scholarly journals A Study on Sensitivities of Tropical Forest GPP Responding to the Characteristics of Drought—A Case Study in Xishuangbanna, China

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 157
Author(s):  
Qian Xiong ◽  
Zhongyi Sun ◽  
Wei Cui ◽  
Jizhou Lei ◽  
Xiuxian Fu ◽  
...  
Keyword(s):  
Tropical Forest ◽  
Rainy Season ◽  
Global Climate ◽  
Gross Primary Production ◽  
Standardized Precipitation Index ◽  
Dry Season ◽  
Extreme Drought ◽  
Dynamic Global Vegetation Model ◽  
The Standardized Precipitation Index ◽  
The Impact

Droughts that occur in tropical forests (TF) are expected to significantly impact the gross primary production (GPP) and the capacity of carbon sinks. Therefore, it is crucial to evaluate and analyze the sensitivities of TF-GPP to the characteristics of drought events for understanding global climate change. In this study, the standardized precipitation index (SPI) was used to define the drought intensity. Then, the spatially explicit individual-based dynamic global vegetation model (SEIB-DGVM) was utilized to simulate the dynamic process of GPP corresponding to multi-gradient drought scenarios—rain and dry seasons × 12 level durations × 4 level intensities. The results showed that drought events in the dry season have a significantly greater impact on TF-GPP than drought events in the rainy season, especially short-duration drought events. Furthermore, the impact of drought events in the rainy season is mainly manifested in long-duration droughts. Due to abundant rainfall in the rainy season, only extreme drought events caused a significant reduction in GPP, while the lack of water in the dry season caused significant impacts due to light drought. Effective precipitation and soil moisture stock in the rainy season are the most important support for the tropical forest dry season to resist extreme drought events in the study area. Further water deficit may render the tropical forest ecosystem more sensitive to drought events.

AN EVALUATION OF METEOROLOGICAL DROUGHT IN DAK LAK PROVINCE

2021 ◽  
Vol 66 (3) ◽  
pp. 195-206
Author(s):  
Thuy Hoang Luu Thu ◽  
Mui Tran Thi ◽  
Vu Vuong Van ◽  
Ly Pham Thi ◽  
Cuc Pham Thi
Keyword(s):  
Climate Change ◽  
Rainy Season ◽  
Water Resource Management ◽  
Global Climate ◽  
Meteorological Drought ◽  
Dry Season ◽  
Practical Significance ◽  
Spi Index ◽  
K Index ◽  
The Impact

Assessment of the degree of meteorological drought in Dak Lak province is carried out using the SPI index and the water balance index K in the period 1985 - 2019. The results show that: According to the SPI index, drought tends to occur more at the time of transition from the dry season to the rainy season, during the rainy season, and from the time of transition from the rainy season to the dry season. The K-index in the period 1985 - 2019 showed there was a dry period at the beginning of the year from January to April. The anomalous drought factor plays a very important role because its large influence can cause damages, and allows assessing the variability of rainfall and the impact of climate change on the region. The study and evaluation of meteorological drought have practical significance, supporting managers in making policies on water resource management, ensuring sustainable economic and social development in the context of global climate change.

scholarly journals Analysis of Drought in the Northern Region of Bangladesh Using Standardized Precipitation Index (SPI)

2019 ◽  
Vol 11 (1-2) ◽  
pp. 199-216
Author(s):  
R Afrin ◽  
F Hossain ◽  
SA Mamun
Keyword(s):  
Standardized Precipitation Index ◽  
Extended Period ◽  
Northern Region ◽  
Precipitation Index ◽  
Rainfall Data ◽  
Extreme Drought ◽  
Severe Drought ◽  
Drought Analysis ◽  
Dry Conditions ◽  
The Standardized Precipitation Index

Drought is an extended period when a region notes a deficiency in its water supply. The Standardized Precipitation Index (SPI) method was used in this study to analyze drought. Northern region of Bangladesh was the area of study. Monthly rainfall data of northern region of Bangladesh was obtained from the Meteorological Department of Bangladesh. Obtained rainfall data was from 1991 to 2011 and values from 2012 to 2026 were generated using Markov model. Then SPI values from 1991 to 2026 were calculated by using SPI formula for analyzing drought. Analysis with SPI method showed that droughts in northern region of Bangladesh varied from moderately dry to severely dry conditions and it may vary from moderately dry to severely dry conditions normally in future but in some cases extreme drought may also take place. From the study, it is observed that the northern region of Bangladesh has already experienced severe drought in 1991, 1992, 1994, 1995, 1997, 1998, 2000, 2003, 2005, 2007, 2009 and 2010. The region may experience severe drought in 2012, 2015, 2016, 2018, 2019, 2021, 2022, 2023, 2024, 2025 and 2026 and extreme drought in 2012, 2014, 2016, 2023 and 2024. J. Environ. Sci. & Natural Resources, 11(1-2): 199-216 2018

scholarly journals Effects of Post-Thinning Precipitation on Soil Acid Phosphomonoesterase Activity in Larix principis-rupprechtii Mayr. Plantations

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 734 ◽  
Author(s):  
Huixia Tian ◽  
Xiaoqin Cheng ◽  
Hairong Han
Keyword(s):  
Rainy Season ◽  
Microbial Biomass Carbon ◽  
Global Climate ◽  
Soil Phosphorus ◽  
Dry Season ◽  
Transformation Rate ◽  
Soil P ◽  
Thinning Intensity ◽  
P Mineralization ◽  
Acid Phosphomonoesterase

Soil phosphorus (P) is one of the essential macronutrients for plant growth. Phosphatase-mediated P mineralization in particular is critical for the biogeochemical cycling of P, and its activity reflects the organic P (Po) mineralization potential in soils. In recent years, global climate change has led to changes in precipitation, which inevitably has affected the P cycle as well. To study these effects of precipitation on soil acid phosphomonoesterase (AcPME) activity, the following combined thinning and precipitation treatments were conducted across Larix principis-rupprechtii Mayr. plantations in China: control (CK), light (LT), moderate (MT), and high thinning (HT). The precipitation treatments included natural precipitation (NP), 30% reduced precipitation (RP30), and 60% reduced precipitation (RP60). Soil moisture, microbial biomass carbon (MBC), and soil P fractions were also determined to link their effects on soil AcPME. The results show that soil AcPME activity was significantly higher in the rainy season, which is associated with higher microbial activity and increased P demand, than in the dry season. Generally, soil AcPME activity was found to increase with thinning intensity. In the dry season, the NP treatment was more conducive to improving soil AcPME activity. In the rainy season, the RP60 treatment inhibited soil AcPME activity under all thinning treatments. The RP30 treatment was only found to offer a significant boost for MT. These results indicate that the potential transformation rate of Po may be more dependent on water in the dry season than in the rainy season. If drought occurs, the Po mineralization rate would decrease for all L. principis-rupprechtii plantations, but excessive rainfall in the rainy season would also impact the turnover of Po into MT adversely.

Impact of meteorological drought on agriculture in the Tensift watershed of Morocco

2019 ◽  
Vol 11 (4) ◽  
pp. 1323-1338 ◽  
Author(s):  
Modeste Meliho ◽  
Abdellatif Khattabi ◽  
Guy Jobbins ◽  
Fathallah Sghir
Keyword(s):  
Agricultural Production ◽  
Temporal Evolution ◽  
Standardized Precipitation Index ◽  
Meteorological Drought ◽  
Water Shortage ◽  
Water Volume ◽  
Annual Crops ◽  
Irrigated Area ◽  
The Standardized Precipitation Index ◽  
The Impact

Abstract Located in the mid-west of Morocco, the Tensift watershed shelters the Takerkoust dam, which provides a part of the water used for irrigation of the N'fis agricultural area, which is an important irrigated area of the Tensift watershed. This study deals with the impact of droughts on water inflows to the Takerkoust dam and how the water shortage caused by droughts affects agricultural production in the N'Fis area. The standardized precipitation index (SPI) was used to illustrate the temporal evolution of drought periods. The trend observed on data showed that the Tensift watershed experienced a succession of droughts and humid periods of varying intensities. Periods of drought have negatively affected water inflows to the Takerkoust dam, and therefore the amount of water allocated to agricultural irrigation. Years that experienced droughts showed a restriction of more than 50% of water volume planned for irrigation. During periods of water scarcity, farmers reduce or completely avoid irrigation of annual crops to save water for irrigation of perennial crops. The water shortage for irrigation has led in some cases to a drop of up to 100% of the surface allocated to the production of annual crops.

Tropical forest dynamics across a rainfall gradient and the impact of an El Niño dry season

2004 ◽  
Vol 20 (01) ◽  
pp. 51-72 ◽  
Author(s):  
Richard Condit ◽  
Salomon Aguilar ◽  
Andres Hernandez ◽  
Rolando Perez ◽  
Suzanne Lao ◽  
...  
Keyword(s):  
Tropical Forest ◽  
El Niño ◽  
Forest Dynamics ◽  
El Nino ◽  
Dry Season ◽  
Rainfall Gradient ◽  
Tropical Forest Dynamics ◽  
The Impact

scholarly journals Spatiotemporal Variation of the Meteorological and Groundwater Droughts in Central Taiwan

2021 ◽  
Vol 3 ◽  
Author(s):  
Hsin-Fu Yeh
Keyword(s):  
River Basin ◽  
Groundwater Level ◽  
Standardized Precipitation Index ◽  
Extreme Drought ◽  
Water Shortages ◽  
Level Data ◽  
Groundwater Drought ◽  
Central Taiwan ◽  
The Standardized Precipitation Index

In recent years, Taiwan has been facing severe water shortages due to extreme drought. In addition, changes in rainfall patterns have resulted in an increasingly notable drought phenomenon, which affects the management and utilization of water resources. Therefore, this work examines basins in Central Taiwan. Long-term records from 13 rainfall and 17 groundwater stations were selected. The Standardized Precipitation Index (SPI) and Standardized Groundwater Level Index (SGI) were used to analyze the drought characteristics of this region. The rainfall and groundwater level data from basins in Central Taiwan were analyzed in this study. The results show that the year 2015 experienced extreme drought conditions due to a correlation with SPI and SGI signals. In addition, with regard to groundwater drought, more drought events occurred in the Da'an River basin; however, the duration and intensity of these events were relatively low, in contrast to those of the Wu River basin. Finally, the correlation between SPI and SGI was observed to vary in different basins, but a certain degree of correlation was observed in all basins. The results show that drought intensity increases with longer drought durations. Moreover, severe droughts caused by rainfall tend to occur at a greater frequency than those caused by groundwater.

scholarly journals Diversity of Pseudoscorpiones (Arthropoda: Arachnida) in two fragments of dry tropical forest in the colombian Caribbean region

Caldasia ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 139-151
Author(s):  
Eduardo Villarreal ◽  
Neis Martínez ◽  
Catalina Romero-Ortiz
Keyword(s):  
Tropical Forest ◽  
Temporal Variation ◽  
Rainy Season ◽  
Dry Season ◽  
Caribbean Region ◽  
Limited Information ◽  
Dry Tropical Forest ◽  
The Caribbean ◽  
Spatio Temporal ◽  
Collection Methods

The Dry Tropical Forest (DTF) is one of the most diverse yet threatened biomes of Colombia. There is limited information about the richness of the order Pseudoscorpiones (Arachnida) in this ecosystem in the country. Pseudoscorpions are ecologically interesting, as they may be good indicators of habitat conservation. However, it is still necessary to gather more knowledge related to its spatio-temporal variation. In this study, pseudoscorpion diversity variation was assessed in two fragments of the Dry Tropical Forest in the Caribbean region of Colombian: Reserva Campesina La Montaña (RCM) and Reserva La Flecha (RLF). Four samplings were carried out between March and September of 2016 to include the dry and rainy season. Pseudoscorpions were collected using litter sifting (SL) and manual capture (MC). A total of 260 individuals belonging to five families and eight species were collected. The most abundant was Pachyolpium granulatum (Olpiidae) and the richest family was Chernetidae. The collection methods were effective and complementary. Spatial variation was significant, but no temporal variation was observed however, there was a marked difference between the abundance at RCM in the dry season and the rainy season. In contrast, at RLF most individuals were found in the dry season in comparison with the rainy season. These new faunistic data is the first of its order in the Atlántico and Bolívar department.

scholarly journals Rogation ceremonies: a key to understanding past drought variability in northeastern Spain since 1650

2019 ◽  
Vol 15 (5) ◽  
pp. 1647-1664 ◽  
Author(s):  
Ernesto Tejedor ◽  
Martín de Luis ◽  
Mariano Barriendos ◽  
José María Cuadrat ◽  
Jürg Luterbacher ◽  
...  
Keyword(s):  
18Th Century ◽  
Standardized Precipitation Index ◽  
Extreme Drought ◽  
Drought Indices ◽  
Independent Evidence ◽  
Superposed Epoch Analysis ◽  
Drought Variability ◽  
Instrumental Period ◽  
Epoch Analysis ◽  
The Standardized Precipitation Index

Abstract. In the northeast of the Iberian Peninsula, few studies have reconstructed drought occurrence and variability for the pre-instrumental period using documentary evidence and natural proxies. In this study, we compiled a unique dataset of rogation ceremonies – religious acts asking God for rain – from 13 cities in the northeast of Spain and investigated the annual drought variability from 1650 to 1899 CE. Three regionally different coherent areas (Mediterranean, Ebro Valley, and Mountain) were detected. Both the Barcelona and the regional Mediterranean drought indices were compared with the instrumental series of Barcelona for the overlapping period (1787–1899), where we discovered a highly significant and stable correlation with the Standardized Precipitation Index of May with a 4-month lag (r=-0.46 and r=-0.53; p<0.001, respectively). We found common periods with prolonged droughts (during the mid and late 18th century) and extreme drought years (1775, 1798, 1753, 1691, and 1817) associated with more atmospheric blocking situations. A superposed epoch analysis (SEA) was performed showing a significant decrease in drought events 1 year after the volcanic events, which might be explained by the decrease in evapotranspiration due to reduction in surface temperatures and, consequently, the higher availability of water that increases soil moisture. In addition, we discovered a common and significant drought response in the three regional drought indices 2 years after the Tambora volcanic eruption. Our study suggests that documented information on rogation ceremonies contains important independent evidence to reconstruct extreme drought events in areas and periods for which instrumental information and other proxies are scarce. However, drought index for the mountainous areas (denoted Mountain later in the text) presents various limitations and its interpretation must be treated with caution.

scholarly journals Climate change causes changes in biochemical markers of kidney disease

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Richard Kobina Dadzie Ephraim ◽  
Christopher Amey Asamoah ◽  
Albert Abaka-Yawson ◽  
Precious Kwablah Kwadzokpui ◽  
Samuel Adusei
Keyword(s):  
Climate Change ◽  
Blood Pressure ◽  
Kidney Disease ◽  
Systolic Blood Pressure ◽  
Rainy Season ◽  
Biochemical Markers ◽  
Climatic Changes ◽  
Dry Season ◽  
Study Participants ◽  
The Impact

Abstract Background Climate change is a significant threat to the health of the Ghanaian people. Evidence abounds in Ghana that temperatures in all the ecological zones are rising, whereas rainfall levels have been generally reducing and patterns are increasingly becoming erratic. The study estimated the impact of climate variation between seasons on biochemical markers of kidney disease. Methods This study conveniently recruited 50 apparently healthy peasant farmers and hawkers at Wa in the Upper West Region of Ghana. A pre-study screening for hepatitis A and C, Diabetes mellitus, hypertension was done. Serum creatinine and urea levels were analyzed to rule out kidney preexisting kidney disease. Baseline data was collected by estimating urea, creatinine, sodium, potassium, eGFR (estimated glomerular filtration rate) as well as for hemoglobin (Hb) and hematocrit (Hct) concentrations. Anthropometric data such as height, weight and blood pressure were measured by trained personnel. The study participants were closely followed and alerted deep in the dry season for the second sampling (urea, creatinine, hemoglobin, hematocrit, blood pressure, anthropometry). Results This study recruited more males (58.82%) than females (41.15%), majority (52.92%) of which were aged 25–29 years with the youngest being 22 years and the eldest being 35 years. The study found body mass index (p < 0.001), systolic blood pressure (p = 0.019), creatinine (p < 0.001), urea (p = 0.013) and eGFR (p < 0.001) to be significantly influenced by climate change. Stage 1 hypertension was predominant among the study participants during the dry season, 8 (15.69%) than was observed during the rainy season, 4 (7.84%) nonetheless the number of participants with normal BMI rose from 49.02% in the rainy season to 62.75% during the dry reason. Additionally, the study observed that the impact of climate change on systolic blood pressure and urea varied based on age and sex. Conclusion This study revealed that climatic changes cause variations in various biochemical parameters used to assess kidney function. Public health education on climatic changes and its implication including precautionary measures should be done among inhabitants of Wa and its environs to reduce its effect. Additionally, appropriate dietary patterns should also be advised to avoid the development of non-communicable diseases such as hypertension and obesity that are known principal causes of Chronic Kidney Disease (CKD).

scholarly journals Assessing the Added Value of Dynamical Downscaling Using the Standardized Precipitation Index

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Jared H. Bowden ◽  
Kevin D. Talgo ◽  
Tanya L. Spero ◽  
Christopher G. Nolte
Keyword(s):  
Climate Model ◽  
Dynamical Downscaling ◽  
Regional Climate ◽  
Standardized Precipitation Index ◽  
Precipitation Index ◽  
Added Value ◽  
Tropical Storms ◽  
The Standardized Precipitation Index ◽  
The Impact ◽  
Resources Planning

In this study, the Standardized Precipitation Index (SPI) is used to ascertain the added value of dynamical downscaling over the contiguous United States. WRF is used as a regional climate model (RCM) to dynamically downscale reanalysis fields to compare values of SPI over drought timescales that have implications for agriculture and water resources planning. The regional climate generated by WRF has the largest improvement over reanalysis for SPI correlation with observations as the drought timescale increases. This suggests that dynamically downscaled fields may be more reliable than larger-scale fields for water resource applications (e.g., water storage within reservoirs). WRF improves the timing and intensity of moderate to extreme wet and dry periods, even in regions with homogenous terrain. This study also examines changes in SPI from the extreme drought of 1988 and three “drought busting” tropical storms. Each of those events illustrates the importance of using downscaling to resolve the spatial extent of droughts. The analysis of the “drought busting” tropical storms demonstrates that while the impact of these storms on ending prolonged droughts is improved by the RCM relative to the reanalysis, it remains underestimated. These results illustrate the importance and some limitations of using RCMs to project drought.

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