Frost risks in the Mantaro river basin

Abstract. As part of the study on the Mantaro river basin's (central Andes of Perú) current vulnerability to climate change, the temporal and spatial characteristics of frosts were analysed. These characteristics included intensity, frequency, duration, frost-free periods, area distribution and historical trends. Maps of frost risk were determined for the entire river basin, by means of mathematical algorithms and GIS (Geographic Information Systems) tools, using minimum temperature – 1960 to 2002 period, geomorphology, slope, land-use, types of soils, vegetation and life zones, emphasizing the rainy season (September to April), when the impacts of frost on agriculture are most severe. We recognized four categories of frost risks: low, moderate, high and critical. The critical risks (with a very high probability of occurrence) were related to high altitudes on the basin (altitudes higher than 3800 m a.s.l.), while the low (or null) probability of occurring risks were found in the lower zones (less than 2500 m a.s.l.). Because of the very intense agricultural activity and the high sensitivity of the main crops (Maize, potato, artichoke) in the Mantaro valley (altitudes between 3100 and 3300 m a.s.l.), moderate to high frost risks can be expected, with a low to moderate probability of occurrence. Another significant result was a positive trend of 8 days per decade in the number of frost days during the rainy season.

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Variation of precipitation concentration from 1960 to 2014 in the Middle and Lower reaches of the Yangtze River Basin, China

Cuadernos de Investigación Geográfica ◽

10.18172/cig.2930 ◽

2016 ◽

Vol 42 (1) ◽

pp. 205 ◽

Cited By ~ 2

Author(s):

L. Zhao ◽

J. M. Wang ◽

Z. Zhao ◽

J. Fang

Keyword(s):

River Basin ◽

El Niño ◽

Rainy Season ◽

Yangtze River ◽

El Nino ◽

Yangtze River Basin ◽

Risk Governance ◽

Positive Trend ◽

Precipitation Concentration ◽

The Mean

Based on the daily rainfall data of 127 stations from 1960 to 2014, this study investigated the spatial-temporal variation of PCD (precipitation-concentration degree) and PCP (precipitation-concentration period), and their possible relations with ENSO (El Niño-Southern Oscillation) in the middle and lower reaches of Yangtze River of China. Main results have indicated that, firstly, the mean PCD was generally below 0.5 across the whole study area, with the lower value located in the northeast and south. Besides, there was a positive trend of concentrated precipitation in the west part while negative in the east. Secondly, the mean PCP ranged from May to July and delayed from south to north, along with a trend of advancing rainy season in the central part. In addition, PCD had a positive relation with ONI (Oceanic Niño Index), while PCP negative. El Niño led the rainy season earlier and the precipitation more concentrated. This study could not only shed a light on the understanding of the variation of precipitation pattern, but also provide theoretical support for regional disaster risk governance and water resources management in the middle and lower Yangtze River Basin.

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Vulnerability analysis of capture fisheries to climate change based on the Province Scale (exposure and sensitivity analysis)

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/869/1/012016 ◽

2021 ◽

Vol 869 (1) ◽

pp. 012016

Author(s):

V Mandhalika ◽

A B Sambah ◽

D O Sutjipto ◽

F Iranawati ◽

M A Z Fuad ◽

...

Keyword(s):

Climate Change ◽

High Sensitivity ◽

Final Analysis ◽

Vulnerability Analysis ◽

Exposure Analysis ◽

Sst Variability ◽

Vulnerability To Climate Change ◽

Important Input ◽

Recorded Data ◽

Very High

Abstract Fisheries has a major contribution for the Indonesian economy both on a local and national scale. However, the phenomenon of climate change can threaten the sustainability of this sector. Therefore, a scientific approach is needed to determine the level of risk and adaptation strategies for fisheries, one of which is through vulnerability analysis. Vulnerability is the final analysis resulted from the analysis of sensitivity and exposure. Both of these analyses are important to determine the parameters that will affect the value of the fishery vulnerability to climate change. This research is focused on sensitivity and exposure analysis with the coverage limit is the province area to determine the sensitivity and exposure index that exists in the study area. The result will be important input in further research for the vulnerability of capture fisheries to climate change. Three provinces in Indonesia were selected through purposive sampling method. The source of data for indices variables were using recorded data in 2009-2020 from relevant sources. Result described that SST variability in the three provinces has the same pattern. In the exposure analysis, the SST is linked to the catch resulting in different exposure statuses in each province. It also illustrated those areas with a very high number of fishermen and catches will have very high sensitivity. The research will support in the sustainable management of capture fish at the province scale.

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Rainfall trend and variability over Opak River basin, Yogyakarta, Indonesia

Journal of the Civil Engineering Forum ◽

10.22146/jcef.60628 ◽

2020 ◽

Vol 1000 (1000) ◽

Author(s):

Wakhidatik Nurfaida ◽

Hendra Ramdhani ◽

Takenori Shimozono ◽

Indri Triawati ◽

Muhammad Sulaiman

Keyword(s):

River Basin ◽

Water Resource ◽

Rainfall Intensity ◽

Kendall Test ◽

Rainfall Data ◽

Positive Trend ◽

Sen’S Slope Estimator ◽

Sen’S Slope ◽

Slope Estimator

Rainfall intensity seems to be increasing nowadays due to climate change as presented in many studies of both global and regional scale. Consequently, cities worldwide are now more vulnerable to flooding. In Indonesia, increasing frequency of floods was reported for the past decades by The National Agency for Disaster Countermeasure (BNPB). To understand the rainfall changes, long-term trend evaluation over a specific area is then crucial due to the large variability of spatial and temporal rainfall distribution. This study investigates the homogeneity and trend of rainfall data from 20 stations over the Opak River basin, Yogyakarta, Indonesia. A long-term ground observation rainfall data whose period varies from 1979 to 2019 were analyzed. Non-parametric Mann – Kendall test was applied to assess the trend, while the magnitude was calculated using the Sen’s slope estimator. An increasing annual maximum of daily rainfall intensity was observed at four stations on a 0.95 confidence level based on the Mann – Kendall test, while the Sen’s slope estimator shows a positive trend at almost all stations. The trend of heavy rainfall frequency was also found to be significantly increased, with only one station showed a decreasing trend. Furthermore, this paper also described the spatial and temporal rainfall variability. Positive trend was mostly found during the rainy season, while the negative trend occurred during the dry season. This could pose a challenge for water resource management engineering and design, such as water supply systems or reservoir management. Understanding this phenomena will benefit hydrologists in preparing future water resource engineering and management.

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Adaptation actions to reduce water system vulnerability to climate change in Tensift River basin (Morocco)

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1307/6/29/292006 ◽

2009 ◽

Vol 6 (29) ◽

pp. 292006

Author(s):

Mohammed Yacoubi Khebiza ◽

M Messouli ◽

F Hammadi ◽

B Ghallabi

Keyword(s):

Climate Change ◽

River Basin ◽

Water System ◽

System Vulnerability ◽

Vulnerability To Climate Change

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Analysis of the Changes in the Water Yield Coefficient over the Past 50 Years in the Huang-Huai-Hai River Basin, China

Advances in Meteorology ◽

10.1155/2018/6302853 ◽

2018 ◽

Vol 2018 ◽

pp. 1-20 ◽

Cited By ~ 1

Author(s):

Xiaoqing Shi ◽

Tianling Qin ◽

Denghua Yan ◽

Ruochen Sun ◽

Shuang Cao ◽

...

Keyword(s):

Land Use ◽

River Basin ◽

Vegetation Index ◽

Yellow River ◽

Rate Of Change ◽

Vegetation Coverage ◽

Water Yield ◽

Yield Coefficient ◽

Positive Trend ◽

Land Use Types

This study analysed the temporal and spatial changes in the water yield coefficient (WYC), which represents the ratio of the gross amount of water resources to precipitation. Factors such as precipitation, rainstorm days, rainless days, vegetation cover change, and land use/cover change were considered to determine the causes of these changes. The results led to the following conclusions: (1) The average annual WYC of the Huang-Huai-Hai River Basin is between 0.03 and 0.58, with an average value of 0.17, which is smaller than the national average WYC of 0.4. (2) Temporally, the WYC varied slightly, with the western part showing a negative trend and the eastern part showing a positive trend. The WYC is positively correlated with precipitation, rainstorm days, and the normalized difference vegetation index (NDVI) and negatively correlated with rainless days. However, a slower change in NDVI produced a faster change in WYC. In areas with land use types exhibiting a large evapotranspiration decrease, the rate of change in the WYC increased. (3) Spatially, the distribution is fairly regular, exhibiting a gradual increase from the northern part of the Yellow River Basin (WYC < 0.1) to the surrounding areas. When the WYC is correlated with precipitation, rainstorm days, rainless days, and NDVI, the R2 values of the linear fitting results are 0.98, 0.91, 0.96, and 0.73, respectively. The WYC is positively correlated with precipitation, rainstorm days, and vegetation coverage and negatively correlated with rainless days, but the correlation coefficient is greatly influenced by the precipitation characteristics and land use types. In areas featuring high proportions of land use types associated with high evapotranspiration, the average WYC is low.

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Precipitation Trends over Time Using Mann-Kendall and Spearman’s rho Tests in Swat River Basin, Pakistan

Advances in Meteorology ◽

10.1155/2015/431860 ◽

2015 ◽

Vol 2015 ◽

pp. 1-15 ◽

Cited By ~ 118

Author(s):

Ijaz Ahmad ◽

Deshan Tang ◽

TianFang Wang ◽

Mei Wang ◽

Bakhtawar Wagan

Keyword(s):

River Basin ◽

Statistical Tests ◽

Annual Precipitation ◽

Positive Trend ◽

Monthly Precipitation ◽

Significance Level ◽

Spearman's Rho ◽

Spearman’S Rho ◽

Swat River ◽

Precipitation Trends

Accurately predicting precipitation trends is vital in the economic development of a country. This research investigated precipitation variability across 15 stations in the Swat River basin, Pakistan, over a 51-year study period (1961–2011). Nonparametric Mann-Kendall (MK) and Spearman’s rho (SR) statistical tests were used to detect trends in monthly, seasonal, and annual precipitation, and the trend-free prewhitening approach was applied to eliminate serial correlation in the precipitation time series. The results highlighted a mix of positive (increasing) and negative (decreasing) trends in monthly, seasonal, and annual precipitation. One station in particular, the Saidu Sharif station, showed the maximum number of significant monthly precipitation events, followed by Abazai, Khairabad, and Malakand. On the seasonal time scale, precipitation trends changed from the summer to the autumn season. The Saidu Sharif station revealed the highest positive trend (7.48 mm/year) in annual precipitation. In the entire Swat River basin, statistically insignificant trends were found in the subbasins for the annual precipitation series; however, the Lower Swat subbasin showed the maximum quantitative increase in the precipitation at a rate of 2.18 mm/year. The performance of the MK and SR tests was consistent at the verified significance level.

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Diversity and habitat preference of aquatic insects along the longitudinal gradient of the Macaé River basin, Rio de Janeiro, Brazil

Revista Brasileira de Biologia ◽

10.1590/s0034-71082001000200007 ◽

2001 ◽

Vol 61 (2) ◽

pp. 249-258 ◽

Cited By ~ 37

Author(s):

D. F. BAPTISTA ◽

D. F. BUSS ◽

L. F. M. DORVILLÉ ◽

J. L. NESSIMIAN

Keyword(s):

River Basin ◽

Aquatic Insects ◽

Habitat Preference ◽

Rainy Season ◽

Rio De Janeiro ◽

Dry Season ◽

Longitudinal Gradient ◽

Order Stream ◽

Surber Sampler ◽

Janeiro State

Diversity and habitat preference of macroinvertebrates were studied in Macaé River basin, Rio de Janeiro State, Brazil, along its longitudinal gradient. We selected stream reaches corresponding to 1st, 2nd, 4th, 5th and 6th orders. A Surber sampler was used to collect four macroinvertebrates samples of each substrate (sand, litter in pool areas, stones, and litter in riffle areas) during the three sampling periods, defined based on the rain regime: April (end of the rainy season), July (dry season), and October (beginning of the rainy season). We identified 46,431 specimens corresponding to 117 taxa. Analysis of diversity numbers (both for family or genus level) indicated that all insect taxonomic orders had higher numbers on 2nd order stream reach, except for Ephemeroptera, on 4th order. However when considering morph-species taxonomic level, the higher diversity number occurred on 4th order stream. The highest richness and diversity numbers were found at the dry season. Considering habitat preference, both litter in pool areas and litter in riffle areas had the highest faunal richness.

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