sidered as the most rainfall-dependent of all human ac- tivities [6,7]. This vulnerability is enhanced for the less economically developed countries in the tropics that, in many cases, are exposed to high climate variability at different spatial-temporal scales. Of particular impor- tance and relevance to Kenya is the El Niño Southern Oscillation (ENSO) phenomenon that has been linked to climate variability in many parts of Sub-Saharan Africa where unique and persistent anomaly patterns have been detected in the rainfall over parts of southern Africa, eastern Africa, the Sahel region during periods of strong and persistent ENSO events [8-12]. The Sub-Saharan Africa is the only region world-wide where food produc- tion per capita has decreased over the last twenty years . Staple crop production occupies an important place in government policies, and one of the top priorities has become the stabilization of crop yields  in the con- text of the long-term drought of the last decades  and the uncertainties of the global climate change . With increased capability to forecast ENSO events well in advance [17-19], there has emerged a growing convic- tion and interest in using climatic information in deci- sion-making process, especially during crop production [20,21]. The assumption we explore here is that the
Generally, rainfall onset, cessation, distribution, and amount have considerable effect on maize yields and food security particularly under rain-fed conditions com- mon in lower eastern Kenya. Rainfall distribution and amount is of paramount importance to rain-fed agricul- ture prevalent in Kenya’s ASALs. The impact of this variability can be very momentous on crop yields espe- cially under rainfall agriculture in the ASALs [7, 16]. The results have shown that the less the rainfall variabil- ity, the less maize yield anomalies thus the more reliable the rain is for maize production. The results appear to support the view of  that higher variations in rainfall above the mean eventually leads to fluctuations in maize yields and thus food insecurity. Within the ASALs which are more dependent on rain-fed agriculture variable rains, increasing temperatures and high evapotranspir- ation will adversely affect maize yields. As recently dem- onstrated  maize yields in Africa at lower altitudes is likely to fall by 20–50 % because of drying and warming as a result of climate change. In many places in lower eastern Kenya recent studies have indicated that there is an increased warming and potential evapotranspiration thereby worsening stress . In terms of adaptation op- tions at household level, it means that the farmers have to turn planting drought and heat tolerant crops.
Access to formal credit is almost non-existent among smallholder farmers in Tharaka sub-county. The most common source of credit was where members make monthly contribution to one another on rotational basis-locally referred to as Merry-go-round . Limited access to credit can be explained by three factors. To smallholder farmers of semi-arid Tharaka, borrowing money for farming does not make economic sense as chances of crop failure are much higher than success. Secondly majority of the farmers are poor and therefore lack collateral, including land title deeds. Third, the sub-county had no operational bank by the time of study. For residents who had bank account, they travel long distances on all-weather roads to Meru or Chuka towns in neighbouring sub-counties. The construction of Kathwana-Chiakariga and Marimanti-Mitunguu roads is expected to open up the sub-county. It is hoped that major banks will open branches and other essential services will be established in the sub-county. There is need for formulation and implementation of pro-poor policies which should include pro- vision of short term production credit as was found in Ghana . Often, access to credit makes it possible to make climate change adaptation decisions. A case in point was in Ethiopia where access to credit had a positive and significant impact on the likelihood of adopting soil conservation, change of planting dates and use of irrigation . In Kenya, there are several efforts by the Ministry of Agriculture and other development agencies in providing credit and farm inputs to farmers. Unfortunately, these efforts are emphasized in high and medium po- tential areas than in semi-aridlands.
Out of the country’s total area (1.87 million km2); 1.13 million km2 (60.2%) is desert and semi desert; the remaining 0.74 million km2 (39.8%) is divided between low rainfall savanna 500 mm of annual rainfall) and the rich savanna (over m rainfall) that extends extensively in the Republic of South Sudan (FAO and UNEP, 2011). Impacts of climate change are also evident in Sudan. Rainfall records from El Fashir, North Darfur, show a marked drop beginning with drought in 1972. More significantly, droughts have become more frequent as 16 of the 20 driest years recorded have occurred since 1972. Climate change models also predict a reduction in the length of the growing period of more than 20%. Environmental stresses mainly affect the rural sector of arid zone which covers about 70% of the country’s total, accommodates about 70% of the country’s population, and where most of agricultural production takes place. Environmental stresses have been associated with onomic problems important of which are poverty, famine, population instability and proliferation of based conflicts. The drought and famine of 85 had been associated with devastating impact on the INTERNATIONAL JOURNAL OF CURRENT RESEARCH
(FEWS NET, 2012) reported over 10 million people to suffer from chronic food insecurity and poor nutrition in 2012 which is about one third of the 39 million people in Kenya reported to suffer from chronic food and nutrition insecurity (FEWS NET, 2013). This was demonstrated in the 2012 military recruitment exercise which experienced a shortage of recruits due to the negative impact of the endemic food shortages on the growth of youths in some of the arid and semi-aridlands (ASALs) in Kenya (Daily Nation Newspaper, 20 th August, 2012). While this could be attributed to many factors; the most affected areas were those that suffer frequent food shortages and depend on food aid due to drought. Therefore, adverse climatic conditions inhibit food availability (World Food Programme, 2009). Adewuyi (2002) identified climate change leading to adverse and erratic weather patterns to inhibit food security in Nigeria. Similarly, inadequate and excessive rainfall, pests and diseases are the main causes of household food insecurity in Uganda (Morse et al., 2009). Sseguya (2009) attributed decreased production per unit area of land in Uganda to erratic and adverse weather conditions. Therefore, living in a region characterized by average annual rainfall, humidity, cloud cover and high day temperature in rural Nigeria increases the likelihood of being food secures (Oni and Fashogbon, 2012). Whereas rural Central, a high rainfall zone in Kenya has consistently reported the least food insecurity (31.4%), the most food insecure has been the North Eastern Kenya at 66% to Lower Eastern Kenya at 45.2% (GOK, 2006). Therefore, food security varies by agro–climatic conditions.
Erratic rainfalls and increasing temperatures are the most serious global problems associated with climate change. They are considered to be some of the most serious threats to sustainable development with adverse impact on the environment, human health, food security, economic activities, natural resources and physical infrastructure (Jiri et al., 2014). The arid and semi-aridlands (ASALs) are hardest hit by the above-mentioned problem. It accounts for more than 40% of the world’s land area and are home to over two billion people, of whom 325million are in Africa. Yet they are among the regions in the world where climate change impacts on ecosystems, livelihoods and human health are potentially the greatest (IPCC, 2014) as cited by (Nyasimi, 2014). The main challenge that confronts farmers in arid and semi-arid areas of Sub-Saharan Africa is managing unreliable rainfall (Tumbo et al., 2010). In Kenya’s ASALs, for example, more than three million pastoralist households are regularly hit by drought, costing
Abstract: Aridity is a severe threat to the ecological environment and it leads to desertification. Aridity has become a more serious hazard to agricultural countries like Pakistan, followed by socio-economic problems. Pakistan is an agrarian country and Punjab province of Pakistan is known as the basket of grain for its population due to its fertile lands and lush green fields. Less or no rainfall can convert any land or region from humid to semi-arid and semi-arid to arid land. Deficiency of moisture also defines arid conditions of any region. Hence, in case of Punjab, aridity is a severe threat to halt the use of full potential of its agricultural land resources. There is an irresistible need to comprehensively assess aridity in Punjab at different time scales and to formulate necessary arrangements and action plans to face this issue on sound footing. Remote sensing can be used to accurately measure aridity on local, regional and global scales. Multi-temporal images of Moderate-resolution Imaging Spectroradiometer (MODIS) MOD13Q1 and MOD11A1 of Punjab province are used for aridity assessment. In this study attempt was made to demarcate arid areas of Punjab in the simplest possible form using different vegetation indices and land surface temperature. Maps are developed by using normalizeddifferencevegetationindex (NDVI), transformed normalizeddifferencevegetationindex (TNDVI), soil adjusted vegetationindex (SAVI) and land surface temperature (LST). A weighted overlay analysis of these indices was also done for further comprehensive analysis of aridity. The results indicate that aridity is more in southern Punjab due to increased temperature and reduced precipitation and in northern regions of the province, aridity is developing especially in those areas, which were semi humid or semi-arid in the past.
DOI: 10.4236/ijg.2019.105033 579 International Journal of Geosciences and March. Evaporation rate constitutes about 90% of the aggregate rainfall . Average predestined infiltration rate is about 4% - 10%  . The climate characteristic of eastern highlands in Jordan is hot in summer and moderate in winters. Low quantities of precipitation happen through comparatively wet months from October to May and they are normally related with the inland steam transport from the Mediterranean Sea. The annual moderate temperature is 17.3˚C. The daily moderate temperature amplitude is from about 8˚C in the winter to 25˚C in the summer. Monthly evaporation average varies from about 85 up to 90 millimeters in December and January to 210 millimeters in April, and up to 300 millimeters in May , and the evaporation extent 567 millimeters in August . The atmospheric dust, arid climate and low precipitation impact the preci- pitation water quality thus growing salt content  .
filter can be parameterized to extract objects (in our case crown canopies) from their surroundings and from larger objects. The feature termed “mean” was used - the objects have grayscale values depending on their distinctiveness - which was rescaled between 0 and 100, resulting in a quantita- tive estimate of the areas covered by canopies. Each image was visually screened and images domi- nated by obvious mis-estimations (strong under- or overestimation) were discarded. The final values represent the subpixel woody coverage, with 100 being fully covered and 0 free of any green leaved woody vegetation. The advantage of this weighted method over a binary tree/no tree classification is that a sub-pixel coverage (i.e. small crowns and edge pixels) receives a lower weight, thus pre- venting overestimation (Extended Data Figs 2,3). Moreover, using such weighting emphasizes larg- er canopies, which makes the product more robust against a rapidly changing (fire, field clearing, etc.) bush layer, which receives a lower weight. Burned areas were manually clipped to keep only high quality training images. In total, 219 images were kept. The accuracy of the method was cali- brated and tested with field data (144 plots) from Senegal. The squared field plots are small (50 x 50 m) and include canopies of all size classes thereby being well suited to validate the VHR prod- uct.
At only one location the water balance could be es- tablished (Vudee sub-catchment), where the reconstruc- tion of the hydrograph is relatively certain. The total volume of the rainfall in the upper catchment (Upper- Vudee (area 14.2 km 2 ), 82.1 mm d −1 , Ndolwa (area 8.4 km 2 ) 77.5 mm d −1 , and Mchikatu (area 3.2 km 2 ) 102.7 mm d −1 ), amounted to 2.15*10 6 m 3 . The volume of runoff observed at the weir site, during the first 24 h was estimated to 0.19*10 6 m 3 , which corresponds to 9% of the rainfall (vol- ume under the hydrograph of Fig. 6; note that the uncer- tain estimation of the peak discharge does not significantly change the volume as the duration of the peak flow was very short). As the amount of evaporation during the day itself can be assumed less than 5% of the recorded rainfall (<4 mm d −1 ), the storage in the (upper) catchment should have increased substantially. This is demonstrated by the in- crease of the base flow observed during the subsequent pe- riod, which increased from about 15 l s −1 before the flood to 75 l s −1 in the subsequent season. The increased storage discharged an approximate 0.54*10 6 m 3 (34% of the rain- fall) in the following season, calculation based on the out- flow of a linear reservoir. The balance (57%) is made up by evaporation in the period following the flood and perco- lation to the regional groundwater system (Mul et al., 2007). Having a large part of the rainfall contributing to slow pro- cesses is not uncommon for flash floods (Gaume et al., 2004; Belmonte and Beltran, 2001), however, 90% is very high, which indicates that the downstream effects could have been much worse. The uncertainties of this water balance analy- sis are linked to the assumptions of calculating the different components: i) uniform rainfall distribution in the three up- stream areas of the Vudee sub-catchment; ii) the assumption of steady flow at peak discharge and iii) the assumption of a linear reservoir for the base flow calculation.
The pH values vary from 6.85 to 7.54 (mean value of 7.2 ± 0.04) during wet and 6.73 to 8.01 (mean value of 7.4 ± 0.08) in dry seasons. These levels however show significant (P=0.003, T=3.416) seasonal variation. The slight difference in mean pH value is due to dilution from rain water and the stirring effect of incoming surface runoff from streams and agricultural farms resulting in mixing of water in canal. High temperatures and decomposition of organic matter during dry season decrease the amount of dissolved oxygen but increase the amount of carbon dioxide which reflects on high levels of carbonates and bicarbonates to show high pH levels. Similar observation was reported in Jebba lake Nigeria .
A common vegetation pattern found in arid and semi-arid ecosystems, usually referred to as spotted or stippled, con- sists of dense vegetation clusters that are irregular in shape and surrounded by bare soil (Lavee et al., 1998; Aguiar and Sala, 1999; Ludwig et al., 1999). Another common pattern is banded vegetation, also known as “tiger bush” in Africa and “mogotes” in Mexico, in which the dense biomass patches form bands, stripes or arcs (Aguiar and Sala, 1999; Ludwig et al., 1999; Valentin et al., 1999; d’Herbes et al., 2001). Banded vegetation is usually aligned along contour lines and is effective in limiting hillslope erosion (Bochet et al., 2000). The bands favor soil conservation by acting as natural bench structures in which a gently sloping runoff zone leads downs- lope onto an interception zone (Valentin et al., 1999). Fig- ure 1 displays a schematic diagram of a banded system show- ing the redistribution of water from bare patches (source areas) to vegetation patches (sink areas). Banded patterns commonly act as closed hydrological systems (Valentin and d’Herbes, 1999), with little net outflow and sediment com- ing out of the system (e.g. at the bottom of the hillslope or catchment outlet). The effect of spotted vegetation on ero- sion is more complex and depends on the connectivity of the bare soil areas. Wilcox et al. (2003) reported the results from the interactions between runoff, erosion, and vegetation from an experimental study in an area with sparse vegetation cover (spotted vegetation) in New Mexico. They concluded that the
In creating leverage for conservation through income generating or enhancing opportunities, NRT focuses on developing wildlife tourism in community conservancies and on enhancing access to markets and micro-inance for existing livelihoods. To begin with, NRT’s approach to wildlife tourism mainly involves facilitating investment in safari camps and lodges through a range of ownership, management, and beneit distribution arrangements. Il Ng’wesi, for example, is owned and operated by Il Ng’wesi members – members that range from local politicians to individuals with diverse livelihood portfolios to strictly pastoralist households comprised of men and women. The NRT suggests that this ownership model affords communities the greatest degree of autonomy over decisions related to wildlife tourism and the revenues it generates. However, tourism ventures might also be community-owned but privately managed, such as Tassia in Lekurruki. In some cases, lodges are both owned and operated by private companies. The NRT sees itself as playing a mediating role of an ‘honest broker’ in its efforts to foster community-private sector partnerships in community conservancies while ensuring transparency and consensus in negotiations (NRT 2015b). As the advantages and disadvantages of wildlife tourism have already been discussed in relation to the management of revenue distribution and use in community conservancies, this section focuses on the management of conservation enterprises designed to generate income and livelihood opportunities for pastoralists through CBNRM.
Application of farm yard manure 5t/ha and 20kgN/ha enhanced vegetative growth resulting to differences in treatment combinations with fertilizer application compared to treatment combinations where fertilizers were not applied. In addition, farm yard manure and nitrogen fertilizer improved the nutrient levels in the soil. Nitrogen plays a key role in vegetative growth because it’s involved in protein synthesis which promotes plant growth (Hassan et al., 2010). The improved soil moisture in flat bed planting led to increased vegetative growth during the short rains 2015. The maize mono crop had reduced plant density which in turn lowered competition for growth resources hence better vegetative growth (Karuma et al., 2014). During the long rains 2015 when the rainfall amount was low, treatment combination with tied ridging, 20kgN/ha in maize mono crop (W2xF3xC1) recorded the highest values for vegetative growth. This is probably because tied ridges were able to effectively conserve the little rain water which was available. Similarly, application of 20kgN/ha resulted to higher vegetative growth. This could be explained by the fact that, nitrogen was readily absorbed and taken up by the plant. However, treatment combinations with application of farm yard manure 5t/ha whether under tied ridges or flat bed planting resulted in reduced vegetative growth during long rains 2015. This could be associated with the fact that, the amount of moisture in the soil was not enough for farm yard manure mineralization to take place. Therefore, the effect of farm yard manure was not realized.
Vegetation indices (VIs) were first developed in the 1970s to monitor terrestrial landscapes by satellite sen- sors and have been highly successful in assessing vegetation condition, foliage, cover, phenology, and processes related to the fraction of photosynthetically active radiation absorbed by a canopy  and   reported that satellite-based remote sensing is a robust, economic and efficient tool for estimating actual ET and devel- oping crop coefficient (K c ) curves. This technique can cover hundreds of sampled fields at a time so that large
ABSTRACT: The present study was conducted in a semiarid region of Karnataka. The study discusses the phytoplankton diversity of the Gogi lake ecosystem. A standard methodology was followed in conducting to complete this study and samples were collected at different points from the lake ecosystem located at the core area of the proposed uranium mining site. Through a field survey, twenty one species of phytoplankton were recorded coming under four classes viz., Bacillariophyceae(8), Chlorophyceae(7),Cyanophyceae (5) Charophyceae (1) and twelve families and Fragilariaceae (4), Bacillariaceae (3), Zygnemataceae(3), Desmidiaceae (2), Oscillatoriaceae (2), Melosiraceae (1), Cladophoraceae (1), Scenedesmaceae (1), Microcystaceae (1), Nostocaceae (1), Phormidiaceae (1), Characeae (1). The data were collected over two seasons- March to May and September to November -2012. A total of 21 species were recorded from the study region of which 10 species were recorded during March to May, while 02 species from September to November, nine species were recorded.
Drought and salinity constitute major environmental constraints which considerably limit plant production, especially in arid and semi-arid zone (Apse et al., 1999). Under these hostile environments, plant species such as acacias (Family Fabaceae, subfamily Mimosoideae), are of major interest for soil remediation due to their adaptive capacity. Among Acacia species, A. seyal (Del.) a typical Sahelian tree, is a nitrogen-fixing species, belonging to one of over 60 African acacias. Native of the Senegal to Sudan Sahelian zone, A. seyal combines tolerance of periodically inundated heavy clay soils with major roles in fuel and fodder production in the southern edge of the Sahara desert (Hall, 1994). Tree, leaves and shoots provide forage, and wood is particularly used for charcoal. The branches are used for fencing and the fruits are often lopped by herders when forage decreases in dry season.
25 field of systems dynamics and sustainability management as advocated in several previous studies (Fisher et al, 2013; Enfors, 2013; Young, 201; Duit et al, 2010; Saysel et al, 2002). While the model itself may not yet be developed for applications in the real world, its underlying principles can be useful in educating for sustainability analysis. Pedagogically, our model can become an educational tool and the lessons from ‘playing’ or using Sueland can help planners and modellers in preparing for different scenarios. Analysing past events such as water crises or energy shortages through the lens of our model would bepedagogically useful. When environmental limits are visible and threatens laissez-faire consumption, superfluous consumption should likely be cut via intervention. Then, consumption that has high impact (collectively or individually) would also be pushed to reduction.
The length of procured plant parts was normally 0.3 to 0.7 cm sometimes reaching 1 cm. The volume of food reserved in the termite nest depended on the year season. In autumn, the food mass in a chamber was 4-10 g (Fig. 2). In spring (April), the total food reserve decreases, as compared with autumn making 0, 5-2, 0 g. Quantitative changes in food in autumn and spring evidence that in winter termites feed on the stock in cells, thus, the anabiosi is not complete. Plant residues in termite alimentary cells in their natural habitats (arid and semi- arid zones) and in the terrain of semi-arid region adjacent to antropocenoses, as well as in areas damaged termites were analyzed to identify that the composition of the termite food depends on the vegetation growing nearby their nests, as well as on building materials shown in facilities as per the Table 3. Under natural habitats, termites do not reserve all species of biotope plants we have discovered, but only certain species (Table 3). So, it is seen in Table that termites preferred to stock residuals of such plants as camelthorn (Alhagi pseudalhagi), various species of saltwort (Aeluropus littoralis, Salsola sogdiana, S. orientalis, S. arbusculiformis, S. folios), small beet Alyssum turkestanicum, Frosted orach (Atriplex cana) and shoreweed (Aeluropus littoralis). In termite areals neighboring to natural habitats, fragments of both cultivated and wild plants were revealed in cells. Among domestic plants, we identified stems, leaves and seeds of wheat (Triticum durum.), maiz