RAINFALL CHANGE DETECTION IN AFRICA USING REMOTE SENSING AND GIS BETWEEN 1999 – 2018

Many researchers used gauge data from weather stations for rainfall estimate across Africa. Since Africa lies within the tropics, there is possibility for variations in rain received from place to place. Therefore, there is need for excessive density of the gauges for accurate estimate of Africa’s rainfall. Due to numerous challenges, these cannot be achieved. This necessitates the application of remote sensing and GIS to detect changes in rainfall amount in Africa between 1999 and 2018. The data used was obtained from remote sensing satellite (TRMM) and analyzed using GIS application (IDRISI Taiga). The Simple Image Differencing was performed on the two annual mean images covering January to December, 1999 and January to December, 2018. This provides reliable information on rainfall estimate that can complement sparsely and unevenly distributed rain gauge network in Africa. The analysis shows that latitudinal locations, to some extent, determine spatial distribution of rainfall in Africa. It is also observed that significant changes in rainfall rate are mainly found around coastal regions. It was recommended that adequate ground data it needed to confirm these findings. African countries should provide adequate and justly distributed weather stations with on-net database for easy access to the data.

A REVIEW ON TECHNIQUES FOR WATER QUALITY MONITORING USING IOT DEVICES

In this paper is discussed the different kinds of environment monitoring systems related to water goodness. Different parameters are discussed to elaborate each water monitoring system with different aspects. The technology aspects of different approach techniques related to water quality monitoring with their way of implementation with the IOT aspect has been evaluated of past four years. In this paper, the workflow of different approaches of the technologies exploited will be discussed critically and also that which approaches focused on what parameters.

AN OVERVIEW ON EMERGING WATER SCARCITY CHALLANGE IN PAKISTAN, ITS CONSUMPTION, CAUSES, IMPACTS AND REMEDIAL MEASURES

Around two-thirds of the earth’s surface covered with water, it is obvious that water is among the most significant aspects that are essential for the life of human being. It is not only important to live, but also important to take a part in social and financial development. Water is God’s personalized gift, as well as the necessity of life. Due to high level of gluttony, misused play of people with the environment and the global climate, shift results in progressive diminishing of natural resources. The problems of freshwater and food security at global level linked to the overwhelming population of the world. To overcome the food and water scarcity challenge, there is required to transfer the freshwater from agriculture sector to other straining purposes. Pakistan is facing the meager water scarcity crises in the last few years, as water is becoming scarce to any specified usage. The quickly growing population, expansion of drainage regions, increasing urbanization and industrialization put a lot of stress on available water supplies. At the moment, there is dire need to harvest rain water by constructing more dams and focus on effective management strategies for further use. Specifically, authors are recommended that, water should be provided demand base instead of supply base irrigation system. Moreover, in addition to land tax, tax on irrigation water quantity/usage should be rectified.

ESTIMATING SEDIMENT YIELD AT TARBELA DAM AND FLOOD FORECASTING THROUGH CONTINUOUS PRECIPITATION-RUNOFF MODELING OF UPPER INDUS BASIN

The live water storage of the reservoirs is decreasing by the sedimentation, which is affecting the reservoir’s capacity and cause a severe problem for the irrigation system at the downstream side. Floods occur at the downstream by the poor management at upstream due to the heavy rainfall and snow melting. For annual accumulations of sediment load and estimation of the peak flow at Tarbela reservoir near Besham Qila station having area of 170,000 km2 was selected. Estimation of the peak flow and sediment yield at the Tarbela reservoir, SWAT (distributed hydrological model) was used. The expected decrease in reservoir storage capacity was also estimated with the SWAT model. For runoff modelling, calibration was done for three years (2004-2006) and validation was also done for three years (2007-2009). Nash-Sutcliffe Efficiency (NSE) and Standard Error of Estimate existed the statistical indices to evaluate the results. Coefficient of determination (R2) was found as 0.75 for the calibration period and 0.80 for the validation. Whereas, NSE for calibration was observed 0.69 and 0.70 for the validation. Monthly mean sediment yield was about 0.13 BCM estimated at the Tarbela reservoir near Besham Qila.

ASSESSMENT OF SEDIMENT YIELD USING SWAT MODEL: CASE STUDY OF KEBIR WATERSHED, NORTHEAST OF ALGERIA

Erosion is identified as one of the most significant threats to land in increasing rates of soil loss and reservoir sedimentation. An integrated approach therefore requires sediment assessment for identification of its sources for efficient watershed management. The present study is aimed to examine the spatial and temporal sediment yield distribution potential and to identify the critical erosion prone zones within Kebir watershed, Algeria using Soil and Water Assessment Tool interfaced in GIS for the period from 1982 to 2014. The model is calibrated by adjusting sensitive parameters and validation is done using observed data from 1982 to 1998. The model performance checked by the coefficient of determination (0.76), Nash–Sutcliffe coefficient (0.75) and relative error (+8.19%) suggests that the model has performed satisfactorily for sediment yield prediction. The simulated outputs of the model show that the 33-year period of sediment load production is estimated to be 19.24×106 tons and a mean annual sediment yield of 856.14 T/km²/yr. Temporally, sixty-four percent (50%) of sediment yield generated in the watershed occurs in five months of the winter and fall seasons. The most erosion vulnerable sub-basins that could have a significant impact on the sediment yield of the reservoirs are identified. Based on this, sub-basin 16, 14, 13, 11 and 8 are found to be the most erosion sensitive areas that could have a significant contribution, of 50%, to the increment of sediment yield. Best management practices are highly recommended for the land sustainability because of the high sediment supply to the dams.

CROP AREA MAPPING BY INTELLIGENT PIXEL INFORMATION INFERRED USING 250M MODIS VEGETATION TIMESERIES IN TRANSBOUNDARY INDUS BASIN

Irrigation water could be managed properly by mapping area of various crops. Remote sensing data can provide useful Land Use Land Cover (LULC) for assessment of different crop area and change detection. The present study was carried out with core objective to map crop area within the Indus Basin’s transboundary. Four major crops (i.e. wheat, rice, cotton and sugarcane) were identified using Normalize Difference Vegetation Index (NDVI) time series that was picked up from MODIS sensors aboard Terra (EOS AM) and Aqua (EOS PM) satellites with 250m pixel resolution. Crop phonological information was used to train each pixel intelligently for interpretation of unanalyzed NDVI data into crops. Eight days of time series data was used for identification and mapping of various crops on the basis of their phenology for the years 2008, 2010 and 2013. Error matrix was prepared to reveal mapping accurateness and ground truthing was also done in particular canal commands within the Indus basin. Furthermore, the temporal variation in cropped area was determined and for accuracy check, secondary data was matched with prepared maps. LULC maps for year 2008, 2010 and 2013 were defined for Rabi and kharif seasons.

GROUNDWATER STORAGE CHANGE ESTIMATION USING GRACE SATELLITE DATA IN INDUS BASIN

Over exploitation of Ground Water (GW) has resulted in lowering of water table in the Indus Basin. While waterlogging, salinity and seawater intrusion has resulted in rising of water table in Indus Basin. The sparse piezometer network cannot provide sufficient data to map groundwater changes spatially. To estimate groundwater change in this region, data from Gravity Recovery and Climate Experiment (GRACE) satellite was used. GRACE measures (Total Water Storage) TWS and used to estimate groundwater storage change. Net change in storage of groundwater was estimated from the change in TWS by including the additional components such as Soil Moisture (SM), Surface water storage (Qs) and snowpack equivalent water (SWE). For the estimation of these components Global Land Data Assimilation system (GLDAS) Land Surface Models (LSMs) was used. Both GRACE and GLDAS produce results for the Indus Basin for the period of April 2010 to January 2017. The monitoring well water-level records from the Scarp Monitoring Organization (SMO) and the Punjab Irrigation and Drainage Authority (PIDA) from April 2009 to December 2016 were used. The groundwater results from different combinations of GRACE products GFZ (GeoforschungsZentrum Potsdam) CSR (Center for Space Research at University of Texas, Austin) JPL (Jet Propulsion Laboratory) and GLDAS LSMs (CLM, NOAH and VIC) are calibrated (April 2009-2014) and validated (April 2015-April 2016) with in-situ measurements. For yearly scale, their correlation coefficient reaches 0.71 with Nash-Sutcliffe Efficiency (NSE) 0.82. It was estimated that net loss in groundwater storage is at mean rate of 85.01 mm per year and 118,668.16 Km3 in the 7 year of study period (April 2010-Jan 2017). GRACE TWS data were also able to pick up the signals from the large-scale flooding events observed in 2010 and 2014. These flooding events played a significant role in the replenishment of the groundwater system in the Indus Basin. Our study indicates that the GRACE based estimation of groundwater storage changes is skillful enough to provide monthly updates on the trend of the groundwater storage changes for resource managers and policy makers of Indus Basin.

WATER RESOURCES HELPS İN THE EXPANSİON OF MOSQUİTOES COLONİES

In Pakistan, water storage bodies are often the most plentiful and active habitats of immature stages of mosquitoes. Mosquitoes are blood feeding type of vectors that bite a particular host and suck blood. As a result, these vectors transmit disease causing agents to the host system. The most common mosquitoes borne viral diseases in Pakistan are Chicken gunya, Dengue fever, west nile and Zika fever. These diseases are common in low and poor living standard areas. Death rate increases due to more attack of these fatal diseases. Mosquitoes breeding sites are water bodies, discarded tyres, water tanks, bottles, cups and ant traps. Various environmental agents i.e. temperature fluctuations and water resources, now increase the rate of mosquitos in most areas of Pakistan. There is a lack of basic medical education and knowledge about its pervention techniques in mosquito affected areas in Pakistan. The purpose of this review is to highlight the current status of emerging mosquito borne viral diseases in Pakistan, i.e. Chicken gunya, Dengue fever, est nile and Zika fever. There is more need of prevention strategies and understanding about factors involved in spreading of mosquito borne diseases.