Core-shell-embedded Mesoporous Silica Capsules for Atmospheric Water Harvesting

A one-step ultrasonic mechanical method was used to synthesize a kind of atmospheric water harvesting material with high water harvesting performance in a wide relative humidity(RH)range,especially at low RH(RH<40%),namely,mesoporous silica capsule(MSC)with core-shell structure.Transmission electron microscopy(TEM),nitrogen adsorption and other characterization techniques were used to study the formation process of nano-microspheres.A new mechanism of self-adaptive concentration gradient regulation of silicon migration and recombination core-shell structure was proposed to explain the formation of a cavity in the MSC system.The core-shell design can enhance the specific surface area and pore volume while maintaining the monodispersity and mesoporous size.To study the water harvesting performance of MSC,solid silica nanoparticles(SSN)and mesoporous silica nanoparticles(MSN)were prepared.In a small atmospheric water collection test(25℃,40%RH),the water vapour adsorption and desorption kinetics of MSC,SSN,MSN and a commercial silica gel(CSG)were compared and analyzed.The results show that the MSC with mesoporous channels and core-shell structure can provide about 0.324 gwater/gadsorbent,79%higher than the CSG(0.181 gwater/gadsorbent).It is 25.1%higher than that of 0.259 gwater/gadsorbentof un-hollowed MSN and 980%higher than that of0.03 gwater/gadsorbentof un-hollowed SSN.The material has a large specific surface area and pore volume,simple preparation method and low cost,which provides a feasible idea for realising atmospheric water collection in arid and semi-arid regions.

Water harvesting experiences from the southern and eastern Africa rainwater network

This paper shares experiences of the southern and eastern Africa rainwater network on rainwater harvesting.It also shares the lessons drawn from policy research awareness creation and networking building of national networks and assessment of promising water harvesting techniques in the Sub-Saharan Africa.The concerted promotional effort of the southern and eastern Africa rainwater network has resulted in the general acceptance of rainwater harvesting as a viable option for boosting domestic water supply agricultural production and environmental sustainability.To date twelve nationally registered rainwater harvesting associations have been established which are providing leadership and capacity building in rainwater harvesting.Governments and donors are also aligning their policies towards providing increased financial institutional and technical support for upscaling rainwater-harvesting techniques. This paper concludes that diligent land and water management is necessary for yielding the highest benefits from rainwater.In addition to enabling policies and institutions there must be ample budgetary support to increase adoption of the technology.

The Use of AHP within GIS in Selecting Potential Sites for Water Harvesting Sites in the Azraq Basin—Jordan

The identification of potential sites for water harvesting is an important step towards maximizing water availability and land productivity in the arid and semi-arid areas. This research aimed to select the optimum sites for water harvesting in the Azraq basin of Jordan through the use of GIS techniques. The Azraq basin is characterized by flash floods that involve large quantities of runoff. The selection criteria in this research were based on six parameters identified based on an extensive literature review. Five experts were then asked to evaluate the importance of each criterion. The consistency ratio between the experts opinions was evaluated using the pairwise comparison method and a final weight was computed for each criterion. A water harvesting suitability map was then generated following the weighted linear combination (WLC) method. The sites that are not suitable for water harvesting within the study area were identified and eliminated following the Boolean method, and final water harvesting suitability map was generated. Finally, the findings of this research can be used to assist in the efficient planning of the water resources management to ensure a sustainable development of the water in Jordan and in other areas suffering from water shortages.

Evaluation of rainwater harvesting and shrub establishment methods for sustainable watershed management in northern Afghanistan

Watershed rangelands in Northern Afghanistan provide various ecosystem services that support the local people's livelihoods,but they are now highly degraded essentially due to the continuous high grazing pressure and recurrent droughts.Effects of shrub establishment method enhanced by water harvesting techniques to rehabilitate degraded rangelands have not been well addressed.The main goal of this study was to evaluate the impact of direct seeding and transplanting of seedlings in combination with semi-circular bunds on growth,yield,and survival rate of four shrub species(Atriplex halimus,Atriplex nummularia,Atriplex lentiformis,andMaireana brevifolia)under semi-arid conditions of Sayyad village,Khulm watershed.Survival rate(%),plant height,width,and plant length(cm)and plant cover(%)were measured for each plant over five occasions.A non-destructive reference unit was used to estimate biomass production.The results showed that growth attributes and biomass production of shrubs were consistently greater in the transplanting compared to direct seeding.On average,the plant length,width,height,volume,cover,and biomass production of transplanted shrubs were greater than direct-seeded shrubs by 24.3%,8.6%,8.7%,121.5%,13.8% and 34.1%,respectively.Biomass production of transplanted seedlings was the highest for A.nummularia(1313.5 g DM/plant)and A.halimus(800 g DM/plant).There was a strong correlation between plant biomass production and plant volume(R^(2)_(Plant volume)=0.88)for the shrub A.nummularia,indicating that plant volume is a key variable for assessing biomass production for this species.Additionally,the survival rate of M.brevifolia was 100% in both planting methods,suggesting that based on better survival this halophytic plant has great potential when restoring degraded rangelands.Collectively,on the basis of better growth rates,yield,and survival,transplanting A.nummularia andA.halimus may enhance shrub establishment and contribute to the rehabilitation of sloping semi-arid degraded areas of Northern Afghanistan.

Round-the-clock water harvesting from dry air using a metal-organic framework

Harvesting water from the atmosphere is an important process to solve the extreme lack of water resources in arid regions. Adsorption-based atmospheric water harvesting(AWH) takes advantage of solar thermal energy to harvest water from air. This technique is particularly suitable for arid regions characterized by low humidity and an abundance of sunshine. Nonetheless, under low humidity conditions, AWH is highly dependent on water-adsorbing materials exhibiting excellent performance. In this work, a metal–organic framework(MOF), namely [Zn_(2)(bpy)(btec)(H_(2)O)_(2)]·2H_(2)O, also denoted as MWH-1, was investigated for application in water harvesting under low humidity conditions(<20%). Notably,MWH-1 displayed outstanding water and thermal stability. At temperatures of 293–333 K and low pressure, activated MWH-1a exhibited competitive water uptake(relative humidity(RH) = 5%,uptake>200 cm^(3)·cm^(-3);RH = 10%, uptake >250 cm^(3)·cm^(-3)). This ensured effective water harvesting at high temperatures during the day. In situ powder X-ray diffraction and Fourier-transform infrared analyses confirmed the sensitive water adsorption process of MWH-1a. The X-ray single-crystal study further demonstrated that single-crystal structures could be completely restored following water harvesting.MWH-1 showed good structural stability and enabled water harvesting under low humidity and high temperature conditions. Thus, it has the potential for application in round-the-clock water harvesting in extremely arid regions.

Multivariate MOF for optimizing atmospheric water harvesting

Atmospheric water harvesting offers a powerful and promising solution to address the problem of global freshwater scarcity.In the past decade,significant progress has been achieved in utilizing hydrolytically stable metal-organic frameworks as recyclable water-sorbent materials under low relative humidity,especially in those arid areas.Recently,Yaghi's group has employed a combined crystallographic and theoretical technique to decipher the water filling mechanism in MOF-303,where the polar organic linkers rather than the inorganic units of MOF are demonstrated as the key factor.Hence,the hydrophilic strength of the water-binding pocket in MOFs can be optimized through the approach of multivariate modulations,resulting in enhanced water harvesting properties.

Influence of Water Harvesting Practices on Farmer＇s Productivity in Semi-Arid Areas of Nigeria

Rain water harvesting practices and their effects on the productivity of farming systems in the semi-arid areas of Nigeria have been investigated using participatory rural appraisal （PRA） technique. There was no direct water harvesting interventions by government agencies in the area. Farmers take advantage of naturally existing depressions and abandoned burrow pits close to their farmlands to harvest rain water for surface irrigation using petrol engine pumps. The reservoirs surveyed were found to be grossly inadequate in the drought period. Water budget analysis revealed that evaporation and seepage losses from reservoirs were high in both agro-ecological zone considered. The application of rain water harvesting practices was found to have increased farmers income by 61% and 125% in the Sahel and Sudan Savannah agro-ecological zones, respectively. Governments at all levels in these areas need to support these farmers in order to boost their production to achieve food security in these drought prone areas. Farmers lack timely access to farm credit and agricultural inputs; the indigenous water harvesting practices identified need to be enhanced with the aid of agricultural engineering extension services.

Planning of Cost Effective Water Harvesting in a Sub Basin of the Subarnarekha River in the State of West Bengal, India

Development and judicious management of available water resources play a key role for economic upliftment of any region. The agricultural pattern and social and demographic status in the upper basin of the Dulung Nala Stream （a tributary of the Subarnarekha River） in the western part of the State of West Bengal, India, reveals growing demand of water in the basin. The paper reports different management plans involving different types of water harvesting structures （and associated different types of water distribution systems） and different crop combinations and with benefit/cost ratios varying from 1.3 to 11.2 for the basin. The study points out that the judicious choice of both the water harvesting structure as well as the water distribution system is important. Proper planning of crop pattern is also to be emphasized for reaping maximum benefit. It further emphasizes that cost- benefit ratio cannot solely govern the choice of structure and that maximum utilization of catchmental water and thus enhancement of agricultural output （and also economic return from the catchment） i.e. quantum of benefit is also important. The water harvesting structures proposed in this study can be implemented in other semi-arid regions of India having almost the same climatic and socio-economic conditions.

Efficient air water harvesting of TpPa-1 COFs@LiCl composite driven by solar energy

Adsorbent-assisted air water harvesting(AWH)may help alleviate the current global freshwater scarcity crisis.However,the weak sorption capacity of various adsorbents and the high energy required to release water are two long-standing problems.Herein,we propose a class of green and clean adsorbent,TpPa-1@LiCl composite,whose sorption capacity is greatly improved to 0.37 and 0.80 g g^(-1)under 30%and 90%relative humidity(RH),respectively,and which has excellent stability,showing only a slight decrease(0.79%)after 10 sorp-tion–desorption cycles(1400 min).This TpPa-1@LiCl composite can reach equilibrium within 2 h and undergo complete desorption in 30 min under air mass 1.5 G irradiation.A corresponding solar-driven AWH device can complete up to 4 sorption–desorption cycles per day,with each cycle capable of collecting 0.34 g g^(-1)water without additional energy input,which implies TpPa-1@LiCl composite has the potential for achieving sorption-assisted AWH with high efficiency and rapid cycling.

Recent Progress of Atmospheric Water Harvesting Using Metal-Organic Frameworks

Atmospheric water harvesting based on vapor adsorption is a newly emerged and potential technology to supply portable water for arid areas.To efficiently harvest vapor from the air,sorbents are required to have conside-rable adsorption capacity,easy regeneration and high stability.With the advantages of porous structure,tunable pore size and tailorable hydrophilicity,metal-organic frameworks(MOFs)have demonstrated excellent performance in vapor adsorption and water generation.In this review,we first discuss the degradation mechanisms of MOFs exposed to water and summarize the structure-stability relationship;by centering on the adsorption isotherms,the connection between the structure of MOFs and the water adsorption property is illuminated;finally,some prospects are suggested in order to push forward the progress of this technology.

Effects of Ridge-Mulching with Plastic Sheets for Rainwater-Harvesting Cultivation on WUE and Yield of Winter Wheat

A field experiment was conducted in a manural loesial soil in middle of Shaanxi Province ofChina, a sub-humid area prone to drought, to study the effects of rainwater-harvestingcultivation on water use efficiency (WUE) and yield of winter wheat. Ridge-furrow tillage wasused, the ridge being mulched by plastic sheets for rainwater harvesting while seeding in thefurrows. Results showed that from sowing to reviving stage of winter wheat, water stored in 0-100 cm layer was significantly decreased whereas that in 100-200 cm layer did not change.Compared to the non-mulching, plastic mulch retained 6.5 mm more water as an average of the twoN rate treatments, having a certain effect on conservation of soil moisture. In contrast, atharvest, water was remarkably reduced in both the 0-100 cm and the 100-200 cm layers, andmulched plots consumed 34.8 mm more water as an average of the two treatments: low N rate (75kg N ha-1) with low plant density (2 300 000 plants ha-1) and high N rate (225 kg N ha-1)with highplant density (2 800 000 plants ha-1), in 0-200 cm layer than those without mulching, the formerbeing beneficial to plants in utilization of deep layer water. Mulching was significant inharvesting water and in increase of yield. Mulched with plastic sheets, biological and grainyields were 22.5 and 22.6% higher for the average of the high N rate than for the low N rate,and the high N rate with low plant density was 29.8 and 29.1% higher in both biological andgrain yields than that of the low N rate with low plant density. With high N rate and high plantdensity, the mulched biological and grain yields were 39.5 and 28.9% higher than the correspondingtreatments without mulching. Of the treatments, that with high N rate and low plant density wasthe highest in both biological and grain yields, and the water use efficiency reached 43.7 kgmm-1 ha-1 for biological yield and 22 kg mm-1 ha-1 for grain yield, being the highest WUE reportedin the world up to now.

Impact of Forestry Interventions on Groundwater Recharge and Sediment Control in the Ganga River Basin

Water related services of natural infrastructure will help to combat the risk of water crisis, and nature-based solutions involve the management of ecosystems to mimic or optimize the natural processes for the provision and regulation of water. Forested areas provide environmental stability and supply a high proportion of the world’s accessible freshwater for domestic, agricultural, industrial and ecological needs. The present work on “Forestry Interventions for Ganga” to rejuvenate the river is one of the steps toward the Ganga River rejuvenation programme in the country. The consequences of forestry interventions for Ganga will be determined on the basis of water quantity and water quality in the Ganga River. The study conservatively estimated the water savings and sedimentation reduction of the riverscape management in the Ganga basin using the Soil Conservation Service Curve Number (SCS-CN) & GEC, 2015 and Trimble, 1999 & CWC, 2019 methodologies, respectively. Forestry plantations and soil and moisture conservation measures devised in the programme to rejuvenate the Ganga River are expected to increase water recharge and decrease sedimentation load by 231.011 MCM·yr-1 and 1119.6 cubic m·yr-1 or 395.20 tons·yr-1, respectively, in delineated riverscape area of 83,946 km2 in Ganga basin due to these interventions. The role of trees and forests in improving hydrologic cycles, soil infiltration and ground water recharge in Ganga basin seems to be the reason for this change. Forest plantations and other bioengineering techniques can help to keep rivers perennial, increase precipitation, prevent soil erosion and mitigate floods, drought & climate change. The bioengineering techniques could be a feasible tool to enhance rivers’ self-purification as well as to make river perennial. The results will give momentum to the National Mission of Clean Ganga (NMCG) and its Namami Gange programme including other important rivers in the country and provide inputs in understanding the linkages among forest structure, function, and streamflow.

Application of Mulching Materials of Rainfall Harvesting System for Improving Soil Water and Corn Growth in Northwest of China

The ridge and furrow rainfall harvesting（RFRH） system is used for dryland crop production in northwest of China.To determine the effects of RFRH using different mulching materials on corn growth and water use efficiency（WUE）,a field experiment was conducted during 2008-2010 at the Heyang Dryland Experimental Station,China.Four treatments were used in the study.Furrows received uncovered mulching in all RFRH treatments whereas ridges were mulched with plastic film（PF）,biodegradable film（BF） or liquid film（LF）.A conventional flat field without mulching was used as the control（CK）.The results indicated that the average soil water storage at depths of 0-200 cm were 8.2 and 7.3%,respectively higher with PF and BF than with CK.However,LF improved soil water storage during the early growth stage of the crop.Compared with CK,the corn yields with PF and BF were increased by 20.4 and 19.4%,respectively,and WUE with each treatment increased by 23.3 and 21.7%,respectively.There were no significant differences in corn yield or WUE with the PF and BF treatments.The net income was the highest with PF,followed by BF,and the 3-yr average net incomes with these treatments were increased by 2 559 and 2 430 CNY ha-1,respectively,compared with CK.BF and PF had similar effects in enhancing the soil water content,crop yield and net income.Therefore,it can be concluded that biodegradable film may be a sustainable ecological alternative to plastic film for use in the RFRH system in northwest of China.

Water Resource Management and Its Role in Development of Integrated Mountainous Agriculture——A Case from Ningnan County of Sichuan Province

This paper reviewed rainwater collection and water resource management in Ningnan County in southwestern mountain of China,as a case study for solving the problems of water management in a simple and sustainable way. In this mountainous agriculture system,private agricultural enterprises were introduced into local mountain agriculture to solve capital fund shortage for the construction of rainwater harvesting system. Agreement was signed by private agriculture enterprises with the target farmers to subscribe for the household agriculture production at a protection price. Cash invested by the enterprise and subsidy from the government were collected for purchasing materials,while the farmers supplied labors for the construction of water harvesting systems. The system solved the share of input and benefits between the local government,enterprise and household farms successfully. In addition,the micro water harvesting tanks and micro irrigate systems extend quickly in this mountainous county. Up to 2007,more than 12 000 rainwater harvesting tanks had been established and more than 8.5×104 hm2 dry arable land accounting for nearly 75% of the total arable land had been irrigated efficiently. Per capita income of farmer had been increased by 14 times in the past 20 years. Considerable potential for further improvement in implementation of the models for solving water shortage and water resource management in mountain region maybe depend on more local private agriculture enterprises and households than the government.

Triboelectric nanogenerator integrated with a simple controlled switch for regularized water wave energy harvesting

Ocean is full of low-frequency,irregular,and widely distributed wave energy,which is suitable as the energy source for maritime Internet of Things(IoTs).Utilizing triboelectric nanogenerators(TENGs)to harvest ocean wave energy and power sensors is proven to be an effective scheme.However,in random ocean waves,the irregular electrical energy output by general TENGs restricts the applications.At present,achieving regularized water wave energy harvesting relies on rather complex mechanical structure designs,which is not conducive to industrialization.In this work,we proposed a novel mechanical controlled TENG(MCTENG)with a simple controlled switch to realize the regularization function.The structural parameters of the MC-TENG are optimized,and the optimal output voltage,output current,and transferred charge respectively reach 1684.2 V,85.4μA,and 389.9 nC,generating a peak power density of 38.46 W·m^(−3)·Hz^(−1).Under real water wave environment,the output of the MC-TENG is regularized and keeps stable regardless of any wave conditions.Moreover,the potential applications of the MC-TENG are demonstrated in powering environmental temperature,humidity,and wind speed sensors.This work renders a simple approach to achieve effective regularized ocean wave energy harvesting,promoting the TENG industrialization toward practical application of maritime IoTs.

GIS-based assessment of non-equilibrium pattern between groundwater recharge and irrigation draft in a semi-arid region of Rajasthan, India

Over-exploitation of groundwater for irrigation can result in drastic reduction in groundwater level in Jodhpur district of western Rajasthan, India. In this study, we used the long-term trend analysis of seasonal groundwater level data to predict the future groundwater scenario in 33 villages of Jodhpur district, assessed the impact of water harvesting structures on groundwater recharge and explored the non-equilibrium between groundwater recharge and irrigation draft in the study area. Analysis of groundwater level data from 26 observation wells in 33 villages in the pre-monsoon period showed that groundwater level decreased continuously at the rate of 2.07 m/a. With this declining rate, most of the tube wells （including the well with the maximum depth of 193 m） are predicted to become completely dry by 2050. Behavior of temporal groundwater level data in the study period （from 2004 to 2012） can be explained by different geospatial maps, prepared using ArcGIS software. Statistical analysis of the interpolated maps showed that the area with the maximum positive groundwater recharge occupied 63.14% of the total area during 2010-2011 and the area with the maximum irrigation draft accounted for 56.21% of the total area during 2011-2012. Higher groundwater recharge is attributed to the increase in rainfall and the better aquifer condition. Spatial distribution for the changes of average groundwater recharge and draft （2008-2009 and 2011-2012） showed that 68.50% recharge area was in positive change and 45.75% draft area was in negative change. It was observed that the area of the irrigation draft exceeded that of the groundwater recharge in most of the years. In spite of the construction of several shallow water harvesting structures in 2009-2010, sandstone aquifer zones showed meager impact on groundwater recharge. The best-fit line for the deviation between average groundwater fluctuation due to recharge and irrigation draft with time can be represented by the polynomial curve. Thus, over-exploitation of groundwater for agricultural crops has result in non-equilibrium between groundwater recharge and irrigation draft.

Water conservation in the Arab region: a must for survival

The Arab region covers an area over 13 million square kilometers in size, with almost 90% of its area classified as arid or ex- tremely arid with very little precipitation, extremely high evaporation and almost no vegetation cover. The region is classified in many international reports as the poorest region in the world in the context of renewable water resources and critical water scarcity which hinders the socio-economfic development of many countries in this region. The rapidly increasing population has reduced the per capita share of renewable water to less than the poverty line of 1,000 m3/（capita＇a） and, in some Arab countries, to less than the extreme poverty line of 500 m3/（capita＇a）. This has led to over-exploitation of non-renewable groundwater and desalination of salty water in many countries with considerable costs and contamination of many renewable sources. Atmospheric processes re- sponsible for aridity in the Arab region are projected to intensify due to climate change, resulting in an alarming decrease in pre- cipitation and increase in evaporation rates. Many concerned entities in the region consider water security as a key element for food security and ultimately political stability. Hence, various efforts have been exerted to identify key problems and suggested solutions. The Arab Water Ministers Council of the Arab League, as well as Reports of the Arab Forum for the Environment and Development （AFED） and the recommendations of the 13th Regional Meeting of the Arab National Committees of the Interna- tional Hydrological Programme of UNESCO （niP）, have all made similar recommendations on the need to address the issues of water scarcity in the Arab region which will be further discussed in this paper. However, none of these reports focused on ＂Water Conservation＂ as an equally important action for coping with water scarcity in the region. There are many definitions for ＂Water Conservation＂ in the scientific literature, including huge water savings from irrigation, industrial use, and domestic use as well as methods and approaches for augmenting water supply through non-conventional practices such as water harvesting and waste water reuse. In this paper, a review is provided for definitions, methods and impacts of water conservation and its role in alleviat- ing water scarcity in the Arab region.

Exploring Crop Yield Benefits of Integrated Water and Nutrient Management Technologies in the Desert Margins of Africa： Experiences from Semi-Arid Zimbabwe

The benefits of integrating locally adaptable water and nutrient management technologies were explored in semi-arid Zimbabwe. On-farm maize based experiments were set up on six farmers＇ fields in Ward 5, Shurugwi. Three tillage systems namely Post-Emergence Tied Ridging （PETR）, Rip ＆ Pot-Holing （RPH） and Conventional Mouldboard Ploughing （CMP） were integrated to three nutrient management regimes, i.e. a control with no fertility amelioration, pit-stored cattle manure band applied at 10 t/ha and the latter with an additional top dressing of ammonium nitrate （34.5% N） at 100 kg/ha. On each site the treatments were set up as a completely randomized split-plot block design replicated 3 times with tillage （water management） as the main treatment and fertility as the sub-treatment. CMP mimicked the farmers＇ common land preparation practice while PETR and RPH systems represented the improved water harvesting tillage techniques. Results revealed significant nutrient management effects right from the first season giving 3-year means of 1,298, 1,977 and 2,490 kg/ha for the control, manure and manure plus fertilizer treatments respectively. On the other hand, water harvesting tillage effects were insignificant initially （2003/4） but had beneficial effects in subsequent seasons （2004/5 and 2005/6） with 3-year grain yield means of 1,624, 2,032 and 2,108 kg/ha for CMP, PETR and RPH, respectively. Maximum yield benefits from integrating PETR and RPH with manure ＋ AN fertility ameliorants amounted to 218 and 261% respectively, compared to CMP with no fertility amendment. The results therefore showed increased benefits when in-situ water harvesting tillage techniques are integrated with appropriate nutrient ameliorants giving realizable food security benefits to the farmer.

Analysis of Different Rare Metals, and Rare Earth Metals in Harvested Rain Water in Gaza Strip/Palestine by ICP/MS-Data and Health Aspects

This rain water samples harvested for drinking and agriculture from Gaza collected in November 2012 were analyzed for different rare metals (Rb, Zr, Ti, Tl, Sb, Sc, Y), and rare earth metals (La, and Ce). These metals usually have no maximum acceptable limits as there is no sufficient data about their toxicity to human health. Their control should be therefore controlled in water to monitor their concentration in water (ground, harvested, etc.). This study was conducted to determine the water quality of harvested water which is used for drinking in the study area. 43 water samples were collected in November 2012 during the first rain from house wells and rain water pools. The concentrations of the metals detected in the collected harvested rainwater vary significantly between the 43 samples, and all of them were detected in all water samples analyzed in this study. The results obtained from this study suggest a possible risk to the population of the study area given the high concentration of some metals that have no maximum allowed concentration, and the fact that for many people in the study area, harvested rain water is a main source of their water supply.

Resilience Techniques due to Cascading Water Effects in Informally Urbanised Hilly Terrains:A Case of Makongo and Goba-Dar es Salaam,Tanzania

The research was carried out in Dar es Salaam’s Makongo and Goba neighbourhoods using an exploratory method covering 200 questionnaires,100 for Goba and 100 for Makongo respectively.There were two significant issues observed:To begin,data from 2003 to 2017 reveal a large increase in urbanisation in both locations.Furthermore,urbanisation led to an increase in hard surface areas,which,according to the analysis,contributed to an increase in surface runoff,which had detrimental consequences for hilly residential settlements,resulting in downstream floods,building destruction,and loss of life and properties.Few residents were aware of water harvesting methods as a technique to deal with surface runoff,but they were not aware that they might be used to harvest water for future use.Policy to harvest,retain and use rainwater is recommended,whereby each plot owner should contain water from his/her plot by harvesting,collecting and retaining it for home use such as farming,fish ponds and other uses.