Quantifying Groundwater Resources,drought And Evapotranspiration Using Remote Sensing Data And Land Surface Models

In most regions of the world,water resources are one of the strategic securities.In some arid and semi-arid world countries,conflicts and disputes about limited water resources have already been started.Water scarcity has been occurring many times these days in many regions of the world,because of the growth in population and expansion of agricultural,energy and industrial sectors,climate change and contamination of water supplies water demand has increased a lot.The water scarcity is being further compounded by droughts increasing with water resources depletion.This increase in water demand put a huge challenge on water resources sector to save it more.Water resources are the main source of human life.Monitoring the changes in water resources for some of those countries is extremely difficult given:(1)their locations in lessdeveloped parts of the world,(2)the general inaccessibility of many of these areas,(3)difficulties in collecting background information,and(4)the unavailability of local funding and expertise to support research in these areas.These water resources need accurate and real time based data that can help in planning and management.In those areas,remote sensing provides the optimal cost-effective vehicle to monitor the water resources in areas such as North china,Middle East,and most of Africa Countries.In this research remote sensing data and modeling approaches are used in the following way.In the first step of research capabilities of GRACE satellite integrated with land surface models were tested by detecting and mapping the changes within groundwater depletion rate in the area of northern china in 10 years from 2002 to 2012.Mostly of the depletion rate due to the impact of human activity by agriculture and irrigation process.Thus GRACE data is used to map the impacts of anthropogenic impact on groundwater resources.Our findings are an average Terrestrial Water Storage(TWS)depletion of 14.09 ± 1.74 × 109 m3/yr(9.39 ± 1.16 mm/yr).The combined(natural + anthropogenic)groundwater trend was estimated at 12.78 ± 1.56 × 109 m3/yr(8.52 ± 1.04 mm/yr)based on GRACE and CLM4.5 data.The trend in anthropogenic variations in groundwater depletion was estimated at 19.50 ± 1.71 × 109 m3/yr(13.00 ± 1.14 mm/yr).In the second step MODIS vegetation health index time series for 8 years(2006-2014)have been used for quantifying the spatiotemporal distribution of agriculture drought in one of the most agriculture area in U.S.A in Kansas State.With validated our results by the depletion rate delivered from AMSER satellite and precipitation rate from TRMM spanning the same time study.Our finding indicate that the total area that affected by drought in all over the 2006-2013 year shows that the 2011-2013 year had larger areas of drought than others those years from 2011-2013 Which have both extreme drought and high drought together.The larger areas were affected by the drought in 2012 which is considered to be the most affected year by drought after 1988.This step aimed to decrease the load of troublesome field data collection and make the process of drought monitoring more robust and fast to help take decisions on time.In the third step we presents in full detail how we can use the total water storage budget delivered from GRACE satellite with in the precipitation delivered from TRMM and runoff data delivered from land surface models to estimate the monthly average of evapotranspiration rate over all china and Hai river basin.The monthly average ET were(45.13 mm)over all china and trend of ET increasing by(3.45 mm).For Hai River Basin(HRB)in North China The monthly average ET(44.12 mm)and trend of ET increasing by(2.72 mm).In the last part of the research a proper discussion has been made on the use of remote sensing and modeling approaches in water resources and cycle component monitoring and points are concluded and recommendations for future are given.