Evaluation of CMIP6 Climate Models for Climate Change Impact Assessments in Upper Awash Basin, Ethiopia

Identifying GCMs that represent the climate of a specific area is crucial for climate change studies. However, the uncertainties in GCMs caused by computational constraints, such as coarser resolution, physical parameterizations, initializations, and model structures, make it imperative to identify a representative individual or group of GCM for a climate impact study. An advanced envelope-based multi-criteria selection approach was used to identify a subset of the most appropriate future GCMs in the Upper Awash Basin. The skill accounting is based on (1) the range of projected mean changes of climate variables, (2) range of variability in climate extremes and, (3) model run performance to represent historical climate data. Statistical downscaling and bias correction were made for the selected model runs. The downscaled and bias-corrected monthly values for precipitation are expected to increase from 0.42% to 2.82% in mid-century and 0.15% to 3.79% by the end century considering the SSP4.5 scenario. For SSP8.5, it increases from 1.45% to 5.51% and 2.57% to 9.78% in the respective periods. Likewise, under the SSP4.5 forcing scenario, the monthly average air temperature projected to be warmer, which increased from 0.68°C to 1.55°C during mid-century and 0.09°C to 1.92°C end-of-century. Meanwhile, for SSP8.5, the projection indicates an increment of 0.19°C to 1.98°C under mid-century and 2.37°C to 7.00°C end-century. The projected change of future precipitation and temperature in the study basin increases the precipitation intensities, wet days and dry spells due to high-temperature increment.

Probability studies of rainfall and crop production in coastal Tamil Nadu

Studies are made of the probability of Occurrence of annual and seasonal rainfall, wet and dry spells on monthly basis throughout the year and on weekly basis during the northeast monsoon season for various stations in coastal Tamil Nadu. It has been observed that amount of rainfall received is more in the stations north of Alangudi and north of Tondi in the northeast and southwest monsoon seasons respectively at all the probability levels. However, the quantum of rainfall is more in stations south of Adiramapattinam during the hot weather period. Number of wet spells are more from July to September in the stations of north costal Tamil Nadu. During the northeast monsoon season also wet weeks are mainly confined to the stations of north coastal Tamil Nadu. Analysis of production figures of some rainfed crops shows more productivity (k8I1\a) in north than in south coastal Tamil Nadu.

The Impact of Climate Change and Variability on Small-Scale Peri-Urban Horticultural Farmers in Domboshawa, Zimbabwe

Zimbabwe is a semi-arid country reliant on regular rains (November-April). Mean annual rainfall is low, and many rivers in the drier parts of the country are not perennial. In the small-scale horticultural sector, irrigation becomes handy. Rainfall exhibits spatial and temporal variability. This scenario is characterized by shifts in the onset of rains, increases in frequency and intensity of heavy rainfall events, increases in the proportion of low rainfall years, decreases in low-intensity rainfall events, and increases in the frequency and intensity of mid-season dry spells. Drought have increased in frequency and intensity. Agriculture is the main source of income for most smallholder farmers who depend on rain-fed cropping and livestock rearing. Adaptation of agriculture to climate variability and change impacts is vital for livelihood. To develop appropriate strategies and institutional responses to climate change adaptation, a clear understanding of climate change impacts on smallholder farmers at farm-level is vital.

Gender Ideologies and Climate Risk

Although African cities are nodes of scalable solutions to climate uncertainty, adaptation efforts rarely build on the gender-climate nexus for sustainability. This article examines how gender ideologies intersect with climate risks, based on case study findings from Kampala in Uganda. Climatic hazards in Kampala include prolonged dry spells and seasonal floods; which destroy infrastructure, contaminate air and lead to unprecedented spread of cholera and malaria. Both conventional and emancipatory gender ideologies are characteristic of how the gender-climate nexus shapes adaptation at neighborhood scale. Women, as custodians of domestic hygiene, navigate the health risks of flooding through trade-offs among competing uses of their time and labour, as men comply with the masculinity code of family safety to repair flooded homes and drainages. Emancipatory gender ideologies on the other hand are manifested by women's and men's agency to adopt alternative energy sources and urban greening that have potential for sustainability.

Agroclimatic classification for assessment Of the crop potential of Karnataka

To plan cropping pattern and to bring out agricultural potential of a region, it is essential that the agro climatic classification is made on an objective and rational basis. Such an attempt has been made in this paper by devising an index called Water Availability Index (WAI). This index takes into account the distribution of the minimum water required by the crop. It utilizes the most probable number of the wet weeks for three threshold values of weekly rainfall and probability of dry spells of more than three weeks. The methodology developed is applied to dry farming tracts of Karnataka State. Using these information along with the information of the soil types and water requirement of different crops, cropping pattern can be assessed in each agro climatic zone, so that optimum use of the available moisture is made in stabilizing the crop production in the State.

A study on effective monsoon and dry spells of short return periods The Indian mountain ranges during monsoon months in two north Bengal districts

This article uses daily rainfall data (April-October) of Cooch Behar (1971-90) and Jalpaiguri (1972-90), the two predominantly rainfed farming districts of Terai zone of West Bengal, to study the, nature of different rainfall parameters of this area. It was observed that the mean date of Onset of Effective Monsoon (OEM) of this region is about one month in advance from the normal occurrence of monsoon over Kerala. However, the monsoon rains, here, retreat at about the same time with those of Kerala. Distribution of the duration of dry spell has been studied to have some idea of the nature of critical dry spells during the monsoon season. The article also examines how prolonged, on the average, are the monsoon breaks for different return periods. Expected length of dry spell (in days) for 2, 5, 10 and 20 years return periods have been estimated with the help of suitably fitted curves for each location.

Spatial variation of clouding / rainfall over southeast Indian peninsula and adjoining Bay of Bengal associated with active and dry spells of northeast monsoon as derived from INSAT OLR data

South Peninsular India (SPI) benefits largely from the rainfall (RF) realised during the North East Monsoon (NEM) season that prevails from October to December spilling over to January in some of the years. Salient aspects of clouding / RF over SPI associated with 13 NEM seasons from 2000-01 to 2012-13 have been analysed using estimates of Outgoing Long wave Radiation (OLR) at 1° × 1° resolution derived from the radiance observations in the infra-red channel onboard the geostationary operational Indian satellite (INSAT) radiometers. OLR is considered as a proxy indicator for convective activity with the value of 230 Wm-2 as the threshold for RF occurrence. Year-to-year mean OLR patterns of the NEM season along with the latitudinal and longitudinal variabilities were analysed for dry, light and active phases of NEM. Based on rigorous analysis of INSAT OLR data for the above 13 years, it has been shown that during the active phase of NEM, Coastal Tamil Nadu (CTN) receives more RF while over BoB the RF is lower and decreases sharply over interior Tamil Nadu. This is a reiteration of a similar result from an earlier study based on 3 years (1996-98) OLR data from polar orbiting NOAA satellites. The spatial variation in OLR over the latitudes of 10.5, 12.5 and 14.5° N along the longitudes of 75.5-85.5° E has revealed the feature that north of 10.5° N, values of OLR are higher with decrease in RF from south to north. During dry phase of NEM in December and January, higher OLR is observed over northern latitudes of BoB than southern latitudes. It has been comprehended that in the southern latitudes of BoB, where higher sea surface temperatures (SST) are prevalent, more moisture is generated and pumped in to upper levels of the atmosphere leading to lower values of OLR compared to northern latitudes.

Crop planning based on rainfall variability for Bastar region of Chhattisgarh, India

Analysis of long-term rainfall data (1986-2018) of Bastar region revealed decreasing trend in total quantum of annual rainfall with varying frequency and distribution. The quantity of winter and summer rains decreased drastically during 2008-18 as compared to earlier two decades (1986-96 and 1997-2007). SW monsoon rain of 2008-18 was more than past two decades, whereas NE monsoon rain changed much in quantity except during 1997-2007. During 1986-96, the pre-monsoon shower was received in April, but later two decades the shower was received in May, which supports for summer ploughing and dry aerobic seeding. The cropping period almost synchronized between 22-43 standard meteorological week (SMW) reaching 93.11 mm per week as maximum rainfall. As the probability of 20 mm rainfall decreased from 75 to 50%, the crop yield got reduced by 30%. The mid-land rice with a probability of 13.47 to 16.07 mm rain per week supported growth phase during 17-21SMW. Whereas, upland rice maturing in 90-100 days could avoid dry spells, if the rice is managed by conservation furrows at the time of sowing. The summer ploughing is preferred with more than 40 mm rain in single day during March to April for mitigating dry spells. On the other hand, preparatory tillage and sowing were performed together in support of ripening niger and horsegram under probability of 75, 50 and 25% rain through crop planning. Maize and small millets reduced yield significantly when rainfall reached 75% deficit, whereas 25% deficit rain did not affect the yields.

Spatial analysis of rainfall variability and rainfed rice crop using GIS Technique in West Bengal (India)

The rainfed areas receive mean annual precipitation in range of 500-1500 mm with high degree of variability and are beset with problems of mid-season drought and associated impacts on the crop productivity. In this paper, analysis of weekly, monthly, annual rainfall and weekly rainfall probabilities in relation to crop productivity has been carried out for all the stations of the study area in West Bengal where rain-fed agriculture is predominant. However, duration of dry spells and its probabilities, climatic derivatives like commencement and cessation of rainy season, length of growing period (LGP) and estimates of water balance parameters have been carried out, in respect of all blocks in the identified three districts in West Bengal. The mean productivity during kharif season indicated that, highest productivity values of 3 to 3.5 t/ha are noticed in the block of central districts of Burdwan, Bankura, Birbhum, Hoogly districts. Perhaps, irrigation facilities in these districts might have helped in arriving at such high productivity rates. Low productivity of 1 to 1.5 t/ha have been noticed in two to three blocks of South 24-Paraganas and in Jalpaiguri districts. The productivity levels of northern districts, viz., Jalpaiguri, Coochbehar, West Dinajpur, South 24-Paranagas vary from 1.5 to 2.0 t/ha. The lowest productivity of 11.28 q /ha in Jaldha and 14.89 q /ha in Manbazar in 1996 can be due to heavy rainfall conditions in June and again in August. The mean productivity pattern of rice crop during kharif season in identified districts was analyzed with respect to occurrence of number of dry spells at different growth stages and average MAI values. The productivity was also related to monthly rainfall (July) and correlations have been mentioned for Jaldha block (0.22) and Manbazar block (0.64). The highest productivity of 2-3 t/ha are recorded in hot sub-humid to humid regions of West Bengal where LGP vary from 150 to 200 days. From the study of the probability of dry and wet spells and MAI during different crop phenophases, the most vulnerable phases can be identified in each region.