The historical-geographical study of the relationship between the regional difference of cotton growing and the coditon of irrigation in Nara basin in Edo period.

据了解，奈良盆地的棉花种植是在水田中进行的，由于几件事而衰落。但在奈良盆地，这种下降并不均匀。为什么会出现这样的地区差异？本研究旨在从灌溉条件的角度厘清这种区域差异。在本研究中，我找到了奈良盆地多个村庄的棉花种植比例，并研究了区域差异。结果表明，水田棉花种植比例最高的是石州县的土一县，最高的是清垣县的山部县。其次，我将棉花生长的过渡分为以下四种类型。第一种类型是江户时期早期水田棉种植的衰落。原因可能是这些地区有充足的灌溉条件，可以由种植棉花转为种植水稻。第二种类型是江户末年棉花种植下降。在这些地区，他们修建了新池塘或修复了旧池塘，灌溉条件得到了改善。第三种是江户晚期棉花种植暂时活跃。除江户晚期地震对塘岸破坏的影响外，该类型棉花的生长与灌溉条件没有关系。最后一种类型是江户时期保持了相同的棉花种植比例。在这种情况下，江户时代没有对灌溉进行改善。推测奈良盆地棉花生长的区域差异与塘灌条件有一定的关系。

It is known that the cotton growing in Nara basin was performed in paddy field and it declined by several affairs. But such decline didn't occur uniformly in Nara basin. Why such regional diffrence occured? This study aims to make clear such regional diffrence from the point of the condition of irrigation.In this study I found the ratio of cotton growing of many villages in Nara basin and studied the regional diffrence. It was found that the ratio of cotton growing in paddy field was the highest in Toichi, Shikijou county, higher in Yamabe, Soekaki county. Secondly I divided into four types of transition of cotton growing as following. The first type is that cotton growing in paddy field declined in early time in Edo period. The reason is thought that these area was rich on condition of irrigation so that they could change cotton to rice growing. The second type is that cotton growing declined at end of Edo period. in these area they constructed new pond or repaired old pond and by doing it hte condion of irrigation changed for the better. The third type is that cotton growing became active tempolary in the late Edo period. In this type there were no relationship between cotton growing and irrigation condition except for the influence of the destroy of pond bank by the earthquake in the late Edo period. The last type is that the same ratio of cotton growing was kept in Edo period. In this type the improvement of irrigation was not done in Edo period. It is guessed that the regional difference of cotton growing in Nara basin has some relationships with the condition of pond irrigation.