally, the increasing and decreasing levels of precipitation, temperature, and discharge across the stations in this study indicate the change in trends. The results of this study could help researchers, policymakers, and water resources managers to understand the variability of precipitation, temperature, and river discharge over the study basin.

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Assessing Climate Change Trends and Their Relationships with Alpine Vegetation and Surface Water Dynamics in the Everest Region, Nepal

Atmosphere ◽

10.3390/atmos12080987 ◽

2021 ◽

Vol 12 (8) ◽

pp. 987

Author(s):

Mana Raj Rai ◽

Amnat Chidthaisong ◽

Chaiwat Ekkawatpanit ◽

Pariwate Varnakovida

Keyword(s):

Climate Change ◽

Surface Water ◽

River Basin ◽

Climate Impacts ◽

Glacial Lake ◽

Annual Precipitation ◽

Series Data ◽

Lake Area ◽

Alpine Vegetation ◽

Koshi River Basin

The Himalayas, especially the Everest region, are highly sensitive to climate change. Although there are research works on this region related to cryospheric work, the ecological understandings of the alpine zone and climate impacts are limited. This study aimed to assess the changes in surface water including glacier lake and streamflow and the spatial and temporal changes in alpine vegetation and examine their relationships with climatic factors (temperature and precipitation) during 1995–2019 in the Everest region and the Dudh Koshi river basin. In this study, Landsat time-series data, European Commission’s Joint Research Center (JRC) surface water data, ECMWF Reanalysis 5th Generation (ERA5) reanalysis temperature data, and meteorological station data were used. It was found that the glacial lake area and volume are expanding at the rates of 0.0676 and 0.0198 km3/year, respectively; the average annual streamflow is decreasing at the rate of 2.73 m3/s/year. Similarly, the alpine vegetation greening as indicated by normalized difference vegetation index (NDVI) is increasing at the rate of 0.00352 units/year. On the other hand, the annual mean temperature shows an increasing trend of 0.0329 °C/year, and the annual precipitation also shows a significant negative monotonic trend. It was also found that annual NDVI is significantly correlated with annual temperature. Likewise, the glacial lake area expansion is strongly correlated with annual minimum temperature and annual precipitation. Overall, we found a significant alteration in the alpine ecosystem of the Everest region that could impact on the water–energy–food nexus of the Dudh Koshi river basin.

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Correction to: Seasonal trend analysis of minimum air temperature in La Plata river basin

Theoretical and Applied Climatology ◽

10.1007/s00704-021-03541-z ◽

2021 ◽

Author(s):

Marisa G. Cogliati ◽

Gabriela V. Müller ◽

Miguel A. Lovino

Keyword(s):

Trend Analysis ◽

River Basin ◽

Air Temperature ◽

Seasonal Trend ◽

La Plata ◽

Minimum Air Temperature

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Spatiotemporal climate and vegetation greenness changes and their nexus for Dhidhessa River Basin, Ethiopia

ENVIRONMENTAL SYSTEMS RESEARCH ◽

10.1186/s40068-019-0159-8 ◽

2019 ◽

Vol 8 (1) ◽

Cited By ~ 1

Author(s):

Gizachew Kabite Wedajo ◽

Misgana K. Muleta ◽

Berhan Gessesse ◽

Sifan A. Koriche

Keyword(s):

Climate Change ◽

Trend Analysis ◽

River Basin ◽

Climate Change Adaptation ◽

Spatial Relationship ◽

Local Scale ◽

Climate Variables ◽

Climatic Zones ◽

Vegetation Greenness ◽

Climate Change Adaptation Strategies

Abstract Background Understanding spatiotemporal climate and vegetation changes and their nexus is key for designing climate change adaptation strategies at a local scale. However, such a study is lacking in many basins of Ethiopia. The objectives of this study were (i) to analyze temperature, rainfall and vegetation greenness trends and (ii) determine the spatial relationship of climate variables and vegetation greenness, characterized using Normalized Difference in Vegetation Index (NDVI), for the Dhidhessa River Basin (DRB). Quality checked high spatial resolution satellite datasets were used for the study. Mann–Kendall test and Sen’s slope method were used for the trend analysis. The spatial relationship between climate change and NDVI was analyzed using geographically weighted regression (GWR) technique. Results According to the study, past and future climate trend analysis generally showed wetting and warming for the DRB where the degree of trends varies for the different time and spatial scales. A seasonal shift in rainfall was also observed for the basin. These findings informed that there will be a negative impact on rain-fed agriculture and water availability in the basin. Besides, NDVI trends analysis generally showed greening for most climatic zones for the annual and main rainy season timescales. However, no NDVI trends were observed in all timescales for cool sub-humid, tepid humid and warm humid climatic zones. The increasing NDVI trends could be attributed to agroforestry practices but do not necessarily indicate improved forest coverage for the basin. The change in NDVI was positively correlated to rainfall (r2 = 0.62) and negatively correlated to the minimum (r2 = 0.58) and maximum (r2 = 0.45) temperature. The study revealed a strong interaction between the climate variables and vegetation greenness for the basin that further influences the biophysical processes of the land surface like the hydrologic responses of a basin. Conclusion The study concluded that the trend in climate and vegetation greenness varies spatiotemporally for the DRB. Besides, the climate change and its strong relationship with vegetation greenness observed in this study will further affect the biophysical and environmental processes in the study area; mostly negatively on agricultural and water resource sectors. Thus, this study provides helpful information to device climate change adaptation strategies at a local scale.

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Formation Condition, Disaster Characteristics and Developing Trend Analysis on Debris Flows in Moxi River Basin, SW China

Landslide Science for a Safer Geoenvironment ◽

10.1007/978-3-319-04996-0_2 ◽

2014 ◽

pp. 5-11 ◽

Cited By ~ 2

Author(s):

Huayong Ni ◽

Zongliang Li ◽

Yongbo Tie ◽

Zhi Song

Keyword(s):

Trend Analysis ◽

River Basin ◽

Debris Flows ◽

Formation Condition ◽

Sw China ◽

Developing Trend

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Trend analysis of selected water-quality constituents in the Verde River basin, central Arizona

10.3133/wri904128 ◽

1990 ◽

Keyword(s):

Water Quality ◽

Trend Analysis ◽

River Basin ◽

Verde River ◽

Central Arizona

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Precipitation trend analysis of Sindh River basin, India, from 102-year record (1901-2002)

Atmospheric Science Letters ◽

10.1002/asl.602 ◽

2015 ◽

Vol 17 (1) ◽

pp. 71-77 ◽

Cited By ~ 30

Author(s):

Sarita Gajbhiye ◽

Chandrashekhar Meshram ◽

Sudhir Kumar Singh ◽

Prashant K. Srivastava ◽

Tanvir Islam

Keyword(s):

Trend Analysis ◽

River Basin ◽

Precipitation Trend

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The «rainfall-runoff» system and its long-term fluctuations in the Siverskyi Donets River Basin (Ukraine)

10.5194/egusphere-egu21-13350 ◽

2021 ◽

Author(s):

Hanna Bolbot ◽

Vasyl Grebin

Keyword(s):

Climate Change ◽

Water Resources ◽

River Basin ◽

Air Temperature ◽

River Runoff ◽

Annual Runoff ◽

Annual Precipitation ◽

Spring Flood ◽

Current Period

The current patterns estimation of the water regime under climate change is one of the most urgent tasks in Ukraine and the world. Such changes are determined by fluctuations in the main climatic characteristics - precipitation and air temperature, which are defined the value of evaporation. These parameters influence on the annual runoff distribution and long-term runoff fluctuations. In particular, the annual precipitation redistribution is reflected in the corresponding changes in the river runoff. The assessment of the current state and nature of changes in precipitation and river runoff of the Siverskyi Donets River Basin was made by comparing the current period (1991-2018) with the period of the climatological normal (1961-1990). In general, for this area, it was defined the close relationship between the amount of precipitation and the annual runoff. Against the background of insignificant (about 1%) increase of annual precipitation in recent decades, it was revealed their redistribution by seasons and separate months. There is a decrease in precipitation in the cold period (November-February). This causes (along with other factors) a decrease in the amount of snow and, accordingly, the spring flood runoff. There are frequent cases of unexpressed spring floods of the Siverskyi Donets River Basin. The runoff during March-April (the period of spring flood within the Ukrainian part of the basin) decreased by almost a third. The increase of precipitation during May-June causes a corresponding (insignificant) increase in runoff in these months. The shift of the maximum monthly amount of precipitation from May (for the period 1961-1990) to June (in the current period) is observed. There is a certain threat to water supply in the region due to the shift in the minimum monthly amount of precipitation in the warm period from October to August. Compared with October, there is a higher air temperature and, accordingly, higher evaporation in August, which reduces the runoff. Such a situation is solved by rational water resources management of the basin. The possibility of replenishing water resources in the basin through the transfer runoff from the Dnieper (Dnieper-Siverskyi Donets channel) and the annual runoff redistribution in the reservoir system causes some increase in the river runoff of summer months in recent decades. This is also contributed by the activities of the river basin management structures, which control the maintenance water users' of minimum ecological flow downstream the water intakes and hydraulic structures in the rivers of the basin. Therefore, in the period of current climate change, the annual runoff distribution of the Siverskyi Donets River Basin has undergone significant changes, which is related to the annual precipitation redistribution and anthropogenic load on the basin.

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