Drought Indicators/indices

Se presenta una breve exposición y análisis de las medidas que han sido instauradas en los últimos años para afrontar la sequía en México; entre ellas destaca el inicio del proceso de transición de un enfoque reactivo basado en la gestión de la crisis a un enfoque preventivo orientado hacia la gestión del riesgo. Éste no puede eliminarse por completo, pero las acciones preventivas permitirán mitigar sus efectos aunque para ello será necesario afrontar y superar varios retos en el futuro inmediato.

Natural hazards such as agricultural droughts impact negatively on crop yields and economic activities.
Characterization of agricultural droughts provides precise and accurate information for decision making
processes during agricultural drought events. Planning and responding to the hazards by government, and
non-governmental organizations in the Sudano-Sahelian belt has been limited in the past due to knowledge
gap on the nature and impact of the hazard. This study seeks to characterize historical agricultural droughts,
assess their impact on crop yields and people’s susceptibility to undernourishment and through forecasting,
unravel what the future holds. Annual effective reconnaissance drought index values are computed using
mean monthly potential evapotranspiration and effective precipitation data. To assess the impact of
agricultural drought, the index’s values are compared to crop yields and prevalence to undernourishment
data. Results show that agricultural drought events of 1983 and 2008 are mild and ephemeral while the 1999
– 2006 event is severe and protracted. While there is 26% chance of materialization of an agricultural drought
in Gourma, the chance of being ephemeral and of moderate category is the highest (8%). It has been
determined that an ephemeral and moderate agricultural drought would trigger below average yields for
maize, sorghum and millet. Mild, moderate and severe events increase prevalence to undernourishment by
2.9 %, 4.3 % and 5.8 % respectively. From 2020 to 2030, a continued materialization of agricultural droughts
is expected.

For agriculture to withstand the adverse effects of climate change and remain productive in spite of unusual weather phenomena, active adaptation is a practicable option for farmers and government agencies alike. Other strategies, such as the construction of water retention ponds and developing climate-adaptable varieties, require heavy funding that, without institutional support, are beyond the Filipino farmers’ financial capabilities. Also, these strategies take many years to build and bear fruit. In view of these shortcomings and vulnerability to extreme weather events, immediate and low-cost adaptation measures are needed for farmers to consider while waiting for the long-term solutions.
This paper presents the development of a methodology using remote sensing and GIS techniques in determining the vulnerability to climate irregularities of a farming community in Pitpitan, Bulakan, Bulacan. This methodology is intended to become part of a GIS-based climate adaptation recommender system that, in consideration of farmers’ customary practices, will help to inform them of alternative adaptive measures in cases of imminent climate issues such as drought and floods.
Search of related literature, personal visits to concerned local government units, and discussions with Pitpitan’s farmers reveal that, in general, farmers are more concerned with drought than with heavy flooding. Thus focus was given on helping farmers cope with drought conditions, and the developed methodology made use of a reduced version of the agricultural drought vulnerability index (ADVI), which is a data-intensive climatic vulnerability assessment index developed in India. ADVI is modified in order to take into account current data shortcomings of the Philippines, and still come up with a potentially useful analysis tool for extreme climate vulnerability of farm parcels in Pitpitan. The resulting thematic maps are then validated by farmers for being accurate and informative.
A prototype table of recommendations was also developed with the reduced ADVI (rADVI) methodology, which aims to provide farmers with suggested adaptation measures based on their parcels’ rADVI ranking and the expected rainfall situation in the Pitpitan area. These recommendations at parcel level were arrived at using GIS that incorporates both established agricultural strategies and local farmers’ knowledge of time-tested strategies.

RESUMEN
El riesgo y las amenazas naturales son condiciones asociadas al devenir de las sociedades, desde el inicio de la historia de la Humanidad con el desconocimiento del funcionamiento de la naturaleza y el temor ante sus fenómenos extremos, hasta la reciente influencia de sus actividades en los procesos de cambio climático. La vulnerabilidad de un sistema es el grado en el que un sistema es susceptible o incapaz de enfrentarse a efectos adversos ante un fenómeno, incluidos la variabilidad y los extremos del clima, y está en función del carácter, magnitud y rapidez del cambio climático, así como de la variación a la que está expuesto, de su sensibilidad y capacidad de adaptación. la evaluación de la vulnerabilidad se concibe en función de dos estructuras de referencia: el modelo Presión-Estado-Respuesta y el marco de referencia Exposición-Sensibilidad-Capacidad de Adaptación. Una forma de evaluar la V es mediante el uso de indicadores e índices adecuados a través de los modelos. Existen diversos estudios que han evaluado la vulnerabilidad por los impactos del CC para los ámbitos ambiental, social o económico; sin embargo, no hay mucho de ellos que realicen estas evaluaciones de manera integral. Se han propuesto y considerado mucho menos indicadores ecológicos que sociales, y la mayoría de los indicadores ambientales de la literatura corresponden a bases de datos obtenidos a escala estatal, nacional e internacional, pero muy pocos a escala local. Se desarrolló un modelo de evaluación del Riesgo-Vulnerabilidad por amenazas clave asociadas al cambio climático (sequía, lluvias torrenciales e incremento del nivel medio del mar) en zonas costeras, integrando índices compuestos bióticos, abióticos y socioeconómicos; a fin de que incida en los instrumentos de gestión local vigentes. Se aplicó y ajustó a 3 estudios de caso (EC). El modelo del 1er EC mostró que 31% de UA con V Alta-Muy Alta; zona urbana de La Paz, sur Cuenca El Novillo, noroeste de El Comitán (26% de superficie total). La Fortaleza del modelo base es su marco conceptual, pero la utilidad del mismo es la parte adaptable, puede ser modificada dependiendo de los indicadores que se tengan disponibles. presentó limitaciones en la subjetividad para la selección y ponderación de los indicadores. El Modelo en el 2º EC demostró que 10 acuíferos en situación crítica por V Alta-Muy Alta (59% de superficie BCS). Se fundamentó en el marco de E-S-CA, con indicadores distintos (amenaza por sequía), ponderación menos subjetiva (AHP) que en el primero. En 3er EC, el Modelo determinó que 20% de zona de estudio con Media V; 16% con Alta-Muy alta V. El Modelo fue más robusto, con agrupación de variables por similitud y significación estadística, pesos por análisis estadístico, y reducción de variables por bajo aporte al modelo. El análisis de sensibilidad del modelo incluyó la transformación, normalización, pesos por valor importancia de cada variable y % contribución de los factores. Este nuevo modelo de vulnerabilidad, integra todos los marcos de referencia existentes en la literatura especializada.

ABSTRACT
Risk and natural hazards are conditions associated with the evolution of societies, from the beginning of the history of Humanity with the ignorance of the functioning of nature and the fear of its extreme phenomena, until the recent influence of its activities on the processes of climate change. The vulnerability (V) of a system is the degree to which a system is susceptible or unable to cope with adverse effects to a phenomenon, including variability and extremes of climate, and is a function of the nature, magnitude and speed of climate change, as well as as of the variation to which it is exposed, of its sensitivity and ability to adapt. Vulnerability assessment is conceived in terms of two main frameworks: the Pressure-State-Response model and the Exposure-Sensibility-Adaptation Capacity model. A way to evaluate V is through the use of appropriate indicators and indices through models. There are several studies that have assessed vulnerability due to the impacts of climate change for environmental, social or economic systems; however, there is not much of them that carry out these evaluations comprehensively. Much less ecological than social indicators have been proposed and considered, and most of the environmental indicators in the literature correspond to databases obtained at national and international level, but very few at local level. A Risk-Vulnerability assessment model was developed for key threats associated with climate change (drought, torrential rains and mean sea level rise) in coastal areas, integrating biotic, abiotic and socioeconomic indexes; so that it affects the current local management instruments. It was applied and adjusted to 3 case studies (EC). The 1st EC model showed that 31% of environmetal units (UA) with High-Very High V; urban area of ​​La Paz, south Cuenca El Novillo, northwest of El Comitán (26% of total area). The strength of the base model is its conceptual framework, but the usefulness of it is the adaptive part, it can be modified depending on the indicators that are available. It presented limitations in subjectivity for the selection and weighting of the indicators. The Model in the 2nd EC showed that 10 aquifers were in critical situation by High-Very High V (59% of BCS total area). It was based on the E-S-AC framework, with different indicators (threat due to drought), less subjective weighting (AHP) than in the first one. In 3rd EC, the Model determined that 20% of study area had Media V; and 16% had High-Very High V. The Model was more robust, with grouping of variables by similarity (Multidimensional Scaling) and statistical significance, weight by statistical analysis (Principal Components), and reduction of variables by low contribution to the model. The sensitivity analysis of the model included the transformation, normalization, weights by importance value of each variable and % contribution of the factors. This new vulnerability model integrates all existing reference frameworks in the specialized literature.

This study proposes the a high-resolution Vegetation Health Index (VHI) as an indicator of the water stress conditions of the vegetation cover. This index integrates satellite derived vegetation and thermal information; it is a function of the NDVI (Normalized Difference Vegetation Index, derived from Sentinel-2) and the LST (Land Surface brightness Temperature, derived from MODIS) normalized against the minima and maxima in a certain period. Successfully applied in numerous case studies (Kogan, 1995, 1997), the VHI has been already tried experimentally for African environments and conditions (Rojas et al. 2011) where it exhibited its performance, making it ready to be tested for insurance purposes. VHI drought maps were generated every 10 days at 20 m resolution for large areas in Kenya. The database is structured as a GIS capable data store for time series data with an online platform (dashboard) which offers to the identified stakeholders a drought monitoring service. The service is undergoing an in-country trail for deployment to Kenyan insurances, farmer cooperatives and Ministries in Kenya. Additional capabilities of the system include capacities analytics from of multi-temporal statistics at field level, drought early warning and agricultural consultancy.

For agriculture to withstand the adverse effects of climate change and remain productive in spite of unusual weather phenomena, active adaptation is a practicable option for farmers and government agencies alike. Other strategies, such as the construction of water retention ponds and developing climate-adaptable varieties, require heavy funding that, without institutional support, are beyond the Filipino farmers’ financial capabilities. Also, these strategies take many years to build and bear fruit. In view of these shortcomings and vulnerability to extreme weather events, immediate and low-cost adaptation measures are needed for farmers to consider while waiting for the long-term solutions. This paper presents the development of a methodology using remote sensing and GIS techniques in determining the vulnerability to climate irregularities of a farming community in Pitpitan, Bulakan, Bulacan. This methodology is intended to become part of a GIS-based climate adaptation recommender system that, in consideration of farmers’ customary practices, will help to inform them of alternative adaptive measures in cases of imminent climate issues such as drought and floods. Search of related literature, personal visits to concerned local government units, and discussions with Pitpitan’s farmers reveal that, in general, farmers are more concerned with drought than with heavy flooding. Thus focus was given on helping farmers cope with drought conditions, and the developed methodology made use of a reduced version of the agricultural drought vulnerability index (ADVI), which is a data-intensive climatic vulnerability assessment index developed in India. ADVI is modified in order to take into account current data shortcomings of the Philippines, and still come up with a potentially useful analysis tool for extreme climate vulnerability of farm parcels in Pitpitan. The resulting thematic maps are then validated by farmers for being accurate and informative. A prototype table of recommendations was also developed with the reduced ADVI (rADVI) methodology, which aims to provide farmers with suggested adaptation measures based on their parcels’ rADVI ranking and the expected rainfall situation in the Pitpitan area. These recommendations at parcel level were arrived at using GIS that incorporates both established agricultural strategies and local farmers’ knowledge of time-tested strategies.

ABSTRACT
Drought is the most complex but least understood of all natural hazards. It is broadly defined as “severe water shortage”. Low rainfall and fall in agricultural production has mainly caused droughts.  A droughts impact constitutes losses of life, human suffering and damage to economy and environment. Droughts have been a recurring feature of Nigeria’s climate therefore study of Historical (1990-2012) droughts may help in the delineation of major areas facing drought risk and thereby management plans can be formulated by the government authorities to cope with the disastrous effects  this hazard. In recent years, Geographic Information Science (GIS) and Remote Sensing (RS) have played a key role in studying different types of hazards either natural or man-made. This study stresses upon the use of RS and GIS in the field of Drought risk Assessment.

El cambio climático está provocando una intensificación en la variabilidad climática natural, con un aumento en la frecuencia y severidad de las sequías en muchas partes del mundo. El peligro por sequía se refiere a la probabilidad de que ocurra un evento de sequía en un espacio y tiempo determinados con suficiente intensidad como para producir daños; la vulnerabilidad ante la sequía es el grado en que un sistema es susceptible e incapaz de hacer frente a los efectos adversos, daños o perjuicios causados por este fenómeno natural; y el riesgo por sequía está determinado por la confluencia del peligro y la vulnerabilidad. Con base en estos conceptos, en este artículo se presentan los resultados de la aplicación de una metodología desarrollada por los autores para determinar índices municipales de peligro, vulnerabilidad y riesgo por sequía en México. Los resultados indican que la metodología es viable para su aplicación a nivel nacional, e inclusive puede ser adaptado para aplicarse a nivel estatal o regional. Su principal ventaja es que se basa en un procedimiento analítico objetivo que permite identificar los municipios más vulnerables desde los puntos de vista económico, social y ambiental, y aquellos con mayor propensión y riesgo de ser afectados por sequía. Se concluye que los resultados obtenidos pueden ser útiles para los tomadores de decisiones y los responsables de formular políticas públicas en varios sentidos, tales como: establecer prioridades en la implementación de medidas de prevención y mitigación; entender dónde y cómo mejorar las capacidades de adaptación; entender dónde y cómo disminuir la exposición y la sensibilidad; y, en última instancia, optimizar la distribución de recursos de los diversos programas gubernamentales orientados al desarrollo social, los cuales contribuyen al fortalecimiento de capacidades para hacer frente a los fenómenos hidrometeorológicos extremos y a la adaptación al cambio climático.

This paper analyses the observed spatiotemporal characteristics of drought phenomenon in Syria using the Standardised Precipitation Index (SPI) and the Standardised Precipitation Evapotranspiration Index (SPEI). Temporal variability of drought is calculated for various time scales (3, 6, 9, 12, and 24 months) for 20 weather stations over the 1961-2012 period. The spatial patterns of drought were identified by applying a Principal Component Analysis (PCA) to the SPI and SPEI values at different time scales. The results revealed three heterogeneous and spatially well-defined regions with different temporal evolution of droughts: 1) Northeastern (inland desert); 2) Southern (mountainous landscape); 3) Northwestern (Mediterranean coast). The evolutionary characteristics of drought during 1961-2012 were analysed including spatial and temporal variability of SPI and SPEI, the frequency distribution, and the drought duration. The results of the non-parametric Mann-Kendall test applied to the SPI and SPEI series indicate prevailing significant negative trends (drought) at all stations. Both drought indices have been correlated both on spatial and temporal scales and they are highly comparable, especially, over a 12 and 24 month accumulation period. We concluded that the temporal and spatial characteristics of the SPI and SPEI can be used for developing a drought intensity-areal extent-and frequency curve that assesses the variability of regional droughts in Syria. The analysis of both indices suggests that all three regions had a severe drought in the 1990s, which had never been observed before in the country. Furthermore, the 2007-2010 drought was the driest period in the instrumental record, happening just before the onset of the recent conflict in Syria.

Study on Indigenous Weather Forecasting Knowledge of Oromia Pastoral Area Community of Ethiopia
Abera Bekele Dinsa (PhD candidate at AAU), Eermiyas Teferi (PhD) lecturer at AAU1, Fayera Senbata (PhD) lecturer at AAU and Tamirat Teshome (PhD) lecturer at AAU
Abstract
Pastoralism is a rational, adaptable, tried and tested production system uniquely suited to the dry lands. Pastoralism occupies a quarter of the world area, which is predominantly arid and semiarid. Pastoralism developed autonomously across the world‘s dry lands from some 7000 years ago. It is still widely practiced today and remains a dominant feature of rural east African in which most household sustain their means of living from keeping domestic livestock. Pastoralism is practiced under marginal condition and high production risk because of different natural and manmade factors in which weather based disaster is the major serious hazard and continuously threatening the livelihood of pastoralists ‘in an alarming rate. In the past pastoralists spread weather risks particularly drought risks through using traditional early warning of weather forecasting signs. This study was conducted in four patoral woredas of Borena, Gudji and Bale zone, pastoral areas of Oromia, Ethiopia with the objectives of undertaking study on the traditional early warning of weather forecasting signs of Oromia pastoralists. To conduct this study, a total of 390 purposely sampled households, 130 focus group discussion participants, 30 knowledgeable key informant interviews and secondary data sources were used. It is identified through this study that from the time immemorial Oromia pastoralist communities have used traditional weather forecasting signs in order to minimize risks ;and to save their lives and livelihoods from the weather related disasters such as drought, flood, disease outbreak and local conflict. As they confirmed, types of the traditional weather forecasting signs that are used by Oromia pastoralists are Sun, moon, stars, and wind direction, behaviors of domestic animals, trees, wild life, birds, livestock intestine, reptiles, social insects, Geda cycle and Aayyana (27 days of the month/days of moon). It is identified that Oromia pastoralists could easily predict normal occurrence of rainfall and/or occurrence of severe drought and other disaster events of the current particular season and also the probable weather events of the future season even up to as long as more than eight year which help them to make seasonal based livelihood decisions and practices.

Rainfall deficiency results in drying up of soil, leading to a drought situation, invariably with grave consequences. The magnitude and pattern of drought can be measured with various drought indices using remote sensing and meteorological data. The present study attempts to analyze spatio-temporal pattern of drought severity, and compare meteorological and vegetative drought indices in Gujarat, an agrarian and drought-prone state in western India. Open source remote sensing and rainfall datasets were analyzed for the monsoon and non-monsoon seasons from 1982 to 2001, a period underscored by 12 major droughts. Four indices, namely Standardized Precipitation Index (SPI), Rainfall Anomaly (RFA), Vegetation Condition Index (VCI), and NDVI Anomaly Index (NAI) were used for analysis. Drought patterns, thus delineated, were found to have very good correlation with rainfall. It was observed that both RFA and NAI could be used as an indicator for assessment of the percentage of area affected by meteorological and vegetative drought in the study area. A comparison between the four indices was of much help in understanding the impact of meteorological drought on vegetative drought. Furthermore, multiple regression analysis revealed that RFA and NAI were better-suited drought indices, among the four under consideration.

Remote sensing has been widely used in monitoring vegetation and in detecting agricultural droughts. The most commonly used data for this purpose is the coarse spatial and the high temporal resolution data of NDVI. This study compares different indices (NDVI, MSI, EWSI, PDI and MPDI) derived from MODIS for assessing drought conditions in Mafraq area in Jordan. The possible improvements in drought monitoring as a result of improved spatial resolution is also investigated in this study by comparing Landsat-NDVI with MODIS-NDVI. Results showed significant relationships among the different indices derived from MODIS and Landsat data. A significant relationship was found between Landsat-NDVI and MODIS-NDVI, with R 2 value of 0.56 and RMSE of 0.078. The Landsat-NDVI was better than MODIS-NDVI in detecting drought conditions for fields of rainfed barley in the northern parts of the study area, while both datasets reflected the aridity conditions prevailing in the study area. The MODIS-PDI showed to be the most accurate indicator that was highly correlated (R 2 = 0.73) with soil moisture measurements. Soil water stress indicators (EWSI and MSI) showed relatively lower correlations with soil moisture and modeled evapotranspiration when compared with Landsat-NDVI and MODIS-PDI. Therefore, the use of MODIS-PDI instead of MODIS-NDVI would be recommended for mapping drought severity without processing historical data. The use of NDVI deviations from historical means would be recommended with medium resolution data of NDVI, providing that temporal resolution would improve and more datasets from earth observation systems (EOS) would be available in real time.

Shortage of food and water resources resulted from climatic crises has alarmed people around the world, in particular that the rain-watered agriculture and vegetation of natural resources suffer from the irregular rainfall in most of the water years. Drought and wetness year causes significant impacts on water resources, crops, commerce, trade and in general, economy and political crises. Give the fact that some countries like Iran are located in the dry belt of the world their rainfall pattern possess unique features: low intensity and high fluctuation. The persistent negative fluctuations of precipitation lead to drought characterized by different severity which imposes extensive damage on ecological and economic condition of the affected areas. Therefore, in this paper the comprehensive review of drought indices is presented and the advantages and disadvantages related to each index is discussed enabling policy makers to manage drought effectively.

In the present paper five significant late medieval drought events, occurred in Hungary (4 cases) and Croatia (1 Dalmatian case), are discussed based on contemporary documentary evidence. Information on long-term lack of precipitation, severe annual (or multiannual) water shortage, extreme low water levels of major rivers or bad harvest and severe food shortage in 1362, 1474, 1479, 1494 and 1507, often accompanied or followed by locust invasions, were documented both in narratives, account books, charters and letters. Apart from causing food shortage or difficulties in transportation (e.g. of salt), these greatest known documented drought events of medieval Hungary were blamed for weakening the country's military defence (e.g. low water-levels) and providing good opportunities for Ottoman-Turkish attacks. These great drought events sometimes occurred one year later than those of the neighbouring areas in Central Europe – a fact that can be probably explained by the bi- or multi-annual nature of dry spells (e.g. in and around 1474, 1479, 1507) that does not necessarily fit the frame of a calendar year.

Konya  Kapalı  Havzasındaki  doğal  kaynakların  etkin  ve  sürdürülebilir  bir  şekildekullanılmasınısağlamak,  tarım  faaliyetlerinde sürdürülebilirliği sağlamak amacıyla bu çalışmakapsamında; Landsat 5-TM görüntüleri yardımıyla 28 yıllık bir periyotta  bölgenin yüzey sıcaklık,  kuraklık haritaları oluşturulmuş. Proje kapsamında 1984, 1989, 1998, 2003, 2007 ve 2011 yıllarına ait  29 adet Landsat-5 TM uydu  görüntüsü temel veri kaynağı olarak kullanılmıştır. Bu uydu görüntüleri öncelikle geometrik ve radyometrik olarak düzeltilmiştir. Daha sonra, düzeltilmiş uydu görüntüleri ile 1984, 1989, 1998, 2003, 2007 ve 2011 yıllarına ait 5 tam çerçeve TM görüntüleri kullanılarak 6 yıla ait mozaik uydu görüntüleri elde edilmiştir. Elde edilen  bu görüntülerden indeks görüntülerinin oluşturulması  aşamasına  geçilmiştir.Oluşturulan Arazi  yüzeyi sıcaklığı(AYS), Bitki  Durum  İndeksi  (BDİ), Sıcaklık –Bitki İndeksleri(SBİ)değerlendirildiğinde  sonuç  olarak  Konya  kapalı  Havzasında  1984  ve  2011  yılları  arasında  yüzey  sıcaklık değerlerinin 2.00-3.00 °C arasında yükseldiği saptanmış. BDİ’ ne göre belli bölgelerde yaz kuraklığı etkisinde artış olduğu, son yıllardaki  yağışlardaki  artış  bölgenin  nefes  almasını  sağlamış  olsa  da  yeni  bir  kurak  dönemin  gelmesi  çok  muhtemel  olarak gözüktüğü söylenebilir.

This study is carried out to study the effect of Gibberellic acid (GA3) and Titanium Dioxide Nanoparticles (Nano- TiO2) on some characteristics of medicinal plant of Ocimum basilicum Lamiaceae) under drought stress. The experiment was conducted as a factorial arrangement in randomized complete block design with four replications in which A, B, C are the three factors and factor A is related to the irrigation content as fc 100%, fc 70% and fc 40% and factor B in three levels with GA3 application with concentrations of 0 (control), 250 ppm, 500 ppm and factor C with three doses of titanium nanoparticles with concentrations of 0%, 0.01% and 0.03%. The results showed that the drought stress caused to decreasing of plant biomass and the foliar relative water content, and
the increasing of catalase and the level of anthocyanin in the medicinal plant of basil, while, the application of gibberellin and titanium nanoparticles caused to improving of the negative effects of the stress.The results of the study indicated that the drought stress causes to decreasing of quantitative and qualitative characteristics of the plant. The best treatments were recognized as follows: in 100% irrigation regime, non-application of gibberellin and application of Nano-TiO2 with concentration of 0.01%; in 70% irrigation regime, the application of gibberellin with concentration of 250 ppm and Nano-TiO2 with concentration of 0.03%; and in 40% irrigation
regime, the application of gibberellin with concentration of 500 ppm and Nano-TiO2 with concentration of 0.03%.

The main objective of this report was to review available information and literature and conduct a detailed temporal and geospatial analysis of recent drought in Southern Africa. An explanation was provided for the concept and causes of drought, as well as the different types of drought prevalent in Southern Africa. A description of the progression of the 2007-2011 southern cape drought was surmised. Included is a report on factors that exacerbated the effects of this drought. Lastly, an analysis of how drought conditions may affect people in rural areas has been provided. Methodology involved an array of data sources, entailing both quantitative and qualitative data.

Indigenous knowledge is the knowledge that the people in a given community have developed over time, and continue to develop. It is based on experience, often tested over centuries of use, adapted to local culture and environment, dynamic and changing. The development of indigenous knowledge systems, covering all aspects of life, including management of the natural resources, has been a matter of survival for the people who generated these systems. Such knowledge systems are cumulative, representing generations of experience, and trial and error experiments.
Over the course of history, large number of communities developed their own culture and lifestyle that are intricately tied to nature and the local ecosystems. Indigenous knowledge is one of the products that remained for centuries, firmly inbuilt into the belief systems, myths, and folklore of society; and it expresses the local solutions. It makes decisions regarding the use of resources and environmental conservation. It helps to avoid the incidence and negative impacts of natural disasters such as drought and floods. It provides guidance on agricultural practices and food preservation, health care, and a host of other activities. It constitutes an environmental management system that is largely community-led. Enforcement of these customs and norms is often ensured by social conformity and by codified threats.

The paper presents an assessment of the temporal variability of atmospheric droughts in the Lublin region in relation to the atmospheric circulation over East Poland from 1951 to 2010. The frequency of atmospheric droughts was determined by sequences of dry periods that lasted >8 and >17 days and on the basis of the SPI index. The largest precipitation deficit was noticed in the 1980s, while atmospheric droughts occurred most often in March and October, and least often in July. Moreover, annual and monthly SPI values showed no statistically significant trends. Anticyclonic types of atmospheric circulation, in particular A, Na, NEa, Ea and SEa, were the most frequent during the dry periods. On the other hand, the least frequent were cyclonic types: C, Wc and NWc. In addition, it was found that atmospheric circulation exerts the largest influence on the variability of SPI index in autumn, and the slightest in summer.

Mozambique is affected by severe floods, droughts, and cyclones. In combination with the social and economic consequences of decades of civil war, it is also a country highly vulnerable to natural disasters. In order to reduce flood risks in the lower part of the Búzi River Basin in central Mozambique, a people-centered Early Warning System was implemented by the Mozambican government in cooperation with the German Cooperation Agency GIZ. Part of this project consists of the implementation of a flood forecasting system. This thesis was developed under this framework with the objective to support this goal. Due to data inconsistencies and gaps, procedures were developed to validate time series analysis, discard inconsistent data, and interpolate results spatially. Precipitation-runoff and hydrological flow routing were developed using the HEC-HMS model. Model parameters obtained in one sub-basin were scaled to other parts of the Búzi River Basin with less or unreliable data. Calibration was performed manually. Diverse improvements were achieved compared to existing forecasting, for instance, regarding lead time and peak flow. Better hydrological data is necessary, specially discharge measurements at high water levels and more reliable hydro-meteorological data in order to provide more accurate flood predictions. Therefore, the model should be used with caution until this data is obtained. Key Words: Búzi River Basin - Early Warning System - Búzi River - Flood forecasting - Hydrological modeling - People-centered

Farmers’ perceptions of changes in their climate are inextricably linked to the livelihood decisions that they make and their ability to bolster their adaptive capacity and reduce their vulnerability to climate variability and change. Yet research has shown that smallholder farmers’ experiences and interpretations of climate variability and change do not translate into perceptions that accurately align with the climate record and thus have considerable consequences for their ability to adapt and reduce their vulnerability to climatic stresses and shocks. Moreover, research has tended to concentrate on farmer’s experiences of weather and climate as the principal factor in the construction of their perceptions, whilst overlooking the role of non-climatic factors. The study takes a social constructivist approach and gendered perspective to investigate farmer perceptions of climate variability and change in the communal areas of agro-ecological zones II and III of Zimbabwe, the climatic and non- climatic factors that lead to the gendered construction of perceptions and the relationship that exists between farmers’ perceptions and those held by research, development and extension actors. Utilizing a mixed methods approach that integrated participatory research tools, a farmer questionnaire, in-depth interviews with farmers and a range of actors and historical climate analysis, the study found no significant change in long-term rainfall trends, but clearly significant increases in temperatures were observed. Farmer’s perceptions of temperature aligned more closely with the climate record than their perceptions of changes in rainfall parameters. Importantly, farmer’s perceptions of changes in rainfall and temperature parameters and overall belief that the climate is changing were significantly gendered, with male farmers’ perceptions tending to be more heightened and negative than those of female farmers, whose overall perceptions tended to align more closely with the climate record. Findings emphasize a number of cognitive mechanisms and mismatches that distort, amplify and attenuate farmer’s experiences of weather and climate and contribute to heightened negative perceptions of climate variability and change. The study demonstrates that these experiences contribute to farmer belief that the climate is changing to a far lesser extent than was originally assumed and that perceptions of temperature change play no statistically significant role in the construction of overall farmer belief that that the climate is changing. Further, findings illustrate the tendency of farmers to attribute changes in the environment and farming system directly to changes in climatic parameters, overlooking a host of non-climatic stressors that have complex and interrelated impacts on the communal farming system. Notably, changes in communal demographics and the broader economic environment have the ability to impact the manner in which farmers perceive weather and climate, with these factors contributing significantly to the construction of farmer belief that the climate is changing. Additionally, the role of weather and climate information was explored, demonstrating that male farmers had greater access to and trust in formal sources of information and consequently had greater exposure to inaccurate climate forecasts and emerging climate change narratives, leading to heightened expectations of climatic change. Findings demonstrate the centrality of gender in determining the ability of individuals to interact with and process experiences of weather and climate, weather and climate information, normative perceptions and mythologies that exist around past climate and agricultural production. Lastly, findings demonstrate that the absence of accurate and timely historical and short-term weather and climate information increases the potential for farmer (mis)perceptions to be incorporated into the perceptions held by research, development and extension actors, increasing the likelihood that actors will transfer misperceptions back to farmers in the work they carry out, creating a self-perpetuating cycle of misperception that contributes to farmer’s heightened negative perceptions of climate variability and change. The study highlights the importance of provision of timely historic and short-term weather and climate information to farmers and actors, as a means of reducing farmer misperception and increasing their capacity to make appropriate livelihood decisions that will reduce their vulnerability to climatic variability and change.

This study proposes the a high-resolution Vegetation Health Index (VHI) as an indicator of the water stress conditions of the vegetation cover. This index integrates satellite derived vegetation and thermal information; it is a function of the NDVI (Normalized Difference Vegetation Index, derived from Sentinel-2) and the LST (Land Surface brightness Temperature, derived from MODIS) normalized against the minima and maxima in a certain period. Successfully applied in numerous case studies (Kogan, 1995, 1997), the VHI has been already tried experimentally for African environments and conditions (Rojas et al. 2011) where it exhibited its performance, making it ready to be tested for insurance purposes. VHI drought maps were generated every 10 days at 20 m resolution for large areas in Kenya. The database is structured as a GIS capable data store for time series data with an online platform (dashboard) which offers to the identified stakeholders a drought monitoring service. The service is undergoing an in-country trail for deployment to Kenyan insurances, farmer cooperatives and Ministries in Kenya. Additional capabilities of the system include capacities analytics from of multi-temporal statistics at field level, drought early warning and agricultural consultancy.

Kuraklık İndeksleri, kuraklığın süresini ve şiddetini gözlemlemek için yaygın olarak kullanılmaktadır. Günümüzde sürekli olarak yaşadığımız iklim değişikliği, su kıtlığının (yetersizliğinin) sınırlarını zorlamaktadır. İzmir ve Aydın, deniz kıyı alanları, göller, akarsular ve yeraltı suyu gibi çeşitli su kaynaklarına sahip olan, Türkiye’nin yükselen ve nüfusu sürekli artan ve ayrıca tarımsal olarak da ön plana çıkan illeridir. Bu nedenle, kuraklığın değerlendirilmesi önemli bir yer teşkil etmektedir. Şimdiye kadar, yapılan bazı çalışmalar bulunmaktadır. Bu çalışmada, önceki çalışmalardan farklı olarak Türkiye’nin Ege bölgesindeki Büyük Menderes, Küçük Menderes ve Gediz havzalarında kuraklık özelliklerini araştırmak için 1973-2020 yılları arasında (47 yıl) toplamda 14 farklı istasyonun uzun süreli yağış ve sıcaklık kayıtları kullanılmıştır. Aynı zamanda, Standart Yağış İndeksi (SPI) ve Standart Yağış ve Evapotranspirasyon İndeksi, kuraklık modellerini araştırmak için 1, 3, 6 ve 12 aylık hareketli ortalama zaman dilimlerinde kullanılmıştır. Sonuçlar, 1 aylık hareketli ortalama endekslerinin incelenen havzalarda hemen hemen aynı sonuçları verdiğini ve genel olarak 1980’ler ve 2005-2010 yılları arasındaki kuraklığın diğer yıllara göre daha fazla olduğunu göstermiştir.
Ancak, daha uzun periyotlar olan 3, 6 ve 12 aylık hareketli ortalama periyotlarında tüm istasyonlar için SPEI ve SPI yöntemi aynı sonucu göstermemekte olup, şiddetli kuraklık dönemleri olmasına rağmen, genel ortalamada kuraklık normal seviyelerde kalmıştır.

This study presents projected drought trend by Standardized Precipitation Evapotranspiration Index (SPEI) and Standardized Precipitation Index (SPI) under RCP4.5 and RCP8.5 scenarios. The Rossby Center Atmospheric Regional Model (RCA4) datasets obtained from the Coordinated Regional  Climate Downscaling Experiment over West Africa were used for the  study for projected period between 2011 and 2100. The ability of the RCA4 to reproduce the past climate was evaluated using Climate Research Unit (CRU) dataset. Drought classification and trends in seasonal and annual variability using Mann–Kendall  trend  test  at  95%  confidence  level  were  also  examined.  The  results  show  that  RCA4  replicates  observed  climate  of  West Africa, evident by strong correlation between the output of the model and CRU dataset. Strong correlation exists between SPI and SPEI at 95% confidence level. The RCA4 model projects a distinct humid period between 2011 and 2060 and drier period from the early 2060s till the year 2100 under RCP4.5 and 8.5 pathways. Projected drought events by the two indices show that areas north of 12°N of West Africa will be hot spot area for mildly and moderately dry events, while the southern part of West Africa will witness pronounced severe and extreme dry events under the two RCPs. Under RCP4.5, SPI trend shows an insignificant increase in almost all the seasons, while the increase is significant in SPEI. At RCP8.5 scenario, SPEI projects a significant decreasing trend in drought events over the three climatic zones and in almost all seasons. The result may  be  applied  to  a  sustainable  climate  change  adaptation  plan.

Aridity is slowly lethal natural calamity for an agricultural county like Bangladesh. Due to aridity and scarcity of irrigational water the agricultural system of Bangladesh is being interrupted. De Martonne index (1923), Lang Rainfall factor (1915), Minar Moisture certainty, UNEP Arid Index (1997), Thornthwaite classification (1948), Pinna Combinative Index and Aridity index of Emberger (1932) were used to estimate the aridity of the whole country. Data from 34 meteorological station were used to reveals the aridity distribution and variation. A version of Arc GIS 10.1 was used for spatial distribution and map preparation. The study period was divided into two distinct time period of 1991-2000 and 2001-2010. The results showed that severity and distribution of aridity is in increasing pattern over the 20 years period. The lower values of all indices indicate the more arid region. The calculated values of all indices of 2010 is lower than the values of 1991, means aridity increases and disperse from 1991 to 2010. Only Embergeraridity index explore that the whole area is under humid climate because of temperature difference is very low. The most arid prone area is northwestern and some of southern part of the country. Agriculture of those regions is highly affected by aridity and that contribute to country food security.

Water Requirement Satisfaction Index (WRSI) at three different probability levels (20%, 50%, and 80%) was used to quantify drought affecting rain-fed maize production in the Free State Province of South Africa based on climate data from 227 weather stations. Results showed high spatial variability in the suitability of different areas: the southern and southwestern localities are unsuitable due to high drought incidences; the northern, central, and western regions are marginally suitable; the eastern, north-erneastern areas and a few patches in the northwest are highly suitable with relatively low drought severity. Proper choice of maize varieties to suit conditions at different localities is crucial. The Mann–Kendall test and coefficient of variation were further used to determine trends and temporal variability, respectively, in the WRSI, seasonal rainfall, and seasonal maize water requirements. Results of this analysis revealed no significant positive trends in the WRSI, no significant negative trends in seasonal rainfall, and no significant positive trends in maize water requirements , contradicting previous findings of increased drought severity. Seasonal rainfall and the WRSI showed high interseasonal variability, while seasonal maize water requirements showed low variability. In view of these observations, it is apparent that realignment of management practices is an overdue prerequisite for sustainable maize production.

Possible future climate change effects on dryness conditions in Poland are estimated for six climate projections using the standardized precipitation index (SPI). The time series of precipitation represent six different climate model runs under the selected emission scenario for the period 1971–2099. Monthly precipitation values were used to estimate the SPI for multiple timescales (1, 3, 6, 12, and 24 months) for a spatial resolution of 25 km for the whole country. Trends in the SPI were analysed using the Mann– Kendall test with Sen's slope estimator for each grid cell for each climate model projection and aggregation scale, and results obtained for uncorrected precipitation and bias corrected precipitation were compared. Bias correction was achieved using a distribution-based quantile mapping (QM) method in which the climate model precipitation series were adjusted relative to gridded precipitation data for Poland. The results show that the spatial pattern of the trend depends on the climate model, the timescale considered and on the bias correction. The effect of change on the projected trend due to bias correction is small compared to the variability among climate models. We also summarize the mechanisms underlying the influence of bias correction on trends in precipitation and the SPI using a simple example of a linear bias correction procedure. In both cases, the bias correction by QM does not change the direction of changes but can change the slope of trend, and the influence of bias correction on SPI is much reduced. We also have noticed that the results for the same global climate model, driving different regional climate model, are characterized by a similar pattern of changes, although this behaviour is not seen at all timescales and seasons .

Drought is one of the most harmful hydro climatic threats to society. Mexico has been historically affected by recurring and long-lasting droughts that have severely impacted society and the economy. Consequently, public programs and policies have been developed in order to reduce the country’s vulnerability to drought, hence the importance of identifying the spatial distribution and the dimension—even in relative terms only—of vulnerability in different regions from social, economic, and environmental perspectives. This article presents a method for obtaining indices and maps of vulnerability to drought in Mexico; indices and maps are based on a set of socioeconomic and environmental indicators that the method combines using an objective analytic procedure that identifies the most vulnerable states and municipalities from social, economic, and environmental perspectives, all of which converge in overall vulnerability to drought. The results obtained indicate that 38.9% of total Mex...